Search Documents

By D. G. Macintyre

Thick westward prograding clastic wedges were deposited along the margin of ancestral North America from Mid-Proterozoic to Mid-Paleozoic time. Periodic rifting and tectonic subsidence resulted in the formation of starved sub-basins along this otherwise passive continental margin. These sub-basins host important sedimentary exhalative barite-zinc-lead-silver deposits. In northeastern British Columbia, a thick succession of Paleozoic basinal facies clastic rocks is preserved within the northwest-trending Kechika Trough. Within the trough, sedimentary exhalative barite and barite-sulfide deposits occur in starved basin sediments of Middle Ordovician, Early Silurian, and Late Devonian age. The last are the most economically sigrrificant and are hosted by carbonaceous cherty argillites and siliceous shales of the Middle to Late Devonian Gunsteel Formation of the Lower Earn Group. The largest deposit, Cirque, has reserves in excess of 35 million tonnes averaging 100J0 (Pb +Zn) and 47 g/t Ag. Other potentially significant deposits include Driftpile Creek, Bear, Mt. Alcock, Fluke, Pie and Elf. Stratiform barite deposits are also common, particularly near the basin-to-shelf transition zone. The Late Devonian barite-sulfide deposits typically are zoned: interlarninated barite-sphalerite-galena-pyrite occurring near suspected vent areas grades outward into bedded barite. Laminated beds of pyrite typically occur in hangingwall siliceous shales, particularly above the inferred vent zone. The apparent absence of epigenetic stringer sulfide zones and footwall alteration implies that the deposits were formed from ponded brines at relatively low temperature. Away from the main deposits, the favourable stratigraphic interval is marked by the presence of thin beds of nodular and laminated barite and thin laminae of pyrite. Thin tuff beds also occur locally in this stratigraphic interval and are evidence for a Late Devonian volcanic event. A paleogeographic reconstruction of the Kechika Trough in Late Devonian to Mississippian time suggests that the barite-sulfide deposits formed in third-order starved basins between uplifted, northwest-trending horst blocks that were capped by shallow-water carbonate banks. The presence of intraformational breccias suggests that fault movement accompanied barite-sulfide precipitation. This tectonic activity may have allowed the escape of heated, overpressured metalliferous brines from permeable reservoirs within the sedimentary pile. Sedimentary exhalative deposits formed where these brines were exhaled as buoyant plumes onto the seafloor, cooled, and ponded in anoxic seafloor depressions.

Jan 1, 1992

By Feng Tianran, Lu Shijie, Shen Zhengchang, Han Zhibin, Tan Ming

"As a kind of non-metallic material, high-purify quartz sand has been widely used in many fields. Flotation is a popular way to process quartz sand. But it is in difficult position for flotation to get high-purify quartz product due to large amount of coarse particles contained in the feed. In this paper, a design principle of special flotation cell for high-purify quartz sand has been put forward base on ore property analysis and laboratory test, and the pilot scale special flotation cell has been developed to meet the requirement of the quartz sand flotation process. The special flotation cell for high-purify quartz sand is featured by middle positioned impeller, false bottom and draft tube, which could decrease the rising distance of mineralized bubble and strengthen the circulation capacity of the lower part of the flotation cell. Hydrodynamic study indicates that high air dispersion degree and strong lower slurry circulation could be produced by pilot scale special flotation cell, which is helpful to create a suitable hydrodynamic environment for quartz sand processing.INTRODUCTIONNatural quartz is a non-metallic mineral, which is widely used as raw material in multiple industry process (Shifu, 2006). High purity quartz, especially containing more than 99.9% silicon dioxide, is characterized by high temperature resistance, small thermal expansion coefficient, highly insulating and so on. The demand of high purity quartz has been rising along with social and economic development, now high purity quartz is widely used in the field of photovoltaic industry, electronic information, communications and aerospace industry.Quartz is a kind of main rocking-forming minerals in the nature. There are seven genetic types, such as natural crystal, quartz sandstone, quartzite, vein quartz, konilite, natural siliceous sand, granite quartz (Baolei, Shuilin, & Dianchao, 2012). The natural crystal is primarily used as raw material to refine high purity quartz, but it is not available for two reasons. On the one hand, the natural crystal is extremely expensive and poor in resources reserves, which can not satisfy the need of large-scale industrial production. On the other hand, the chemical component of natural crystal is instability, it may lead to low stable product performance in large industrial applications, and it is also difficult to achieve raw materials standardization. Therefore, there are a lot of studies to search for other technological methods to obtain high purity quartz from other genetic quartz types."

Jan 1, 2016

By Donald J. MacNeil

THE opinion, based upon geological knowledge, that certain areas within the Province of Nova Scotia might yield commercial quantities of petroleum, is not new. It dates back to at least 1864, when the Pioneer Oil and Salt Company drilled some shallow holes in search of oil near lake Ainslie, Cape Breton. As a matter of fact, several companies were engaged in oil exploratory work near lake Ainslie at about that time; included among them were the Inverness Oil and Mining Company, the Victoria Oil Company, the American Oil Company, and the Cape Breton Oil and Mining Company. Oil exploration by these and other companies was conducted sporadically on Cape Breton island until 1914. In several instances, the depth of the test holes exceeded 1,000 feet; the deepest was carried to 3,260 feet. The Lake Ainslie area was selected because oil seepages were present along certain sections of the lake shore, but the tests that were drilled to tap the oil-bearing zone failed to yield anything of commercial value. Currently, there are three areas in Nova Scotia wherein active exploratory work is being conducted, namely, at Pugsley Siding close to Amherst; at Kennetcook, Hants county; and near Mabou, Inverness county. The Pugsley Siding test is being drilled by the Sun Oil Company, of Philadelphia; the work at Kennetcook is under the direction of the Nova Scotia Oil and Gas Company; two relatively deep holes were drilled by the Lion Oil Refining Company in 1944 near Mabou, and, as a result of the additional geological information derived therefrom, another test probably will be drilled by this Company in the same area. Aside from these activities in the search for petroleum, the oil possibilities of several other sections of the Province are being studied by means of surface geological mapping.

Jan 1, 1945

By George R. Elliott

Introduction The pages that follow present a brief chronological survey of views which have been held, and of legislation enacted, for the regulation of the natural gas and oil industry in the Turner Valley field, especially as regards conservation of the natural gas. To provide a necessary background for an adequate understanding of the progress of events in western Canada, there is included also a compilation, from technical and legal authorities, of some of the more important measures which have been adopted for the regulation of the oil and gas fields of the United States, where these measures have had, or are likely to have, a bearing on the course of our domestic industry. Owing to exigencies of space, it has been possible to refer only to the most outstanding proposals and legislation, and to these in the briefest possible form. Although, so far as Canada is concerned, the data presented are restricted almost entirely to the Turner Valley field, it is the hope of the writer that the paper may prove of value for purposes of reference: for any similar gas and oil fields discovered in western Canada will certainly revive and intensify the problem of the proper steps to be taken for the conservation of the gas. Definition of 'Conservation The term conservation has been so misunderstood and misrepresented that, to many persons in Alberta, it means little more than closing-in wells. In the light of the definition of Charles E. Hughes, that 'True conservation of a raw material is its economical use', the subject of natural gas conservation is inseparably involved with the study of the function of the -gas and with the development of the principles of unit operation.

Jan 1, 1934

By A. D. Mufch, G. P. Mitchell

"THE HARDY MINE of Falconbridge Nickel Mines Limited is located in Lot 9, Concession 1, Levack Township, Sudbury District, Ontario, 20 miles northwest of the city of Sudbury, and a mile west of the town of Levack. The ore deposit is one of the many nickel-copper sulphide bodies found on, or near, the lower contact of the well-known Sudbury norite-micropegmatite irruptive, and is one of a family of ore deposits which occur on the northwest rim of the irruptive.The property was acquired by purchase in 1935. In the same year a magnetometer survey along the footwall contact of the norite, which is covered by about 150 feet of glacial sands and clays, first indicated the location of the orebody. Drilling from 1935 to 1942 outlined the extent of the ore. Shaft sinking was commenced in the fall of 1951, and the mine is now approaching full production at a rate of about 300,000 tons per year.There are several major differences between the geology of the Levack area and the Falcon bridge area, which lies at the opposite extremity of the irruptive, 28 miles to the east. The purpose of this paper is to describe the essential features of the geology of the Levack area as seen in the Hardy mine, and to supplement the recent papers on other properties in the Sudbury area by Davidson (1), Lochhead (2), and Yates (3).General GeologyA recent review of the regional geology and an extensive bibliography of the Sudbury area can be found in the two papers by H. C. Cooke (4, 5). Some of the recent related references are: Jas. E. Thomson (6), E. M. Abraham (7), Franc. R. Joubin (8), W. G. Q. Johnstone (9)."

Jan 1, 1949

By A. J. Reed, W. R. Bergey, Carr. J. M.

"The Highmont copper-molybdenum deposits are at Gnawed Mountain in the Highland Valley porphyry copper district, 125 miles northeast of Vancouver. This district is near the center of the lower Jurassic Guichon Batholith, where a north-trending swarm of porphyry dikes is crossed by west-northwesterly structural belts in which fracturing, intrusion of porphyry and breccia, and mineralization areconcentrated.The Highmont deposits are 2 miles southeast of, and in the same southernmost structural belt as, the Lornex deposit. The main deposits occur on either side of a composite dike of granodiorite, porphyry and breccia which strikes west-northwestward in fractured quartz diorite. North of the dike, the adjacent Nos. 1 (East) and 2 (West) zones together contain 150 million tons of open-pit ore mineable in two separate pits. These two zones will support a 25,000-tpd mill with a grade in the first five years of approximately 0.46 per cent copper equivalent. South of the dike, the Nos. 3 and 4 zones are partly explored and will provide large additional reserves. In these various zones, chalcopyrite, bornite and molybdenite form disseminations and fracture-fillings accompanied by quartz, K-feldspar, tourmaline, sericite, specular hematite and other minerals. Bornite extends for varying distances north of the dike, beyond which chalcopyrite is locally accompanied by pyrite. Higher-grade mineralization tends to coincide with fracture swarms, or with shear zones and faults which largely parallel these swarms. The ore zones are reflected by geochemical soil anomalies which show some glacial dispersion. LP. surveys gave weak but significant responses, expressed as per cent frequency effect. The ore zones occur within a strong magnetic gradient, but do not show a significant magnetic response."

Jan 1, 1971

By W. A. Jones

THE estimation of the average value of gold ore involves many considerations, among them the correct sampling of the deposit, the dilution by waste, and the loss of high-grade fines. It is a common experience that, after all these factors have been evaluated, adjustment of the assays is necessary before satisfactory agreement between the calculated mine grade and the mill heads is obtained. In fact, at many mines the latter correction overshadows all others in the preparation of routine estimates. For this reason it is proposed to deal only with the mathematical treatment of mine assays and the problem of bringing estimates into conformity with the corrected mill heads. Mine assays differ from physical measurements because the range of values is very great and these are not symmetrically distributed above and below the average, there being fewer high than low results. There is no widely accepted mathematical procedure for determining the average of series of measurements which exhibit these characteristics. Customary practice consists in empirically reducing high assays until a satisfactory agreement with mill heads is reached. It was thought that more confidence could be placed in grade estimates if a logical basis for calculations could be devised .. In an attempt to find a fundamentally sound procedure, amenable to practical application, many series of assays comprising over 235,000 channel samples (1) were studied at Hollinger Consolidated Gold Mines, Limited. Such an investigation could only be made where records covering many years of operation are available and where tabulating and calculating machines are in use. The results are recorded in the hope that the relationships noted for the large groups of assays used are of fundamental character and that the data will be useful to others dealing with the problem of grade estimation.

Jan 1, 1943

By M. Pfeifer, M. N. Brodie, D. J. Barratt

"This paper reviews design trends related to the various SAG mill configuration and drive options available today. The impact of these options on capital and operating costs is assessed, and key technical issues reviewed. The discussion is based on the conventional North American ’pancake’ mill configuration. IntroductionDuring the past decade mill technology has evolved significantly in the following key areas:• improvements in variable speed motors continue with on-going advances in electronics;• ring motors, or gearless drives, are becoming more common in mill sizes 32 ft and larger, with ratings of 10 000 HP and greater;• geared drives have become available up to ratings of 9500 HP per pinion, compared to the earlier 6000 HP guideline;• improvements in speed reducer technology due to the use of carburized and ground precision gearing, make the high speed motor-speed reducer drive more competitive with the direct coupled low speed motor drive;• a unique speed reducer drive is being introduced to this industry which combines ring gear drive pinions with speed reduction. mprovement in gear alignment is claimed, and the overall drive arrangement is more compact than is possible with a conventional speed reducer drive;• the first 38 ft and 40 ft diameter mills have been designed and manufactured; and • application of large multi-shoe bearings have made shell supported mill configurations available for all, including the largest sizes. These designs have flat instead of conical mill shell ends, and have the potential for technical and cost advantages compared to conventional trunnion supported designs.This proliferation of mill design features provides several options to those involved in planning and design of milling plants, and requires more extensive evaluation to optimize mill design features to best suit specific project requirements."

Jan 1, 1999

By Marty Hudyma

Large seismic events have been reported in mines in the Sudbury mining camp for more than 70 years. Nevertheless, no detailed record of the events has been compiled. In 2008, the Sudbury Regional Seismic Network (SRSN) research project was initiated to collect more accurate data with regard to the magnitude and locations of mining-induced seismic events in and near the mines in the Sudbury Basin. The data is used to better understand the mechanisms of the events and cause-effect relations between mining and seismic events. Through the collection of a central database of large seismic events, new insight is being be gained into why some mines are much more prone to large events than others. Fifteen low cost seismic stations have been distributed throughout the Sudbury basin. The data from each seismic station is uploaded to a central server using the internet. Data recorded on the SRSN is processed on a daily basis, and a weekly summary of blasts and events is issued to project sponsors. Seismic events smaller than local magnitude +1.0 have been identified and located. Event location accuracy is less than 2 kilometres, however, many events have been located less than 1 km from a mine. The SRSN fills a seismic monitoring gap between the in-mine microseismic monitoring systems and the earthquake monitoring system operated by the Geological Survey of Canada. Since July 2008, more than 600 mine blasts and more than 450 mining-induced seismic events have been recorded in the Sudbury basin. This paper primarily discusses the technical aspects of the design and operation of the SRSN. The SRSN is a Canadian Mining Industry Research Organisation (CAMIRO) research project, with industry sponsorship and support from FNX Mining, Itasca Canada, Vale Inco and Xstrata Nickel.

Oct 1, 2010

By L. A. Forsyth

"SINCE I received and accepted your invitation to present to this meeting a paper on A Canadian Integrated Coal and Steel Industry, I have given the subject a great deal of intensive study.Two conclusions have emerged from my considerations: first, that the subject should be dealt with by a person having a firm grasp of its technical aspects; and second, that it is a subject which requires expert analysis of the complicated problems it presents in pure economics.A third conclusion inevitably results from the two just mentioned -namely, that the mantle of the prophet which has been draped up-on my shoulders is too large for me to wear, because I am neither a practical nor a theoretical coal and steel man; and I am not an economist.With the warning that I have discovered, and am keenly conscious of, the inadequacy of my background for the task, I shall attempt to place before you those aspects of my subject which appear to high-light it from a layman's point of view.In the first place, in .order to avoid confusion as between my audience and myself, some definition of terms may be required.As I interpret it I am discussing -a coal and steel industry, using the last word in the generic and not the unit sense, self-sufficient in the provision of all its needs from within the geographical limits of Canada.Now, I start with the proposition that, in the very broadest aspects of such a concept, the Corporation of which I happen to be the executive head meets my definition as a combination of operations resulting in one fully integrated unit of a coal and steel industry."

Jan 1, 1952

By John Wightman

LOCATION OF PROPERTY THE property of Caribou Gold Mines, Limited, is situated in the north-eastern part of Halifax county, seven miles south of the Canadian National railway line at Upper Musquodoboit. Approach to the village is by a secondary road, improved recently by waste rock from the mine dump. A two-wire telephone line, seven miles long, built and owned by the present operators, provides communication to the nearest telephone exchange, Parker's Corner. HISTORY In 1870, the Caribou area was recognized as a proclaimed gold district. From then on, operations were intermittent, with periods of considerable activity by small companies until there were no fewer than seven mines in a district two miles long by three-quarters of a mile wide. These were the Holman, Truro, Caffrey, MacDonald or Elk, Lake, Dixon, and Hilchey properties, all of which have had separate stamp-mills, and have produced gold for varying periods. Depths of the workings range from 100 feet to 1,000 feet. Power was generated at each property by means of steam boilers. At the present time, the Consolidated Mining and Smelting Company of Canada, Limited, controls all the leased areas, approximately 800 acres, and is operating by means of one central vertical shaft. GEOLOGY The district in and about Caribou Mines has an elevation of approximately five hundred feet above sea level. The area is fairly well wooded, with rock outcrops here and there. These outcrops, along with information from test-pits and shafts, have been the basis for the very excellent geological map of the district prepared by E. R. Faribault some years ago. The rock structure, which is one of the best examples in Nova Scotia of an elliptical dome, has its anticlinal axis in a northeast-southwest direction, and flat plunges in the same directions.

Jan 1, 1938

By Tsuyoshi Adachi

Photovoltaic (PV) system is especially taken notice as one of important renewable energy resources, because PV has potential to provide a certain amount of energy supply as well as without greenhouse gases emission. Considering recent rapid increasing demand for PV system, more expansion of PV system is expected in the future. However, some precious metals and minor metals such as silver, indium and others are used as component materials of solar cell in PV system. Even if energy supply would become renewable, strict limitation of these metals still remain because amount of natural resources and recycling of metals has restrictions intrinsically. The aim of this study is to reveal the possibility of materials supply restrictions for Photovoltaic system quantitatively and to propose several measurements to assess supply risks for materials. Especially, silver supply potential which is used as wire line in PV system as well as PV demand forecast to estimate material use in the future are focused on. We divide underlying supply risk into 5 measurements and analyze them by time series, i.e. price volatility, resource potential, recycling ratio, production type and supply concentration are investigated. Comparing these factors of silver with other metals, the potential of silver supply for PV is presented. In addition to it, we propose another method to quantify country risk applied an insurance pricing model in finance pricing theory and combine it with the supply concentration measurement. As a result, supply risk of silver will increase gradually in the near future because of its resource constraints and supply-demand balances although silver market is sufficiency competitive one. From the country risk analysis, Peru is not only a significant supply country but also has the highest country risk. Some higher risk countries will increase the level of supply risk even if the concentration ratio of supply indicates moderate level.

Aug 1, 2013

By A. W. White

Introduction To discuss all the technical details of incorporation laws, security laws, underwriting procedures, codes, and ethics-as laid down by varous associations -would be impossible in the time which has been allotted to me. My remarks, therefore, will be made in a very general way and will naturally be coloured with experiences which my firm and I have had. There is a common expression that "money makes the mare go". I hardly have to mention here that the best prospect in the country is of very little value unless its prospects can be developed-and this requires large capital expenditures. The art and problems surrounding the raising of this money is a long and interesting story. Since by its very nature mining is risky, the appraising of its risks in the many phases of its development programme is continuous. Very few men-if any-and very few corporations -if any -can afford to take all the risk of mining. Because of taxation policies-and the very scheme of present-day living -the truth of this statement can be seen throughout the whole industry by a close examination of the records. Since this is so, it is essential that the mechanics of distributing risk on a sound, and equitable basis be known to those engaged in the business and to the investor or spectator who proposes to risk his funds in the industry. Perhaps the greatest stimulant to modern business activities has been the creation of corporate bodies. It is evident, from the number of charters being granted by various jurisdictions, that this method of doing business is becoming more and more important. A limited company -or corporation-can be defined as a fictitious person existing solely in contemplation of the law.

Jan 1, 1951

By Eugen Gluck, Gus Van Weert, Peter Kondos

"Microwaves have the capability to heat up sulphides, especially clusters of particles of approx. 1 mm. Some sulphides absorb microwaves more readily than others. Molybdenite is especially effective in this regard, possibly due to its flaky nature and/or electrical conductivity. Even where it occurs in low concentrations in a deposit, individual rocks may be ore grade due to the high monetary value of MoS2. Such rocks often result from crushing mined veinlets or stockwork, or are contained in the cutoff grade fraction of ROM. Machine segregation of rocks high in MoS2 by infrared sensors after microwaving could therefore advantageously be used to upgrade lower grade ore between Mine and Mill. This would reduce the size of the latter, and thus its CAPEX and OPEX. Such upgrading could also yield shipping ore for a distant Mill, or extend ore reserves.Barrick Gold Corp. has been supporting the development of MW/IR sulphide sorting for the past three years. The results of MW/IR sorting work on molybdenite and other (pyritic) ore samples from a variety of sources are being presented here.INTRODUCTIONThis paper looks at mechanized, i.e. machine ore sorting technologies currently available and under development, and what conditions would be needed for the potential application of such ore sorting to sulphide mining and milling. Current machine sorting involves no-contact sensing technology for rocks, and signal processing after sensing to activate airblast segregation of certain rocks, normally the smallest mass to keep compressed air costs down.The forerunner of modern sorting is probably magnetic separation, which utilizes an inherent property of certain ores to divert it into mag and non-mags fractions. Radiometric ore sorters, which have been applied successfully for decades in the pre-concentration of uranium ores (Wotruba and Riedel, 2006) initiated modern sorting. In the 90’s, sensor-based machine sorting became a viable means of increasing the overall economic recovery of a resource. This technology became driven by the availability of low cost computing equipment and the concurrent development of algorithms, and by the availability of extremely fast response sensors and air actuators, allowing the sorting equipment to run faster, dropping the cost per tonne. It has been in industrial minerals processing that rock sorting has been most widely adopted, not really surprising. Liberation occurs on a different scale than in the base metal industry. Most industrial minerals are mined from massive deposits, requiring (in the past) no upgrading. Many of these operations now run into product contamination problems, which ore sorting can solve. One illustration: in Finland, a quarry is separating limestone from dolomite at 500 tonnes / hour, with individual rocks weighing up to 15 kg. Many of these industrial minerals operations have stockpiles of earlier discarded below-quality rocks, now being reprocessed with the help of ore sorting. The economics of this are very favourable, going from zero or negative value (stockpiles can not be left when closing the mine) to full product value for at least a portion of the stockpile. This suggests that in the future the economics of overburden sorting could become attractive under the right circumstances and such treatment could well become an integral part of open pit mine development."

Jan 1, 2009

By Fred W. Snow

THE mines of the Consolidated Copper and Sulphur Company, consisting of the Eust1s, the Albert, and the Capel mines, are situated w Ascot township, Quebec, about ten miles southeast of Sherbrooke, on the main line of the Quebec Central railway. Of these mines, only the Eustis is now producing, and it has been operated almost continuously for the past seventy years. Mining methods have been improved in recent years but are still old fashioned when compared with those employed in more modern and up-to-date mines. The ore is of milling grade and is mined for its copper and sulphur con-tent. Silver is present in small quantity, together with a trace of gold. The ore is mined by the shrinkage stope method. Pillars are frequently left as supports for the hanging-wall to prevent serious dilution of the ore and are sometimes recovered after the ore is drawn from the stope. Occasionally, small blacks of ore in close proximity to the shaft are mined by a cut-and-fill method. HISTORY ALBERT AND CAPEL MINES: The Albert and the Capel mines, originally known as the Capelton mine, were discovered in 1863 by George Capel (1). By the end of 1866 the Albert shaft had been sunk to a depth of 121 feet on an incline of about 30 degrees where a vein five feet thick was encountered. In 1879, these mines passed into the hands of G. H. Nichols and Company, by whom they were operated practically continuously until 1907. When mining operations ceased in that year, the shafts had reached depths on the incline of approximately 2,300 feet and 1,000 feet, respectively. These mines have been allowed to cave and fill with water and have been inaccessible for many years.

Jan 1, 1936

By Z. Abbasloo, A. Masoomi, L. Ebrahimi, A. Mortazavi, A. Keshavarz

"Investigation and 3D analysis of Heap no. 2 of Meydook copper complex was the subject of this study. In this project all geological and geotechnical investigations conducted in the mine were evaluated aiming at determination of Heap no. 2 design parameters. The main objective of the project was to evaluate the potential for construction of Heap. No. 2 on a waste dump built in a valley in the north side of the pit.Considering the space limitation for dump location this was a viable alternative to reduce the costs associated with heap no. 2 construction. Moreover, it allowed for a significant reduction in overall mining costs. Considering the project condition, a 3D analysis of heap major structures including; valley rock foundation, waste dump, and low grade ore was carried out. Five sets of analyses were conducted and the displacement and stress fields were calculated within the heap no. 2 components. In all analyses conducted the subsident profile was determined for the valley base rock and heap foundation (waste dump). Moreover, the shear interaction between heap and waste dump was evaluated at the heap interface. The analyses results showed that the maximum settlement at the heap base is about 4-5 cm and the waste dump provides a safe and reliable base for heap construction. Moreover, the analysis results showed that the selected %5 grade for the heap interface is good and does not pose any risk in terms of heap Interface shear displacements. A sensitivity analysis of heap mechanical parameters was also conducted. The obtained results show that if the friction angle of heap material is reduced below 25 degree due to acid spraying process, the heap walls become unstable and the heap geometry must be redesigned."

Jan 1, 2015

By R. P. Nicholson

On September 3rd, 1947, the Acadia Coal Company put into operation a central coal preparation plant. This plant was designed to process all coals mined by this Company in the Pictou County coal field. The problem, briefly, was to make a three-way separation of the raw coal fed into the plant. It was desired to remove all stone, metal, and wood from the marketable coal and to produce a splint coal from the raw material which would be suitable for making power. This splint coal product is belted directly to the power plant which is adjacent to the wash plant. To attain this object it was therefore necessary, first, to wash the raw coal, removing all splint, stone, metal, and wood. The stone, metal, wood, and highest-ash splint had then to be removed by a second washing in order to obtain the lower-ash splint for use in the power plant. The plant is on the east side of the Allan colliery, in the town of Stellarton (see accompanying photograph). It is of steel frame construction with wood siding, covered on the exterior with corrugated galvanized iron. Considerable concrete had to be poured for the foundation piers as the plant site is largely 'fill' ground. This necessitated the construction of extremely heavy footings containing a large amount of reinforcing steel. In all, 884 cu. yds. of concrete were poured for the various pits, tanks, and foundations; its average test was about 3,500 lb. per square inch. At the time the plant was constructed, the steel shortage in Canada and the United States was acute and, in order to obtain steel for the structure which is four stories high- an unused part of the Allan bankhead was torn down. Enough steel was obtained from this demolition to fabricate the new plant.

Jan 1, 1948

By Engineering Staff

"This paper briefly describes the surface mining operations at Smoky River Coal Limited (formerly McIntyre Mines Limited, Coal Division) near Grande Cache, Alberta. Geology, mining methods, equipment, manpower and reclamation and environment topics are discussed. Introduction Smoky River Coal Limited, a wholly-owned subsidiary of McIntyre Mines Limited of Calgary, Alberta, produces a high quality, low sulphur, low volatile bituminous coking coal from its minesite located at west central Alberta, approximately 20 km from the town of Grande Cache and 360 km west of Edmonton (Fig. I). Most of the coal property is contained within a 30 km long by 20 km wide block lying in a northwest-southeast direction in mountainous terrain. Elevations vary from 920 m above sea level ·at the plant·site on the Smoky River to 1,600 mat the upper levels of current and proposed mining operations. A total of 11 coal seams have been identified. Only two seams, No. 4 Seam and No. 10 Seam are currently considered of major commercial value. These seams are recovered by both surface and underground mining. Approximately 650Jo of the plant feed coal is obtained from a conventional shovel/truck surface mine; the balance is mined underground by room-andpillar methods. Background In 1921, McIntyre Mines Limited acquired some 26,300 hectares of coal leases at Smoky River. Since then the leases were explored intermittently by different companies including McIntyre. In the mid-l 960s exploration activities increased and several feasibility studies were completed. Development of the area was undertaken by McIntyre in 1968 and, in August of the same year, a long-term contract was signed with a consortium of Japanese steel mills for delivery of 2 x 106 t of clean coking coal for 15 years commencing in 1970. Production was focussed on underground mining, using longwall methods."

Jan 1, 1985

By Sunil S. Gandhi

"The Mountain Lake deposit is a tabular sandstone-type uranium deposit, hosted by the basal unit of Middle Proterozoic Dismal Lakes Group. Uranium occurs mainly as sooty pitchblende disseminated in stratiform lenses within gently dipping quartzose sandstone. It is associated with copper sulphides, pyrite, hematite, and traces of nickel and cobalt arsenides and of silver.Exploration HistoryUranium showings on the PEC claim group were discovered during 1969 by an airborne radiometric survey carried out over the Dismal Lakes-Great Bear Lake area by Aquitaine of Canada Limited (Bizard and Salat, 1969). Some drilling was done in the vicinity of the showings in 1975 by the company under a joint venture with Eldorado Nuclear Limited but the results were not encouraging (Hassard and Woollett, 1975). During 1972, Trigg, Woollett and Associates Limited conducting surveys for Imperial Oil Limited, discovered numerous high-grade radioactive boulders scattered over a distance of several kilometres north and west of the showings, and the area north of the PEC claims was staked as the YUK claims (Ahuja, 1974). A systematic study of the boulder distribution and Pleistocene geology suggested a source additional to the showings. More intensive exploration followed, and in 1976 drilling just north of the PEC claim group boundary intersected the main deposit at a depth of 75 m to 150 m, beneath overburden up to 60 m thick. Part of the deposit extends into the PEC claim group which is under exploration by the Aquitaine-Cominco Joint Venture.The following brief description is based on the presentations in 1978 by F. Hassard of Trigg, Woollett and Associates Limited at the Geoscience Forum in Yellowknife, and by S.S. Gandhi of the Geological Survey of Canada at the Mineralogical Association of Canada Uranium Short Course in Toronto."

Jan 1, 1986

By Gilles Carrière

"The Suffield mine is situated five miles southwest of the city of Sherbrooke, in the Eastern Townships of Quebec. lt is the property of Suffield Metals Corporation Limited, a wholly owned subsidiary of Ascot Metals Corporation Limited.The old Suffield or Griffith mine had been worked intermittently from 1863 to 1906, without ever producing much ore. In 1951, diamond drilling done by Ascot Metals proved over one million tons of ore in three new bodies. The average grade of this ore was 0·018 ounces of gold per ton, 2-40 ounces of silver, l ·28 per cent copper, 0·59 per cent lead, and 6-45 per cent zinc. Since then the mine has been active, producing between 300 and 700 tons daily. More recent exploration has found continuations of the ore zones.General GeologyThe ore of the Suffield mine is found in porphyritic rhyolites of the Sherbrooke group (Silurian), at or close to its contact with sediments of the Beauceville group (Ordovician). The contact shows pronounced folds as well as irregularities due to erosion of the sediments prior to the outpour-ing of the lavas. On surface the general strike is north, and the dip is steeply east.The footwall sediments consist of interbedded black graphitic slates and. dark-coloured chloritic quartzite, overlain in many places by a thin bed of magnetite-hearing quartzite.The rhyolite host rock is a light grey rock, containing very abundant quartz and feldspar phenocrysts in a microcrystalline matrix of the same minerals. Some sericite is always present, especially in the vicinity of the ore zones, where the rock shows a pronounced schistosity.Several narrow basic dykes, with an easterly strike and vertical dip, cut all other formations. Most are lamprophyres, of either the monchiquite or camptonite type, but one has been identified as a diabase."

Jan 1, 1949