The Stanleigh Uranium Mines had also held a total of 108 claims in historical Township 149 and 155, within the Blind River Area of Algoma District. It was in 1956, when two vertical, four compartment shafts were sunk on historical claim S.75393, in Township 149. The work in sinking this shaft was also done by contract in which the No. 1 Shaft was 1,579 feet deep, and the No. 2 Shaft had reach a depth of 1,227 feet. This resulted in confining lateral development towards developing a pumping station that was cut at a depth of 1,200 feet in the No. 2 Shaft. Exploratory work at the time had also continued when five diamond drill holes were drilled from the surface and three more, begun in the previous tear were completed. Drilling during this time period had also reach a total length of 17,474 feet that was done from 8 surface holes.
The Shaft sinking program at the Stanleigh Uranium Mine Project was also completed by the end of 1957. Both of the newly developed shaft would reach different depths as the No. 1 Shaft was 3,792 feet and the No. 2 Shaft had reach a depth of 3,650 feet. This resulted in sinking the No. 1 four compartment, vertical shaft by 2,213 feet and the No. 2 three compartment, vertical shaft, had also been sunk an additional 2,423 feet. A level that was commonly known as the 3,500-foot level was cut and stationed in each shaft. It was also considered to have been engineered at a depth of 3,493 feet in the No. 1 Shaft and 3,649 feet below the collar at the No. 2 Shaft operation. Lateral development on the 3,500 foot level of the No. 1 Shaft had also resulted 1,594 feet of drifting, 855 feet of crosscutting, and 20 feet of raising. Preparations at the time were also made towards extending the 3,500-foot level of the No. 2 Shaft that was opened up by 419 feet of drifting, 970 feet of crosscutting, 128 feet of raising. Most of the lateral development work at this time had also been completed by using trackless equipment in the Stanleigh Uranium Mine Project. Diamond drilling that was completed by the company resulted in two surface holes, totalling 1,444 feet and 23 underground drill holes, totalling 4,367 feet. Other properties adjoining the Stanleigh Uranium Property were held by Thorncrest Exploration, Limited to the north and Kamis Uranium, Limited to the south. Agreements were also made between these two companies as the Stanleigh Uranium Mines, Limited, had wanted to conducted3,854 feet of drilling from the Thorncrest Ground and one hole, 3,362 feet was additionally drilled from the surface of the Stanleigh Ground.
Construction in 1957, would also follow suite when the milling and mining plant was near completion. Before the mill and mining plant could be developed it was reported that some interruption had cause delays when a fire had broken out and destroyed the Pachuca Tank area. In regards to this it was also stated that the production at the Stanleigh Uranium Mine was delayed by four months time in repairing the tank area.
Other major work was also commence on the headframes which were made out of steel asbestos sheeting, and the No. 1 and 2 Hoisting Houses were equip by two Bertram Nordberg double drum hoists of different sizes. Even more construction would follow at this time when a grinding plant and crushing house became developed and had been equipped with 1 Symons Standard Crusher, 1 Symons Shorthand Crusher, 1 Buchanan Jaw Crusher, and 2 Symons rod deck screens.
A compressor house would also follow suite in this development phase as it would consist of 3, 125 Psi Canadian Ingersoll Rand Compressors, 3, 45 Psi Canadian Ingersoll Rand Compressors, and a Beckerton and Day, 1,200 kw., Mirrless Standby Diesel Engines. This resulted in also building a Mine Air Heating House that had 2 Roots Connerville, type RCR, rotary positive blowers. A massive milling complex was also added to this major project that had consisted of 2 Dominion Rod Mills, 2 Dominion Ball Mills, 2 Atkins Duplex Classifiers, two Dorr Tray Thickeners, two Wemco Washing Thickeners, one Gypsum Thickener, one U3O8 Thickener, sixteen Dorr Oliver String Thickeners, two Conkey Filters, four Elmco Disc filters for neutral service, four Elmco Disc Thickeners for Acid Service, three Whitco Equipment Clarifiers, one Bartlett Snow Steam Dryer, sixteen Pachuca leaching tanks, eleven Pachuca tailing neutralization tanks, twelve Ion Exchange of Canada, Ion Exchange columns, and two, 1,000-ton Acid Storage Tanks. The Stanleigh Uranium Mine would also go through another phase of construction when a Laboratory, Boiler House, Service Building, Cold Storage Warehouse, Steam Plant, Sodium Chlorate Building, Bunk House, Dining Room, and 20 Dwellings were constructed. The total production from hoisting during 1957, resulted in taking out 50,320 tonnes of ore that was hoisted from this mining uranium mining project.
Development of the so called 3,500-foot level in each shaft operation was completed in 1958, in which it was now called the No. 9. Further more lateral development work would also escalate when the two 3,500-foot levels were connected between the No. 1 and No. 2 Shafts. Other development at the time was also made towards cutting and station two other levels that became known as the No. 8 and No. 13 Levels. Lateral development would also continue onward when 2,220 feet of drifting, 4,449 feet of Crosscutting, and 1,363 feet of raising was done.. This would also result in additional lateral development that was concentrated on preparing the levels for trackless. The finish connections between the No. 1 and 2 shaft had also made it functional for using the No. 1 Shaft for hoisting and the No. 2 Shaft as a Service Shaft. Mining operations in 1957, had also been extended 1,600 feet along strike, and 600 feet on the dip. Laterally developing this area would also indicated initial ore recovery of about 55% to be considered obtainable and plans were being made towards recovering this ore by Pillar Recovery. Development that was completed on the ore horizon was also stated to have been slightly better then 2 pounds of Uranium oxide Per tonne of ore mined from this section that had a width of 9 ½ feet. This had also became diluted to 1 ½ pounds of Uranium Oxide per tonne in the hanging wall overbreak into the barren rock, and by the Deliberate inclusions of the lower grade foot-wall material. Different practices were also taken into consideration in regards to reduce dilution, increase overall grades and recovery, reduce hanging wall pressure in the workings, and simplify the distribution offresh air, in which an altered method of mining was adapted that was called long-wall stoping. Plans would also include installing a rail haulage that was place along the footwall beds of the Stanleigh Uranium Mine. The method that became adapted would only simplify the mining of the ore bed when its intercepted by intrusive dikes and anormous faults. Before this newly altered method of mining would be used it had also came with costs of expenditure of equipment and development. Most of the work would also not increase mine production or even the ore reserves but would gradually obtain the required amount of Uranium Oxide for the Eldorado Contract. Mining operations from the Stanleigh Uranium Mine would also additionally provide 230,330 tonnes of ore hoisted, 63,616 tonnes of ore stockpiled, 50,208 tonnes of waste, and 15,373 tonnes of material from lateral development.
Downfalls towards mill start up had also been delayed in 1958, by the cause of a fire that had destroyed the Pachuca Tanks in 1957. This delay at the time had also resulted in 65 days of delay time to this massive milling facility. Milling operations at the Stanleigh Uranium Mine had rather also commence on March, 14, 1958, and the crushing plant was also place into operation. Results of the mill tune up period was also considered to have been free from difficulties and a rapid build up of ore tonnage had made it possible in milling the ore from the stockpile. It would also be in June, which was the final month of the financial period that ore treatment would increase to 2,567 tonnes per day, at an indicated recovery of 93%. Milling operations at the Stanleigh Uranium Mine had ended up treating a total of 210,561 tonnes, which had produce 293,166 tonnes of packed uranium oxide and a total of 273,715 tonnes was shipped. The Stanleigh Uranium Mines, Limited would also have on hand a total of 19,451 tonnes of uranium oxide and 53,312 tonnes that was still within the mill circuit.
A major expansion project had rather commenced in 1959, when No. 1 Stanleigh Shaft had been sunk further 54 feet to a depth of 3,846 feet. Prior to sinking the No. 1 Shaft further the 14th level was also cut and station on the mines 3,606-foot horizon. This would also result in establishing another level known as the No. 9 at a depth of 3,531 feet in the No. 2 Stanleigh Shaft. Mining operations at this time would also become extended to 2,600 feet along strikeand about 2.400 feet up the dip from the No. 2 Stanleigh Shaft. As lateral development had continued it was also met with the expectation of ore-grade and would entirely exceed the results from surface drilling. It was also during this year when the mining department was concerned with the effects of changing mining methods from trackless mining operation to convential mining without dropping a serious tonnage. Plans in accomplishing this task were also made towards shifting the emphasis gradually from one method to the other. Some of the ore was rather derived from conventional mining methods in July, although stoping operations did not start till October, 1959. Other major contributions towards this new method had also allowed the mill-head grades to rise in conjunction. During the first three months of the fiscal year it was also reported that head assays were at 2.056 pounds of uranium oxide per tonne of ore mined. These statements were also followed by corresponding figure for the last three months that was 2.150, consisting of ore from trackless methods grading 2.026, and conventional ore grading 2.246 pounds of uranium oxide. A small portion of trackless mining methods would also continue when it was focus on recovering ore from pillars of old work out stope sections. Further plans in June, 1959, were also aimed at confining operations to trackless mining methods on virgin ground that was being explored to the northwest. Upon examination it was found that the dip and beds of ore were very suitable for deploying the trackless mining methods in regards to its thickness. Production of ore that was raised from the underground workings would result in 841,843 tonnes, and it would also include 159,914 tonnes of waste material, and 848,321 broken ore reserves. Almost all the ore during that year was mined using trackless mining methods that had supplied 61% of the ore and remainder was from conventional stoping and development.
Milling operations during 1959, were also considered to have been dominated by the changes made in flow sheets that improved efficiency and economy of mining operations. It would also include the additions that were made in the Ion Exchange Regeneration Plant in August and an increase in pulp density in the leeching section in November. This would result in precipitation by the means of using anhydrous ammonia instead of caustic soda. Further so, this would also result in improvement towards costs and had also been effective in regards to improving grades of ore being mined from the Stanleigh Uranium Mine Project. Mill production at this time was also considered to have treated 846,347 tonnes, in which had produced 1,688,039 pounds of Uranium Oxide. Production of uranium oxide had also been accommodated with mill-head grades of 2.082 pounds per tonne and the recovery was 95.76%, which gave a yield of 1.994 pounds per ton.
The first closure of the Stanleigh Mine had resulted in 1960, when Stanleigh Uranium Mines had amalagamated with Preston-East Dome Mines, Limited. This at the time had rather formed a new company organization that was commonly known as the Preston Mines, Limited. Mining along with milling operation would also continued from January, 1st to November, 30th, 1960. Diamond drilling at this time was also aimed at increasing ore reserves for the sale of this property that resulted in completing 676 underground holes, totalling 16,206 feet in length. Most of this had also resulted in hoisting 958,546 tonnes of ore that was taken from the Stanleigh Uranium Mine at the time. From all production the Stanleigh Uranium Mine Mill was credited for treating 983,454 tonnes, grading 2.11 pounds of Uranium Oxide. From this total head-grade the mill was able to recover 1.99 pounds of uranium oxide, in which it would recover 1,958,130 pounds of Uranium Oxide.
Rio Algom Mines, Limited would additionally restart production at the historical Stanleigh Mine Site in 1983. Most of the start up to bring this mine into production was mainly caused due to the fact that the Quirke Uranium Mine was undergoing reduction. Work at the time had also resulted in completely dewatering both shaft operations at the Stanleigh Uranium Mine Project This was also followed by rehabilitating the old workings and preparing the old buildings for operation. Lateral development would also take place in regards to extracting the rich uranium oxide ore that had average well over 2 pounds per tonne of ore mined.
In 1984, the Stanleigh Uranium Mine Project that was owned by Rio Algom Mines, Limited had continued to undergo extensive renovations. This would also be followed by lateral development that had taken place in brining the mine to production levels of 4,000 tonnes of ore per day. Predictions were also made in regards to the company producing over 7 million pound of Uranium Oxide that would be taken out from the company’s Quirke and Stanleigh Mining Projects.
By 1985, Rio Algom Mines, Limited, would also bring the Panel Mining operation back into production. This would also included two other mining operations that were well in production at the time. Lateral development followed by massive ventilation shafts were also developed and sunk to depth of nearly 3,000 feet below the surface. Most of the work was followed by developing this project to the south west at the time as most of the ground previously worked was left abandoned. A large amount of lateral development which included drifting, crosscutting and raising had opened up the new portion of the property that was previously not worked. Production from the mine was also maintained at this point in time as the Stanleigh Uranium Mine Project was well producing over 4,000 tonnes of ore per day. In order to sink the new ventilation shaft the company would have to clear a large portion of land that was being further explored and developed. Production from the mine would also amount to a total of 1,440,000 tonnes of ore that had underwent treatment at the time. From all this production the milling facility owned by Rio Algom Mines, Limited would recover 2,721,600 pounds of uranium oxide that was used in Japanese Reactors and the contract that was obtained from Hydro One as it was needed for atomic energy.
Geology of the Stanleigh Uranium Mine Property
A large portion of this property is commonly considered to be largely made up of sparse conglomerate and minor feldspathic quartzite of the Gowganda Formation. Its also known to commonly be cut by northwesterly-trending and west trending diabase dikes, Between the Stanleigh and Milliken Mines the Nordic quartz diabase sill-like intrusion lies near the south boundary of the property. Predictions on further depth may also provide evidence that the attitude steepens and the ore-body may become dike like. Within the eastern section of this property near Sheriff Lake is known to be occupied by the Bruce Group between the upper Mississagi formation and the Espanola Limestone. Much of the Espanola Limestone is also expose and the uncomformable relationships of the Gowganada Formation to the Espanola Limestone and Espanola Greywacke can also be seen.
Most of the uranium mines are known to also be apart of the Matinenda Formation which is uraniferous oligomictic conglomerate. These are divided by two beds of ore grade conglomerate, in which each are about 10 feet thick and separated by a quartzite bed that's 5 to 22 feet thick. Each of these beds are also considered to strike east and dip at about 0.08 to 0.10 degrees N. The presents of mineralization in the are commonly known to compose of Brannerite, Uraninite, pyrite, and Monazite. Each of these conglomerate beds are also known to be correlated with the Nordic and Basal Reefs which are known as the principal ore beds. Its also to the northeast where Brittle to smooth basal is known to occupy the area at around Sheriff Lake. In evidence there is also a third reef higher in sequence and is believed to be correlated with the Pardee Reef.
Structural control of Formations
Its also the Matinenda Formation that is responsible for hosting all the uranium deposits of the Elliot Lake Area. This foremost formation is up to 180 m thick in the Elliot Lake Area, and is known to change gradually in the Thessalon and Sault Ste Marie areas. The Matinenda Formation is also probably less than 50 m thick, where as just west of Sudbury it is as much as 600 m thick but thins rapidly eastward and becomes intercalated with the mainly metavolcanic rocks of the Stobie Formation, and the mudstones of the McKim Formation. Near the City of Sudbury and to the east, the Matinenda Formation rather dies out due to alteration processes. Its commonly known to also be hosted by medium to coarse grained, poorly sorted subarkose, arkose, and beds of pyrite, and uraniferous, quartz pebble, conglomerate. The Subarkose, and arkose is known to mainly consist of poorly sorted quartz and feldspar grains that are set in a subordinate matrix of sericite and comminuted rock fragments. Much of the ratio between potassic to sodic feldspar is approximately 8:1. It also has minor constituents of pyrite, calcite, chlorite, zircon, and rarely leucoxene coated iron oxides, and monazite. These deposits hardly contain any magnetite or ilmenite, and are very high in potash-soda ration.