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By Peter R. Drummond

THE paper consists of four sections: (1) a discussion of early work; (2) presentation of the results of a chemical investigation of Falcon-bridge nickel-copper blast-furnace matte; (3) application of the results of this investigation to mattes in general; and ( 4) a summary of conclusions. All general discussion will be confined to the fundamental system of ferrous-cuprous sulphides (FeS-Cu2S). Nickel-, lead-, and zinc-bearing mattes will be treated as minor varieties of the parent system. DISCUSSION OF EARLY INVESTIGATIONS Matte investigations may be divided into three classes: first, those treating the sulphides as alloys-theoretical studies of the system FeS-Cu2S, such as those of Hofman (ll)t or Carpenter and Hayward (2); second, chemical research on mattes made under smelter conditions, such as that carried out by Hawley (3) or Avetision ( 4); third, combinations of the . above, such as the investigations of Gibb and Philp (5) or Fulton and Goodner (6). Much research in the first of these classes, including determinations of . freezing points and of data for structure-composition diagrams of the system FeS-Cu2S, was carried out in the period 1890-1910. LeChatelier and Ziegler (1, 13) proved that FeS, when heated alone above its melting point, dissociated in part, and Friedrich ( quoted by Fulton, 6) showed the same for Cu2S. The reactions may be expressed by the following equations: [xFeS yFe + yS (volatilized)+ (x -y)FeS xCu2S )'Cu+ yS ( vohtilized) + (x -)')Cu,S ] Sulphur is lost by volatilization, leaving a melt of metallic iron plus ferrous sulphide in the one case, and of metallic copper plus cuprous sulphide in the other. If the mixed sulphides are heated far above their melting points, there results either an iron-rich matte containing Fe-FeS-Cu2S or a copper-rich matte containing FeS-Cu2S3-Cu, depending on the relative amounts of each sulphide in the mixture.

Jan 1, 1940

By R. Gatzweiler

The Key Lake nickel-uranium deposits are situated within the Wollaston domain of the Churchill structural province. The host rocks of the two orebodies are of Aphebian and Helikian age. The orebodies occur mainly within a 5.2-km-Iong, northeast-trending zone which coincides with the intersection of the sub-Athabasca unconformity and a reverse fault striking east-northeast. The principal controls of mineralization are structural and lithostratigraphic (i.e., post-Athabasca faults, the sub-Athabasca unconformity and graphitic metapelites in the lower Aphebian, close to the Aphebian/Archean unconformity). Grades of up to 35% U3O8 and 20% Ni are recorded over intervals of up to 2 m. Some hypogene zonation exists and the nickel mineralization tends to underlie the high-grade uranium ore. The ore minerals include pitchblende, a-U307, coffinite, gersdorffite, millerite, niccolite, bravoite, zoisite, sericite, chlorite and kaolinite. The kaolinite is a post-ore, supergene alteration product. Chemical studies of the sub-Athabasca paleo weathering profile sho w that regolithization is characterized by depletion in Si02 and K20 and concomitant enrichment in Al203 and perhaps MgO. In the paleoweathering profile the ferromagnes ian minerals are chloritized, the Ksfeldspars sericitized and the plagioclase saussuritized. Preliminary geochronologic data from the ores reveal U/Pb ages of -1228 my, - 960 my and 89 my, and Rb /Sr data indicate basement ages of -1850 my and - 1372 my. Aphebian pelitic protoliths, carrying U and Ni, may have released some metals during post-Hudsonian weathering, and minor concentration in structural and geochemical traps may have taken place prior to the deposition of the Athabasca strata. However, it is felt that the bulk ofthe ore-grade mineralization wasgenerated after the deposition of the Athabasca formation and after faulting, probably during a major regional thermal/ intrusive episode of Grenvillian age. Several episodes of remobilization took place between 1228and 89 my ago.

Jan 1, 1979

By G. R. Cope, C. D. Spence

"The Mac porphyry molybdenum prospect is located 100 km east of Smithers in central British Columbia. The identification of anomalous levels of molybdenum, copper, and silver in three adjacent lakes, sampled during a regional lake sediment survey, lead to the discovery of molybdenite mineralization in float. Subsequent magnetic and soil geochemistry surveys, together with prospecting and mapping, located the source of the float. Mineralization is hosted by a leucocratic granite stock of the Upper Jurassic to Lower Cretaceous Francois Lake Intrusions which has intruded Carboniferous and Permian Cache Creek Group volcanic and sedimentary rocks. The stock measures 500 m by 300m at surface and is mineralized throughout. Sulphide mineralogy is simple and consists of molybdenite with minor pyrite and local chalcopyrite. Molybdenite occurs within fractures and as selvages along quartz stockwork veins and is best developed near the margins of the stock.Known mineralization is coincident with distinct soil geochemistry and magnetic anomalies. Two additional areas of the property display similar features and these remain to be tested.IntroductionThe Mac property is situated in the Babine Lake area of central British Columbia on NTS map sheet 93K/13E, approximately 100 km east of the town of Smithers (Fig. 1). The property lies on the western margin of the Hogem Range at the northern tip of the Nechako Plateau. The centre of the claim block lies at 54°51 ' 30""N and 125 °34 '30""W.Topographically, the claims are characterized by gently rolling hills ranging in elevation from 900 m to 1500 m. Slopes are forested with tall conifers and underbrush is minimal. Flat-lying areas are swampy with tall grasses and scrub brush.Presently, the property is only accessible by helicopter from bases located in Smithers and Fort St. James. Recent road construction by the British Columbia Forest Service has brought road access from Burns Lake to within 5 km due south of the property. It is expected that in the near future, roads will be advanced into the claim area to facilitate logging of mature timber."

Jan 1, 1995

By F. Nava-Alonso, E. Pérez-García, A. Uribe-Salas, J. C. Fuentes-Aceituno, A. A. González-Ibarra, E. N. Castillo-Ventureño

"Precious metals cannot easily be recovered from tellurides by the standard cyanidation process. This work assesses the cyanidation of synthetic samples of precious metals tellurides and explores some alternatives for the leaching of these species (i.e. cyanidation in presence of lead nitrate and thiosulfate leaching). For this purpose, three chemical systems were studied: (1) cyanidation of silver telluride and the effect of lead (II) nitrate addition, (2) cyanidation at high alkalinity and high cyanide concentration of a gold-gold telluride sample containing tellurium and tellurium dioxide, and (3) thiosulfate leaching of silver telluride employing cupric sulfate as oxidant and EDTA as complexing agent for copper. Results showed that standard cyanidation dissolves 10.5% of silver from silver telluride in six hours, while with the addition of 100 mg/L lead increased the silver dissolution up to 100% in the same time. The standard cyanidation of the gold-gold telluride sample dissolves only metallic gold in six hours, while when cyanide concentration and pH were increased, gold and gold telluride were simultaneously dissolved. Finally, thiosulfate leaching dissolves 43.1% of silver from silver telluride in six hours.INTRODUCTION Precious metals tellurides are classified as refractory ores due to the difficulties associated with processing them by the standard cyanidation method. The increasing presence of gold/silver tellurides in some deposits around the world, specifically in Sonora, Mexico, requires new approaches to the cyanidation process, or the development of new leaching techniques. Treatments have been proposed for the recovery of gold and silver from their tellurides, including roasting, preoxidation, cyanidation with lead nitrate, and the use of leaching agents other than cyanide (Zhang, et al., 2010; Ellis and Deschenes, 2016). This work presents preliminary results of three options to recover precious metals from pure tellurides: the cyanidation of gold telluride at high cyanide concentration and high alkalinity, the addition of lead nitrate to the standard cyanidation process, and the use of sodium thiosulfate as leaching reagent."

Jan 1, 2017

By A. Hayatdavoudi, D. Chitila, F. Boukadi

"Shale oil and gas have provided a tremendous boost to energy production in the United States even though the characteristics and behavior of shale are yet to be fully understood. Hydraulic fracturing is often applied to horizontal shale wells to stimulate production. This experiment seeks to determine effects of cyclic variable temperature, water vapor and exposure time on shale micro fracture propagation. We used 22 small Pierre shale specimens and subjected them to aforementioned conditions. Fractures developed in 19 specimens. Combination of high temperature and high water vapor generated the largest number of micro fractures on the specimen surfaces.INTRODUCTIONShale oil and gas have contributed immensely to energy independence in the United States. Most if not all shales depending on their total organic content (TOC) and their clay content bear the promise of being a source rock. For example, the Eagle Ford shale play, located in south Texas, is one of the key contributors to the recent rise in oil and gas production in the United States. Data from the U.S. Energy Information Administration (EIA), published in 2014, states that monthly oil production from Eagle Ford wells increased from 340 barrels per day (bbl/d) in January 2009 to nearly 1 million bbl/d in June 2013. Natural gas production has also increased at a similar rate over the same period, from 5.8 million cubic feet per day (MMcf/d) to nearly 4,000 MMcf/d (EIA, 2014).According to the railroad commission of Texas (RRC) 2014 published information, the Eagle Ford shale play is an important play because it produces gas and more oil than other shale plays in the United States. It is an organic-rich play with carbonate shale percentage in the 70% range in south Texas and the shale content increases moving to the northwest. High carbonate proportion renders this play brittle and suitable for hydraulic fracturing treatments."

Jan 1, 2015

By Adam Jordens

Along with gravity separation and froth flotation, magnetic separation is one of the most common techniques for separating minerals. Minerals are separated by a magnetic force that is dependent on a combination of the applied magnetic field, the magnetic field gradient and the magnetic properties of the minerals themselves. Minerals may be classified as diamagnetic, paramagnetic or ferromagnetic based on the way they interact in a magnetic field. The magnetic susceptibility of a material may be determined by using a vibrating sample magnetometer to determine the magnetic moment of the material in an applied magnetic field and then converting this measured moment into the material?s magnetic susceptibility. In the case of rare earth minerals, magnetic separation is commonly used to remove ferromagnetic iron-bearing gangue minerals and to concentrate paramagnetic valuable minerals such as monazite and xenotime. These magnetic separation steps are frequently preceded by a gravity separation step as many iron oxides and rare earth minerals have specific gravities that are much larger than those of typical gangue minerals. By varying the magnetic field intensity it may be possible to use magnetic separation to selectively separate the paramagnetic and ferromagnetic minerals that report to the concentrate after gravity separation. Test work on a Canadian rare earth ore has shown that a gravity concentration step using a Knelson concentrator was able to selectively concentrate heavy magnetic minerals as evidenced by increased recoveries, relative to the Knelson tailings and fresh feed, after processing through a wet variable intensity magnetic separator. Mass pull to the Knelson concentrate was 4.5 % and the magnetic recovery of this concentrate, at 0.94 T, was approximately 40 % higher than the magnetic recovery from the Knelson tailings (70 % versus 30 %). The products of the wet high intensity magnetic separation were also analysed using a vibrating sample magnetometer to determine the magnetic susceptibilities of the various concentrate and tailings products.

Aug 1, 2013

By William D. Gallant, Thomas M. Barczak, Carol Tasillo

"This paper describes the results of full-scale testing of several multi-layered wood crib configurations that were tested in the Bureau of Mines mine roof simulator in cooperation with the Cape Breton Coal Research Laboratory and Cape Breton Development Corporation of Sydney, Nova Scotia. Nine different crib configurations currently being used as wood packwall supports for advancing longwall applications in Canada were evaluated. Configuration parameters understudy included the aspect ratio (height-to-width relationship) and percentage of solid material used in the crib construction. Test results and generalized wood crib behaviour are discussed in detail. Recommendations are made concerning crib constructions to maximize strength and stability. A cost benefit analysis of multi-layered wood crib configurations is made. A comparison of laboratory results and underground observations of several wood packwall supports in the Sydney coalfield suggest in situ load capacity is less than that measured in laboratory testing. Reasons for the apparent decrease of in situ load bearing capability are described.IntroductionA cooperative effort was undertaken by the U.S. Bureau of Mines with the Cape Breton Development Corporation (CBDC) and the Cape Breton Coal Research Laboratory (CBCRL) to evaluate the behaviour of gateside packing materials used in advancing longwall mining applications in the Sydney coalfield. As part of this effort, full-scale tests were conducted on wood packwall supports in the Bureau's 3-million pound (13.3 MN) active load frame.Nine different pack configurations were evaluated as part of this study. The wood packwall supports were multi-layered crib constructions from 6 in. (0.15 m) by 6 in. (0.15 m) cross section timbers using timber s 30 in. (0.75 m) and 60 in. (1.5 m) in length . The percentage of solid material in the crib constructions varied as illustrated in Figures 1 and 2. A summary of crib constructions is provided in Table 1."

Jan 1, 1991

By Daniel Lachapelle, Nuri Hmidi, Turgut Yalcin

"Simulation can serve as a convenient tool in studying the behaviour and performance of grinding circuits by facilitating the evaluation of various scenarios and identification of optimum operating conditions. This technique was applied to the St Andrew Goldfields Ltd.’s Stock Mine Mill which is a 1300 tpd gold milling facility, offering custom milling services as well as processing the Company’s own ores. Lack of adequate instrumentation in the mill poses a challenge in attaining optimum performance especially with changing ore types and characteristics. The grinding process is monitored essentially by manual measurement and adjustment of pulp densities at various streams. A simulation program was designed to assist in the effective implementation of this mode of grinding control. Product sizes from both the primary and secondary grinding circuits were correlated empirically to relevant process variables using a database formed from the results of past sampling campaigns. The simulator was created in Microsoft Excel whose data analysis and optimization tools coupled with its Visual Basic Programming capabilities were found to provide an excellent environment for the development of a cost-effective, efficient and user-friendly simulation program.INTRODUCTIONGrinding is often a very costly unit process in milling operations, mainly due to the excessive energy consumption associated with it. For example, for a Canadian copper-zinc flotation mill, grinding was listed as being the most costly item taking up 30.4% of the total milling expenses, followed by the flotation cost at 2 1 .O% (Kidd Creek Mines Ltd., 1982). A survey on 45 copper flotation mills around the world showed the average grinding cost to be 34.5% of the total milling cost (Weiss, 1985).Overgrinding aggravates the cost issue, while insufficient grinding either causes loss of valuable minerals to tails or results in low-grade concentrates. Therefore, it is essential that grinding circuits be carefully controlled and monitored. To this end, a great deal of effort has been devoted over the years to the modelling and simulation of grinding systems in order to assist in the efficient running of these processes."

Jan 1, 2001

By M. B. McClenaghan, O. P. Lavin, Ian Nichol

"Abstract-Exploration in most areas of Canada has to contend with problems posed by glacial overburden. In many areas exploration for gold has been based on the sampling of tills, frequently by deep overburden drilling, and analyses of heavy mineral concentrates. Notwithstanding the significant role that till geochemistry has played in the discovery of some important gold deposits over the last few years, increased appreciation of the nature of the glacial history and stratigraphy and the character of gold within till has led to the recognition of a number of ways whereby the effectiveness of exploration can be improved upon.In order for till geochemistry to be useful in exploration, a number of conditions must be fulfilled, including:1. mineralization, or alteration halo related to mineralization, subcropping at the bedrock /over­ burden interface; 2.glacial erosion and dispersal of a recognizable signature of mineralization into the glacialsediments; 3, preservation of glacial sediments containing this geochemical component (trace metal or mineral) at positions subsequently selected for sampling (normally drill sites); 4. correct identification of specific till units and associated ice movement history; 5. collection of adequately large and representative samples; 6. appropriate sample preparation and processing; 7, appropriate geochemical analyses; and 8. correct data processing and interpretation.While we have no control over the first two geological conditions, and only limited controlover till availability, we can control the quality and thoroughness of sampling, sample identification, sample preparation, analysis and interpretation. In particular attention needs to be focussed on obtaining a large enough sample to be adequately representative, an unbiased sample must be collected, together with appropriate sample processing, analysis, data processing and interpretation. It is considered that by modifying or extending existing approaches to gold exploration the chances of exploration success can be increased. In particular, analyses of both the heavy mineral and minus 63 ?m fractions of till is recommended because gold in till may occur in different size fractions."

Jan 1, 1992

By R. R. Rogers

Abstract The degree of cathodic protection of steel and the anode corrosion rate were determined when anodes and waters of different compositions were used at temperatures similar to those in domestic hot water tanks. Twenty different anode materials, sixteen of them magnesium-zinc-aluminium alloys, were immersed in six different synthetic waters resembling those to be found in various parts of Canada. The results showed that (1) both the degree of cathode protection and the average anode corrosion rate are affected materially by the composition of the anode material and of the water; (2) poor cathode protection is associated with low anode corrosion rate; (3) when the cathode is fully protected, the anode corrosion rate may be comparatively low or comparatively high, depending upon the composttion of the water; (4) an important relationship exists between the magnesium content of the preferred anode and the composition of the water; (5) the degree of protection is increased as the SO4 + Cl concentration of the water is increased and thus as its specific resistance is decreased. Introduction Fairly recently, the use of the active metal magnesium for the cathodic protection of less active metals has received a considerable amount of attention. This interest has been stimulated by the fact that the wartime demand for magnesium was greatly in excess of the present peacetime demand and there is a natural desire to continue operating the large magnesium plants which were built during the war. Information regarding the use of zinc and aluminium for this purpose also has been published. There is a great demand for domestic hot-water tanks which will resist corrosion satisfactorily. This problem is rather complex in view of the fact that the composition of the water used in such tanks varies greatly and depends upon the locality. The present investigation deals with the effect of water composition and anode composition on the cathodic protection of steel under conditions approaching those which exist in hot water tanks.

Jan 1, 1948

By Rajiv Kalra

This paper reviews the following aspects of the world?s largest manufactured Grinding Mill?s in terms of diameter and power, along with the world?s biggest shop assembly and trial run of the mills delivered to Sino Iron Magnetite Project in Australia. 1. An overview of the basic flow sheet of the Sino Iron (Magnetite) Project located in Australia 2. An overview of in-house designed CITIC Heavy Industries 12.2 m (40ft) F x 11 m(36ft) LG ? 28MW AG mills including FEA and major components 3. In-house manufacturing at CITIC-HIC work in Luoyang China of all major components for 6 off Ø12.2 m(40ft) AG mills and 6 off Ø7.9 m(26ft) x 13.6 m(44.6ft) LG-2 x 7.8 MW Ball Mills 4. Major aspects of design and preparation of the biggest shop trial run of Ø7.9 m(26ft) x 13.6 m(44.6ft) LG Ball Mill witnessed by international EPCM?s and clients in July 2009. 5. Major aspects of one piece assembly of 1300 tonne rotating element of the Ø12.2 m(40ft) x 11 m(36ft) LG AG Mill and Ø7.9 m F (26) x 13.6 m(44.6ft) LG Ball Mill at the port of the export China and transport to Australian Port and then to site. 6. An insight to unique installation methods used for Ø12.2 m(40ft) and Ø7.9 m(26ft) rotating element lifting on the mill foundation in one piece assemblies. 7. CITIC Heavy Industries present capability for in house design and manufacture of Grinding Mills up to Ø13.7 m (45 ft) with 35 MW Gearless drives and Ø12.2 m(40ft) with 2 x 10 MW Geared Mill drives

Jan 1, 2012

By A. P. Annan, C. Vaughan, J. L. Davis

"The increase in the price of gold in the last decade has led to a significant increase in placer gold exploration around the world. Placer deposits occur in depressions along ancient river and stream channels. In many instances these channels have been covered with materials from subsequent erosion or glacial activity. Use of high resolution geophysical techniques to map the bedrock and soil strata can improve the probability of finding the placer deposits. The buried bedrock surface is often the factor controlling deposition. Ground probing radar (GPR) and seismic sounding are complementary high resolution techniques which can be used to map bedrock topography and soil stratigraphy. Current radar instrumentation operates best in coarse grained soils. Penetration depths of up to 30 m have been attained, and stratigraphic horizons have been mapped with spatial resolutions of better than 0.5 m. Although its spatial resolution is considerably lower than radar, seismic refraction achieves superior penetration in electrically conductive environments such as clay and silt soils. The seismic refraction method thus proves to be complementary to the radar method. The seismic reflection technique is analogous to the radar method. Current seismic instrumentation and energy sources however, provide limited spatial resolution and do not permit the use of seismic reflection for reflecting horizons lying at depths of less than 20 m to 30 m.This paper discusses the use of both radar and seismic methods for placer exploration. The radar and seismic techniques, the field methods, equipment, and data displays are presented. Field examples illustrate the high resolution mapping capabilities of the techniques. The radar data agree very well with the borehole data, and in fact they sometimes detect subtle soil strata variations associated with changes of permeability that were not initially observed in the borehole logging. The radar method can give a continuous profile of water table and bedrock in sandy soils. Seismic soundings are necessary to differentiate between the bedrock and water table reflections observed by the radar."

Jan 1, 1987

By Zihe Ren, Edouard Asselin, Marcus Tomlinson, Tianbi Zhang, Jing Liu

"Raman spectroscopy is used to quantify the extent of disorder in the carbonaceous matter associated with preg-robbing ores. Previous studies of Goldstrike ores showed that the height and width of the peaks for the “D” (disordered) and “G” (graphite) bands, the so-called “Raman ratio” had a strong correlation to the preg-robbing value (PRV) measured for various ore samples. A brief literature review on Raman spectroscopy as it applies to preg-robbing ores is presented. Further, recent studies, presented here, have shown no correlation between the Raman ratio and the PRV for a wide variety of ores. This suggests that the extent of organic carbon crystal disorder is not the main factor in determining preg-robbing characteristics.INTRODUCTION Valuable base metals, such as nickel, cobalt, molybdenum, vanadium and tungsten, are used in a wide range of important technological applications. The demand for many of these metals has increased significantly over the last few decades, driven especially by economic expansion in Asia generally and China in particular. This has led in turn to a large growth in the output of mines in order to satisfy this increasing demand, as shown by the data in Table 1 (USGS, 1994, 2014). These data reflect an even longer trend of growth of these metals, with nickel, for example, showing an average rate of 5.3% per year from 1980 until 2015 (International Nickel Study Group, 2017). This rapid and sustained rate of growth means that annual mine outputs for nickel, tungsten, molybdenum and vanadium have had to double roughly every 11 to 14 years, whilst cobalt mine output has had to double roughly every 7 years, over the period from 1994 until 2014. With the average working life of a nickel mine being between 17 and 22 years (Statista, 2017), this means that from the time a nickel mine opens until it closes, the industry needs to find the equivalent of another three or four mines of a similar output to satisfy this relentless growth in demand for the metal."

Jan 1, 2017

By D. Atkinson

"Porphyry molybdenum-tungsten mineralization on the east flank of Hudson Bay Mountain crops out over 5 km2 and is intersected to depths of 2 km. Features such as a hornblende-biotite aureole, mineralogical zoning and dike, vein and fracture geometries within lithologies of the Middle to Lower Jurassic Hazelton Group and Cretaceous Skeena Group reflect an intrusive complex, the Upper Cretaceous to Early Tertiary Hudson Bay Mountain stock which has been intersected by drill holes. The stock is believed to be the mineralizing agent. A southeast-dipping granodiorite sill has been outlined by drilling within the Hazelton Group. Molybdenite and scheelite veins cut all rock types; however, the granodiorite sill hosts a higher density of fine-grained, banded, quartz-molybdenite and pegmatitic quartz-molybdenite veins reflecting a competency contrast between the intrusive sill and other country rock. Due to the relative abundance of these veins, grade is higher within areas of the sill. Above the 15000£ cross-cut 20.6 million tonnes grading 0.401% MoS2 and 0.041% W03 have been defined. During exploration of the deposit sampling procedures had to be adjusted because of the nugget effect attributed to drill intersections of banded and pegmatitic veins.IntroductionMolybdenite was discovered in outcrop at the foot of Kathlyn Glacier on Hudson Bay Mountain and first reported by the Geological Survey of Canada in 1944. The deposit has several names: Hudson Bay Mountain or Glacier Gulch, both after its location, and Yorke-Hardy after the original staker.The deposit is on the east flank of Hudson Bay Mountain, 9 km northwest of Smithers, west-central British Columbia, within NTS area 93L/14 (54° 49' North, 127° 18' West, Fig. 1). Hudson Bay Mountain, on the southern edge of the Bulkley Valley, is a dominant topographical feature reaching 2590 m elevation. Mineralization is partly overlain by the Kathyln Glacier which is visible from Highway 16. Access to the 3100 m of underground development is from a portal at 1066 m elevation on the east slope of Hudson Bay Mountain."

Jan 1, 1995

By I. G. L. Sinclair

"ABSTRACTTill geochemistry was the principal exploration tool employed by Selco in the investigation of a zinc prospect in Lanark Township, Ontario. The geochemical studies were undertaken after the discovery at surface of marble boulders containing bands of sphalerite and lesser amounts of galena.The source of these mineralized boulders was sought by means of B-horizon soil geochemistry, followed, where appropriate, by back-hoe trenching and till sampling. The thickness of the tiff in this part of Ontario seldom exceeds 3 m or 4 m and it was generally possible to sample complete profiles of the till and thus to obtain detailed information concerning the dispersion of zinc. Drilling and trenching at the up-ice extremity of the zinc dispersion trains showed the source of the float to be sub-economic bands of sphalerite in the Grenville marble. IntroductionTill geochemistry was used extensively by Selco during the period 1975 through 1980. It was the principal exploration technique employed in a program seeking carbonate-hosted lead-zinc deposits of the Balmat-Edwards type in the Grenville rocks of southeastern Ontario. This paper describes the use of the method to locate the bedrock source of a group of sphalerite boulders found at the surface near the village of Hopetown in Lanark Township (Fig. I) . Geochemical investigations at this locality were the subject of a previous publication by the author (Sinclair, 1979).All of the analytical work related to this project was done by Bondar-Clegg & Co. Ltd. in their Ottawa laboratory. In all cases the -80 mesh fraction of the till was analyzed. The total zinc content was determined by atomic ab sorption spectrometry after hot aqua regia digestion; readily extractable zinc was determined by atomic absorption after samples had been cold-leached for 18 hours in an ammonium citrate hydroxylamine hydrochloride solution, the pH of which was adjusted to 8.5"

Jan 1, 1986

By J. Baz-Dresch

"The most cost-effective method of placement of the high strength fill used in the Cannon Mine' s overhand cut-and-f ill bench stopes was determined to be truck haulage. Constraint s imposed by the mine layout dictated the use of a truck which could dump its load in a fifteen-foot high drift. The Dux Teledumper truck was selected as the most suitable unit for this application based upon operational and maintenance parameters which included a telescoping, tilting dump box; large load capacity; and robust construction. Development of the truck continues through the cooperation between the manufacturer and user. INTRODUCTIONThe Cannon Mine is situated in the centre of Washington state, approximately midway between the cities of Spokane on the east and Seattle on the west. The mine complex is located three block s south of the Wenatchee city limits at the eastern base of the Cascade Mountain range.Asam era Minerals (U.S.) Inc., with 5I% ownership, operates the Cannon Mine. Breakwater Resources, Ltd. holds the remaining 49%.Annual paroduction is 520 000 tons per year, presently on a 21-shift per week operating schedule for both the mine and the mill.All production is presently won by overhand bench stoping with backfill. Stoping starts with 15-ft high by 24- or 30-ft wide sill cuts driven above and below a stope block . A drop rai se and slot are used to open a bench which is then slabbed toward the open slot. Truck-placed backfill is dumped into the mined - out stope from the upper sill cut. This stoping sequence is repeated until the top of the ore block is reached . The top sill cut is then tightly filled with backfill to minimize subsidence and to provide adequate roof support during extraction of the pillars.Mining equipment consists of hydraulic drills and rubber-tired, diesel scoops and trucks."

Jan 1, 1989

"The Pierre Beauchemin Mine attained commercial production in January 1989, and went on to produce 23 968 ounces of gold for the year, 3% higher than forecast. Underground development was accelerated to prepare the way for the production of an estimated 40 000 ounces in 1989.IntroductionThe Pierre Beauchemin Mine is located nine miles west of the city of Rouyn-Noranda (Fig. I).As a result of the amalgamation with Sullivan Mines in October 1987, the mine is now entirely owned by Cambior Inc.The Eldrich deposit was discovered in 1953and began production in 1955, closing in 1962 following the decrease in gold prices and the simultaneous decrease in silica content in the ore, which was sold to the Noranda smelter for flux. A total of 717 000 tons grading 0.14 oz Au/t were produced during this period.From July 1984 to October 1987, an underground exploration program was carried out by Sullivan on the Eldrich mining concession and the nearby Flavel property. The first phase of the program included reinstallation of surface facilities and dewatering of the Eldrich Mine. Following the completion of the first phase, extensive exploration was carried out, including a major program of diamond drilling. It was then decided to deepen the shaft to a depth of 1800 ft to access a new zone called the No.5 Zone .Following the amalgamation with Sullivan in October 1987, Cambior assumed the role of operator for the project, and continued the shaft deepening work that had already been started. A feasibility study was completed in April 1988 and the Cambior board of directors approved a production decision for the Eldrich-Flavel project.The preproduction program extended from May to December 1988 and was aimed at preparing the stopes in the upper part of the mine and at developing the mine infrastructure at the bottom of the mine.The mine was officially opened in August 1988. Cambior renamed the project the Pierre Beauchemin Mine in recognition of Pierre Beauchemin's pioneer-work."

Jan 1, 1990

By Gérald Riverin, Bernard Salmon, Marlo Gagnon, Réemi Asselin, Alain Cazavant, Michel LaBrie

"The Ansil deposit is located in the Noranda mining camp in the southern part of the Abitibi greenstone belt. /twas discovered in 1981 and production began in 1989 with proven reserves of 1.58 Mt grading 7.2% copper, 0.9% zinc, 26.5 glt of silver and 1.6 glt of gold. It is centered at a depth of 1.3 kilometre and represents one of the deepest ore discoveries ever made from surface.The deposit consists of a single massive sulphide lens located at the contact between the Northwest Rhyolite and the Rusty Ridge Andesite. The lens strikes north-south and dips 50° east. The thickness of the lens may reach up to 35 m and can change very abruptly both along strike and along dip. The maximum thicknesses of the sulphide lens are reached in its upper (western) and at its lower (eastern) edges, thus giving the deposit its present shape of two sulphide domes connected by a thinner central portion. The lower dome is underlain by a thick accumulation of massive magnetite which may reach 10 to 15m in thickness. The upper and lower domes are underlain by two distinct pipe-shaped zones of stringer and disseminated sulphides which merge with a larger stringer zone at depth.The Ansi/ deposit displays strong relationships between its morphology and the distribution of metals. Hydrothermal alteration consists of chloritization and sericitization. Chlorite alteration is closely associated with stringer sulphide mineralization while sericite is developed in diffuse zones bordering the chloritic zones. Unlike other similar deposits, the Ansil deposit is characterized by very extensive alteration and sulphide mineralization in the hangingwall of the massive sulphides. Several features of the deposit are consistent with an origin from a submarine hydrothermal system which was particularly long-lived, and which thus promoted the build-up of very high fluid temperatures with extensive replacement (and enrichment) of pre-existing sulphides after their original deposition onto the seafloor."

Jan 1, 1990

By M. F. Goudge

ROCK wool, one of the most recent additions to the list of Canadian-made, insulating materials, is a soft, light, fibrous material consisting of interlaced, flexible, glassy fibres so exceedingly fine that, individually, they are almost invisible to the naked eye and will float in air. In the process of manufacture, a suitable rock, generally a self-fluxing argillaceous dolomite consisting of nearly equal proportions of acidic and basic constituents, is melted to a completely fluid state and then converted into fibres either by a blast of steam or air, or by a mechanical device. The increase within the past five years in the number of plants in the United States making rock wool and slag wool has been remarkable, especially in view of the depressed conditions prevailing 'with most industries during this period. In 1930, there were only 8 plants reporting production of .these materials, whereas at the present time there are 44 plants in the United States listed as making these products, and there are 3 plants in Canada. In 1929, the total sales of rock-wool products in the United States amounted to-$2,377,324. In 1934, according to the National Rock and Slag Wool Association, 26 member companies reported sales of $3,695,405, and in 1935 the sale's of 30 member companies had a value of $5,571,469. The establishment of the rock-wool industry in Canada followed the publication in 1931 of a report (1) by the Mines Branch, Department of Mines, Ottawa, in which was set forth the results of field work and laboratory studies which indicated that large deposits of rock in the Niagara peninsula, hitherto regarded as valueless, were suitable for the making of rock wool. This report was supplemented in 1934 by another report (2), giving the results of further laboratory and commercial-scale tests on the rock from these particular deposits, which proved conclusively that rock wool of good quality could be made from the rock in question.

Jan 1, 1936

By J. -P. Tshibangu, M. Ramos da Silva, F. Descamps, C. Schroeder, J. -C. Verbrugge

"The mechanical behaviour of rock materials is largely influenced by the stress state and pore pressure; this needs to be considered in many applications, such as petroleum engineering, tunnelling or stability of underground excavations.Conventional triaxial tests (d2 = d 3) are generally used to assess the influence of confining and pore pressure. In this work, those tests are performed on a porous rock named Sorcy limestone, along with more advanced stress paths like triaxial extension (d 2 = d 1) and purely deviatoric tests with independent pore pressure control. Those tests are combined to a true triaxial study on the dry rock in order to investigate the effect of true triaxial stresses and, hence, build three-dimensional limiting envelopes accounting for the influence of pore pressure.Three-dimensional limiting envelopes of dry Sorcy limestone are built in meridian and octahedral planes. The shape of the octahedral sections changes with the mean stress from triangular to hexagonal and then quasi circular. At even higher mean stresses, the evolution continues towards a triangle with apexes oriented in the direction of triaxial extension stress states. In meridian sections, the deviatoric stress first increases with the mean stress. The transition between this deviatoric mechanism and the cap surface occurs at different mean pressures depending on the Lode angle.Terzaghi’s effective stress is found to govern the yield and plastic behaviour of saturated Sorcy limestone. Triaxial tests show that the limiting envelope does not depend on the loading path (conventional compression and purely deviatoric stress paths). In triaxial extension, the brittle-ductile transition is observed for a higher mean pressure than in triaxial compression, as previously found for true triaxial tests on the dry rock.Finally, it is shown that upon appropriate normalisation, the dry and saturated yield envelopes come very close one to each other. This suggests that only the size of the yield envelope changes between dry and saturated state (pore pressure = 5 MPa); its shape does not seem to evolve."

Jan 1, 2015