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By J. J. Denny

IN November, 1932, an investigation of silicosis was undertaken at the Mcintyre Porcupine mine, Schumacher, Ont., after a discussion of the p"roblem with Sir Frederick Banting and his staff. As a result, it was decided to carry on dusting experiments with animals at the mine in a manner that would duplicate as far as possible actual industrial conditions. At that time 50 guinea pigs were placed in the crusher house tunnel of the mill where a considerable quantity of fine dust, containing approximately 35 per cent of free silica, was being constantly produced. These animals lived in this atmosphere for periods up to one year, and, while on autopsy large amounts of dust were found in the lungs, not a single case of silicosis had developed. These negative results suggested, among other things, that the mine gases might be a predisposing factor in the production of silicosis, and the results of this investigation (1) led us to undertake the study of the hydrogen-ion concentration of the condensate of the atmosphere, both in the mine and in various sections of the mill. The CO, combining power of blood serum on a series of 400 miners was also studied at this time. While these results were inconclusive, the variation in the hydrogen-ion concentration of the condensate between the surface and underground atmospheres encouraged us to investigate the effect of neutral, weak acid, and alkaline solutions on the solubility of siliceous materials. Gye and Purdy (2) were the first to point out that the chemical reaction, and not the physical presence of siliceous material, was responsible for the production of the fibrosis in silicosis. This work was investigated by Gardner and Cummings (3), who showed that the tissue reaction to quartz was definitely proportional to the size of the particle. They found that 1-3 micron particles of quartz produced an acute proliferative fibrotic response, while the 10-12 micron particles produced only a foreign-body reaction up to a period of three years. It is accepted that the dangerous silica particles retained by the lung are under 5 microns in diameter.

Jan 1, 1937

By J. E. Nesset

Significant progress has been made over the past few years on characterizing and understanding the hydrodynamic properties of frothers and collectors and their effect on flotation performance. This new understanding of the relationship between chemistry and hydrodynamics has dramatic implications for how flotation circuits should be controlled and optimized. Previous work has shown that choosing a frother of the right 'strength' is critical to the optimization process, and the work and discussion presented here serve to strengthen the argument. In addition, we know that collector chemistry may also influence hydrodynamic properties and needs to be taken into consideration. To achieve the desired outcome, the overall system of reagents and operating parameters must be considered. This paper describes and discusses some of the findings from recent research on frother and collector chemistry effects (on hydrodynamics), and how this knowledge can be used to improve flotation performance. Examples from plant experience are discussed.

Jan 1, 2009

By Rong. G., T. Q. Lin, W. Du

Based on analysis of the evolutionary history of the valley in Baihetan, the mechanism of asymmetrical evolution, gradual migration-incision evolved from left bank to the right, is revealed in Baihetan river valleys. The process of in-situ stress evolution is carried out by using the Universal Distinct Element Code (UDEC). Consequently, the numerical results which indicate the main regulations of that stress field are as follow: (1) The phenomenon termed "high in-situ stress fold" appears in the bottom of the valley. With the maximum principal stress being 28-34 MPa, the stress increases significantly at a vertical depth of approximately 130 m. (2) The in-situ stress presents zonal distribution along the bank slope. It is apparent that the in-situ stress field consists of stress relaxation zone (SRZ), stress concentration zone (SCZ) and original stress zone (OSZ). The horizontal depth of stress relaxation zone varies from the left bank (roughly 200 m) to the right (about 120 m). Furthermore, the stress evolution of the left bank slope is studied. As a result, it is found that asymmetrical erosion contributes to the difference of the in-situ stress distribution as a critical factor, between the left bank and the right. And for an asymmetrical valley, the evolutionary process of in-situ stress field is a circular procedure, which includes the incision of valley, the accumulation of landslides and the migration of valley.

Jan 1, 2015

By R. A. Wyman

A comparison of the amount of minus-28-mesh product produced by a standard grinding test procedure is provided for 45 non-metallic materials. The percentage of product, the weight of product per unit of energy used and the weight of product per mill revolution are shown. The results exhibited excellent reproducibility and demonstrated an accurate comparison of grindability for non-metallic materials.

Jan 1, 1977

By S. L. Gertsman

Canadian steel foundry practice has made marked progress during the past decade. Equipment suppliers, development engineers, and foundry personnel have focussed their attention on every phase of the foundry operation, with a resulting lower demand on manpower and materials. Also, more rigid specification requirements as to dimensional tolerances and quality have necessitated improvement and increased control at every stage from the pattern shop to the cleaning room. The growing trend toward mechanization is clearly evident. Equipment such as sand mixers, sand reclamation systems, material handling devices, moulding machines, core blowers, etc., is being increasingly employed by the steel foundryman. This equipment not only increases production but also tends to lessen the human variable so prevalent and disconcerting in the early days of steel founding. The result has been an improved and more reliable steel casting, which is gradually obtaining wider acceptance by design engineers. The purpose of this paper is to discuss briefly some of the practices being used, and also the direction of development that is being pursued by Canadian steel foundrymen.

Jan 1, 1948

By Earle J. Klohn

"The design, construction and operation of tailings dams is rapidly becoming a major consideration for most new mining developments, as well as for many existing operations. In North America, under pressure from public opinion, various government agencies have in recent years enacted legislation covering the design, construction and operation of tailings dams. In British Columbia, comprehensive legislation has been passed during the past year (1971). All of these new regulations may be placed into two broad categories: regulations concerning the safety of the dam and appurtenant structures, and regulations concerning the prevention of pollution. Both types of regulation affect the design of the tailings dam facilities. Consequently, they must be considered jointly by the designer. A good tailings dam design must satisfy the basic requirements of safety, pollution control, storage capacity and economy. To achieve this, 'the design must be based on a thorough understanding of both the geotechnical problems involved and the requirements of the mining development. Obviously, this requires close cooperation between the designing geotechnical engineers and the mining operators. This paper outlines the major engineering factors that should be considered in the investigation, design, construct ion and operation of tailings dams. Basic methods of tailings dam construction are reviewed and the advantages and disadvantages of each briefly discussed. Comparisons are made between the design and construction of conventional water supply dams and tailings dams. Examples are presented of some of the problems that may arise during construction and operation of a tailings dam. The paper also explains the need for basic instrumentation of tailings dams and for carrying out simple field tests and measurements during construction and operation. Of prime importance is the downstream monitoring of surface and subsurface seepage flows. These observations are invaluable where contamination of surface and/or subsurface water may become a contentious issue at some future date. Each tailings dam design must be based on a study of the particular requirements of that project. To make a proper evaluation, adequate data must be available concerning a large number of items•, including such things as: topography, hydrology, geology, subsoil properties, seismicity, government regulations, fineness of mill grind, mill water balance, availability of suitable construction materials, volume of water to be stored behind starter dam, downstream development or liability, and many others. The large number of variables involved in such an evaluation often result in the designer considering two or more alternative designs. Selection of the final design, which is usually based on detailed cost analyses of the alternatives, must be made in close consultation with the owner."

Jan 1, 1972

By Constantin D. Pitis

Similarly to notions of constant capital/expenses in business or magnetization power for electric motors an energetic base load (E0) is always necessary to set up a mining process. Denominated as ?non-productive energy? or base load, (E0) is a constant component of the entire energy consumption of the process, while another component the ?productive energy? (Ep) is variable, being function of the production/throughput (M). By using these new concepts, the author creates an energetic model proposing a new method of assessing changes in mining processes (throughput) that can reveal possible energy savings (DSM component) or energy losses. Proposed mathematical model of assessing (E0) and energy savings by using ?Marginal Energy Usage Index? (MEUI) enables creation of historical benchmarks and direct on line energetic (efficiency) assessment of mining processes and/or equipments. The paper analyses the case of assessing possible energy savings that can be obtained by: ?? Improving efficiencies of various equipments (by retrofit) ? reducing E0 ?? Improving the process control or other process changes ? reducing Ep ?? Monitoring persistence of the adopted Energy Conservation Measures (ECMs). For the new plant design, the proposed method enables prediction of Customer Baseline in various mine/process configurations. The method could become part of a ?preventive action? in design process by offering a reliable tool of assessing additional financial effort (Incremental cost) when choosing various higher efficiency equipments and/or processes.

Oct 1, 2009

By T. M. Korzekwa, R. L. Cavanagh

Following considerable experience with the beneficiation of Wabana iron ore by standard methods, a study was made of the benefits to be obtained by semi-reduction. The basis of the laboratory program was an extensive mineralogical and liberation investigation which guided subsequent work. Partial reduction and beneficiation on a laboratory scale was carried out on lump ore and fines. The reduced ore was magnetically concentrated and the concentrated fines were briquetted. Data are presented on reducibility, sizing vs reduction rate, magnetic cobbing and separation, and the elimination of phosphorus. Past work is reviewed briefly and comments are made on the relation of laboratory to pilot-scale tests.

Jan 1, 1967

By Jack Young

U. S. Steel Canada Inc.’s Lake Erie Works is the last green field integrated plant to be built in North America. The plant was designed using the best available environmental technology to develop an environmentally friendly production facility. A summary of the technology and measures used in the construction of the plant are summarized in this paper.

Jan 1, 2015

By G. F. MacDonnell

THE Privateer mine consists of a group of mineral claims situated in the Zeballos area, on the west coast of Vancouver island, approximately 180 miles north of Victoria. Although Zeballos is a comparatively new mining camp, its transportation facilities can be considered exceptionally good. General freight and supplies are brought in by either C.P.R. or Frank Waterhouse steamers from either Victoria or Vancouver. Service by these boats varies from five to ten days and the trip from Victoria takes approximately two days. Passengers may use the C.P.R. boats, or, if speed is essential, they may fly, in which case they have the choice of two flying companies, namely, Canadian Air-ways, Limited, and Ginger Coote Airways. The average flight from Vancouver takes approximately two hours. Excellent unloading facilities are provided at the beach by a government dock for the steamers and a floating dock for aeroplanes. The mine, which is approximately five miles from the beach, is serviced by a fairly good gravel road, which has proved satisfactory for all haulage purposes. Zeballos has the reputation of having one of the heaviest rainfalls on the west coast, but as no accurate records have been kept, no comparisons can be made. H. C. Gunning, in his report, comments on the weather from 1929 to 1932, and one would judge that the practically continuous rainfall did not add to the pleasures of the field work. During the summer of 1938, the opposite condition prevailed and the area had exceptionally dry and pleasant weather. The snowfall is generally light at the lower elevations, but very heavy higher up. No extreme cold weather is encountered during the winter, which is generally short.

Jan 1, 1939

By E. Asselin, G. K. Yue

"In the present study, electrochemical measurements, especially cathodic potentiodynamic polarization (CPC) and cyclic potentiodynamic polarization (CPP), have been employed to study the kinetics of ferric reduction on chalcopyrite in aqueous Fe(II)Fe( III)H2SO4 solution at 90 °C and 110 °C. Results from the calculation of speciation in the above solution reveal that, at both 90 °C and 110 °C, the real Fe3+/Fe2+ ratio is much lower than the nominal ratio, which leads to smaller VALUES (for the reversible potential of the ferric/ferrous couple. Exchange current densities of the ferric/ferrous couple were obtained and are on the order of 106 10 5 A/cm2 a t 9 0 °C and 1 07 10 6 A/cm2 at 110 °C, respectively. The Tafel slopes from the CPP method are higher than those from the CPC method at both 90 °C and 110 °C. The transfer coefficients were about 0.360.59 at 90 °C and 0.370.65 at 110 °C. Based on the exchange current densities obtained, the rate constant kc was calculated. It was found that kc at 90 °C was slightly larger than at 110 °C, especially for the results obtained by the CPC method. The average rate constants are 862.17 cm/s for CPC and 65.30 cm/s for CPP at 90 °C, and 477.69 cm/s for CPC and 63.53 cm/s for CPP at 110 °C for nominal Fe3+/Fe2+ ratios ranging from 1:1 to 1000:1. INTRODUCTIONChalcopyrite is one of the most abundant copper-bearing minerals, accounting for approximately 70% of the world’s known copper reserves (Wang, 2005). Most of the currently proposed leaching processes are based on sulfuric acid with ferric ions and/or dissolved oxygen as oxidants. Some of these processes have been piloted in attempts to implement these technologies on an industrial scale, such as Activox (U.S. 5,232,491, 1993), Nenatech (U.S. 5,993,635, 1999), Dynatec (U.S. 5,730,776, 1998), AAC/UBC (U.S. 6,503,293, 2003), Total Pressure Oxidation (U.S. 5,698,170, 1997), CESL (U.S. 5,874,055, 1999) and Galvanox (U.S. 7,846,233, 2010).To date, much effort has been devoted to understanding the kinetics and mechanisms of the oxidative processes (Biegler & Horne, 1985; Córdoba, Muñoz, Blázquez, González, & Ballester, 2008, 2009; Ghahremaninezhad, Asselin, & Dixon, 2010; Hirato, Majima, & Awakura, 1987; Hiroyoshi, Kuroiwa, Miki, Tsunekawa, & Hirajima, 2004; Warren, Wadsworth, & El-raghy, 1982) or the cathode reduction reactions of chalcopyrite itself (Arce & González, 2002; Biegler & Swift, 1976; Biegler, 1977; Nava, González, Leinen, & Ramos-Barrado, 2008), by chemical or electrochemical methods. However, as the most important cathodic processes in chalcopyrite leaching systems, the cathodic reductions of ferric ions or dissolved oxygen are worth measuring due to their effects on the overall leaching rate, as predicted by mixed potential theory."

Jan 1, 2012

By S. H. Ash

Introduction Probably the newest thing in mining safety is the apparent dissatisfaction on the part of the mineral industry, as represented by both management and labour, and the general public of many nations in which mining is conducted, with the safety record of the mining industry. This is reflected by published comments in the technical press;' in labour periodicals, in popular Journals and periodicals, and in the daily press (5, 11). Despite what may be said to the contrary, mining in the United States is becoming safer, and this trend has been evident for several years (see Figures 1 to 4). Because the author's experience has been mostly in the United States this paper will discuss briefly some recent observations in the United States that have a bearing on mining safety. Because coal mining is of primary interest to the Mining Society of Nova Scotia, the paper treats mostly of coal-mining safety; however, many hazards in mining .are common to all mines, regardless of the minerals mined.

Jan 1, 1950

By C. M. Díaz, P. J. Mackey, P. Coursol

In a recent paper [1], the present authors discussed calculated energy consumption numbers in copper sulphide concentrate smelting for four different smelting technologies. For the present study, from among these technologies, they selected the Noranda/Teniente continuous bath smelting followed by Peirce Smith (PS) converting route to investigate the impact on total energy requirement of some key process variations, such as tuyere injection of dry concentrate vs. slingering of wet concentrate over the molten bath, continuous converting vs. conventional batch PS converting and commercially proven slag cleaning alternatives. In their calculations, the authors used the same thermochemical model and methodology used in their earlier paper. This approach to explore plant design options provides an interesting basis for evaluating flowsheet modifications that could lead to significant copper smelting energy savings. The METSIM software was used in the present paper to carry out heat and mass balance computations for 8 different flowsheet configurations. The results are presented and discussed in the paper with respect to copper recoveries, energy requirements and CO2 emissions.

Jan 1, 2011

By K. Swedburg, M. Samuels

"The expansion of the concentrator at New Gold’s New Afton copper-gold mine in British Columbia, Canada, completed in 2015, included an increase in the required retention time of the cleaning circuit. On site pilot testing of a Woodgrove Staged Flotation Reactor (SFR) had shown that a high grade copper concentrate would be produced with excellent recovery. The SFR was selected rather than conventional tank cell technology based on the much smaller footprint (which rendered a separate and expensive building extension unnecessary), high concentrate grades demonstrated in testing, and the lower energy requirement. Three SFRs, each capable of taking a nominal feed of 700 cubic meters per hour were installed and commissioned 10 months after the receipt of order. The SFRs operate in series and all of the cells produce a final concentrate typically grading 32% Cu, while the overall SFR stage recovery averages 55%. The tailings from the SFRs are treated in the original conventional three-stage cleaner circuit where the remaining values are recovered in a concentrate grading 28% Cu. Design production was achieved within days of the initial start-up of the SFR circuit.INTRODUCTIONThe New Afton concentrator, located near Kamloops, British Columbia, Canada processes a copper-gold ore with a designed head grade of 0.96% Cu, 0.72 g/tonne Au, and 2.22 g/t Ag.The New Afton Mine is a block cave mining operation. Ore is undercut from the bottom up and removed at the extraction level from a grid of draw points. Ore is trammed to the ore passes by underground loader and dropped to a haulage level for transport by trucks to the gyratory crusher. From the crusher, the ore is conveyed to the mill via a 4.5 kilometre long conveyor system. Block caving was chosen for the New Afton deposit because the underground infrastructure could be built below the historical open pit of the Afton Mine (a previous operation of Teck Resources) and this method is favorable to large-scale low-cost mining.The New Afton deposit is a copper-gold, alkalic porphyry system. Hypogene mineralization is characterized by discontinuous copper sulphide veinlets and disseminations, principally chalcopyrite and minor bornite, along with pyrite as the second most dominant sulphide. Gold particles vary in size from 5 µm to 40 µm and occur as native gold and electrum, associated mostly with the chalcopyrite grains and never with the pyrite. In some instances, a second alteration phase has resulted in the copper sulphides being replaced by tennantite-tetrahedrite locally and along faults that transect the mineralized body. The design head grade of arsenic is 244 PPM, although the presence of tennantite is inconsistent and can vary from trace levels to 15% of the total copper. No arsenopyrite is present in the hypogene ores. Supergene mineralization, consisting of native copper with accessory chalcocite occurs in minor amounts along faults and highly oxidized near-surface portions of the deposit."

Jan 1, 2016

By David W. H. Ellis

This presentation will discuss over 2 dozen past, present and future oils sands projects in Alberta. The very early projects as well as the most recent along with the ones that never got off the ground and the ones in production are all included. For each, the following will be given (where known): owners, location, type (mining/SAGD/refinery), production, capital budget, spent to date, status. Some overall impacts will be discussed.

May 1, 2004

By Y. Guglielmi, C. Gout, P. Henry, P. Dick, C. Nussbaum

For a decade, observations and experiments conducted in underground environments worldwide (mines, underground research laboratories - URL) made it possible to bridge the scale gap between laboratory scale and large scale faults. Indeed, underground rock laboratories allow developing decameter scale relatively well constrained experiments at the smallest distance from the hypocenters. URL’s experiments allowed developing new monitoring technologies coupling pressure-strain-seismic measurements and reproducing complete earthquakes sequences analogous to natural ones. They also allowed exploring past movements of faults and sometimes also paleofluids in three dimensions and characterizing different fault architectures and hydromechanical properties in unaltered conditions. This is particularly important in the study of faults affecting clay formations which could not be observed at the Earth’s surface because of the high alteration. Here we show how examples from the Mont Terri (Switzerland) and Tournemire (France) The URLs may help in (i) defining the concepts of fault architecture in shales, (ii) estimating fault hydromechanical properties from field decameter scale experiments. Some key results are that faults which are critically stressed or at the rupture limit can reactivate for stresses variations within the range of those produced by shallow underground excavations, and that slight micrometer-to-millimeter scale reactivations may lead to large factor-of-10-to-1000 permeability increases. Such promising results show that URL’s experiments may bring new insights on some key processes that control the relations between fault stability and permeability evolutions in very permeable layers.

Jan 1, 2015

By A. R. Miller, R. A. Stanton, M. J. Male, G. R. Cluff

"The Dubawnt Group consists of continental sedimentary and volcanic rocks which fill structural depressions - Baker Lake Basin, Yathkyed Lake and Angikuni Lake subbasins- whose evolution was controlled by late Aphebian extension, between 1.9-1.8 Ga. Structurally controlled uranium mineralization having the signature U + Mo + Ag + Pb + Cu ± Zn is spatially related to (i) intersecting fault systems that record multiple movements, (ii) chemically reactive lithologies containing sulphide, chlorite or graphite/ carbonaceous matter in the Archean and Aphebian basement complex and as alkaline volcanics of the overlying Dubawnt Group and (iii) areas containing thick successions of basal Dubawnt Group red clastic sediments.The most significant uranium occurrence found to date is the Lac Cinquante deposit, which contains 14 million pounds U3O8 of drill-indicated reserves. Mineralization is hosted in Archean meta-volcanic and metasedimentary rocks of the Henik Group adjacent to the basal Dubawnt unconformity in the northeastern A ngikuni Lake subbasin and occurs as plunging pods in and peripheral to a fractured and brecciated tuffaceous meta-sediment- sulphide+ carbonaceous exhalite. This deposit exhibits many features typified by the classical vein deposit at Beaverlodge, northern Saskatchewan.Epigenetic stratabound U + Cu + Ag ± Mo mineralization, typified by the 74-1E prospect in the eastern Baker Lake Basin, is hosted in thermally altered Kazan redbeds adjacent to alkaline dykes.At the eastern end of the Baker Lake Basin, small prospects having an elemental signature U + Se + Cu + Ag +Au are interpreted as unconformity-related mineralization associated with the Helikian The/on Basin.The Dubawnt Group rocks of the Baker Lake Basin, subbasins and adjacent basement complex contain uranium mineralization of two eras- Late Aphebian and Helikian."

Jan 1, 1986

By W. Dingley, G. R. Hoey

"Thirteen Canadian sulphide ore mines were surveyed for corrosion control. The mines visited were a small, yet representative, proportion of this segment of the Canadian mining and metallurgical industry. Information on metallic corrosion and methods used to control it in underground workings and mills was gathered (a) by discussing corrosion problems with company personnel, (b) by examining equipment and structures during under-ground and mill tours, (c) by photographing corrosion sites, and (d) by collecting and analyzing mine water samples.The corrosion survey, which is summarized in the re-port, leads to the following general conclusions. Mine environments are corrosive, particularly when the mine w1a-ter is acidic. Because of a lack of good corrosion control measures, excessive deterioration of equipment due to corrosion occurs in mines. Mill environments are also corrosive, but in some cases good preventive measures are being taken to effectively control corrosion losses.Ways to reduce corrosion losses in sulphide ore mines and mills are discussed. The main areas for more corrosion research and development are selection of materials of construction, protective coatings, cathodic protection, inhibitors, equipment design, and mining and milling practices."

Jan 1, 1971

By S. B. V. Stewart, W. W. Forsyth

"Since the Mathew's method for open stope design was first proposed by Golder Associates in 1980 it has been applied at a number of mine sites in Canada. The initial hypothesis was based on a relatively small amount of data and the intervening period has allowed the collection of a significant amount of new data to test the validity of the method.This paper examines a brief history of the evolution of rock mass classification systems to provide background and emphasize their empirical and non-rigorous approach. It also presents the new data which appear to indicate that the initial hypothesis was reasonably good. The modification to the original graph proposed by Potvin is discussed as well as the applicability of the method to predicting the onset of caving. The original graph has been updated and has been subdivided into four zones described as ""stable""; ""potentially unstable""; ""potential major failure""; and ""potential caving"". The method is recommended as a useful open stoping design tool provided it is recognized that it is not a rigorous design method.Finally the paper proposes a recommended approach for application of the method by would-be users and addresses some typical pitfalls that may be encountered."

Jan 1, 1995

By W. E. Roscoe

The probability of making an exploration discovery in Canada can be calculated from Derry's (1970) data on exploration expenditures and number of discoveries over the last nineteen years. Considering an average exploration "try" to be $30,000, the probability of a discovery with one try has decreased tenfold from about 0.01 in 1951 to 0.001 in 1969. A plot of these probabilities can be extrapolated to the future, giving a 1969-71 three-year average probability of 0.00096 with 90 per cent confidence limits of 0.00042 and 0.00153. Using this probability, various calculations can be made, such as (1) the probability of making at least one discovery for any given exploration expenditure, (2) the probability of ultimate ruin or survival of the exploration investment process and (3) the expected value of an exploration investment. There is a critical minimum amount per discovery that must be re-invested in exploration, no matter how large the original investment is, for exploration to survive at all in the long run. Currently, this critical minimum is $31,200,000 with 90 per cent confidence limits of $19,600,000 and $71,400,000.

Jan 1, 1971