Oyu Tolgoi Copper-Gold-Molybdenu Mine
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It was since the time of Bronze Age that the Oyu Tolgoi Mine was recognized as a potential prospect site. This had resulted in sinking several production pits that were observed on the property at the Oyu Tolgoi Copper-Gold-Molybdenum Mine Project. Most of these pits were rather circular, and had shown minor copper smelting slag in the area.
The Oyu Tolgoi is located in the remote South Gabi Region of Mongolia, and is situated 570 km. south of the capital city of Ulaanbaatar. Much of the Oyu Tolgoi Project is located between Mongolia, and the Chinese Boarder.
Mongolia was largely explored by Russians and geologists that had made their first geological observations in Mongolia during the late 19th century. After the 1917 Russian Communist revolution, the Soviet State had paid significant attention to geology as an applied science to serve its industrial and military interests. No additional work was carried out in the Mongolia area till about the 1940’s, that were being conducted by Soviet Geologists.
By 1940’s, the Soviet Geologists had shortly after undertaken the design of several regional geological maps in Mongolia. One of these maps, and reports that had been prepared would indicated economical importance to the area as copper deposits were noted in the Oyu Tolgoi Area. Further reports would indicated that the Oyu Tolgoi Area has the economical potential to mine copper from the area. It had been further geological mapping and surface observation work that indicated these conclusions of the Oyu Tolgoi Copper-Gold-Molybdenum- Mine by 1957.
Many of the local people in the area had known the potential of mineral resources in what is now referred as the Oyu Tolgoi area. One of the very first evaluations of the area had referred this as the Bor Ovoo, also known Brown Hill area. All the geological maps that were prepared on this area by Soviet Geologists, and research institutions had also referred this area as the Bor Ovoo (Brown Hill). Only little work was done on the property from the 1940’s to the mid 1950’s, and further work would be done in the 1980’s.
It was during the 1980’s, when the property was first revisited by Soviet Geologists once again. As this had happened it was reported that local knowledge was crucially important for helping with geological studies. One of the major points of this work was aimed geological prospecting and mapping projects in Mongolia.
Further work would be carried out by Mongolian geologists that would conduct preliminary geological and geochemical mapping studies in the Oyu Tolgoi area in the 1980’s. A geologist by the name of D. Garmajav, was initially one of the first discoverers of copper staining and alteration in the area during field work that was undertaken in 1983. Mr. D. Garamjav, would later lead the team to discovering a high-grade copper-gold zone at Oyu Tolgoi. He would additionally guide Magma Copper to the area as this had warranted further exploration work on the property.
1996 – 2000– Magma Copper/BHP Billiton
The property along with Magma Copper would be shortly after acquired by BHP Billiton, and the company would commence explorations in the area. This was in parts of a reconnaissance program that was carried out in the South Gobi desert during the 1997 field season. Extensive work was carried out on the property by BHP Billiton who had conducted geological mapping, stream, and soil sediment surveys, and magnetic and induced polarization surveys on the property. BHP Billiton would additionally conduct six diamond drill holes, totalling a length of 1,100 metres in September, and October, 1997. This resulted in encountering encouraging results that warranted follow up drilling of a second phase diamond drilling program.
A second diamond drilling program was first commenced on April, 1998, and would be aimed at completing an additional 13 core holes, totalling 2,000 metres. It had also been during this progressive diamond drilling campaign that encouraging results were met with in four of the holes on the Oyu Tolgoi Copper Property. A third phase drilling program would later be conducted in September, 1998, that amounted to completing four holes, totalling 800 metres in length. These holes that were drilled had failed to intersect any significant mineralization and the project was suspended pending a review that would be made. After conducting a review it was advise to keep explorations going on the Oyu Tolgoi Copper-Gold Property. But it was shortly after that BHP would discontinue its progressive exploration campaign on the Oyu Tolgoi Copper-Gold Prospect.
2002 – 2003 – Ivanhoe Mines
Ivanhoe would additionally commence environmental studies on the Oyu Talgoi Project on May, 2002. It was also during this time period that an environmental base line study was submitted to the Mongolian Government's Ministry for Nature and Environmental in March, 2003. With this environmental base line study had came the necessary Environmental Impact Assessment and Environmental Protection Plan processes. One of the very first EIA document, for the transport corridor south of Oyu Talgoi to the Chinese border, was submitted in April, 2004, and approved by the government in May, 2004. One of the second EIA documents had also covered the topic on the water supply system, that was submitted on June, 2005. Ivanhoe’s Oyu Talgoi Environmental assessment plan had also met with the international standards and requirements of the Mongolian Environmental Impact Assessment Legislation. The main company in charge of taking out this work was Sustainability Pty, Ltd., of Perth Australia, and its principal, John Miragliotta, with studies conducted by Eco-Trade Co, Ltd.
2004 – 2005 – Ivanhoe Mines
Work that was undertaken in 2004, had resulted in an independent scoping study that had concluded that Ivanhoe Mine’s Oyu Tolgoi Copper-Gold project had enough mineralization to warrant mining. This study had rather evaluated a wide range of development possibilities to assess alternative production rates, mining strategies, and processing options. Work of this type had additionally called for a base-case scenario that would warrant the predevelopment plan of constructing a 60,000 tonne per day conventional flotation process plant. The majority of this work was done in order to feed the new milling complex with ore from open pits on the Southwest and Central Oyu Deposits. It would also be in year five that the project would double to 120,000 tonnes of ore per day with the construction of a second milling circuit. The erection of the second mill would additionally treat ore that came from the Hugo South Pit, and higher grade material from a 12 million tonne per year underground mine at Hugo North. Other predictions were made on the mine life as the Oyu Tolgoi Mine had projected a life of 29 years. This had largely been based on the potential inventory of mining just over 1 billion tonnes averaging 0.95% Cu, and 0.26 gram gold per tonne. It had also been about 78% of this modeled resource which had been classified as inferred, while the remainder is in indicated categories. Based on average recoveries of 89.6% copper, and 65.8% gold, production is expected to total 8.0 million tonnes of copper (19.5 billion lbs.) and 5.7 million oz. gold over the life of the mine.
The initial capital cost of constructing stage 1 is estimated to cost up to US$529 million, while the overall cost of both stages comes in at US$1.17 billion. Much of the reports surrounding financing of the mine project was within Ivanhoe’s capability. This had also given Ivanhoe the option of selling non-core assets or selling a minority participation in the Oyu Tolgoi Project, by one or more strategic partners. Total gold production for the first four years would also amount to recovering 400,000 oz. Au from the Oyu Tolgoi Mine.
A preliminary engineering study had also been undertaken on the Oyu Tolgoi Mine, and would propose for the development of large open pit operations, This would also be achieved by some modernized mining equipment, that includes 350-tonne haulage trucks, and large capacity electric shovels. Further geological work had revealed that the mineralization appears to be amenable to processing in a conventional flotation concentrate. The ore processing plant would be designed to incorporate the largest proven mills into the grinding circuit. Plans towards building the ore processing plant would be done around two grinding modules, each of which is capable of handling 20 million tonnes per year. Each of the modules would additionally consist of a 12.2 metre-diameter semi-autogenous grinding (SAG) mill, with a 21-MW wrap around the motor coupled with two 7.7- by 11.6 metre, 15.5 MW ball mills. Much of the grinding module had been in support by a flotation circuit, and the tailings would be fed to a containment dam area in the southeastern corner of the mining lease.
Stantec would also provide assistance towards Ivanhoe’s Oyu Tolgoi Mine Site in realizing their production targets by providing engineering, design, procurement, and quality assurance for the No. 1 and No. 2 Shafts. Other plans were also in the making to explore, develop, and mine the area by constructing a total of five shafts. The company had been largely in charge of designing the No. 1 Shaft for initial ore-body access, definition drilling, and a future hoisting facility. Engineering plans that were done on the hoisting facility were aimed at making it capable of lifting 2,500 tonnes of ore per day. One of the major stations that were cut for this project would be engineered at the 1,285-m horizon. Much of the shaft sinking work was aimed at mining deeper copper-gold ore-bodies at the Hugo Deposit.
2005 – 2006 – Ivanhoe Mines
Ivanhoe Mines would make a decision on the summary of phase to expand the case study of the Oyu Tolgoi Copper-Gold Mine property. The major expansion project would call for the development of a block cave system mine at the Hugo South Deposit, and would proceed with the stripping of stages 3 and 4 of the open-pit mine. Phase 2 was largely aimed at bringing the project to production stage from underground block cave mines, and would double the capacity of the concentrator. Further expansion would also continue as a second SAG milling circuit was in the plans of development. Most of the work was largely focus on increasing the Oyu Tolgoi’s combined open-pit and underground production to about 140,000 tonnes of ore per day by year 7. It had also been stated that the Hugo North mill feed, which was combined with feed from stages 3 and 4 of the open pit development plan would be taken for processing. This would additionally maintain the proposed production of 140,000 tonnes of ore per day that would be taken from the Oyu Tolgoi Copper-Gold Mine. An assumption had also been made at this time as IDP would indicate that Oyu Tolgoi Copper-Gold Mine could produce approximately 35 billion pounds of copper, and 11 million oz. of gold over the projected, initial 35-year life of the mine.
The Oyu Tolgoi Copper-Gold Mine also has significant potential to increase known resources at the Oyu Tolgoi Mine. By allowing this it would also provide an ultimate rate of production from the expanded concentrator that could exceeded the projection provided in the IDP. It had also been at this time that engineering work was aimed at developing the concentrator with a single SAG semi-autogenous grinding circuit with an initial throughput rate of 70,000 tonnes of ore per day. Mining would first be achieved by developing open pit operations that would be focus on taking the ore from the Southwest Deposit. It would also be indicated that during the first three years of operation, mill feed will be primarily produced from stage 1 and 2 of the open pit centred on the gold rich, higher grading Hugo North Deposit. Predictions made had assumed that mining of the Hugo North Deposit would be initiated in year 3. By year five it was predicted that the Hugo North would be the predominant source of mill feed for the concentrator. This would also facilitate an increase in year 6, as 85,000 tonnes of ore would be mined on a daily basis.
It had also been during the year of 2005, that shaft work was underway at the Oyu Tolgoi Mine in the Gabi Desert of Mongolia. Ivanhoe at this point in time had contracted McIntosh Engineering Inc., of Tamp, USA, to conduct this work on the shaft. McIntosh Engineering had additionally recognized the importance of the Oyu Tolgoi copper-gold porphyry property. McIntosh Engineering was largely engaged in the sinking and development of the No. 1 Shaft that would provide an access point to the Hugo North and South Deposits.
Some of the major surface construction work that was done during 2005, was largely focus on constructing the No. 1 Shaft Headframe, hoisting plant, and associated infrastructure. Predictions that were made on shaft sinking had reported that this work would be commence in the fourth quarter of 2005.
Additional work had also been contracted to the Redpath Group of North Bay, Canada, that’s known as the leading shaft sinking firm in the world. Upon completion of the sinking phase it would also result in a complete detailed feasibility studies on the Oyu Tolgoi Copper-Gold Mine. Sinking of the No. 1 Oyu Tolgoi Shaft was predicted to be completed by the third quarter of 2007, and would be followed by underground drifting, and diamond drilling for further delineation drilling and rock characterization work. McIntosh had also received a contract for the engineering and sinking of the No. 2 Oyu Tolgoi Shaft, which was being designed as a 10-metre-diameter production and service shaft.
Planning for the development of the No. 2 Shaft had also been done as it was being currently designed as a 10.0 m diameter shaft, and will have one of the tallest shaft headframes in the world, measuring 96-m in height. The Oyu Tolgoi Mine is a copper/gold porphyry deposit that is currently being mined by block caving methods. It had also been further development planning that would result in hiring several engineering, mining, and environmental consultants, that was led by Australian based AMEC Minproc, and including U.S. based Stantec Engineering. One of the new plans which was made at the time was aimed at providing an update to the original 2005 Integrated Development Plan. The new plan that was set fourth had additionally supported Ivanhoe Mine’s commitment to advance the Oyu Tolgoi into full construction.
Upon geological mapping and observation it was also stated that further enhance can be made on the economics of the project. Much of the exploration work executed by Ivanhoe had also been aimed at expanding and upgrading the resources that were used as the basis for assessment work. Mining plans that were made at the time had also not fully exploited the May, 2005, estimate resources, and the excellent potential to add significant new resources. Ivanhoe, and its contract engineering firms had also indicated the potential of increasing the mine life a Oyu Tolgoi Mine to about 40 years. Exploration work that was continued had also discovered another high-grade copper-gold mineralization to the north of the Oyu Tolgoi Boundary. These discoveries were additionally made on the Shivee Tolgoi Property, that was owned or is owned by Entrée Gold Inc. Agreements were also made with Ivanhoe, and Entrée Gold to conduct explorations on the property with the rights to earn up to 80% of resources discovered on the property. Drilling during that year had also continued to expand the strike length of the Hugo Far North Copper-gold discovery to more than 600 metres beyond Oyu Tolgoi’s northern boundary.
Drilling that was done on the Hugo South Deposit had consisted of completing a total of 583 diamond drill holes for the Southern Oyu Tolgoi Open Pit, totalling 273,000 metres. This had also included the Southwest, South, Wedge and Central Zones, and an additional 287,000 metres in 267 holes in the Hugo North and South Deposits.
An estimation made by AMEC had estimated that the Oyu Tolgoi Project has a measured, and indicated resource estimation totalling 1.15 billion tonnes grading 1.30% Cu, and 0.47 g/t Au per tonne. This estimation that was made would contain 32.9 billion pounds of copper, and 17.3 million oz. Gold, at 0.60% copper equivalent cut off. AMEC would also estimate that the Oyu Tolgoi Project would contain an inferred resource estimate of 1.16 billion tonnes grading 1.07% Cu, and 0.23 g/t Au. The inferred resource estimation would also contain 26.2 billion pounds of copper, and 8.4 million oz. of gold. The total measured plus indicated ore reserves were estimated to contain 1,146,160,000 tonnes of ore grading 1.30% Cu, and 0.47 g/t gold per tonne. In total the indicated category towards ore reserves would be estimated at 32,850,000 lbs. of copper, and 17,340,000 oz. of gold.
2006 – 2007 – Ivanhoe/Rio Tino
An announcement was made on October, 18, 2006, that the world’s mining leader Rio Tinto had came to agreements to form a strategic partnership by investing in Ivanhoe, and through an Ivanhoe-Rio Tinto Technical committee partnership. It was also within these agreements that Rio Tinto would engineer, construct, and operate Ivanhoe’s Oyu Tolgoi Copper-Gold mining complex in Mongolia’s South Gabi region. In doing so, Rio Tinto had purchased approximately 37.1 million Ivanhoe shares at a price of US$8.18, representing a 25% premium to Ivanhoe Mines closing price on October 17, 2006, and a premium of 30% to Ivanhoe’s 20 day moving average share price to October, 15, of US$6.29. By completing this investment agreement, Rio Tinto would secure approximately 9.95% of Ivanhoe Mines share capital.
Development work would also progress on the No. 1 shaft, which is a 6.7 metre-diameter exploration and production shaft at Oyu Tolgoi. Much of the shaft sinking that was undertaken between McIntosh and Redpath Group, had continued onward as it would bottom out at a depth of 600 metres. It had also been during this time period that the planned depth of the No. 1 Shaft would be engineered to 1,340 metres below the surface. The No. 1 Oyu Tolgoi Shaft would also be scheduled for completion by late 2007, with underground drifting, and drilling occurring in 2007 and 2008. Upon completion of this shaft it would also allow for the early exploration of a high-grade upper portion of the Hugo North deposit, as well as expedite the conversion of the current Hugo North resources into proven and probable reserves.
Some of the major surface construction work had involved site preparation, excavation for the concentrator foundations, and the construction of accommodation facilities that were progress. Other preparations were being made towards the No. 2 Shaft, a 10-metre diameter production and service shaft. It was also in 2006, that a technical committee was called on the for the finalization of the location and development plan for this shaft before work begins on the pre-sinking excavation. Much of this work was followed by the on schedule work in starting the construction of the No. 2 Head-frame in the spring of 2007.
Ivanhoe had additionally made plans to transfer the company’s Mongolian Coal Division to Asia Gold Corp during the second quarter of 2006. This agreement was largely made in exchange for approximately 82.6 million shares of Asia Gold Corp. It had been on August 8, 2006, that the majority shareholders of Asia Gold Corp had voted 99% in favour of the merger transaction. An acceptance had also been made by the Mineral Resources and Petroleum Authority of Mongolia that would allow this transfer through applications made by Ivanhoe.
The Oyu Tolgoi is located in the remote South Gabi Region of Mongolia, and is situated 570 km. south of the capital city of Ulaanbaatar. Much of the Oyu Tolgoi Project is located between Mongolia, and the Chinese Boarder.
Mongolia was largely explored by Russians and geologists that had made their first geological observations in Mongolia during the late 19th century. After the 1917 Russian Communist revolution, the Soviet State had paid significant attention to geology as an applied science to serve its industrial and military interests. No additional work was carried out in the Mongolia area till about the 1940’s, that were being conducted by Soviet Geologists.
By 1940’s, the Soviet Geologists had shortly after undertaken the design of several regional geological maps in Mongolia. One of these maps, and reports that had been prepared would indicated economical importance to the area as copper deposits were noted in the Oyu Tolgoi Area. Further reports would indicated that the Oyu Tolgoi Area has the economical potential to mine copper from the area. It had been further geological mapping and surface observation work that indicated these conclusions of the Oyu Tolgoi Copper-Gold-Molybdenum- Mine by 1957.
Many of the local people in the area had known the potential of mineral resources in what is now referred as the Oyu Tolgoi area. One of the very first evaluations of the area had referred this as the Bor Ovoo, also known Brown Hill area. All the geological maps that were prepared on this area by Soviet Geologists, and research institutions had also referred this area as the Bor Ovoo (Brown Hill). Only little work was done on the property from the 1940’s to the mid 1950’s, and further work would be done in the 1980’s.
It was during the 1980’s, when the property was first revisited by Soviet Geologists once again. As this had happened it was reported that local knowledge was crucially important for helping with geological studies. One of the major points of this work was aimed geological prospecting and mapping projects in Mongolia.
Further work would be carried out by Mongolian geologists that would conduct preliminary geological and geochemical mapping studies in the Oyu Tolgoi area in the 1980’s. A geologist by the name of D. Garmajav, was initially one of the first discoverers of copper staining and alteration in the area during field work that was undertaken in 1983. Mr. D. Garamjav, would later lead the team to discovering a high-grade copper-gold zone at Oyu Tolgoi. He would additionally guide Magma Copper to the area as this had warranted further exploration work on the property.
1996 – 2000– Magma Copper/BHP Billiton
The property along with Magma Copper would be shortly after acquired by BHP Billiton, and the company would commence explorations in the area. This was in parts of a reconnaissance program that was carried out in the South Gobi desert during the 1997 field season. Extensive work was carried out on the property by BHP Billiton who had conducted geological mapping, stream, and soil sediment surveys, and magnetic and induced polarization surveys on the property. BHP Billiton would additionally conduct six diamond drill holes, totalling a length of 1,100 metres in September, and October, 1997. This resulted in encountering encouraging results that warranted follow up drilling of a second phase diamond drilling program.
A second diamond drilling program was first commenced on April, 1998, and would be aimed at completing an additional 13 core holes, totalling 2,000 metres. It had also been during this progressive diamond drilling campaign that encouraging results were met with in four of the holes on the Oyu Tolgoi Copper Property. A third phase drilling program would later be conducted in September, 1998, that amounted to completing four holes, totalling 800 metres in length. These holes that were drilled had failed to intersect any significant mineralization and the project was suspended pending a review that would be made. After conducting a review it was advise to keep explorations going on the Oyu Tolgoi Copper-Gold Property. But it was shortly after that BHP would discontinue its progressive exploration campaign on the Oyu Tolgoi Copper-Gold Prospect.
2002 – 2003 – Ivanhoe Mines
Ivanhoe would additionally commence environmental studies on the Oyu Talgoi Project on May, 2002. It was also during this time period that an environmental base line study was submitted to the Mongolian Government's Ministry for Nature and Environmental in March, 2003. With this environmental base line study had came the necessary Environmental Impact Assessment and Environmental Protection Plan processes. One of the very first EIA document, for the transport corridor south of Oyu Talgoi to the Chinese border, was submitted in April, 2004, and approved by the government in May, 2004. One of the second EIA documents had also covered the topic on the water supply system, that was submitted on June, 2005. Ivanhoe’s Oyu Talgoi Environmental assessment plan had also met with the international standards and requirements of the Mongolian Environmental Impact Assessment Legislation. The main company in charge of taking out this work was Sustainability Pty, Ltd., of Perth Australia, and its principal, John Miragliotta, with studies conducted by Eco-Trade Co, Ltd.
2004 – 2005 – Ivanhoe Mines
Work that was undertaken in 2004, had resulted in an independent scoping study that had concluded that Ivanhoe Mine’s Oyu Tolgoi Copper-Gold project had enough mineralization to warrant mining. This study had rather evaluated a wide range of development possibilities to assess alternative production rates, mining strategies, and processing options. Work of this type had additionally called for a base-case scenario that would warrant the predevelopment plan of constructing a 60,000 tonne per day conventional flotation process plant. The majority of this work was done in order to feed the new milling complex with ore from open pits on the Southwest and Central Oyu Deposits. It would also be in year five that the project would double to 120,000 tonnes of ore per day with the construction of a second milling circuit. The erection of the second mill would additionally treat ore that came from the Hugo South Pit, and higher grade material from a 12 million tonne per year underground mine at Hugo North. Other predictions were made on the mine life as the Oyu Tolgoi Mine had projected a life of 29 years. This had largely been based on the potential inventory of mining just over 1 billion tonnes averaging 0.95% Cu, and 0.26 gram gold per tonne. It had also been about 78% of this modeled resource which had been classified as inferred, while the remainder is in indicated categories. Based on average recoveries of 89.6% copper, and 65.8% gold, production is expected to total 8.0 million tonnes of copper (19.5 billion lbs.) and 5.7 million oz. gold over the life of the mine.
The initial capital cost of constructing stage 1 is estimated to cost up to US$529 million, while the overall cost of both stages comes in at US$1.17 billion. Much of the reports surrounding financing of the mine project was within Ivanhoe’s capability. This had also given Ivanhoe the option of selling non-core assets or selling a minority participation in the Oyu Tolgoi Project, by one or more strategic partners. Total gold production for the first four years would also amount to recovering 400,000 oz. Au from the Oyu Tolgoi Mine.
A preliminary engineering study had also been undertaken on the Oyu Tolgoi Mine, and would propose for the development of large open pit operations, This would also be achieved by some modernized mining equipment, that includes 350-tonne haulage trucks, and large capacity electric shovels. Further geological work had revealed that the mineralization appears to be amenable to processing in a conventional flotation concentrate. The ore processing plant would be designed to incorporate the largest proven mills into the grinding circuit. Plans towards building the ore processing plant would be done around two grinding modules, each of which is capable of handling 20 million tonnes per year. Each of the modules would additionally consist of a 12.2 metre-diameter semi-autogenous grinding (SAG) mill, with a 21-MW wrap around the motor coupled with two 7.7- by 11.6 metre, 15.5 MW ball mills. Much of the grinding module had been in support by a flotation circuit, and the tailings would be fed to a containment dam area in the southeastern corner of the mining lease.
Stantec would also provide assistance towards Ivanhoe’s Oyu Tolgoi Mine Site in realizing their production targets by providing engineering, design, procurement, and quality assurance for the No. 1 and No. 2 Shafts. Other plans were also in the making to explore, develop, and mine the area by constructing a total of five shafts. The company had been largely in charge of designing the No. 1 Shaft for initial ore-body access, definition drilling, and a future hoisting facility. Engineering plans that were done on the hoisting facility were aimed at making it capable of lifting 2,500 tonnes of ore per day. One of the major stations that were cut for this project would be engineered at the 1,285-m horizon. Much of the shaft sinking work was aimed at mining deeper copper-gold ore-bodies at the Hugo Deposit.
2005 – 2006 – Ivanhoe Mines
Ivanhoe Mines would make a decision on the summary of phase to expand the case study of the Oyu Tolgoi Copper-Gold Mine property. The major expansion project would call for the development of a block cave system mine at the Hugo South Deposit, and would proceed with the stripping of stages 3 and 4 of the open-pit mine. Phase 2 was largely aimed at bringing the project to production stage from underground block cave mines, and would double the capacity of the concentrator. Further expansion would also continue as a second SAG milling circuit was in the plans of development. Most of the work was largely focus on increasing the Oyu Tolgoi’s combined open-pit and underground production to about 140,000 tonnes of ore per day by year 7. It had also been stated that the Hugo North mill feed, which was combined with feed from stages 3 and 4 of the open pit development plan would be taken for processing. This would additionally maintain the proposed production of 140,000 tonnes of ore per day that would be taken from the Oyu Tolgoi Copper-Gold Mine. An assumption had also been made at this time as IDP would indicate that Oyu Tolgoi Copper-Gold Mine could produce approximately 35 billion pounds of copper, and 11 million oz. of gold over the projected, initial 35-year life of the mine.
The Oyu Tolgoi Copper-Gold Mine also has significant potential to increase known resources at the Oyu Tolgoi Mine. By allowing this it would also provide an ultimate rate of production from the expanded concentrator that could exceeded the projection provided in the IDP. It had also been at this time that engineering work was aimed at developing the concentrator with a single SAG semi-autogenous grinding circuit with an initial throughput rate of 70,000 tonnes of ore per day. Mining would first be achieved by developing open pit operations that would be focus on taking the ore from the Southwest Deposit. It would also be indicated that during the first three years of operation, mill feed will be primarily produced from stage 1 and 2 of the open pit centred on the gold rich, higher grading Hugo North Deposit. Predictions made had assumed that mining of the Hugo North Deposit would be initiated in year 3. By year five it was predicted that the Hugo North would be the predominant source of mill feed for the concentrator. This would also facilitate an increase in year 6, as 85,000 tonnes of ore would be mined on a daily basis.
It had also been during the year of 2005, that shaft work was underway at the Oyu Tolgoi Mine in the Gabi Desert of Mongolia. Ivanhoe at this point in time had contracted McIntosh Engineering Inc., of Tamp, USA, to conduct this work on the shaft. McIntosh Engineering had additionally recognized the importance of the Oyu Tolgoi copper-gold porphyry property. McIntosh Engineering was largely engaged in the sinking and development of the No. 1 Shaft that would provide an access point to the Hugo North and South Deposits.
Some of the major surface construction work that was done during 2005, was largely focus on constructing the No. 1 Shaft Headframe, hoisting plant, and associated infrastructure. Predictions that were made on shaft sinking had reported that this work would be commence in the fourth quarter of 2005.
Additional work had also been contracted to the Redpath Group of North Bay, Canada, that’s known as the leading shaft sinking firm in the world. Upon completion of the sinking phase it would also result in a complete detailed feasibility studies on the Oyu Tolgoi Copper-Gold Mine. Sinking of the No. 1 Oyu Tolgoi Shaft was predicted to be completed by the third quarter of 2007, and would be followed by underground drifting, and diamond drilling for further delineation drilling and rock characterization work. McIntosh had also received a contract for the engineering and sinking of the No. 2 Oyu Tolgoi Shaft, which was being designed as a 10-metre-diameter production and service shaft.
Planning for the development of the No. 2 Shaft had also been done as it was being currently designed as a 10.0 m diameter shaft, and will have one of the tallest shaft headframes in the world, measuring 96-m in height. The Oyu Tolgoi Mine is a copper/gold porphyry deposit that is currently being mined by block caving methods. It had also been further development planning that would result in hiring several engineering, mining, and environmental consultants, that was led by Australian based AMEC Minproc, and including U.S. based Stantec Engineering. One of the new plans which was made at the time was aimed at providing an update to the original 2005 Integrated Development Plan. The new plan that was set fourth had additionally supported Ivanhoe Mine’s commitment to advance the Oyu Tolgoi into full construction.
Upon geological mapping and observation it was also stated that further enhance can be made on the economics of the project. Much of the exploration work executed by Ivanhoe had also been aimed at expanding and upgrading the resources that were used as the basis for assessment work. Mining plans that were made at the time had also not fully exploited the May, 2005, estimate resources, and the excellent potential to add significant new resources. Ivanhoe, and its contract engineering firms had also indicated the potential of increasing the mine life a Oyu Tolgoi Mine to about 40 years. Exploration work that was continued had also discovered another high-grade copper-gold mineralization to the north of the Oyu Tolgoi Boundary. These discoveries were additionally made on the Shivee Tolgoi Property, that was owned or is owned by Entrée Gold Inc. Agreements were also made with Ivanhoe, and Entrée Gold to conduct explorations on the property with the rights to earn up to 80% of resources discovered on the property. Drilling during that year had also continued to expand the strike length of the Hugo Far North Copper-gold discovery to more than 600 metres beyond Oyu Tolgoi’s northern boundary.
Drilling that was done on the Hugo South Deposit had consisted of completing a total of 583 diamond drill holes for the Southern Oyu Tolgoi Open Pit, totalling 273,000 metres. This had also included the Southwest, South, Wedge and Central Zones, and an additional 287,000 metres in 267 holes in the Hugo North and South Deposits.
An estimation made by AMEC had estimated that the Oyu Tolgoi Project has a measured, and indicated resource estimation totalling 1.15 billion tonnes grading 1.30% Cu, and 0.47 g/t Au per tonne. This estimation that was made would contain 32.9 billion pounds of copper, and 17.3 million oz. Gold, at 0.60% copper equivalent cut off. AMEC would also estimate that the Oyu Tolgoi Project would contain an inferred resource estimate of 1.16 billion tonnes grading 1.07% Cu, and 0.23 g/t Au. The inferred resource estimation would also contain 26.2 billion pounds of copper, and 8.4 million oz. of gold. The total measured plus indicated ore reserves were estimated to contain 1,146,160,000 tonnes of ore grading 1.30% Cu, and 0.47 g/t gold per tonne. In total the indicated category towards ore reserves would be estimated at 32,850,000 lbs. of copper, and 17,340,000 oz. of gold.
2006 – 2007 – Ivanhoe/Rio Tino
An announcement was made on October, 18, 2006, that the world’s mining leader Rio Tinto had came to agreements to form a strategic partnership by investing in Ivanhoe, and through an Ivanhoe-Rio Tinto Technical committee partnership. It was also within these agreements that Rio Tinto would engineer, construct, and operate Ivanhoe’s Oyu Tolgoi Copper-Gold mining complex in Mongolia’s South Gabi region. In doing so, Rio Tinto had purchased approximately 37.1 million Ivanhoe shares at a price of US$8.18, representing a 25% premium to Ivanhoe Mines closing price on October 17, 2006, and a premium of 30% to Ivanhoe’s 20 day moving average share price to October, 15, of US$6.29. By completing this investment agreement, Rio Tinto would secure approximately 9.95% of Ivanhoe Mines share capital.
Development work would also progress on the No. 1 shaft, which is a 6.7 metre-diameter exploration and production shaft at Oyu Tolgoi. Much of the shaft sinking that was undertaken between McIntosh and Redpath Group, had continued onward as it would bottom out at a depth of 600 metres. It had also been during this time period that the planned depth of the No. 1 Shaft would be engineered to 1,340 metres below the surface. The No. 1 Oyu Tolgoi Shaft would also be scheduled for completion by late 2007, with underground drifting, and drilling occurring in 2007 and 2008. Upon completion of this shaft it would also allow for the early exploration of a high-grade upper portion of the Hugo North deposit, as well as expedite the conversion of the current Hugo North resources into proven and probable reserves.
Some of the major surface construction work had involved site preparation, excavation for the concentrator foundations, and the construction of accommodation facilities that were progress. Other preparations were being made towards the No. 2 Shaft, a 10-metre diameter production and service shaft. It was also in 2006, that a technical committee was called on the for the finalization of the location and development plan for this shaft before work begins on the pre-sinking excavation. Much of this work was followed by the on schedule work in starting the construction of the No. 2 Head-frame in the spring of 2007.
Ivanhoe had additionally made plans to transfer the company’s Mongolian Coal Division to Asia Gold Corp during the second quarter of 2006. This agreement was largely made in exchange for approximately 82.6 million shares of Asia Gold Corp. It had been on August 8, 2006, that the majority shareholders of Asia Gold Corp had voted 99% in favour of the merger transaction. An acceptance had also been made by the Mineral Resources and Petroleum Authority of Mongolia that would allow this transfer through applications made by Ivanhoe.
2007 – 2008 – Ivanhoe/Rio Tinto
Development work on the Oyu Tolgoi Copper-Gold Project had continued to progress by a partnership agreement with Ivanhoe, and Rio Tinto. It was during 2007, that the Oyu Tolgoi Site had celebrated a safety record with 2.5 million hours worked without lost-time incident in early October, 2007. Most of the major development work was progress towards sinking the No. 1 Oyu Tolgoi Shaft that would bottom out at 1,300 metres. It had been at this depth that a level would be opened up by a drift level, and additional sinking was commenced to allow for underground infrastructure that would continue to the end of the year. Planned lateral development would also allow for additional exploration of the Oyu Tolgoi high-grade underground deposits, and for the allowance of initial production, and ultimately ventilation to the underground mine workings. Most of the lateral development work was also scheduled to commence within the operating year of 2008. Upon completion of the No.1 shaft, together with the horizontal exploration tunnels, would provide access to the deep Hugo-Dummett Deposit. This would also allow the company to complete it geotechnical assessment that was largely required in order to advance the underground deposit to a feasibility level, and was scheduled for completion by 2008.
Plans would also be made towards conducting block cave planning for the Hugo-Dummett Deposit in 2007. A detailed study would also be commenced, and would continue through the operating year of 2008, and would incorporate the findings of the characterization drift. The drift was aimed at providing the geotechnical parameters to determine the detailed block-cave footprint design and mine development requirements.
Work would also continue to progress at the No. 2 Oyu Tolgoi shaft, that’s largely planned to be the initial, primary underground production, and service shaft. Some of the main work that was completed on the shaft had included concrete work to bring the subsurface works to grade or near to grade by the onset of winter. Included in this work would result in completing work on the below surface collar foundation to support the head-frame, and to accommodate a conveyor gallery, and vent plenum.
It was also at this time that work on the concentrator was approximately 20% complete at the Oyu Talgoi Mine Property. Much of concentrator engineering had also reached 71% completion by October, 2007, and was scheduled for substantial completion in March, 2008. Other construction work was being confined to the construction of a camp that would continued to be built. The combined capacity of the three camps that were being developed had been capable of accommodating 2,408 beds. This had also been followed by the engineering for the diesel power station, which would provide construction power to the project.
Ivanhoe Mines would additionally complete approximately 14,755 metres of diamond drilling on the Oyu Tolgoi Project during the third quarter of 2007. This included 9,175 metres of drilling on the newly discovered Hergua Deposit within the Javkhlant concession of the Entrée Gold-Ivanhoe Mines. Most of the work was additionally completed by joint venture agreements on a property adjoining the southern boundary of Oyu Tolgoi. In addition, 2,600 metres of drilling was completed for geotechnical characterization on the Entrée Gold-Ivanhoe Shivee Tolgoi property at the northern boundary of Oyu Tolgoi, and on the east side of the Hugo North Deposit. The remaining 2,972 metres of drilling had been split between sterilization drilling under the proposed coal-fired power plant in the southwest corner of Oyu Tolgoi Project, and exploration drilling on other induced polarization (IP) targets.
A primary focus was aimed at further exploring the Heruga Deposit, that was formerly referred as the Sparrow South IP target. Diamond drilling that was commenced on the Heruga Deposit had outline this zone in 19 diamond drill holes, totalling a length of 21,000 metres of core drilling. Much of the holes were largely spaced on 200- to 300- metre centres, having defined a 1,100 metre strike length of continuous copper, gold, and molybdenum mineralization up to 400 metres in width. The north-south striking deposit is also open on the east side and to the south. However, it was series of drill holes across the northern strike extension that had failed to intersect the deposit, that may have terminated in the hanging wall of the mineralization.
One of the major highlights for the work completed in 2007, was the discovery of the Heruga Deposit that mark a new style of molybdenum-rich mineralization. This rich mineralization of molybdenum had not been previously discovered along the trend of the Oyu Tolgoi project. No additional work was done towards age dating, but the deposit is largely hosted by Late-Devonian basaltic volcanic and quartz monzodiorite that are nearly identical to the host rocks of the Oyu Tolgoi Deposits. One of the main structural corridors that bounds the Heruga Deposit also is flanked by Devonian and Carboniferous volcanic rocks that are similar to the Oyu Tolgoi structural corridor.
In total the Oyu Tolgoi Trend is known for consisting of the Heruga Deposit, and an area of lower grade copper-gold mineralization known as the Airport North Zone. The Airport North Zone was first discovered during the operating year of 2006, and would warrant further exploration work that had defined its potential. From the major amount of work undertaken it was now estimated that the Oyu Tolgoi Trend has a strike length of 20 kilometers. The trend had also been well defined by the regional gradient array IP surveys that were conducted by Ivanhoe Mines geophysical team. Much of the IP survey that was conducted had located four chargeability anomalies along the Oyu Tolgoi trending line that extend approximately 15 km. south-southwest into Ivanhoe Mines 100% owned exploration tenement from the Heruga Discovery.
It was on September, 2007, that Ivanhoe Mines would announce that Rio Tino would provide a convertible credit facility of up to $350 million to finance ongoing mine development. The proceeds of the credit facility that would be used to ensure that long-lead-time orders for the manufacturing of mining equipment, such as trucks, tires, electric motors, ball mills, and development work on the No. 1 and No. 2 Shafts.
Development work on the Oyu Tolgoi Copper-Gold Project had continued to progress by a partnership agreement with Ivanhoe, and Rio Tinto. It was during 2007, that the Oyu Tolgoi Site had celebrated a safety record with 2.5 million hours worked without lost-time incident in early October, 2007. Most of the major development work was progress towards sinking the No. 1 Oyu Tolgoi Shaft that would bottom out at 1,300 metres. It had been at this depth that a level would be opened up by a drift level, and additional sinking was commenced to allow for underground infrastructure that would continue to the end of the year. Planned lateral development would also allow for additional exploration of the Oyu Tolgoi high-grade underground deposits, and for the allowance of initial production, and ultimately ventilation to the underground mine workings. Most of the lateral development work was also scheduled to commence within the operating year of 2008. Upon completion of the No.1 shaft, together with the horizontal exploration tunnels, would provide access to the deep Hugo-Dummett Deposit. This would also allow the company to complete it geotechnical assessment that was largely required in order to advance the underground deposit to a feasibility level, and was scheduled for completion by 2008.
Plans would also be made towards conducting block cave planning for the Hugo-Dummett Deposit in 2007. A detailed study would also be commenced, and would continue through the operating year of 2008, and would incorporate the findings of the characterization drift. The drift was aimed at providing the geotechnical parameters to determine the detailed block-cave footprint design and mine development requirements.
Work would also continue to progress at the No. 2 Oyu Tolgoi shaft, that’s largely planned to be the initial, primary underground production, and service shaft. Some of the main work that was completed on the shaft had included concrete work to bring the subsurface works to grade or near to grade by the onset of winter. Included in this work would result in completing work on the below surface collar foundation to support the head-frame, and to accommodate a conveyor gallery, and vent plenum.
It was also at this time that work on the concentrator was approximately 20% complete at the Oyu Talgoi Mine Property. Much of concentrator engineering had also reached 71% completion by October, 2007, and was scheduled for substantial completion in March, 2008. Other construction work was being confined to the construction of a camp that would continued to be built. The combined capacity of the three camps that were being developed had been capable of accommodating 2,408 beds. This had also been followed by the engineering for the diesel power station, which would provide construction power to the project.
Ivanhoe Mines would additionally complete approximately 14,755 metres of diamond drilling on the Oyu Tolgoi Project during the third quarter of 2007. This included 9,175 metres of drilling on the newly discovered Hergua Deposit within the Javkhlant concession of the Entrée Gold-Ivanhoe Mines. Most of the work was additionally completed by joint venture agreements on a property adjoining the southern boundary of Oyu Tolgoi. In addition, 2,600 metres of drilling was completed for geotechnical characterization on the Entrée Gold-Ivanhoe Shivee Tolgoi property at the northern boundary of Oyu Tolgoi, and on the east side of the Hugo North Deposit. The remaining 2,972 metres of drilling had been split between sterilization drilling under the proposed coal-fired power plant in the southwest corner of Oyu Tolgoi Project, and exploration drilling on other induced polarization (IP) targets.
A primary focus was aimed at further exploring the Heruga Deposit, that was formerly referred as the Sparrow South IP target. Diamond drilling that was commenced on the Heruga Deposit had outline this zone in 19 diamond drill holes, totalling a length of 21,000 metres of core drilling. Much of the holes were largely spaced on 200- to 300- metre centres, having defined a 1,100 metre strike length of continuous copper, gold, and molybdenum mineralization up to 400 metres in width. The north-south striking deposit is also open on the east side and to the south. However, it was series of drill holes across the northern strike extension that had failed to intersect the deposit, that may have terminated in the hanging wall of the mineralization.
One of the major highlights for the work completed in 2007, was the discovery of the Heruga Deposit that mark a new style of molybdenum-rich mineralization. This rich mineralization of molybdenum had not been previously discovered along the trend of the Oyu Tolgoi project. No additional work was done towards age dating, but the deposit is largely hosted by Late-Devonian basaltic volcanic and quartz monzodiorite that are nearly identical to the host rocks of the Oyu Tolgoi Deposits. One of the main structural corridors that bounds the Heruga Deposit also is flanked by Devonian and Carboniferous volcanic rocks that are similar to the Oyu Tolgoi structural corridor.
In total the Oyu Tolgoi Trend is known for consisting of the Heruga Deposit, and an area of lower grade copper-gold mineralization known as the Airport North Zone. The Airport North Zone was first discovered during the operating year of 2006, and would warrant further exploration work that had defined its potential. From the major amount of work undertaken it was now estimated that the Oyu Tolgoi Trend has a strike length of 20 kilometers. The trend had also been well defined by the regional gradient array IP surveys that were conducted by Ivanhoe Mines geophysical team. Much of the IP survey that was conducted had located four chargeability anomalies along the Oyu Tolgoi trending line that extend approximately 15 km. south-southwest into Ivanhoe Mines 100% owned exploration tenement from the Heruga Discovery.
It was on September, 2007, that Ivanhoe Mines would announce that Rio Tino would provide a convertible credit facility of up to $350 million to finance ongoing mine development. The proceeds of the credit facility that would be used to ensure that long-lead-time orders for the manufacturing of mining equipment, such as trucks, tires, electric motors, ball mills, and development work on the No. 1 and No. 2 Shafts.
2008 – 2009 – Ivanhoe Mines/Rio Tino
The No. 1 Oyu Tolgoi Shaft was officially completed on Janaury 27, 2008, and was largely celebrated by the Oyu Tolgoi Team. The shaft which was sunk had been designed to be 6.7 metres in diameter, with the final depth bottoming out at 1,386 metres. A large portion of development that was undertaken had made this shaft concrete lined, and was now one of the deepest mine shafts in Mongolia’s history. Lateral development was largely undertaken on the mines 1,300 metre level, that involved tunnelling into Oyu Tolgoi’s Hugo-Dummett North high-grade underground copper-gold deposit. The level by this time had facilitated the needs for exploration and initial production from the underground mine. One of the major contribution that were being planned by the two companies were aimed at using this shaft for ventilation purposes.
Surface construction work would also progress in the year of 2008, as major expanding was done to the infrastructure during the previous year. Construction work that was undertaken at the Oyu Tolgoi Mine site had include completing the work on the centralized camp, and the supply of power, and other utilities. The major amount of work was largely confined to the sinking and completion of the No. 1 Shaft operation. Additional surface construction work was done on the surface of the No. 2 Shaft, and to winterize the main camp area. Some of the major progress that was done had been focus on completing the concrete head-frame to 14 metres below grade and extending the conveyor gallery, and ventilation system. Some of the other construction work was also followed by the completion of a diesel power station, an operations water supply, and a road that was extended to the border of China. Upon completion of the diesel power station, it would additionally provide power to the Oyu Tolgoi Project.
It had also been by the years end that the concentrator facility was nearly 80% Completed, and site excavation work was approximately 25% complete. The major focus of 2008, was the procurement for the concentrator equipment so that the mine could reach its first production stage. It was also during this time that the measured and indicated ore reserves had now stood at 1,285,840,00 tonnes of ore grading 1.33% Cu, and 0.42 g/t Au. In total estimated recoveries the tonnage would produce approximately 40,680,000 lbs. of copper, and 20,970,000 oz. of gold. Inferred resources had stood at 2,157,130,000 tonnes of ore grading 0.80% Cu, and 0.35 g/t Au per ton. This would additionally result in total recoveries of approximately 38,230,000 lbs of copper, and 24,220,000 oz. of gold.
In March, 2008, Ivanhoe Mines would announce one of the very first resource estimations for the Heruga Deposit. It was strongly advised that the Heruga Deposit had contained an inferred resource estimate of 760 million tonnes grading 0.48% Cu, 0.55 g/t Au, and 142 ppm Mo In total estimated recoveries the Heruga Deposit was estimated to contain eight billion pounds of copper, and 13.4 million oz. of gold. Heruga had also contained an inferred resource estimate of 210 million tonnes grading 0.57% Cu, 0.97 g/t Au, and 145 ppm Mo, totalling 2.6 billion pounds of copper, and 6.4 million ounces of gold. In order to conduct this resource estimation it was reported that a total thirty four drill holes, including daughter holes, were drilled on nine sections spaced at 150-300 metre intervals, for a combined strike length of 1,800 metres. This deposit is rather described to be open ended, with one rig currently drilling on the northern-most section if the deposit, which is 150 metres south of the Oyu Tolgoi boundary. The drilling program being completed was aimed at exploring extensive copper/gold mineralization at the Oyu Tolgoi Mine.
The No. 1 Oyu Tolgoi Shaft was officially completed on Janaury 27, 2008, and was largely celebrated by the Oyu Tolgoi Team. The shaft which was sunk had been designed to be 6.7 metres in diameter, with the final depth bottoming out at 1,386 metres. A large portion of development that was undertaken had made this shaft concrete lined, and was now one of the deepest mine shafts in Mongolia’s history. Lateral development was largely undertaken on the mines 1,300 metre level, that involved tunnelling into Oyu Tolgoi’s Hugo-Dummett North high-grade underground copper-gold deposit. The level by this time had facilitated the needs for exploration and initial production from the underground mine. One of the major contribution that were being planned by the two companies were aimed at using this shaft for ventilation purposes.
Surface construction work would also progress in the year of 2008, as major expanding was done to the infrastructure during the previous year. Construction work that was undertaken at the Oyu Tolgoi Mine site had include completing the work on the centralized camp, and the supply of power, and other utilities. The major amount of work was largely confined to the sinking and completion of the No. 1 Shaft operation. Additional surface construction work was done on the surface of the No. 2 Shaft, and to winterize the main camp area. Some of the major progress that was done had been focus on completing the concrete head-frame to 14 metres below grade and extending the conveyor gallery, and ventilation system. Some of the other construction work was also followed by the completion of a diesel power station, an operations water supply, and a road that was extended to the border of China. Upon completion of the diesel power station, it would additionally provide power to the Oyu Tolgoi Project.
It had also been by the years end that the concentrator facility was nearly 80% Completed, and site excavation work was approximately 25% complete. The major focus of 2008, was the procurement for the concentrator equipment so that the mine could reach its first production stage. It was also during this time that the measured and indicated ore reserves had now stood at 1,285,840,00 tonnes of ore grading 1.33% Cu, and 0.42 g/t Au. In total estimated recoveries the tonnage would produce approximately 40,680,000 lbs. of copper, and 20,970,000 oz. of gold. Inferred resources had stood at 2,157,130,000 tonnes of ore grading 0.80% Cu, and 0.35 g/t Au per ton. This would additionally result in total recoveries of approximately 38,230,000 lbs of copper, and 24,220,000 oz. of gold.
In March, 2008, Ivanhoe Mines would announce one of the very first resource estimations for the Heruga Deposit. It was strongly advised that the Heruga Deposit had contained an inferred resource estimate of 760 million tonnes grading 0.48% Cu, 0.55 g/t Au, and 142 ppm Mo In total estimated recoveries the Heruga Deposit was estimated to contain eight billion pounds of copper, and 13.4 million oz. of gold. Heruga had also contained an inferred resource estimate of 210 million tonnes grading 0.57% Cu, 0.97 g/t Au, and 145 ppm Mo, totalling 2.6 billion pounds of copper, and 6.4 million ounces of gold. In order to conduct this resource estimation it was reported that a total thirty four drill holes, including daughter holes, were drilled on nine sections spaced at 150-300 metre intervals, for a combined strike length of 1,800 metres. This deposit is rather described to be open ended, with one rig currently drilling on the northern-most section if the deposit, which is 150 metres south of the Oyu Tolgoi boundary. The drilling program being completed was aimed at exploring extensive copper/gold mineralization at the Oyu Tolgoi Mine.
2009 – 2010 – Ivanhoe Mines/ Rio Tinto
For the most part, the pit optimization and mine design was largely focus on the preliminary resource model by OT LLC in February, 2005. The model was also known for forming the basis of the AMEC model which was produced in May, 2009. Much of the model that was prepared by AMEC had used resources classified as measured, and Indicated in the block motel that were used for the optimization and production scheduling. Other optimizations were done on the waste dumps that were redesigned in order to check the materials balance and to modify the dumps. The waste dumps at the Oyu Tolgoi Mine were also being planned to be apart of the TSF walls on the eastern side of the pits.
It had also been the main conventional style open pit mining methods that would use 42 m3 hydraulic shovels and 220 ton diesel trucks. Further studies that were undertaken on the open pit would use alternative equipment fleets that were recommended. One of the main development strategies used in the open pit optimization was aimed at minimizing the early mining costs, and maximizing the early return form the open pit operation. The main design had called for a mining width of approximately 40-50 metres that was adapted at the final pit floor. Some of the main haul roads that were designed for the open pit had used a 10% gradient and are 30 m wide. It had also been at the bottom of each stage, that the single width ramps of 15 m were designed. Some of the main development plans for the pit benches were aimed at making them 15 m high, and 6-12 m wide, which were adapted within the overall slope guidelines. An overall slope of roughly 18 degrees was considered within the preliminary design of the waste dumps and stockpiles. Much of the open pit mining work is also largely focus on the Southern Oyu deposits, that contain the Southwest, Central, South, Far South, Wedge, and Bridge Zones. Plans were made towards mining these zones in phases, as development would first start on the Southwest Zone of the Southern Oyu Deposit. This would be additionally followed by the Southwest, Wedge, and Bridge Zones, the South and Far South Zones, the Central, Southwest Zones, and eventually all the southern Oyu Deposits.
One of the very first pits known as the stage 1 pit, had been designed to be 700 m in diameter, and had mainly been developed to mine high-grade ore. This had largely been in parts of rich mineralization that was first observed in the area, and outline by diamond drilling. Development of the main southwest pit would be achieved to approximately 150 m below surface, and 250 m deep, providing feed for the first 18 months of the mine's life.
Upon completion of this work it would also result in preparing mining operations for the southwest stage 2 pit area. This would largely push the stage 1 limits to approximately 150 m back to develop the high-grade ore-body to a depth of 350 m.
As mining slows down this would lead to the stage 3 cutback which is similar to the stage 2 cutback in width but mines a much larger perimeter. Much of the U shape cut back was aimed a mining the western, eastern, and southern pits to a depth of 400 m.
This would be followed by the stage 4 and 5 designs that were largely focus on the Far South and South Deposits of the Oyu Tolgoi Copper-Gold Mine Project. By developing these two pits it was also stated that independent ramp exits would be developed in order to allow the ore and waste to be deferred at much later time Most of this would taken place upon the completion of mining on the main Southwest Ore from stages 1 to 3. This would also be followed by stage 6 targets that would mine relatively high-grade copper zones within the chalcocite blanket. Upon completion of this stage, progress would be made towards stage 7, that includes the development and mining of the Central Pit Zone in covellite mineralization.
_____________________________________________________________________________________________________________________
The first stage calls for the removal of approximately 74,000,000 tonnes of waste, and nearly 51,000,000 tonnes of ore grading 0.57% Cu, 0.85 g/t Au, and 1.42 g/t Ag. In total combination between the waste and ore, it was reported that the amount of rock removed would be 126,000,000 tonnes at a stripping ratio of 1.45.
Stage 2 would generally involve the removal of approximately 125,000,000 tonnes of waste, and 73,000,000 tonnes of ore grading 0.49% Cu, 0.55 g/t Au, and 1.30 g/t Ag. The total amount of rock removed would additionally amount to 198,000,000 tonnes at a stripping ratio of 1.70
This would later followed by stage 3, that involves the removal of approximately 171,000,000 tonnes of waste, and 84,000,000 tonnes of ore grading 0.45% Cu, 0.45 g/t Au, and 1.35 g/t Ag. By completing stage 3, this would result in taking out a combined estimation of 255,000,000 tonnes of rock at a stripping ratio of 2.02.
The stage 4 development plan calls for the removal of approximately 43,000,000 tonnes of waste, and 40,000,000 tonnes of ore grading 0.60% Cu, 0.19 g/t Au, and 1.88 g/t Ag. Upon completion of stage 4, this would result in taking out nearly 83,000,000 tonnes of rock at a stripping ratio of 1.06.
Much of the stage 5 development plan would call for the removal of approximately 22,000,000 tonnes of waste, and 15,000,000 tonnes of ore grading 0.40% Cu, 0.32 g/t Au, and 1.05 g/t Ag. A total combination of 36,000,000 tonnes of rock would be taken out in categories classified as waste and ore at a stripping ratio of 1.48.
Development of the stage 6 area would then be undertaken in removing approximately 19,000,000 tonnes of waste, and 14,000,000 tonnes of ore grading 1.00% Cu, 0.12 g/t Au, and 1.46 g/t Ag. The total amount of rock removed combine would be set at approximately 33,000,000 tonnes at a stripping ratio of 1.40.
Stage 7 would result in the removal of approximately 163,000,000 tonnes of waste, and 149,000,000 tonnes of ore grading 0.64% Cu, 0.15 g/t Au, and 1.36 g/t Ag. By completing this work it would amount to taking out a combine estimation of approximately 312,000,000 tonnes of rock at a stripping ratio of 1.09.
The second final stage known as 8, would additionally remove approximately 459,000,000 tonnes of waste, and 227,000,000 tonnes of ore grading 0.39% Cu, 0.30 g/t Au, and 1.19 g/t Ag. Once stage 9 is complete, this would result in taking out a combined estimation of approximately 686,000,000 tonnes of rock at a stripping ratio of 2.02.
Stage 9 which is the final stage, would call for the removal of approximately 1,100,000,000 tonnes of waste, and 302,000,000 tonnes of ore grading 0.46% Cu, 0.35 g/t Au, and 1.13 g/t Ag. Upon completion of stage 9, this would result in a total combination of 1,401,000,000 tonnes of rock at a stripping ratio of 3.65.
_____________________________________________________________________________________________________________________
For the most part, the pit optimization and mine design was largely focus on the preliminary resource model by OT LLC in February, 2005. The model was also known for forming the basis of the AMEC model which was produced in May, 2009. Much of the model that was prepared by AMEC had used resources classified as measured, and Indicated in the block motel that were used for the optimization and production scheduling. Other optimizations were done on the waste dumps that were redesigned in order to check the materials balance and to modify the dumps. The waste dumps at the Oyu Tolgoi Mine were also being planned to be apart of the TSF walls on the eastern side of the pits.
It had also been the main conventional style open pit mining methods that would use 42 m3 hydraulic shovels and 220 ton diesel trucks. Further studies that were undertaken on the open pit would use alternative equipment fleets that were recommended. One of the main development strategies used in the open pit optimization was aimed at minimizing the early mining costs, and maximizing the early return form the open pit operation. The main design had called for a mining width of approximately 40-50 metres that was adapted at the final pit floor. Some of the main haul roads that were designed for the open pit had used a 10% gradient and are 30 m wide. It had also been at the bottom of each stage, that the single width ramps of 15 m were designed. Some of the main development plans for the pit benches were aimed at making them 15 m high, and 6-12 m wide, which were adapted within the overall slope guidelines. An overall slope of roughly 18 degrees was considered within the preliminary design of the waste dumps and stockpiles. Much of the open pit mining work is also largely focus on the Southern Oyu deposits, that contain the Southwest, Central, South, Far South, Wedge, and Bridge Zones. Plans were made towards mining these zones in phases, as development would first start on the Southwest Zone of the Southern Oyu Deposit. This would be additionally followed by the Southwest, Wedge, and Bridge Zones, the South and Far South Zones, the Central, Southwest Zones, and eventually all the southern Oyu Deposits.
One of the very first pits known as the stage 1 pit, had been designed to be 700 m in diameter, and had mainly been developed to mine high-grade ore. This had largely been in parts of rich mineralization that was first observed in the area, and outline by diamond drilling. Development of the main southwest pit would be achieved to approximately 150 m below surface, and 250 m deep, providing feed for the first 18 months of the mine's life.
Upon completion of this work it would also result in preparing mining operations for the southwest stage 2 pit area. This would largely push the stage 1 limits to approximately 150 m back to develop the high-grade ore-body to a depth of 350 m.
As mining slows down this would lead to the stage 3 cutback which is similar to the stage 2 cutback in width but mines a much larger perimeter. Much of the U shape cut back was aimed a mining the western, eastern, and southern pits to a depth of 400 m.
This would be followed by the stage 4 and 5 designs that were largely focus on the Far South and South Deposits of the Oyu Tolgoi Copper-Gold Mine Project. By developing these two pits it was also stated that independent ramp exits would be developed in order to allow the ore and waste to be deferred at much later time Most of this would taken place upon the completion of mining on the main Southwest Ore from stages 1 to 3. This would also be followed by stage 6 targets that would mine relatively high-grade copper zones within the chalcocite blanket. Upon completion of this stage, progress would be made towards stage 7, that includes the development and mining of the Central Pit Zone in covellite mineralization.
_____________________________________________________________________________________________________________________
The first stage calls for the removal of approximately 74,000,000 tonnes of waste, and nearly 51,000,000 tonnes of ore grading 0.57% Cu, 0.85 g/t Au, and 1.42 g/t Ag. In total combination between the waste and ore, it was reported that the amount of rock removed would be 126,000,000 tonnes at a stripping ratio of 1.45.
Stage 2 would generally involve the removal of approximately 125,000,000 tonnes of waste, and 73,000,000 tonnes of ore grading 0.49% Cu, 0.55 g/t Au, and 1.30 g/t Ag. The total amount of rock removed would additionally amount to 198,000,000 tonnes at a stripping ratio of 1.70
This would later followed by stage 3, that involves the removal of approximately 171,000,000 tonnes of waste, and 84,000,000 tonnes of ore grading 0.45% Cu, 0.45 g/t Au, and 1.35 g/t Ag. By completing stage 3, this would result in taking out a combined estimation of 255,000,000 tonnes of rock at a stripping ratio of 2.02.
The stage 4 development plan calls for the removal of approximately 43,000,000 tonnes of waste, and 40,000,000 tonnes of ore grading 0.60% Cu, 0.19 g/t Au, and 1.88 g/t Ag. Upon completion of stage 4, this would result in taking out nearly 83,000,000 tonnes of rock at a stripping ratio of 1.06.
Much of the stage 5 development plan would call for the removal of approximately 22,000,000 tonnes of waste, and 15,000,000 tonnes of ore grading 0.40% Cu, 0.32 g/t Au, and 1.05 g/t Ag. A total combination of 36,000,000 tonnes of rock would be taken out in categories classified as waste and ore at a stripping ratio of 1.48.
Development of the stage 6 area would then be undertaken in removing approximately 19,000,000 tonnes of waste, and 14,000,000 tonnes of ore grading 1.00% Cu, 0.12 g/t Au, and 1.46 g/t Ag. The total amount of rock removed combine would be set at approximately 33,000,000 tonnes at a stripping ratio of 1.40.
Stage 7 would result in the removal of approximately 163,000,000 tonnes of waste, and 149,000,000 tonnes of ore grading 0.64% Cu, 0.15 g/t Au, and 1.36 g/t Ag. By completing this work it would amount to taking out a combine estimation of approximately 312,000,000 tonnes of rock at a stripping ratio of 1.09.
The second final stage known as 8, would additionally remove approximately 459,000,000 tonnes of waste, and 227,000,000 tonnes of ore grading 0.39% Cu, 0.30 g/t Au, and 1.19 g/t Ag. Once stage 9 is complete, this would result in taking out a combined estimation of approximately 686,000,000 tonnes of rock at a stripping ratio of 2.02.
Stage 9 which is the final stage, would call for the removal of approximately 1,100,000,000 tonnes of waste, and 302,000,000 tonnes of ore grading 0.46% Cu, 0.35 g/t Au, and 1.13 g/t Ag. Upon completion of stage 9, this would result in a total combination of 1,401,000,000 tonnes of rock at a stripping ratio of 3.65.
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Blasting would be done through blast holes for ore and waste production drilling that will be 17 m deep x 305 mm in diameter. Most of the blasting would be carried out by a contractor including the supply and storage of the blast supplies. It had also been at this time that ammonium nitrate fuel oil (ANFO) would be used in dry holes, and heavy ANFO in wet holes. Assumptions were also made as 90% of the blasting conditions will mostly be dry, powder factors of 0.63 for ANFO, and 0.66 for emulsion explosives. Much of the material is also assumed to be blasted, in which free digging may possibly be achieved in the first or second benches. Other effects on the open pit operation were caused due to the construction of the power station area, and diesel fuel diamond drill were purchase to overcome this factor.
A primary loading unit would also be set up as this would be achieved by 42 m3 bucket hydraulic shovels within the open-pit operation. Most of the mining of the ore would be undertaken by shovels from the lower pit stage, and the others will be confined to stripping waste for the development of the next stage. Plans would also be aimed at using one of the shovels to move between the pit stages in order to assist with mining of the pit stages planned for the Oyu Tolgoi Copper-Gold Mine. By doing this work it would lead to the production of ore that would be generally taken to the crusher or stockpile for reclaim. Most of the waste taken from the workings would also be distributed to the dump areas proposed for this project by temporary ramps accessing the upper levels of the pits or via the final designed ramps in the pit stages. Effective open pit mine dewatering would also be done by using diesel pumps from in-pit sumps to a dam at the process plant. Other plans were aimed at sizing the pumps depending on the open-pit depth at the Oyu Tolgoi Mine Project in South Gabi Desert, Mongolia.
It had also been during the year of 2010, that SRK would additional prepare an underground geotechnical study on the Hugo North, and a cave mining Geotechnical Study that was undertaken in 2009. The 2009 study was mainly aimed at being carried out and confined to updated resource, ore reserves, and underground geotechnical information. It was from this study that much of the ore-body footprint had changed drastically since the earlier review that was undertaken on the mine. By this time, mining had advanced significantly as a narrower ore-body known as the Entrée Zone had been opened up by development on the northern part of the mine. Ongoing work had also been confined to new stress and rock deformations measurements from the exploration drift that had provided foregoing opportunities to calibrate the numerical models, and to provide more realistic results, and conclusions.
Decisions had also been made to mine the Hugo-Dummett underground deposit by methods of block caving, and had been considered as a productive method for the this project. The Hugo-Dummett is also very similar to the other deposits outline In dimension and tonnage that was widely adapted as an effective method around the world. Stantec which was formerly known as McIntosh Engineering would also design the block cave based on the Hugo North Lift 1 Mineral Reserve. Upon examination and through progressive development/diamond drilling, it was noted that the Hugo North Deposit plunges to the northeast. Much of the caving that was undertaken had been nearly 2 km long by 100 to 300-m wide, and 100 to 500 m high. It had also been the resource dimensions that were quite suitable to adapt the block caving methods within the underground workings at Oyu Tolgoi. Development of the No. 1 and No. 2 Shafts were largely confined to opening up levels in deeper horizons of the mine.
Hugo North is commonly known for extending +500 mean sea level and to depths well below -400 mean sea level. These deposits are considered to also be quite extensive, and much of the ground conditions are predominantly poorer than what had been required for a non- caving mining method to be employed. In addition to this, the size, shape, geotechnical characteristic, and grade of the deposits are capable of using bulk mining methods. It had also been base on these factors that the caving method was the proposed choice of developing the ore-bodies. This had also been additionally progressed as many of the other third party consultants, and economic consideration had paved the way for block caving mining methods. Some of the major advantages in adapting this method would include low unit cost, high productivity, and high production rates Some of the disadvantages in adapting this mining method would include much higher breaking requirements, possible ore loss and dilution, impact on surface facilities, and possible loss of developed production areas due to cave management and geological structure problems.
An ore handling system had also been developed in order to provide transport for the cave as ore is taken from the drawpoints on the extraction level at depth of 1,300-m. Lateral development resulting in panel drifts had been known to provide access to all the drawbells within the mine. These panel drifts rather come in pairs, as they share an ore-pass, and the spacing that was made between the ore-pass was 60 m. Ore haulage is done by LHD's that transport the ore from the drawbells to an ore-pass located along the eastern perimeter drift in order to provide the LHD's with a maximum one-way haul distance. Much of the ore-passes are commonly considered to be discharged into chutes to 50 ton trucks on the haulage level of the mine. From here the trucks than transport the ore to the primary gyratory crushers through one-way haulage loops. The haulage level is rather known as a one-way travel to reduce congestion within the mine area. Development had resulted in developing haulage drifts that are located 40 below the haulage level at the 1,300 m horizon.
A total of three Gyratory crushers are also installed and located along the west side of the footprint. Its each of these crushers that discharge to a 700 ton bin, and apron feeder which is located within the mine workings. Much of the feed is also considered to discharge into a transfer conveyor that generally transports the ore to the main inclined conveyors. From here the ore is transfer to the large bins that are located near the main shaft area at the Oyu Tolgoi Mine Site. Each of the bins that are situated near the shafts are known to commonly feed a set of high speed measuring conveyors which directly load the skips. Each of the skips are also hoisted to the surface in order to be discharge into bins from which ore is transferred to the main overland conveyor, and then to the milling facility.
On May, 2009, OT LLC would retain Golder Associates Limited to carry out a reiveiw of the proposed pit slope design at Oyu Tolgoi. It was with the exception of extensive surface weathering that extends to depths of approximately 50 m to 50 m, the rocks are generally hard and competend. The measured mean intact rock laboratory unconfined compressive strengths were also known to range from 113 to 206 MPa.
A primary loading unit would also be set up as this would be achieved by 42 m3 bucket hydraulic shovels within the open-pit operation. Most of the mining of the ore would be undertaken by shovels from the lower pit stage, and the others will be confined to stripping waste for the development of the next stage. Plans would also be aimed at using one of the shovels to move between the pit stages in order to assist with mining of the pit stages planned for the Oyu Tolgoi Copper-Gold Mine. By doing this work it would lead to the production of ore that would be generally taken to the crusher or stockpile for reclaim. Most of the waste taken from the workings would also be distributed to the dump areas proposed for this project by temporary ramps accessing the upper levels of the pits or via the final designed ramps in the pit stages. Effective open pit mine dewatering would also be done by using diesel pumps from in-pit sumps to a dam at the process plant. Other plans were aimed at sizing the pumps depending on the open-pit depth at the Oyu Tolgoi Mine Project in South Gabi Desert, Mongolia.
It had also been during the year of 2010, that SRK would additional prepare an underground geotechnical study on the Hugo North, and a cave mining Geotechnical Study that was undertaken in 2009. The 2009 study was mainly aimed at being carried out and confined to updated resource, ore reserves, and underground geotechnical information. It was from this study that much of the ore-body footprint had changed drastically since the earlier review that was undertaken on the mine. By this time, mining had advanced significantly as a narrower ore-body known as the Entrée Zone had been opened up by development on the northern part of the mine. Ongoing work had also been confined to new stress and rock deformations measurements from the exploration drift that had provided foregoing opportunities to calibrate the numerical models, and to provide more realistic results, and conclusions.
Decisions had also been made to mine the Hugo-Dummett underground deposit by methods of block caving, and had been considered as a productive method for the this project. The Hugo-Dummett is also very similar to the other deposits outline In dimension and tonnage that was widely adapted as an effective method around the world. Stantec which was formerly known as McIntosh Engineering would also design the block cave based on the Hugo North Lift 1 Mineral Reserve. Upon examination and through progressive development/diamond drilling, it was noted that the Hugo North Deposit plunges to the northeast. Much of the caving that was undertaken had been nearly 2 km long by 100 to 300-m wide, and 100 to 500 m high. It had also been the resource dimensions that were quite suitable to adapt the block caving methods within the underground workings at Oyu Tolgoi. Development of the No. 1 and No. 2 Shafts were largely confined to opening up levels in deeper horizons of the mine.
Hugo North is commonly known for extending +500 mean sea level and to depths well below -400 mean sea level. These deposits are considered to also be quite extensive, and much of the ground conditions are predominantly poorer than what had been required for a non- caving mining method to be employed. In addition to this, the size, shape, geotechnical characteristic, and grade of the deposits are capable of using bulk mining methods. It had also been base on these factors that the caving method was the proposed choice of developing the ore-bodies. This had also been additionally progressed as many of the other third party consultants, and economic consideration had paved the way for block caving mining methods. Some of the major advantages in adapting this method would include low unit cost, high productivity, and high production rates Some of the disadvantages in adapting this mining method would include much higher breaking requirements, possible ore loss and dilution, impact on surface facilities, and possible loss of developed production areas due to cave management and geological structure problems.
An ore handling system had also been developed in order to provide transport for the cave as ore is taken from the drawpoints on the extraction level at depth of 1,300-m. Lateral development resulting in panel drifts had been known to provide access to all the drawbells within the mine. These panel drifts rather come in pairs, as they share an ore-pass, and the spacing that was made between the ore-pass was 60 m. Ore haulage is done by LHD's that transport the ore from the drawbells to an ore-pass located along the eastern perimeter drift in order to provide the LHD's with a maximum one-way haul distance. Much of the ore-passes are commonly considered to be discharged into chutes to 50 ton trucks on the haulage level of the mine. From here the trucks than transport the ore to the primary gyratory crushers through one-way haulage loops. The haulage level is rather known as a one-way travel to reduce congestion within the mine area. Development had resulted in developing haulage drifts that are located 40 below the haulage level at the 1,300 m horizon.
A total of three Gyratory crushers are also installed and located along the west side of the footprint. Its each of these crushers that discharge to a 700 ton bin, and apron feeder which is located within the mine workings. Much of the feed is also considered to discharge into a transfer conveyor that generally transports the ore to the main inclined conveyors. From here the ore is transfer to the large bins that are located near the main shaft area at the Oyu Tolgoi Mine Site. Each of the bins that are situated near the shafts are known to commonly feed a set of high speed measuring conveyors which directly load the skips. Each of the skips are also hoisted to the surface in order to be discharge into bins from which ore is transferred to the main overland conveyor, and then to the milling facility.
On May, 2009, OT LLC would retain Golder Associates Limited to carry out a reiveiw of the proposed pit slope design at Oyu Tolgoi. It was with the exception of extensive surface weathering that extends to depths of approximately 50 m to 50 m, the rocks are generally hard and competend. The measured mean intact rock laboratory unconfined compressive strengths were also known to range from 113 to 206 MPa.
Ventilation requirements were largely aimed at determining the airflow that are generally specified for the production and development areas of the mine. This would also include airflow to the transportation and haulage levels of the No. 1 Shaft, and for fixed facilities within the underground workings at the Oyu Tolgoi Mine. In accordance with requirements mine ventilation is completed by a third party review of the main ventilation design. A software program known as VnetPC is used to develop models at representative stages within the mine design of this project. Much of the air quantity is largely based on diesel emission dilution of 0.06 m3/s/kW of diesel engine rating for the mine project. These diesel engine rating are also generally based on the technical specifications for major equipment that is needed to efficiently operate. The ventilation produces a total airflow volume of 1850 m3/s that is required at full production in order to provide adequate ventilation for mobile equipment, fixed facilities, and personnel within the mine workings, One of the main designs for the final ventilation system was a pull network with all primary ventilation fans located on the exhaust side of the mine workings. Other problems that were face had been the concern in dust control within the underground working, and primarily in the dry conditions predicted from the hydrology modelling done. Dry drawpoints would also be the source of much higher than average dust within the panel drifts that were developed. This generally relies on the high levels of silica content than normal levels that the severity of the dust problem may be increased in these sections.
One of the major challenges in developing this project was the development of the undercuts to ventilate in block cave mining. Development of the undercut face would generally retreat as the cave mining method advances within the underground workings. A general recourse is considered to be made to the auxiliary ventilation system in order to provide ventilation. This had also been quite similar to the multiple lateral development headings, and an allocation of 35 m3/s is sufficient for each loader, and truck. There had also been some series in re-use of the air with the auxiliary systems depending on the mining rate, and layout. In order for the mine to achieve a production rate of 84,200 tonnes per day, it required a loader in each of the active production drifts. These are largely remotely operation that are capable of being adjustable by regulator controls, and the inactive production drifts could also be ventilated with a fraction of the designed air flow system.
Much of the mine air heating system at the No. 2 Shaft is largely composed of several finned heat exchanger coils supplied with heat by a district hot water circulation loop. These coils are rather arrange in parallel within an insulated building. Its also within this building that pair of boost fans are installed on the rear of the mine air heater to draw air into the building, and through the coils. From here the heated air is then supplied to the headframe sub-collar where its drawn underground by the primary ventilation fans.
The Hugo North Deposit does not have an underground warehouse as much of the material and supplies are kept in the central surface warehouse. As development progress this resulted in developing underground storage areas that are the shops, fuel station, explosive magazine, etc. The main storage areas that were designed are currently known to supply three days worth of material within the underground mine workings.
One of the major challenges in developing this project was the development of the undercuts to ventilate in block cave mining. Development of the undercut face would generally retreat as the cave mining method advances within the underground workings. A general recourse is considered to be made to the auxiliary ventilation system in order to provide ventilation. This had also been quite similar to the multiple lateral development headings, and an allocation of 35 m3/s is sufficient for each loader, and truck. There had also been some series in re-use of the air with the auxiliary systems depending on the mining rate, and layout. In order for the mine to achieve a production rate of 84,200 tonnes per day, it required a loader in each of the active production drifts. These are largely remotely operation that are capable of being adjustable by regulator controls, and the inactive production drifts could also be ventilated with a fraction of the designed air flow system.
Much of the mine air heating system at the No. 2 Shaft is largely composed of several finned heat exchanger coils supplied with heat by a district hot water circulation loop. These coils are rather arrange in parallel within an insulated building. Its also within this building that pair of boost fans are installed on the rear of the mine air heater to draw air into the building, and through the coils. From here the heated air is then supplied to the headframe sub-collar where its drawn underground by the primary ventilation fans.
The Hugo North Deposit does not have an underground warehouse as much of the material and supplies are kept in the central surface warehouse. As development progress this resulted in developing underground storage areas that are the shops, fuel station, explosive magazine, etc. The main storage areas that were designed are currently known to supply three days worth of material within the underground mine workings.
The extent of this mine would require several bays that are generally estimated from the fleet size, and equipment used at the Oyu Tolgoi Mine Project. In order to minimize expense in cost only a minimal amount of bays can actively incorporated into one shop at the mine site. These are generally considered to also be shared between the main shop, which consists of 12 service bays, and two satellite shops having 3 service bays each. Most of the design of these bays was aimed at providing access to the working areas during different phases of the mine's life span. Service bays are also located at either end of the each panel drift so that vehicles can easily access the bays on a breakdown basis. It had also been the much needed service trucks that would attend to the majority of these breakdowns that may occur. The main maintenance shop is rather located along the service drifts from the No. 2 Shaft on the west side of the extraction level. By developing this location it had provided efficient means of access to the service shaft, and ventilation airways. Development of this shaft was largely focus on providing an area to service diesel LHD's, secondary breaking rigs, and jumbos, trucks, rock bolters, and support equipment.
All the satelite shops are also developed along the east side of the main extraction level at a depth of 1,300 m below the surface. Further engineering plans would be made towards servicing different parts of the mine workings. For example, one of these satelite shops would service the north portion and a second one would service the southern portion of the mine workings. This would also result in constructing an additional satelite shop that's situated near the No. 1 Shaft, which is largely being used for preproduction development. The main reason for developing satelite shops is that they are known to provide fast turnarounds for minor repairs and servicing close to the main working areas. By adding these satelite bays to service portions of the underground working it would reduce congestion in the main shop. Most of the construction work of these satelite shops was largely being aimed to facilitate minor repairs, tire and bucket changes, and the required equipment planned maintenace. Much of the main design in laying out the satelite bays was aimed at providing three drive-through service bays, a wash bay, lunch room, tire storage, and a small warehouse/tool shop. Each of the satelite bays are also composed of a lunch room during break periods within the underground workings.
All the satelite shops are also developed along the east side of the main extraction level at a depth of 1,300 m below the surface. Further engineering plans would be made towards servicing different parts of the mine workings. For example, one of these satelite shops would service the north portion and a second one would service the southern portion of the mine workings. This would also result in constructing an additional satelite shop that's situated near the No. 1 Shaft, which is largely being used for preproduction development. The main reason for developing satelite shops is that they are known to provide fast turnarounds for minor repairs and servicing close to the main working areas. By adding these satelite bays to service portions of the underground working it would reduce congestion in the main shop. Most of the construction work of these satelite shops was largely being aimed to facilitate minor repairs, tire and bucket changes, and the required equipment planned maintenace. Much of the main design in laying out the satelite bays was aimed at providing three drive-through service bays, a wash bay, lunch room, tire storage, and a small warehouse/tool shop. Each of the satelite bays are also composed of a lunch room during break periods within the underground workings.
Some of the main development work had been focus on continuing the No. 2 shaft in order to provide facilities for hoisting material to the surface from deep, underground. The engineering of the No. 2 Shaft was strictly aimed at developing, and mining the copper-gold ore from the deep Hugo-Dummett Deposit. Other construction projects were aimed at constructing a 97 m tall reinforced concrete headframe for the No. 2 Oyu Tolgoi Shaft. It had also been during the year of 2009, that much of the surface construction work of the No. 2 Oyu Tolgoi Shaft was completed in 2009. Some of the main construction work had included sight earthworks that were being done in preparation for laying out the foundation for the concentrator.
By 2009, the No. 2 Oyu Tolgoi Shaft was officially completed to a depth of 1,385 m below the surface, and it was by 2010 that the shaft was supporting the initial development program undertaken. Much of the major program is confined to mining and developing one of the most deepest copper-gold deposits known as the Hugo-Dummett. Lateral development would continued as planned and would also include the continuation of the ramp down to the Crusher 1 area. By this time the south characterization drift was completed, and the No. 3 crosscut was developed through to align with the North Characterization drift. Much of the development rate in 2009, was 45% above plan, with 1,074 m of lateral development work achieved. Underground lateral development was no progressing towards the northward drive along the ore-body. Some of the latest exploratory diamond drilling that was undertaken had continued to show visible gold within the underground mine workings.
Other preparations were being made towards driving a raise bore ventilation shaft at the No. 1 Shaft to provide ventilation to the underground workings. The main projection of completing this raise was estimated to be fully completed by July, 2011, and this would allow future development rates to increase by approximately 75%. Not only would this allow for the increase in development but would also provide a second mining fleet to the underground workings at Oyu Tolgoi. Some of the main orders were also being made for an Atlas Copco M2C Jumbo, a Sandvik LHD517. a Sandvik LH550 truck, one Normet Spraymec, and two Normet Transmixers.
Ivanhoe would progress with it major exploration diamond drill campaign in 2009, that resulted in completing 20,024 m of diamond drilling on the Oyu Tolgoi Project. This would also include the completion of 17,060 m of diamond drilling in areas between the SW Oyu and Heruga (New Discovery Zone) in 14 holes, including 5 daughter holes. A total of 2984 m of diamond drilling was also completed in 5 holes that was in parts of exploration work between the Oyu Tolgoi, and surrounding areas.
The hole which were drilled in the New Discovery Zone are considered to be in five northwest-southwest-oriented sections that are 500 m apart. It was of these holes drill that only two of them had been quite successful in intersecting mineralization. The diamond drilling program was fist initiated in 2008, and completed by the year of 2009 on the New Discovery Zone. It was rather these holes that contributed to the importance of the New Discovery Zone as they were spaced out in sections that were 1.5 km apart. Much of the mineralization in the Far South deposit is rich in bornite, and appears to be quite similar to the Hugo-Dummett Deposit. The other four holes drill had been aimed at targetting induced polarization (IP) anomalies that were outlined through surveying. All of these holes were terminated after intersecting a major north-north-easterly oriented structural fault on the property. It was believed that the fault was the extension of the West Bat Fault that rather terminates on the western side of the Hugo-Dummett Deposit.
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Drill Hole From To Intervals Au Cu Mo CuEq%
OTD1487 1978 m 1994 m 16 m 0.1 g/t 1.65% 38 ppm 1.73% 2028 m 2053.7 m 25.7 m 0.85 g/t 0.89% 62 ppm 1.47%
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OTD1487A 1978 m 1994 m 16 m 0.09 g/t 1.55% 38 ppm 1.63%
2028 m 2126 m 98 m 0.96 g/t 0.88% 115 ppm 1.56%
2258 m 2336.3 m 78.3 m 2.13 g/t 0.82% 126 ppm 2.24%
1978 m 2336.3 m 358.3 m 0.85 g/t 0.54% 66 ppm 1.12%
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OTD1495A 2034 m 2314 m 280 m 0.06 g/t 0.84% 13 ppm 0.88%
2330 m 2377.2 m 47.2 m 0.10 g/t 1.32% 8 ppm 1.39%
2034 m 2377.2 m 343.2 m 0.06 g/t 0.87% 12 ppm 0.91%
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OTD1498 1978 m 2100 m 122 m 0.05 g/t 0.42% 54 ppm 0.48%
2240 m 2318 m 78 m 0.07 g/t 0.61% 12 ppm 0.66%
2346 m 2418 m 72 m 0.07 g/t 0.44% 41 ppm 0.51%
1800 m 1910 m 110 m 0.17 g/t 0.44% 189 ppm 0.65%
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Geological Mapping that was undertaken in the year of 2009, was largely focus on the southern end of the Oyu Tolgoi trend and the Javhalaad group of licences further south. The mapping program that was undertaken had shown that the Oyu Tolgoi trend is known to probablly curve to the south-west at the southern end of the Heruga, and is largely cut by an east-west-trending belt of younger granites.
2011 - 2012 - Ivanhoe Minrs/Rio TInto
After much of the design became officialise, it was during 2011 that pre-stripping of overburden was commenced in order to access ore of the Phase 1 development plan of the open pit. Most of the work which was achieved at this time was aimed at hauling clay material to the tailing-storage facility. Other major infrastructure projects would include the establishment of laydown and access ramps, and road building at the Oyu Tolgoi Open Pit Project. A fleet of mining equipment and machinery was first miniated in September, 2011 with the release of the first Bucyrus RH340 hydraulic shovel, and Kamastu 930E hault trucks. It was towards the end of 2011, that a total of 13.2 million tonnes of total material had been removed with drill/blast production at approximately 80,000 metres drilled and over 3,000 tonnes of explosives consumed for blasting. The total of measured and indicated reserves within the Southern Oyu Deposit had stood at 567,230,000 tonnes of ore grading 0.62% Cu, and 0.55 g/t Au. In total tonnage the Southern Oyu Deposit contains approximately 7,750,000 lbs. of Cu, and 10,030,000 oz. Au. This also includes an inferred resource estimate of 88,500,000 tonnes of ore grading 0.47% Cu, 0.41 g/t and 0.41 g/t Au, containing 920,000 lbs. Cu, and 1,170,000 oz. Au.
Underground development had also continued at the Hugo-Dummett Deposits that was undergoing Phase 2 of underground block cave mining at the Hugo North Deposit. Lateral development at this time had progress on the 1,300-m level that resulted in completing 6,460 m of work, and for a total of 10,241 m of tunneling completed since 2008. Further plans would be aimed at shutting down all lateral development work on February, 2012, as the hoisting equipment would be upgrade at the No. 1 Shaft. All of this work was planning on being commenced in March, 2012, and would be completed by August, 2012. It had been during the year that plans were made to recommence underground lateral development at the Oyu Tolgoi Hugo-Dummett Deposit on September, 2012.
Majority of the work in 2011, was confined to designing of the underground No. 4 Shaft and No. 5 raise to ventilate the mine workings. Plans were aimed at constructing the No. 5 ventilation rasie by raising a bore, and had proven to be quite difficult in doing that which suffered delays. Most of the challenges and stoppage to lateral development was mainly caused due to poor ground conditions in the mine. The crucial part of the work was mainly aimed at constructing the ventilation raises in order to meet requirements for development, and to provide alternative means of egress if the No. 1 Shaft is unavailable.
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Deposit Tonnage Cu Au Contained Metal (Cu) Contained Metal (Au)
Hugo North - OT LLC -indicated 703,200,000 tons 1.82% 0.39 g/t 28,220,000 lbs. Cu 8,820,000 oz. Au
Shivee Tolgoi - Indicated 117,000,000 tons 1.80% 0.61 g/t 4,640,000 lbs. Cu 2,290,000 oz. Au
All of Hugo North Indicated 820,200,000 tons 1.82% 0.42 g/t 32.910,000 lbs. Cu 11,080,000 oz. Au
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Hugo North - OT LLC - Inferred 722,800,000 tons 0.97% 0.30 g/t 15,460,000 lbs. Cu 6,970,000 oz. Au
Shivee Tolgoi - Inferred 95,500,000 tons 1.15% 0.31 g/t 2,420,000 lbs. Cu 950,000 oz. Au
All of Hugo North - Inferred 818,300,000 tons 1.00% 0.30 g/t 18,040,000 lbs. Cu 7,890,000 oz. Au
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Hugo South - Inferred 490,330,000 tons 1.05% 0.09 g/t 11,350,000 lbs. Cu 1,420,000 oz. Au
Hugo North & South- Inferred 1,308,630,000 tons 1.02% 0.22 g/t 29,430,000 lbs. Cu 9,260,000 oz. Au
_____________________________________________________________________________________________________________________Heruga Javkhland EJV inferred 910,000,000 tons 0.48% 0.49 g/t 9,570,000 lbs. Cu 14,300,000 oz. Au
Heruga Ivanhoe Inferred 60,000,000 tons 0.48% 0.37 g/t 39,120,000 lbs. Cu 17,360,000 oz. Au
All Heruga Inferred 970,000,000 tons 0.48% 0.48 g/t 40,610,000 lbs. Cu 25,390,000 oz. Au
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All of Oyu Tolgoi
Measured: 101,590,000 tons 0.64% 1.10 g/t 1,430,000 lbs. Cu 3,590,000 oz. Au
Indicated: 1,285,840,000 tons 1.38% 0.42 g/t 39,120,000 lbs. Cu 17,360,000 oz. Au
Measured + indicated: 1,387,430,000 tons 1.33% 0.47 g/t 40,680,000 lbs. Cu. 20,970,000 oz, Au
Inferred: 2,367,130,000 tons 0.78% 0.33 g/t 40,616,000 lbs. Cu 25,390,000 oz. Au
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Exploration and development work had continued to define several type of small-scale structures in the Hugo North Ore-body. Some of these new structures that were identified had included joints, bedding planes, and veins within the underground workings. Upon observation it was apparent that most of the material is within economical limits of the ore-body that could be characterized as jointed rock mass with at least four or five joint sets. Strong and weak joints have also been encountered within the underground workings, but are typically considered to be undulating smooth. Underground mapping was also largely carried out from the No. 1 shaft at depths ranging between 500 m to 1,300 m below the surface. Mapping haf been done through the characterization drifts as it continued to progress on other development that was being achieved on various levels.
The main objective that was set fourth within the characterization drift program was mainly being aimed at providing access fpr the underground mapping, sampling, instrumentation, and drilling. All of this was widely being carried out in order to investigate the geotechnical and geological situation in the more detailed than could be done from the surface.
By 2009, the No. 2 Oyu Tolgoi Shaft was officially completed to a depth of 1,385 m below the surface, and it was by 2010 that the shaft was supporting the initial development program undertaken. Much of the major program is confined to mining and developing one of the most deepest copper-gold deposits known as the Hugo-Dummett. Lateral development would continued as planned and would also include the continuation of the ramp down to the Crusher 1 area. By this time the south characterization drift was completed, and the No. 3 crosscut was developed through to align with the North Characterization drift. Much of the development rate in 2009, was 45% above plan, with 1,074 m of lateral development work achieved. Underground lateral development was no progressing towards the northward drive along the ore-body. Some of the latest exploratory diamond drilling that was undertaken had continued to show visible gold within the underground mine workings.
Other preparations were being made towards driving a raise bore ventilation shaft at the No. 1 Shaft to provide ventilation to the underground workings. The main projection of completing this raise was estimated to be fully completed by July, 2011, and this would allow future development rates to increase by approximately 75%. Not only would this allow for the increase in development but would also provide a second mining fleet to the underground workings at Oyu Tolgoi. Some of the main orders were also being made for an Atlas Copco M2C Jumbo, a Sandvik LHD517. a Sandvik LH550 truck, one Normet Spraymec, and two Normet Transmixers.
Ivanhoe would progress with it major exploration diamond drill campaign in 2009, that resulted in completing 20,024 m of diamond drilling on the Oyu Tolgoi Project. This would also include the completion of 17,060 m of diamond drilling in areas between the SW Oyu and Heruga (New Discovery Zone) in 14 holes, including 5 daughter holes. A total of 2984 m of diamond drilling was also completed in 5 holes that was in parts of exploration work between the Oyu Tolgoi, and surrounding areas.
The hole which were drilled in the New Discovery Zone are considered to be in five northwest-southwest-oriented sections that are 500 m apart. It was of these holes drill that only two of them had been quite successful in intersecting mineralization. The diamond drilling program was fist initiated in 2008, and completed by the year of 2009 on the New Discovery Zone. It was rather these holes that contributed to the importance of the New Discovery Zone as they were spaced out in sections that were 1.5 km apart. Much of the mineralization in the Far South deposit is rich in bornite, and appears to be quite similar to the Hugo-Dummett Deposit. The other four holes drill had been aimed at targetting induced polarization (IP) anomalies that were outlined through surveying. All of these holes were terminated after intersecting a major north-north-easterly oriented structural fault on the property. It was believed that the fault was the extension of the West Bat Fault that rather terminates on the western side of the Hugo-Dummett Deposit.
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Drill Hole From To Intervals Au Cu Mo CuEq%
OTD1487 1978 m 1994 m 16 m 0.1 g/t 1.65% 38 ppm 1.73% 2028 m 2053.7 m 25.7 m 0.85 g/t 0.89% 62 ppm 1.47%
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OTD1487A 1978 m 1994 m 16 m 0.09 g/t 1.55% 38 ppm 1.63%
2028 m 2126 m 98 m 0.96 g/t 0.88% 115 ppm 1.56%
2258 m 2336.3 m 78.3 m 2.13 g/t 0.82% 126 ppm 2.24%
1978 m 2336.3 m 358.3 m 0.85 g/t 0.54% 66 ppm 1.12%
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OTD1495A 2034 m 2314 m 280 m 0.06 g/t 0.84% 13 ppm 0.88%
2330 m 2377.2 m 47.2 m 0.10 g/t 1.32% 8 ppm 1.39%
2034 m 2377.2 m 343.2 m 0.06 g/t 0.87% 12 ppm 0.91%
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OTD1498 1978 m 2100 m 122 m 0.05 g/t 0.42% 54 ppm 0.48%
2240 m 2318 m 78 m 0.07 g/t 0.61% 12 ppm 0.66%
2346 m 2418 m 72 m 0.07 g/t 0.44% 41 ppm 0.51%
1800 m 1910 m 110 m 0.17 g/t 0.44% 189 ppm 0.65%
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Geological Mapping that was undertaken in the year of 2009, was largely focus on the southern end of the Oyu Tolgoi trend and the Javhalaad group of licences further south. The mapping program that was undertaken had shown that the Oyu Tolgoi trend is known to probablly curve to the south-west at the southern end of the Heruga, and is largely cut by an east-west-trending belt of younger granites.
2011 - 2012 - Ivanhoe Minrs/Rio TInto
After much of the design became officialise, it was during 2011 that pre-stripping of overburden was commenced in order to access ore of the Phase 1 development plan of the open pit. Most of the work which was achieved at this time was aimed at hauling clay material to the tailing-storage facility. Other major infrastructure projects would include the establishment of laydown and access ramps, and road building at the Oyu Tolgoi Open Pit Project. A fleet of mining equipment and machinery was first miniated in September, 2011 with the release of the first Bucyrus RH340 hydraulic shovel, and Kamastu 930E hault trucks. It was towards the end of 2011, that a total of 13.2 million tonnes of total material had been removed with drill/blast production at approximately 80,000 metres drilled and over 3,000 tonnes of explosives consumed for blasting. The total of measured and indicated reserves within the Southern Oyu Deposit had stood at 567,230,000 tonnes of ore grading 0.62% Cu, and 0.55 g/t Au. In total tonnage the Southern Oyu Deposit contains approximately 7,750,000 lbs. of Cu, and 10,030,000 oz. Au. This also includes an inferred resource estimate of 88,500,000 tonnes of ore grading 0.47% Cu, 0.41 g/t and 0.41 g/t Au, containing 920,000 lbs. Cu, and 1,170,000 oz. Au.
Underground development had also continued at the Hugo-Dummett Deposits that was undergoing Phase 2 of underground block cave mining at the Hugo North Deposit. Lateral development at this time had progress on the 1,300-m level that resulted in completing 6,460 m of work, and for a total of 10,241 m of tunneling completed since 2008. Further plans would be aimed at shutting down all lateral development work on February, 2012, as the hoisting equipment would be upgrade at the No. 1 Shaft. All of this work was planning on being commenced in March, 2012, and would be completed by August, 2012. It had been during the year that plans were made to recommence underground lateral development at the Oyu Tolgoi Hugo-Dummett Deposit on September, 2012.
Majority of the work in 2011, was confined to designing of the underground No. 4 Shaft and No. 5 raise to ventilate the mine workings. Plans were aimed at constructing the No. 5 ventilation rasie by raising a bore, and had proven to be quite difficult in doing that which suffered delays. Most of the challenges and stoppage to lateral development was mainly caused due to poor ground conditions in the mine. The crucial part of the work was mainly aimed at constructing the ventilation raises in order to meet requirements for development, and to provide alternative means of egress if the No. 1 Shaft is unavailable.
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Deposit Tonnage Cu Au Contained Metal (Cu) Contained Metal (Au)
Hugo North - OT LLC -indicated 703,200,000 tons 1.82% 0.39 g/t 28,220,000 lbs. Cu 8,820,000 oz. Au
Shivee Tolgoi - Indicated 117,000,000 tons 1.80% 0.61 g/t 4,640,000 lbs. Cu 2,290,000 oz. Au
All of Hugo North Indicated 820,200,000 tons 1.82% 0.42 g/t 32.910,000 lbs. Cu 11,080,000 oz. Au
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Hugo North - OT LLC - Inferred 722,800,000 tons 0.97% 0.30 g/t 15,460,000 lbs. Cu 6,970,000 oz. Au
Shivee Tolgoi - Inferred 95,500,000 tons 1.15% 0.31 g/t 2,420,000 lbs. Cu 950,000 oz. Au
All of Hugo North - Inferred 818,300,000 tons 1.00% 0.30 g/t 18,040,000 lbs. Cu 7,890,000 oz. Au
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Hugo South - Inferred 490,330,000 tons 1.05% 0.09 g/t 11,350,000 lbs. Cu 1,420,000 oz. Au
Hugo North & South- Inferred 1,308,630,000 tons 1.02% 0.22 g/t 29,430,000 lbs. Cu 9,260,000 oz. Au
_____________________________________________________________________________________________________________________Heruga Javkhland EJV inferred 910,000,000 tons 0.48% 0.49 g/t 9,570,000 lbs. Cu 14,300,000 oz. Au
Heruga Ivanhoe Inferred 60,000,000 tons 0.48% 0.37 g/t 39,120,000 lbs. Cu 17,360,000 oz. Au
All Heruga Inferred 970,000,000 tons 0.48% 0.48 g/t 40,610,000 lbs. Cu 25,390,000 oz. Au
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All of Oyu Tolgoi
Measured: 101,590,000 tons 0.64% 1.10 g/t 1,430,000 lbs. Cu 3,590,000 oz. Au
Indicated: 1,285,840,000 tons 1.38% 0.42 g/t 39,120,000 lbs. Cu 17,360,000 oz. Au
Measured + indicated: 1,387,430,000 tons 1.33% 0.47 g/t 40,680,000 lbs. Cu. 20,970,000 oz, Au
Inferred: 2,367,130,000 tons 0.78% 0.33 g/t 40,616,000 lbs. Cu 25,390,000 oz. Au
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Exploration and development work had continued to define several type of small-scale structures in the Hugo North Ore-body. Some of these new structures that were identified had included joints, bedding planes, and veins within the underground workings. Upon observation it was apparent that most of the material is within economical limits of the ore-body that could be characterized as jointed rock mass with at least four or five joint sets. Strong and weak joints have also been encountered within the underground workings, but are typically considered to be undulating smooth. Underground mapping was also largely carried out from the No. 1 shaft at depths ranging between 500 m to 1,300 m below the surface. Mapping haf been done through the characterization drifts as it continued to progress on other development that was being achieved on various levels.
The main objective that was set fourth within the characterization drift program was mainly being aimed at providing access fpr the underground mapping, sampling, instrumentation, and drilling. All of this was widely being carried out in order to investigate the geotechnical and geological situation in the more detailed than could be done from the surface.
Mine access for personnel, equipment, and materials are transported into and out of the mine via the service cage at the No. 2 Shaft. For the most part, the cage has a payload capacity of 38 tonnes with the dimensions being 3.2 m wide by 8.75 m long. The major design of the cage system within the No. 2 Shaft was done to allow hoisting of fixed and mobile equipment with minimal disassembly. Work personnel of the mine are bused from a central change house facility to the staging building near the collar of the No. 2 Shaft. Personnel who work within the mine walk to the shaft via a pathway tunnel and the cage lowers them to the main station, where they disembark and walk through a personnel walkway drift to the bus-loading area on the northeast side of the station. The bus than transports the personnel to a locker area that's located adjacent to the main lunchroom. There is also an auxiliary hoist shaft that is capable of transporting the personnel to the workings when the main cage of the No. 2 Shaft is unavailable or otherwise occupied.
2013 - 2014 -
Preparations were being made to mine the Hugo North ore-body by underground panel caving methods that have been chosen for this project. It was during that year when detailed designs were being establish of the first three panels of the Hugo North Lift 1. Much of the underground development within the Oyu Tolgoi Mie was currently suspended, and would recommence development after successful outcome of discussions between Rio Tinto and the Government of Mongolia. Predictions that were made on the Hugo North Lift 1 would schedule production in 2019, and ramp up to produce an average of 95 ktpd. In order to support mining within the Hugo North Lift 1, it was recommended to drive two declines, and to develop nearly 203 km of lateral development. This would also include the completion of five shafts, 6.8 km of raise boring, and 137,000 m3 of mass excavations that would be completed.
Other changes had also been made to the design of the underground workings as OT LLC had determined that a conveyor decline would be developed as the primary materials handling method. It had also been within this plan to design the conveying and hoisting capacity that was set fourth from the underground working to produce 140 ktpd. The main design and engineering plan of the conveyor decline was mainly aimed at providing an upside opportunity to take advantage of the potential improvement to productivity, and increased production from Lift 1. Much of the major development in constructing this conveyor decline would also facilitate for possible early access to a block cave om Hugo South or the future Hugo North Lift 2.
The Haulage Drift Level consists of truck haulage drifts that are 5.0 m high by 5.0 m wide and driven at a maxinum 3% gradient to follow the extraction level. Its from the extraction level that the ore reports to the haulage level truck loading chutes through the production of ore passes within the mine. These chutes all consist of loading bays that allow trucks to back into the chute area for loading of the ore that comes from the extraction level. Much of this allows for continous travel on the haulage loop without interruption from loading trucks. Loaded trucks are also known to exist the chute area, and proceed to the crushers through a haulage loop, which is a one-way travel route. The main purpose for connecting the haulage loops is mainly aimed at providing the much flexibility of directing ore to any available cursher in the mine area. A dispatch system rather directs development truck to enter the haulage loop via the internal ramp to dump development muck into the crushers. A total of Gyratory Crushers are installed within the mine, and below the haulage level, along the west side of the footprint. The first crusher known as Crusher No. 1 is adjacent to the northern part of the mining footprint, where caving is initiated, and the second Crusher Known as the No. 2 Crusher is situated near the central part of the mining footprint. From here cushed ore is then loaded onto a single inclined main conveyor that transports the ore to skip loading stations at the No. 2 Shaft. The ore can also be transferred to a 500 m long conveyor for delivery to the ore bins at Shaft No. 3.
Open pit mining at the South Oyu Tolgoi Deposit was in progress of pre development that was undertaken in the operating year of 2013. During this time it was reported that the pit design had not be revised and that the ten phases used for the previous study have not been updated. Ore reserves within the South Oyu Tolgoi were largely re-estimated by using the updated Base Data Template prices, recoveries, and other parameters.