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By J. E. Hawley

"The property of Francoeur Gold Mines, Limited, lies directly west of the Armfield mine in Beauchastel township, Abitibi district, and 12 miles west and slightly south of Noranda. The gold deposits are of particular interest because of their replacement character and close association with fault zones. The property was originally staked in 1923 following the discovery oi a mineralized zone near the eastern boundary. This became No. 1 orebody. Later discoveries in 1936 of No. 2 and No. 3 orebodies led to underground development and actual mining in July, 1938. A fourth orebody, No. 8, was found in 1939.The following is the production record up to December 31st, 1947:Beginning in September, 1944, ore was shipped to Noranda as siliceous flux, but late in 1946 milling of low-silica ore from No. 1 orebody was undertaken until operations were temporarily suspended in 1947.The four main ore deposits, Nos. 1, 2, 3, and 8, consist of siliceous ferrocarbonate and albite replacement bodies mineralized with fine pyrite and specularite in schistose fault zones in Keewatin volcanics. Barren to low grade quartz veins though present in some are uncommon, but small stringers of quartz are usually present wherever here and there visible gold is found. Nos. 1, 2, and 3 deposits lie in a major fault zone that extends completely across the property from west to east (over 7,000 feet) and dips N.40° to 50°, and are separated by intervals of 1,800 to 2,000 feet respectively. The fourth lies in a smaller fault zone striking east and dipping on the average 65°S.No. 1 orebody has been explored by mining to a depth of 500 feet, No. 2 to 400 feet, and No. 3 to slightly less than 300 feet . The greater part of No. 8 lies above a depth of 200 feet, but a raise has recently .been driven through from the west end of the 5th level of No. 1 to the 2nd level on No. 8 zone. Most of the ore of No. 8 zone above the 2nd level and of Nos. 2 and 3 above the 3rd levels has been removed."

Jan 1, 1954

By W. L. Ott, C. L. Lewis

"AbstractA technique is described for preparation of palladium sponge and for spectrochemical analysis of the metal in this form. The precision and accuracy of the method are discussed. Analyses are compared with previous spectrochemical analyses of palladium in the black form. Good agreement was found in the two sets •of results and it is concluded that they are more reliable than wet chemical .analyses of the same material.IntroductionFOR SEVERAL YEARS the problem of platinum metal analysis by spectrochemical methods has been under investigation at the Spedtrographic Laboratory, Department of Geological Sciences, Queen's University. The problem, briefly -stated, is as follows: Samples of platinum, palladium,-rhodium, ruthenium, and iridium are received as fine metal powders, called sponge. Direct spectrographic analysis of this material has not been found satisfactory due to its heterogeneity •as regards contaminant metals, which may be present up to a total of one per •cent or more. Further-more, spectrographic standards are difficult to obtain and difficult to prepare accurately by adding weighed portions of contaminant metals to the sponge. The fact that •contaminant metals in original samples are probably alloyed with the major constituent is a further difficulty since complete fusion of these refractory metals proved impractical in the present case as a means of standard preparation. It •has, therefore, been found most satisfactory to dissolve the metals, prepare standards by addition of solutions of contaminant metals, and to reduce both standards and samples to a homogeneous form. A previous paper, by Hawley, Wark, Lewis and Ott (2) dealt with a method for spectrochemical analysis of platinum and palladium in their black form. Since completion of research on the black technique, the possibility of analyzing palladium accurately in its sponge form has• been investigated."

Jan 1, 1953

By K. J. G Hedges

"Once a health based guidance limits for exposure to diesel exhaust have been established, and as part of a multi-disciplinary team, the program for exposure reduction should incorporate the plan-do-check-adjust cycle. Setting a suitably protective (health based) occupational exposure limit (OEL) for diesel particulate matter (DPM) and nitrogen dioxide is a key driver to reduce exposure. It is important to go beyond regulations and reduce exposure to diesel exhaust, DPM, as low as reasonably achievable (ALARA) such as that prescribed under the Australia, Queensland Mining and Quarrying Safety and Health Regulation 2017 where under section 135 Limiting workers exposure, the workers exposure must not exceed the exposure limit applying to the worker for the hazard; and is ALARA. It appears that previously acceptable OELs are no longer safe. Therefore it is important that the internal responsibility system be implemented and the precautionary principle approach be followed, especially as it may be some time before a suitably protective OEL specifically for DPM is in place. One leading multi-national mining company BHP Billiton has acknowledged a significant lag that exists between regulatory action and the level of science that informs health risk. This company is managing exposure to diesel exhaust to as low as technically feasible. This same company that has set an interim target for managing diesel exhaust to 0.03 mg/m3 is achieving these levels which paves the way for other mining companies and general industry including construction. The Occupational Cancer Research Centre 2017 recommends reducing personal exposure to within 0.02 mg/m3 (EC) for underground mining and 0.005 mg/m3 for other workplaces. Controlling DPM is important to prevent cancer however it is also important that that nitrogen dioxide (NO2) be reduced (ALARA) and that careful selection of control technology be considered such as the proper selection of a diesel oxidation catalyst so that the level of NO2 does not in fact increase. The example from BHP Billiton provides a leading practice including using a multi-disciplinary approach and the importance of controlling emission at source and having an auditable diesel emissions based monitoring program in place."

Jan 1, 2019

By A. J. Petrina

"At Craigmont Mines Limited, Merritt, B.C., tests were begun in March, 1965 to evaluate the use of shotcrete as a method of ground support m development headings; previously, ail drifts had. required support, which was accomplished mainly by timber and occasionally by the use of rockbolts. The tests demonstrated conclusively the effectiveness of shotcrete for supporting Craigmont's ground. Gradually, the use of timber for ground support was virtually eliminated in favour of shotcrete. This paper describes the equipment used, the operation of the equipment, pertinent cast data and opera ting details. Also discussed are other uses developed for the shot-creting equipment, the use of reinforcing bar rockbolts, and a method used at Craigmont for lining long vertical ore passes with steel plate and concrete as part of the raising cycle."

Jan 1, 1968

By Wei Sun, Xiangsong Meng, Xiaodong Li, Weisheng Huang, Yuehua Hu, Chonggao Cao, Haisheng Han, Wensheng Chen, Runqing Liu, Central South University

"The similar flotability of scheelite, fluorite, and calcite resulted in the difficult separation by flotation. This work revealed the effect of water glass on the flotation of scheelite by FTIR and the wettability change of the usual cleavage plane, and proved that water glass inevitably influenced the flotation of tungsten minerals to a large extend in traditional fatty acid flotation process. A new collector, benzohydroxamic acid complexes, was found to be selective for the separation of scheelite and calcium minerals with little water glass. Hence a novel flotation process was developed for the recovery of tungsten minerals in shizhuyuan mine in China. Normal temperature flotation of tungsten minerals was developed to instead of the classical “Petrov's process” for scheelite-calcite-fluorite type ores. Compared with the traditional process, the recovery was improved by 10% and the grade of scheelite concentrate was above 55%. The disappearance or decreasing of water glass contributed to improving the recovery of tungsten and fluorite and the circulation of water and reagents.INTRODUCTIONChina is rich in tungsten resources and the proved reserves accounted for 60% of the world's reserves (Cai Gaipin et al., 2009). However the wolframite has been dried up and the scheelite resource has become the main resource of the tungsten metal. Scheelite deposits were classified to scheelite-silicate type and scheelite-calcite-fluorite type based on the associated gangue minerals. Scheelite was easy to separate from the silicate minerals. Flotation separation of scheelite from calcium minerals creates difficulties because of the existence of the same cation in the minerals and similar physicochemical characteristics such as solubility, hardness, specific gravity, PZC (point of zero charge) etc.(Arnold & Warren, 1974; Yongxin & Changgen, 1983; Ozcan & Bulutcu, 1993a; Deng et al., 2015, 2016;). The conventional collectors used in the flotation of scheelite ores are generally fatty acids or fatty acid derivatives ( Yongxin & Changgen, 1983; Oliveira & Sampaio, 1988; Sivamohan, 1988; Shi et al., 2014; Bo et al., 2015). It is difficult to separate scheelite especially from calcite with these reagents because the adsorption mechanism of these collectors occurs through chemisorption of the oleate ion onto the mineral surface (Atademir et al., 1979; Changgen and Yongxin, 1983; Hiçyìlmaz et al., 1993; Hu et al., 2011). Therefore, it is almost impossible to separate them by fatty acid flotation without using any selective depressant. Although oleoyl sarcosine was used as a selective collector in the flotation of fluorite and siliceous scheelite ores (Ozcan & Bulutcu, 1993b; Ozcan et al., 1994), this selectivity is not adequate for a low-grade calcitic scheelite ore. Unfortunately, the reagents such as organic colloids (dextrine, starch), quebracho, sodium phosphates, sodium silicate solutions containing polyvalent cations (hydrosols), etc. (Yongxin and Changgen, 1983; Schubert et al., 1990; Shi et al., 2014; Bo et al., 2015) used for calcite depression also depress scheelite to a large extent."

Jan 1, 2016

By M. Fafard, M. Dupuis, P. Goulet, J. Bédard

Start-up of a Hall-Heroult cell is a delicate task that can affect pot performance and pot life. Modem practices for high amperage cells involve preheating the lining before the molten electrolyte is poured in. Different preheating methods and heat-up schedules are used throughout the industry, and the optimum between a short start-up and damage minimization to the cell is elusive. Direct electrical coke-bed preheating is one of the most common techniques. This practice typically results in a non-uniform surface temperature distribution and can generate detrimental thermal gradients in the cathode blocks. Numerical modeling is an invaluable tool to study this complex problem and can help improve the preheating procedures. The modeling of the mechanical response of the lining is critical to detect risks of cathode block cracking or the development of gaps where liquids could leak into. Taking into account the baking of ramming paste, the quasi-brittle nature of carbon and the contact interfaces between different materials are examples of key elements to consider. A finite element slice model of a cell was built and simulations of different electrical preheating scenarios were performed using the inhouse code FESh++ to demonstrate what can be learned through thermo-chemomechanical modeling. The potential industrial application of the model is discussed.

Jan 1, 2006

By John Kostuik

"This paper discusses the outlook for uranium resources, and comments briefly on the measures needed to meet market objectives. Areas of recent exploration interest are also discussed.THE PREVIOUS SPEAKER has capably described the truly phenomenal growth in demand for energy from all sources. The basic factors -population growth and industrial development -which will create energy demand are so fundamental to national economies that the ascending energy demand curve will be little affected by short-term factors.Because of the economic and practical advantages of nuclear power and the degree of present acceptance by electric utilities, there is no doubt that uranium will be a principal source of primary energy in industrial countries -and this will happen within a decade. Indeed, during this period it will be the fastest growing source of energy, capturing, for example, more than half of the electric utilities' expansion in the United States by 1980. The ready availability of energy sources from domestic and foreign resources is so essential to industrial nations that the long-range outlook for their adequacy is of prime importance. There has been international concern about the availability of uranium resources at reasonable cost to adequately support and foster the development of the nuclear power industry. Canada, fortunate in having established reserves and a potential in excess of any forseeable domestic demand, can confidently look forward to being a principal supplier to the industry."

Jan 1, 1969

By P. Belley

Prior to 2006, the filtration unit for leached sludge treatment (filter press) permitted the filtration, washing and drying of cake to 17% (w/w) moisture. That year saw moisture content abruptly increase to 20% (w/w), drastically changing the rheological properties of the cake. The cake became sticky and agglomerated. This led to major disruptions of operations and plant capacity (cake release and cake conveyor problems, complicating the subsequent steps of the process). The conditions for the filtration, washing and drying, were simulated to ease cake unloading without aggravating dust emissions (moisture about 17% (w/w)). All of the laboratory tests yielded a moisture content above 17% (w/w). Therefore, we concluded that the moisture problems were not due to a recipe change in primary material, but to an operational problem in the filter press. Through the laboratory results, the filter press operating conditions (washing ratio, drying pressure and drying time) were optimized to enable a reduction in cake moisture to 17% (w/w).

Jan 1, 2007

By F. Dubuc

"The Adams Mine of Jones & Laughlin Steel Corporation is situated on the Boston Township iron range near Kirkland Lake, Ontario. Eight different orebodies have been outlined, with a total open-pit crude tonnage of. about 100,000,000 tons or the equivalent of 30,000,000 tons of concentrate. The ore consists of fine-grained, well-bedded Early Precambrian iron-formation composed essentially of alternating layers of chert and magnetite. Grade averages about 22 per cent magnetic Fe.The iron range varies in width from 3,000 to 4,000 feet and is made up of several horizons of iron-formation, cherty ""quartzite"" and volcanic rocks. The latter consist mostly of basic lava flows and minor amounts of tuff. Dips are rarely Jess than 50 degrees, and the range is believed to represent an overturned limb of a major synclinal structure. Dykes of syenite and lam prophyre, along with local younger diabase, intrude the rocks of the iron range."

Jan 1, 1966

By Richard N. Zimmer

This paper discusses the installation of corrugated steel linings in bored raises at Inco's Thompson Mine. The procedure for the installation of these linings is outlined and the relative advantages are compared with conventional methods of ground support. Future trends in the use of corrugated steel products are then discussed.

Jan 1, 1978

By E. L. Bruce

EUROPEAN Russia is mainly a great plain, the average elevation of which is only 600 feet above sea level and the maximum elevation less than 1,200 feet (Figure 1). The main divide between the Arctic ocean and the Black sea and Caspian sea is an indistinguishable topographic feature from which the Dneiper and Don rivers flow southward to the Black sea and the Volga river to the Caspian. The valleys of these rivers are but little below the general level (Figure 2). To the south, this great, rolling plain is broken by a low ridge of Precambrian gneisses and intrusive rocks. The Crimea is an upland from which the descent to the Black Sea coast is precipitous (Figure 3). The Ukrainian Soviet Socialist Republic occupies the southern part of the plain. It is the southwestern unit of the Union, bordered by Rumania and Poland on the west and by the Crimean Soviet Socialist Republic on the south.

Jan 1, 1938

By R P. Douglas

During 1955, Cominco commenced an exploration pro-gram in northern New Brunswick; in the following year, what is now the Wedge mine was discovered. The mineralization is mainly pyrite, with associated chalcopyrite and minor amounts of sphalerite and galena. The property was brought into production at 750 tons per day in early 1962. The ore is trucked 10 miles to the Heath Steele concentrator, where a copper concentrate grading about 19.5 per cent is produced and shipped to the Japanese markets through the port of Dalhousie, New Brunswick. Introduction THE Wedge mine, owned by The Consolidated Mining and Smelting Company of Canada Limited (Cominco), is located in the Newcastle-Bathurst area of New Brunswick. It is 42 miles by road northwest of Newcastle and 37 miles southwest of Bathurst (Figure 1). The mine is located on the north side of the Nipisiquit river in one of the more mountainous areas of the Province, the local relief rising to 1,500 feet above sea level. There is an almost complete forest cover of mixed hardwoods and conifers -the val-leys and hillsides being covered by balsam, spruce and pine, the swamps by cedars and black spruce and the highlands by mixed hardwoods.

Jan 1, 1965

By G. S. Hume

THE Plains of east-central Alberta herein described embrace an area from Viking east to the Saskatchewan boundary and from North Saskatchewan river south to Coronation and Monitor (Figure 1). By far the greater part of this area is deeply drift-covered, and .outcrops of bedrock are relatively few and often widely separated. Within the area there are large morainal hills and others of considerable extent that superficially have all the characters of morainal hills but contain a core of bedrock. These latter, then, were hills when the ice sheet traversed the country and only have been modified by glacial agencies. In many places on them, the drift is but a thin veneer, as is certainly the case in part of the Neutral hills (Figure 2) northeast of Coronation and north of Monitor. In other cases, however, as in the Blackfoot hills, southwest of Lloydminster, the drift is sufficiently thick to conceal practically all the bedrock and in many places no information is available as to whether a bedrock core, representing a pre-glacial hill, is present. There is no question, however, that the larger river valleys, as for example those of the North Saskatchewan and Battle rivers, are in part at least pre-glacial. Proof of this can be demonstrated in many places, because obviously the valleys must have been present in pre-glacial times to allow glacial deposits to have accumulated in them. It is also known that inter-glacial deposits occur. At one locality in Battle River valley, in sec. 30, tp. 45, range 2, west of the 4th mer., the following section occurs( l ): 15 feet of boulder clay with granite and other boulders. 56 feet of stratified sands, clays, and gravels containing pebbles of Precambrian rocks and fresh-water shells. From this it is apparent that the 56 feet of stratified sands, clays, and gravels must have derived their Precambrian pebbles from a previous glaciation of which the overlying boulder clay represents another ice advance in this area. Thus, although the river valleys contain glacial and interglacial deposits, they have not been filled by them to such an extent that the drainage has been diverted, and in many places, especially in the case of Battle river and some smaller streams, the size of the valley is altogether out of proportion to the size of the stream it now contains.

Jan 1, 1937

By Pizhi Zhao, Yingdong Li, Hailong Cao, Yingjuan Feng

"Three types of anodic films (unsealed, hot water sealed and agent sealed) were prepared to study the effects of anodizing pores structure on the adhesive bonding performance of AA5754 automotive sheets. The morphology of the anodic films was examined by using scanning electron microscope (SEM) and the composition was examined by glow discharge optical emission spectroscopy (GDOES). The adhesive bonding strength and durability in corrosive environment were investigated by using single lap shear test and salt spray corrosion test (SST), respectively. The results showed that the pores structure could significantly influence the adhesive bonding performance. The unsealed sample showed porous structure and provided high bonding strength, however, the durability was poor in corrosive environment. The hot water sealed sample showed fine and loose hydrated alumin a structure on the surface and provided high durability in corrosive environment, but the bonding strength was low. In contrast, the agent sealed sample provided both high bonding strength and durability in corrosive environment.INTRODUCTIONAdhesively bonded aluminum joints by using adhesives have been widely used for the realization of lightweight design in industrial applications like automotive and aerospace industry[1, 2]. Durable bonds which are capable of taking structural loads can be created due to a careful consideration of the way in which the joint is formed, the type of adhesive and the appropriate treatment of the adherend surfaces prior to bonding[3-6]. Experiences demonstrate that the surface treatment is the most critical step which could not be disregarded, since it is essential to achieve long-term service capability [7].In structural applications, a bonded assembly is expected to maintain a significant load and may be combined with exposure to harsh environmental conditions in its service life. For this purpose, the pretreatment for structural bonding of aluminum alloy must provide not only strong tensile strength and durability but also good corrosion resistance. Chromic acid anodizing (CAA) process provides an anodized layer which has good corrosion resistance while also exhibiting useful adhesion characteristics as well as lacquer coating retaining characteristics[8].However, the use of Cr (VI) is unadvised from a health and environmental point of view since it is toxic and carcinogenic, and this process is gradually limited even prohibited. Boeing's phosphoric acid anodizing(PAA) process provides a more open pore structure allowing penetration of high molecular primers/adhesives[8]and PAA process is the most widely used pre-surface treatment suitable for adhesive bonding between aluminum alloy components. Rahimi et al. demonstrated that nanostructure can be produced by PAA process and is affected by the time of pretreatment and anodizing parameters [9]. Xu et al.investigated the influence of surface energy and roughness on adhesive bonding through PAAprocess and provided improved adhesion performance under certain anodizing parameter[10]. However, PAA process is normally not recommended for a major concern of deterioration of the mechanical performance of the joints as a result of exposure to a wet and corrosive environment. Sulfuric acid anodizing(SAA)process, recently, has been widely used for corrosion protection and good base coating for the adhesion of lacquers in aerospace manufacturing[11]. The good performance is explained by properties such as the porous morphology and high adsorptive power of the oxide film, the chemical and electrical inertness of the anodized layer. Moreover, modified sulfuric acid could also used for adhesive bonding. Lunder et al. found that anodizing in hot sulfuric acid is promising as a simple, very rapid and environmentally friendly pre-treatment for adhesive bonding[12].Saeedikhani et al. studied the process of phosphoric/boric/sulfuric acids anodizing and found it was is a promising pre-treatment for adhesive bon"

Jan 1, 2018

By R. M. S. Häggblad

The article deals with stabilisation and regeneration of Ce02 and Ce02/Zr02 based Pt water gas shift catalysts, subject to high initial deactivation. The reaction gas species effect on the catalyst deactivation was investigated by H2-TPR. Activity measurements enabled the effect of different promoters, some added to the Ce02 based catalysts and some to the Ce02/Zr02 based Pt catalysts, to be investigated. The catalysts were also characterised by BET and CO-TPR. Deactivated catalysts activity was restored by using various regeneration methods. Of the two selected carriers the Ce02/Zr02 based Pt catalyst showed the highest resilience to deactivation. For the two different carriers, Ce02 and Ce02/Zr02, Wand Re were the best promoters when the catalyst was subject to deactivation. Experiments with Hr TPR indicate a fast initial change in the platinum oxides concentration and composition. The CO-TPR was used to make conclusions about the various regeneration effects of water and oxygen on the catalyst. Finally it is suggested that not one deactivation mechanism is possible and which mechanism that dominates is dependant on the catalyst and the reaction gas composition.

Jan 1, 2005

By Peter A. Adcock, Rob Fraser

Interest in monitoring nucleation overpotential in electrometallurgical processes dates back some 40 years or more. Conversely, remarkable progress has been made in recent years on describing in detail the processes involved in the formation of thin films by electrodeposition. The newer body of work underscores a need for greater clarity in speaking about the role of nucleation and in the acquisition and interpretation of nucleation overpotential measurements – the aim of this paper. In electrometallurgy, it is generally desirable to form deposits that remain smooth, compact, and relatively fine-grained while the deposit grows to a thickness on the order of 5-10 mm, about 100 times thicker than technological thin films. Hence, we distinguish two kinds of nucleation that can result in formation of new grains:- (1) initial nucleation (onto the substrate surface) of islands that coalesce into growing deposit, and (2) ongoing nucleation of new grains on the deposit surface long after the substrate has been covered and ceases to have a direct influence. Nucleation overpotential of the first type should be measured on an electrode surface truly representative of a real industrial substrate. The second type requires judicious choice of electrode material – an “ideal foreign substrate”. In general neither the industrial substrate nor native metal to be deposited is suitable for measurement of the second type of nucleation overpotential, because of interference by other processes. For the future, clear terminology is needed to distinguish these two types of nucleation potential. The second is the one for which the type of plot dubbed by Moats and Derrick as an “Adcock plot” and by us as a “Kerby-Adcock plot” was first conceived and correlated with relatively thick zinc electrodeposits. The data of Moats and Derrick showing trends for copper electrodeposition on stainless steel and on copper electrodes are interpreted within this framework.

Jan 1, 2016

By B. Qiu

The large surface ground movements induced by underground mining could threaten the safety of the pipelines laid across the subsidence-prone area. Existing analytical methods for the stress analysis of buried pipeline over mine subsidence area were based on the assumption of ?thin? pipeline, which limited their applicability. This paper presents the improved model with the capability to determine the stress distribution of the ?thick? pipeline. The pipe-soil interaction in this model was also updated to adapt various pipe soil contact conditions. In addition, the time-dependent effects of dynamic subsidence effects were also added to the model. A case of protecting a long section of a buried large-diameter pipeline over two longwall panels in a shallow mine is shown. The stress distribution along the pipeline is determined and the overstressed sections are identified. A partial uncovering plan was developed based on the predicted stress and complicated terrain at the site.

Aug 1, 2013

By Minghao Hu, Hongbo Zhao, Jun Wang, Wenqing Qin, Rui Liao, Central South University

"In the present work, X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS) analysis and electrochemical analysis were carried out to investigate the intermediate species and electrochemical dissolution process of chalcopyrite in the presence of sulfur and iron oxidizing microorganisms. For bioleaching of chalcopyrite by the sulfur oxidizing microorganism Acidithiobacillus caldus, the redox potential was always lower than the appropriate value and chalcopyrite was mainly directly oxidized to polysulfide (Sn 2-), thus resulting in low copper extraction. As for bioleaching of chalcopyrite by the iron oxidizing microorganism Leptospirillum ferriphilum, chalcopyrite was mainly directly oxidized to polysulfide at the initial stage where redox potential was lower than the appropriate value and resulted in low dissolution rate. At the middle stage where redox potential was appropriate (about 350–480 mV vs. Ag/AgCl), chalcopyrite was mainly transformed to intermediate species of Cu2S rather than polysulfide, thus resulting in high dissolution rate. At the later stage where redox potential was higher than the appropriate value, chalcopyrite was mainly directly oxidized to polysulfide which caused the later passivation of chalcopyrite. Finally, a model of electrochemical dissolution process of chalcopyrite in the presence of sulfur and iron oxidizing microorganisms was provided.INTRODUCTIONBiohydrometallurgy is considered as one promising mineral processing technique in processing low grade ores due to the advantages of simplicity, low cost and eco-friendly. Chalcopyrite (CuFeS2) is the most abundant copper-bearing resource, accounting for appropriately 70% of the known reserves in the world, while is recalcitrant to bio-hydrometallurgy mainly due to the coated passivation layer (Klauber, 2008; Li, Kawashima, Li, Chandra, & Gerson, 2013). However, the detailed dissolution and passivation mechanisms of chalcopyrite bioleaching are still uncertain. The microorganisms assisting chalcopyrite dissolution can be mainly classified into three types, including mesophilic microorganisms (e.g., Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans), moderately thermophilic microorganisms (e.g., Acidithiobacillus caldus, Sulfobacillus thermosulfidooxidans and Leptospirillum ferriphilum), and extremely thermophilic microorganisms (e.g., Metallosphaera sedula, Sulfolobus sp., Acidianus sp., and Sulfurcoccus mirabilis). Moderately thermophilic microorganisms have a better prospect in the future industrial application of chalcopyrite bio-hydrometallurgy (Olson, Brierley, & Brierley, 2003; Rohwerder, Gehrke, Kinzler, & Sand, 2003). Hence, investigating the detailed dissolution and passivation mechanisms of chalcopyrite bioleaching by moderately thermophilic microorganisms is of important significance, which will provide essential information for promoting chalcopyrite bioleaching by moderately thermophilic microorganisms in laboratory or industrial plant."

Jan 1, 2016

By F. H. Edmunds

Introduction This paper, it is hoped, will serve as an introduction to further work upon the origin of the soils and to a more complete interpretation of the geology of Saskatchewan from a study of the soils of the Province. The great difficulty that is encountered in mapping the structure of the prairie regions of the west must be evident to all who have made the attempt. The rarity of good exposures, due to the extensive coverings of glacial drift, is the greatest obstacle, making it difficult to determine the exact stratigraphical position of such exposures as may be found. In many cases palæontological evidence is lacking, or, if available, our present knowledge of the stratigraphy is insufficient to justify division of the formations into horizons; and until many of these formations have been subjected to petrographic investigation, little can be done in using lithological differences as an aid to the correlation of the usually sparse outcrops met with in the Province. Topography may be of the utmost value as an indication of geological structure when considered in conjunction with other evidence. It does not necessarily follow that, because an area in Saskatchewan has resemblances in surface configuration to an area of oil-producing land in Texas, there is sufficient justification for sinking money in wells without further investigation. Such - investigation should include the study of available soil maps.

Jan 1, 1929

By J. F. Henderson

THIS paper relates to an area of more than 5,000 square miles in the Northwest Territories extending north from Great Slave lake and including-the Yellowknife, Beaulieu River and Gordon lake areas. Within the last three years much interest in the area has been created by the discovery of remarkably rich gold-bearing veins and the realization that thousands of square miles of unprospected ground are underlain by rocks like those in which the veins have been found. Probably there were more prospectors in this area in 1938 than in any other part of Canada. The area lies 650 miles north of Edmonton, and 425 miles north of the terminus of the Northern Alberta railway at Waterways, Alberta. The Athabaska and Slave rivers provide an excellent water route from Waterways to Great Slave lake for large oil and wood burning boats and barges which operate from the latter part of May to October. The only portage is around a 16-mile stretch of rapids on the Slave river between Fort Fitzgerald and Fort Smith. The town of Yellowknife, on the north side of Great Slave lake, has sprung into existence during the past year and is the centre for distribution of supplies for the Yellowknife-Beaulieu region. The Con-Rycon and Negus gold mines, which came into production in September, 1938, and February, 1939, respectively, lie about two miles south of the townsite. Excellent airplane service is available from Edmonton to Yellowknife and from Yellowknife to all parts of the area. The prospector and mining operator have come to rely almost entirely on the airplane for supplies and for the transportation of personnel, camp equipment, and canoes from Yellowknife to localities selected for intensive prospecting.

Jan 1, 1939