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By E. H. Kranck

Introduction Baffin Island is still too in-accessible to be of interest to the mining industry. However, twenty years ago few people dreamed of mining iron ?ore in Labrador. A journey by air to the most remote places in the Arctic is today no more remarkable than a trip to Europe, and the technical difficulties of mining minerals of high value are not insurmountable. Some ?observations concerning the geology and mineral possibilities of Baffin Island, the largest of the Arctic islands, may therefore interest the members of the Institute, in spite of problematic practical value of the subject. The following short account is mainly based on observations made during the Baird Expedition of the Arctic Institute of North America last summer 1950), and on information available from earlier expeditions. Early Work Baffin Island was one of the first parts of Canada to attract prospectors. Frobisher sent a shipload of rocks, which he believed contained precious metals, from Baffin Island to England. This attempt, however, was a failure and no further serious prospecting work has, so far as I know, been done. During the past few years geological mapping has been carried out by the Geological Survey of Canada (Fortier. Davison, 1949-1950) in the southern parts ?of the island, along the coast of Hudson strait. In 1942, Weeks mapped the coast from Pangnirtung to the head of Cumberland fiord, and Netteling river up to Netteling lake. In the northern parts of the island, only scattered observations have been made ?by Bell, Watkins, Baird, and others.

Jan 1, 1951

By L. V. Bell

THE object in prospecting is to find ore. With the exception of certain discoveries of more or less accidental nature, intelligent prospecting as conducted today is, whether consciously or not, based upon a process of elimination. In the following discuss on it is proposed to evaluate those factors that enter into the eliminating of certain tracts of ground and, conyersely, the concentrating of attention upon others. The danger of generalizations as to the barrenness of cer.ain areas, without having due regard for all such factors, is emphasized. The fact that our conception as to what areas or rock formations are to be regarded as favourable or unfavourable is, in some measure at least, changing with new discoveries under diverse and unexpected circumstances, adds more point to the discussion. The criticism might be raised that the subject is treated largely from the standpoint of geology, but that may be met by stating that it is, and must continue to remain, precisely from this standpoint that the prospecror directs his activities. Briefly, the geologist may render the greatest service to the prospector in the early steps of selecting (a) the general territory in which to prospect; (b) the area to be intensively prospected; and, finally, (c) those parts of the claim or claims to be prospected in detail. Although certain phases of the discussion will be, in some measure, of general application, we shall here concern ourselves essentially with prospecting in the pre-Cambrian shield. Furthermore, the subject is so large that it has been decided to limit it to a consideration of that portion of the pre-Cambrian rocks in which is situated the mining district of western Quebec, of which the writer can speak with more personal knowledge. This limitation need not, however, seriously detract from whatever merit the discussion may possess, since the deposits concerned cover a fairly wide range of metallic ores, including gold, copper with associated zinc, and, lastly, molybdenum.

Jan 1, 1936

By A. Ignatieff

"THE WORLD'S coal resources represent the largest component of non-renewable energy resources. Coal is now regaining Its position following a temporary decline, particularly in North America during a period of about a quarter of a century. This period provided the opportunity to improve both surface and underground mechanization, thereby increasing the productivity and improving conditions for humans in the mines. Similarly, in preparation, improved cleaning of coal from various impurities including sulphur was achieved, to meet the more demanding requirements for coking coal. Progress was also made in combustion, particularly related to the reduction of pollution. Canada participated in most of these developments, despite the country's strong commitment of the use of hydrocarbons during this period. _Bearing in mind the vastness of this land (3.85 million sq. miles) by comparison with countries like U.S.A., U.S.S.R., and China, Canada's coal resources estimated to date are not large and they are scattered. The original evaluation of 1913 estimated the ""reserves"" from seams over one foot in thickness and a limiting depth of 4,000 ft at 1.2 trillion metric tons. D:. ~.R. MacKay, in his evaluation for the 1946 Royal Commission on the coal industry, known as the Carroll Commission, reduced the ""reserves"" to 99 billion short tons. The increased knowledge now available would indicate that the 1913 estimated was too liberal and the 1946 estimate too conservative but both were closer to a resource than to a reserve designation. Some adjustments of Dr. MacKay's estimates were made in 1970 by B.A. Latour of the Geological Survey of Canada and L.P. Chrismas of Energy, Mines and Resources Canada (EMR). In the last decade the Alberta Energy Resources Conservation Board has developed its own methods of evaluating coal resources and reserves. A methodical approach of exploration and evaluation was carried out by Saskatchewan jointly with the federal government of the lignite resources of Southern Saskatchewan. A similar joint program is in progress in Nova Scotia. Meanwhile, the industry itself carried on an extensive exploration program on the outcrops of promising projects in the Inner Foothills belt of Alberta and British Columbia in preparation for surface mining on a very large scale, with some development of hydraulic mines. All these activities have been reflected in the increase of the country's resources and reserves, which now fortunately are separately defined. In 1979 EMR issued Report E.R. 79/9(1>; the data were developed in 1978 and provided to the World Energy Conference Organization<2>. In 1980 the World Coal Study (Wocol), an international group that included Canada carried out a study which updated the W.E.C. data, indicating some reduction of the 1978 figures; quantities were reported in million metric tons of coal equivalent (C.E.)*(Jl."

Jan 1, 1985

By G. O. Prickett, P. Somasundaran

An application of the statistical and computer techniques in basic mineral processing research is illustrated by means of a case history involving the study of starch adsorption on calcite. Multi-factorial experimental designs and computer techniques were used for determining the effect of different system variables, such as solution pH, sodium oleate concentration and starch concentration, and to obtain a mathematical model of the response. Response maps enabled the investigators to see the effects clearly and to predict the results of changes in factor levels within the design region. Use of time-shared computers and plotters made data processing and analysis efficient and relatively inexpensive.

Jan 1, 1973

By W. R. Horn

"WHAT I PROPOSE TO DO is to review or report very briefly and generally on the most important subject areas of environmental concern within the mining industry and to indicate the progress being made. First, however, it seems to me both appropriate and necessary to refer to what I said in an address to the CIM Annual Western Meeting, in November 1971, in Vancouver. At that time, I tried to convey: that the awareness and alertness of this far-flung and diversified industry was sharply on the up-swing; that the knowledge of helpful technology for the abatement of pollution by water and solids was significantly increasing; that most mines were doing something about it; that many had already achieved a recycling of process water to a really significant extent; that progress was being made - though not without considerable difficulty - on the large-scale neutralization and subsequent chemical treatment of acid- and metals-bearing waters; that increasing work was being done by individual mining companies on methods for the vegetation of completed tailings impoundments; and that it had been possible to develop a meaningful estimate of the amount of money to be spent by the industry on environmental control measures during the period 1971-75 (as much as $500,- 000,000 ) . Reference was also made at that time to the constructive work in hand toward the fixation, elimination or dispersion of sulphur from smelters and to the considerable attention which was being given by the indust(y itself toward in-plant problems, e.g., dust and noise. Finally, note was taken of the fact that the inclusion of environmental control costs in the pre-operational financial provisions of new mining operations is now established practice."

Jan 1, 1973

By R. W. Boyle

"The concept of using chemical methods in prospecting dates back at least to the middle of the 16th century. Modern methods of geochemical prospecting, however, based on secondary haloes and utilizing trace-element techniques, were first practised in the U.S.S.R. and the Scandinavian countries in the 1930's. After 1945, methods based on soils, stream sediments and vegetation were rapidly developed in the U.S.A., the United Kingdom, Canada, France and other countries.The modern methods of geochemical prospecting owe their rapid development in the 20th century to the following:1.-Recognition of the primary and secondary dispersion haloes and trains that are associated with all mineral deposits. 2.-Development of accurate and rapid analytical methods utilizing the spectrograph and the various specific sensitive colorimetrie reagents, especially dithizone. 3.-Development of polyethylene laboratory ware of all types and the development of resins. This permitted greater freedom of field analyses and reduced the incidence of contamination.4.-Development of gas chromatography. This permitted the rapid and accurate determination of hydrocarbons in petroleum prospecting.Future research in geochemical prospecting should be focused on the following tasks: 1.-Definition of geochemical provinces and their relation to mineral deposits. 2.-Development of methods for discovering large low-grade deposits. 3.-Development of methods for discovering deeply buried deposits. 4.-Further development of methods to outline primary haloes. 5.-Eiucidation and formulation of techniques to relate the size and intensity of anomalies to the grade of the deposits. 6.-Development and refinement of biogeochemical methods, especially those based on indicator plants, chlorotic or toxic effects, and microbiological techniques. 7.-Definition of the types of primary and secondary haloes associated with accumulations of oil and gas."

Jan 1, 1967

By M. Ye. Shulgina, M. L. Bolotin, S. A. Prokopev, Ye. S. Prokopev

Iron ores concentration at Russia’s operations is carried out using conventional flow sheets. They comprise the two-four stage grinding followed by one-two stage magnetic separation. This results in the maximum recovery of magnetite to concentrate and the tailings generation. The final concentrate is generated only during the last stage of magnetic separation. Technologically, this flow sheet layout is not effective at recovering the liberated magnetite grains during grinding to the resulting concentrate. Advanced models of magnetic separators do not allow for the selective separation of the tailings and the portion of the resulting iron ore concentrate. Magnetic product which is the ore mixture of the liberated magnetite grains, high grade and low grade intergrowths is directed to the next grinding stage. In this case, regrinding of the liberated magnetite occurs. In addition, the performance of hydrocyclones during classification in closed grinding circuits is poor. Their classification efficiency does not provide the material separation in accordance with the size. In this case, simultaneous separation in accordance with the density occurs. The quartz particles with the size of 300 mm have similar velocity and trajectory like the particles of magnetite with the size of 60 mm. As a result, light and coarser intergrowths report to the overflow and free heavy magnetite grains report to underflow and return to regrinding (“the density effect”). This resulted in a significant increase of a mill circulating load, the decrease in the feed throughput and higher power consumption. In this connection, the development of iron ore concentrate stage recovery with the focus on gradual liberation of the intergrowths is getting much attention. Gravity concentration technique, particularly, spiral separation is effective at solving the problem of stage recovery not only the dump waste product but also high grade magnetite concentrates at the early concentration stages. This can be attributed to a significant difference in magnetite (4.9-5.2 g/cm3) and host minerals (quartz 2.7 g/cm3) densities, which is the principal during gravity concentration. The test work on concentration of various products samples from current operations (the mills discharges, concentrates from various stages of wet magnetic separation and cyclones underflows) was carried out. Spiral separators SV-500 and ShV-500 manufactured by Spirit LLC were used for the test work. High grade iron ore concentrate (69.05% Fe) was generated during primary wet magnetic separation concentrate concentration using a spiral separator. During the concentration of mills discharges the content of iron in the resulting concentrates and middlings of wet magnetic separation II stage was 64.5% and 64.6%, respectively. The recovery of iron to the concentrates of spiral separation was 33.6-42.0%. The studies presented demonstrate that by using spiral separation for iron-bearing ores concentration, you can separate magnetite liberated grains at the early concentration stages, decrease their regrinding and circulating loads in grinding circuits. This process is able to improve the overall recovery and economics of iron ores concentration process.

Jan 1, 2016

By M. Ye. Shulgina, M. L. Bolotin, S. A. Prokopev, Ye. S. Prokopev

Iron ores concentration at Russia’s operations is carried out using conventional flow sheets. They comprise the two-four stage grinding followed by one-two stage magnetic separation. This results in the maximum recovery of magnetite to concentrate and the tailings generation. The final concentrate is generated only during the last stage of magnetic separation. Technologically, this flow sheet layout is not effective at recovering the liberated magnetite grains during grinding to the resulting concentrate. Advanced models of magnetic separators do not allow for the selective separation of the tailings and the portion of the resulting iron ore concentrate. Magnetic product which is the ore mixture of the liberated magnetite grains, high grade and low grade intergrowths is directed to the next grinding stage. In this case, regrinding of the liberated magnetite occurs. In addition, the performance of hydrocyclones during classification in closed grinding circuits is poor. Their classification efficiency does not provide the material separation in accordance with the size. In this case, simultaneous separation in accordance with the density occurs. The quartz particles with the size of 300 mm have similar velocity and trajectory like the particles of magnetite with the size of 60 mm. As a result, light and coarser intergrowths report to the overflow and free heavy magnetite grains report to underflow and return to regrinding (“the density effect”). This resulted in a significant increase of a mill circulating load, the decrease in the feed throughput and higher power consumption. In this connection, the development of iron ore concentrate stage recovery with the focus on gradual liberation of the intergrowths is getting much attention. Gravity concentration technique, particularly, spiral separation is effective at solving the problem of stage recovery not only the dump waste product but also high grade magnetite concentrates at the early concentration stages. This can be attributed to a significant difference in magnetite (4.9-5.2 g/cm3) and host minerals (quartz 2.7 g/cm3) densities, which is the principal during gravity concentration. The test work on concentration of various products samples from current operations (the mills discharges, concentrates from various stages of wet magnetic separation and cyclones underflows) was carried out. Spiral separators SV- 500 and ShV-500 manufactured by Spirit LLC were used for the test work. High grade iron ore concentrate (69.05% Fe) was generated during primary wet magnetic separation concentrate concentration using a spiral separator. During the concentration of mills discharges the content of iron in the resulting concentrates and middlings of wet magnetic separation II stage was 64.5% and 64.6%, respectively. The recovery of iron to the concentrates of spiral separation was 33.6-42.0%. The studies presented demonstrate that by using spiral separation for iron-bearing ores concentration, you can separate magnetite liberated grains at the early concentration stages, decrease their regrinding and circulating loads in grinding circuits. This process is able to improve the overall recovery and economics of iron ores concentration process.

Jan 1, 2016

By D. J. Scarpato

"Slope construction in shale can present some interesting challenges for geotechnical design engineers and contractors alike. There are challenges that can be expected and designed-for; however, all too frequently, such challenges manifest themselves as “surprises” in the field. Common constructability challenges can include those such as drill hole deviation during drilling for controlled blasting; and, excavation slope instability arising from inconsistent perimeter control drilling. Drill hole deviation results from the cumulative effects from both drilling mechanics and rock mass conditions. Once a hole has initiated the deviation trajectory, it is difficult to rectify drill steel position. Although such challenges are not necessarily unique to shale, they are often exacerbated by weak, weathered and transversely isotropic nature of bedrock conditions. All too often, the working assumption is that shale is “soft” and easily excavatable; however, this blanket assumption can prove to be costly. This paper is intended to provide design professionals and contractors with the practical considerations needed to avoid the “surprises” associated with drill hole deviation, and minimize the potential for costly claims.INTRODUCTIONFor all the slopes that have been excavated worldwide, and for such advancements in excavation technology and field characterization, one might be tempted to believe that the industry almost has slope development down to a science. This is frequently not the case, especially for weak/weathered and anisotropic bedrock. Excavation contractors are still pushed to the limits of what their technology can achieve, and engineers are all too often called to the field during construction, to make potentially risky onthe- fly decisions relative to excavatability, short and long-term slope stability, and project safety. Although there have been a host of other research papers and journal articles that have been written on the subject of deviation over the past 30 years (Brown, Geen, Sinha, 1981), the problems associated with drill hole deviation are still all too frequent. This fact is especially true for civil engineering surface excavations in bedrock."

Jan 1, 2015

By R. L. Christie

"THE ISLANDS lying north of the Canadian mainland, and the large Boothia and Melville peninsulas, form one of the great archipelagos of the world; this sparsely vegetated and nearly unpeopled region extends about 1,500 miles east to west and 1,200 miles from the mainland to the northern tip of the northern-most island. Sea access to most of the islands is restricted by ice to the summer season, and the 'polar pack' ice of the Arctic Ocean presses the year round against the northwest margin of the archipelago. Although the region is remote, the accessibility has greatly increased through a network of weather stations, airfields and air routes connecting with southern centres.The area considered in this paper is that part of the island region underlain mainly by sedimentary rocks. In broad terms, this includes the land and sea areas of the archipelago and the adjacent continental shelf, but excludes the dominantly 'Shield' terrain of Baffin Island, and of Melville and Boothia peninsulas. An impression of the size and potential of this sedimentary region may be gained by comparing some areas: the land area of islands underlain mainly by sedimentary rocks is over 300,000 square miles or about 50,000 square miles greater than the area of Alberta. The total area of the region, including the continental shelf and the inter-island areas, may be double this figure, and may approximate one-seventh of the land area of Canada."

Jan 1, 1970

By C. McLachlan, J. R. Donald

"Positioned at the forefront of the seafloor minerals industry, DeepGreen Resources is on track to becoming a leading producer of base and strategic metals obtained from vast high-grade seafloor polymetallic nodule deposits. DeepGreen believes the seafloor minerals industry is an opportunity for developing a more environmentally and societally attractive way to produce cleaner base and strategic metals. Polymetallic nodules contain nickel, manganese, copper, cobalt and other base and strategic metals. Polymetallic nodules represent an exceptional multi-metal-bearing resource, and no current metallurgical operation or flowsheet exists that can recover the primary metallic values while managing the distinct mineralogy. DeepGreen Resources is developing a new process to maximize the business outcomes consistent with the highest environmental standards, including targeting a near zero waste facility. The present paper discusses the history, context and driving forces of polymetallic nodule project development. An overview of DeepGreen?s Nauru Ocean Resources Inc. (NORI) project is presented along with a literature review of polymetallic nodule processing and the on-shore project development scope and plan at DeepGreen Resources is outlined.INTRODUCTION AND CONTEXT Polymetallic Nodules in the Clarion-Clipperton Zone Containing nickel, cobalt, copper and manganese, polymetallic nodules occur in most oceans of the world. The nodules lie on the seafloor sediment. The largest deposit in terms of nodule abundance and metal concentration occurs in the Clarion-Clipperton Zone (CCZ) on vast abyssal plains at a depth of 4,000 to 6,000 metres. The CCZ is located almost entirely in international waters as presented in Figure 1. It has been estimated that the CCZ contains (International Seabed Authority, 2010): •,>21 billion tonnes of nodules; •,>270 million tonnes of nickel; •,>6 billion tonnes of manganese; •,>234 million tonnes of copper; •,>46 million tonnes of cobalt. There are several active hypotheses for the mechanism of formation of the nodules including precipitation, hydrothermal decomposition of basaltic debris, and involvement of microorganisms. Nodules require a nucleus to start forming, which could be a piece of pumice, a shark tooth, old nodule piece, basalt debris or even microfossils like radiolaria and foraminifera. Nodules form concentrically with layers of iron and manganese hydroxides around a core. Although composed mainly of Mn, Fe, silicates and hydroxides, it is the significant content of Ni, Cu, Co, Zn and Rare Earth Elements (REE) that is generating the economic interest in harvesting these deposits. Nodules vary in size from micro-nodules to about 20 cm, the common size being two to eight centimeters. A typical polymetallic nodule and polished cross-section is presented in Figure 2."

Jan 1, 2017

By L. Narhi, K. Haavanlammi

"Approximately two thirds of annual nickel production is used as a raw material in the making of stainless steel, and about 60% of these nickel products are in the form of metallic nickel such as nickel cathode or briquettes. In the stainless-steel production process nickel is blended with iron and chrome-based raw materials, and metallic nickel is typically only required for final steel fine-tuning. Outotec offers a new FeCrNi technology to enhance the nickel value chain for stainless steel producers. This involves the use of an HPAL-based intermediate nickel product (e.g., mixed hydroxides or NiO) as raw material in the Outotec FeCrNi process, for the production of a FeCrNi Master Alloy. The new process, designated as the FeCrNi process, offers multiple benefits compared to existing technologies such as: higher tolerance for impurities in the HPAL intermediate product, avoiding the need for further nickel refining, and the improved recovery of all metals in the FeCr process. The complete new FeCrNi value chain is based on proven technologies such as HPAL and the Outotec FeCr-process. This new innovative and promising value chain offers improved efficiencies for the HPAL based nickel production process combined with excellent sustainability aspects.INTRODUCTION In today’s global economy there is a constant need to improve the efficiency and sustainability of the metals production. The requirements for modern metal refining are tightening and cost efficient, safe and sustainable operation is the precondition for all investment. Outotec is offering now a novel way to combine FeCr and Nickel production to create a completely new value chain to source nickel to stainless steel. BACKGROUND Nickel The current nickel mine production is in the level of 2,000 tons annually and it is split 44% from sulphide based deposits and 56% from laterite deposits (Figure 1). Most (40%) of the nickel is refined to pure nickel metal whereas other products are FeNi (19%) and Nickel Pig Iron NPI (20%) (Roskill). The remaining part, roughly 21%, is nickel chemicals and intermediates. Most of the new investments in nickel are in the direct shipping of laterite to produce nickel pig iron. HPAL process is considered in few projects but no major HPAL projects have been started since the Ambatovy plant in Madagascar. Ambatovy reached the commercial production in 2014. The main primary nickel used is stainless steel manufacturing. In the year 2016 about 68% (~1,360 kt) of primary nickel production was used in stainless steel."

Jan 1, 2017

By J-S. Marois, F. Cappucitti, Y. Dodier, D. Downey, G. Matton

"The flotation processes of the Niobec Mine have been affected by a seasonal loss of recovery and a significant increase in reagent consumption over the past few winters. This paper discusses the problem-solving methodology that was used to identify the root causes, to develop solutions and to implement changes that resolved the problem to restore the process to summer-like conditions year-round. Mainly, it was found that the process water was contaminated by phosphates ions, which adversely affected the carbonate pre-flotation, and caused detrimental effects on the subsequent niobium flotation. The phosphate ions were being generated by the process itself, but were consumed by algae in summer conditions. It was determined in laboratory studies that concentrations as low as 5 ppm were enough to affect the circuit and that the multiple additions of process water throughout the circuit was worsening the effect. Also, temperature was found to have an impact on the reagent performance. The performance of the plant was restored by implementing a natural treatment of our process water with a simple cost-free rearrangement of our circuit streams. In addition to that, our extensive geometallurgical program was used to provide ore to the plant restricting phosphate generation in the process. Also, a modification of the collector was developed and introduced in the carbonate pre-flotation that provided improved performance during the periods of low pulp temperature.INTRODUCTION Niobec is one the three major global producers of niobium presently in operation. Situated in the Saguenay-Lac-St-Jean region of Quebec and in operation since 1976, the site produces ferroniobium (FeNb) to be used mainly in High Strength Low Alloy (HSLA) steel, which is known to have better mechanical properties than carbon steel. The Niobec operation consists of an underground mine, a concentrator and a converter plant. The concentrator concentrates niobium-bearing minerals, mainly pyrochlore and columbite, to produce a high-content Nb2O5 concentrate which is then converted to FeNb in the converter plant by an aluminothermic reaction. The Niobec concentrator flowsheet, which has gone through many expansions and optimisation over the years, consists of grinding, desliming, flotation and leaching steps. The flotation steps are numerous, sensitive and difficult to operate due to the non-selective nature of oxide mineral collectors. Thus, the pyrochlore concentration process at Niobec still faces many challenges and is constantly going through periods of continuous improvement."

Jan 1, 2018

By Thomas H. Heine

"The Rabbit Lake uranium deposit is located at 58° 11’00”N.. 103°42'36""W., close to the west side of Wollaston Lake, and approximately 800 km north of Saskatoon. The orebody is hosted by Aphebian Wollaston Group rocks, initially deposited as a series of shallow-water marine sediments consisting, in part, of carbonates and possible saliferous petites. Metamorphism during the Hudsonian Orogeny, peaking at about 1850 Ma, recrystallized the sediments to upper amphibolite grade paragneisses. This was accompanied by partial anatexis. The waning stages of Hudsonian orogenesis appear to be marked by minor granitic intrusive activity.The post-Hudsonian period was marked by a long interval of physical and chemical erosion, resulting in the unroofing of the Wollaston metamorphic complex. The entire region underwent extensive lateritic weathering under tropical to subtropical conditions. Carbonates were especially vulnerable and, in the Rabbit Lake area, suffered extensive solutioning with accompanying formation of collapse breccias. Old zones of weakness also underwent periodic reactivation.It was during this period that uranium was leached from the surrounding meta-sediments by oxidizing meteoric waters, and transported into the karsted and fractured rocks of the Rabbit Lake doline.Athabasca Group sediments eventually covered the deposit, their diagenesis taking place at about 200 °C and 900 bars. This allowed the partial to complete recrystallization of the initial mineralization, resulting in a minimum age of 1281 ± 11 Major ""first""-generation pitchblende. Periodic fault/fracture reactivation modified the hydrologic regime within the deposit, resulting in episodic mobilization and recrystallization of pitchblende and other uraniferous species. This is clearly shown in the open pit at the present time: uranium is being mobilized and recrystallized on damp pit walls as bayleyite and liebigite due to the modification of the hydrologic system by mining activities.The uranium mineralization occurs mainly as fracture fillings, coatings, and impregnations within breccia zones and intensely altered metasediments. Lesser mineralization is intimately associated with phyllosilicates which form the matrix of a carbonate-col/apse mega-breccia. The primary ore mineral is pitchblende, consisting of five generations, and from which a large suite of secondary uraniferous minerals have formed. On a gross scale the metal content of this deposit appears to be simple, consisting almost exclusively of U, but minor Ni, As, Cu, Se, Fe and Co are also present. The eastern limit of the mineralization is defined by a vertically-dipping microgranite dyke - breccia complex, containing high-grade uranium values. The orebody is truncated to the west and at depth by the Rabbit Lake reverse fault. Minor mineralization occurs as fracture fillings in unaltered plagioclasite in the footwall of the ore body. Precipitation of uranium from solution could have taken place by a number of processes. A mobile reductant (methane, carbon dioxide, etc.) may have been generated from graphite present in some of the host rocks of the orebody. Sulphides are also a common accessory and may have aided in the formation of a reducing environment. Phyllosilicates may have acted as adsorbants for uranium, allowing for its fixation. This metal has also been incorporated into the phyllosilicates themselves."

Jan 1, 1986

By Alex Rown

"THE SYDNEY COAL FIELD has long been afflicted by high costs and low productivities. However, a distinct possibility now exists that improvements can be made in costs, productivities and revenues. If these hopes materialize, the Sydney coal field will once again be regarded as a valuable asset in our national inventory of energy and metallurgical coals. The economic possibilities for the Sydney collieries depend on performance at the pits and in the market place. Because this audience is already well informed about colliery planning, I would like to start with an assessment of the modern coal market insofar as it may relate to the Sydney field. Since 1950 we have seen a vast growth in the population and industrial empires of the western world which has resulted in an enormous and escalating demand for energy. If the energy supply pattern of the first 50 years of this century had been followed, this would have led to an immense demand for coal."

Jan 1, 1972

By A. Alfantazi, M. Mahon

The current efficiency in zinc electrowinning is a key indicator of the performance in a cell house. This is typically measured by comparing the weight of the cathode to the electric current applied over the deposition period. This calculation can be cumbersome because the deposition history of each pulled set of cathodes will be unique. It will depend on the applied current and electrolyte conditions from onset of deposition until the cathode is removed and stripped. Not accounting for these can introduce errors to the calculated current efficiency. To track this history and reconcile the current efficiency, a time based computer process simulation was made of an industrial cell house. Two months of hourly recorded measurements from the cell house were input to the simulation, including current to the cell houses, concentrations, flow rate, and temperature of the purified leach solution. The simulation’s predictions of the concentration of zinc in the circulated, spent, and returned electrolyte all showed good agreement with the industrial data over the two months giving a validated zinc balance. The simulation was then tuned to predict the instantaneous current efficiency for all times, as well as the expected masses for the deposits given their deposition history.

Jan 1, 2014

By M. J. Collins

The Advocate Mines Limited asbestos property is 6 km north of Baie Ve rte on the northeast coast of Newfoundland. Mining began in the early 1960s and was concluded in 1981. The chrysotile asbestos deposit lies at the north end of the Baie Verte Lineament, the interface between a closing ocean floor and continental margin. Asbestos occurs within ultramafic rocks of abducted ophiolite massifs that were thrust westward against Fleur-de-Lys Supergroup metasediments (continental rise sediments) in the Lower to Middle Ordovician. The asbestos-bearing ultramafics belong to the Central Ultrabasic Sequence of the Advocate Complex. Serpentinized peridotite of this sequence has a 'waste cap' core that grades outward to increasingly sheared rock. Asbestos is found mainly in a northtrending, basin-shaped zone surrounding the core, specifically within fractured serpentinized peridotite that abuts the sheared rock. Asbestos appears as stockworks of chrysotile cross fibre veins and is concentrated between brown, narrow brucitic dunite dykes and sills. Shear contacts commonly surround the ultrabasic body. Cross faults and complex Jointing also exist. The Advocate Mines Limited mill produced 65,000 tonnes of Group IV fibres and 1 l , 000 tonnes of Group VJ fibres annually. The bagged product enjoyed markets worldwide.

Jan 1, 1984

By D. Want

In titanium-lined autoclave design the most critical point of its mechanical reliability is its titanium batten strips present at the circumferential and longitudinal barrel-weld seams. Recently an Australian Company, W.E. Smith Hudson (WESH) P/L, has developed a fully flush batten strip and is building autoclaves with this design. Significant research and development has been performed in the process. In this presentation, design aspects of these batten strips are presented that cover topics such as residual-stress magnitudes during fabrication, affect of preheat during batten-strip welding and residual stress in respect to fatigue life. There has been little research done regarding the affects of residual batten stress in relation to fatigue life. Considerations of this &apos;grey&apos; area of design will be discussed based on the author&apos;s research data and finite element analysis.

Jan 1, 2005

By W. B. Agocs

"IntroductionWITH THE DISCOVERY of natural radioactivity at the end of the 19th century, and the design of equipment for the detection of this phenomenon, radioactivity surveys bad their inception. Early in the 20th century it was found that almost all rocks are radioactive to a certain degree. This radioactivity is due to the nuclear disintegration of six naturally radioactive elements: potassium, thorium, uranium, rubidium, samarium, and lutecium.The radioactivity of these elements manifests itself by the emission of some concentration of alpha, beta, and gamma 'rays'. Of these, the alpha and beta 'rays' are, respectively, helium atoms and electrons, while the gamma 'rays' are short wave length x-rays generated in the nuclear disintegration by the transformation of mass into energy.The alpha and beta rays, being particles of matter, are stopped ve• easily by material barriers, but gamma rays are extremely penetrating and they will pass through a foot or more of rock or several inches of lead.The radioactivity may be detected by the causing of ionization by the radiation. The radiation detectors may be divided into four classes: ionization chambers, proportion al counters, and Geiger counters, all of which use gas for ionization, and scintillation counters, in which a solid is ionized. The basic principle of all these detectors is the same; the difference lies in the method used to measure the degree of ionization produced by the rays. Currently, the scintillation counter is displacing, the other instruments in radioactivity surveying."

Jan 1, 1955

By B. A. Monkman

"IntroductionONE OF :THE most effective methods by which the construction industry is combatting mounting building costs is by making increased use of lightweight materials, thus reducing the dead load to be carried •by structures. This applies to non-metallic materials as well as to metallic ones, and particular attention has been given to developing lightweight aggregates for use in concrete.The use of lightweight aggregates is not new and, in fact, dates back to the Roman Empire, when pumice was used in the walls and domes of the Roman buildings. More recently, and up to a decade or so ago, the demand for these aggregates was met from deposits of volcanic cinders, pumice, scoria, etc., and from the by-products of blast furnaces and coal burning boilers. However, these sources of supply are no longer sufficient to meet the demand, for transportation costs pretty well restrict the use of the natural lightweight aggregates to the western cordillera regions where the deposits of these materials occur, and the use of expanded slag aggregates to the areas neighbouring the plants where slags are produced. As for cinders, the supply has been greatly reduced by the conversion of industry to fuel oil, natural gas, and powdered coal, and the large stockpiles which existed previously have been pretty well exhausted.Industry's approach to the problem of a decreasing supply, in the face of an increasing demand, has been characteristically direct. The solution has been to construct plants whose sole .purpose is to produce economically an acceptable light-weight aggregate from materials close at hand."

Jan 1, 1955