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By V. A. G. Preto, W. H. White, J. E. Harakal

Potassium-argon age dating performed recently on intrusive rocks from Copper Mountain indicates that the satellite Smelter Lakes and Voigt stocks have radio-metric ages which are indistinguishable from that of the Copper Mountain stock, as determined by Sinclair and White (1967). The complex of intrusive rocks known as the Lost Horse Intrusions also yields essentially the same radiometric age, as do biotite-sulphide-pegmatite veins on Copper Mountain.

Jan 1, 1971

By A. Scheltema Beduin, H. Oterdoom, A. Haaks, C. Kempe, A. Liedtke

"For the Kazchrome DC Ferrochrome plant, SMS-group specifically designed an electrode column that would minimize downtime. Special features include the possibility for on load electrode jointing, on load slipping, and back-slipping. Electrode consumption is strongly related to furnace load and impedance, and is very low at high loads, which makes the graphite electrode an alternative to consider even in AC applications. The electrode could also be applied in other DC applications, as for example TiO2 slag, the novel Conroast process, or (twin) DC FeNi furnaces, and could possibly be installed during bigger shut downs. This paper will describe some of the design considerations and operational performance data on this novel column in the FeCr industry that could also be of interest for the FeNi or PGM industry if these would continue to develop towards DC technology.INTRODUCTION Every DC furnace has a cathode and an anode. The anode applied is commonly known as the Concast design, though the original design was by ABB who handed it over to Concast, subsidiary of the SMS-group. Some well-known DC furnaces outside the steel industry where the Concast bottom has been installed are listed in Table 1 as well as a few other key design features.Sidewall cooling and some other data have been left out for reasons of space, and being a lesser relevant design feature to this paper. HES stands for Hollow Electrode System, in which feed is charged through an electrode. Table 1 is built up chronologically according to first start-up date. Below comments are given to briefly explain some of the columns in Table 1: •,“Arm” in the “Cathode” column means that the design of the cathode holding and regulating mechanism consists of an electrode arm as depicted in Figure 1. •,Charging is relevant as some operations started with HES charging, whereas recently most new operations have started without HES but only charging chutes, of which at least some are close to the electrode and possibly others installed closer to the sidewall. •,“Dome” in the “Roof” column means that the design of the roof involves a center piece that can be exchanged if worn. •,The optimal roof design still seems to be a topic of debate, where no design is without problems."

Jan 1, 2017

By J. B. Mitchell

Many of the pre-production and plant startup problems that we regard as inevitable are actually caused by poor organizational methods. Traditional methods of organization can be modified to provide clear definitions of responsibility, continuity and depth of involvement of key personnel in order to overcome these problems.

Jan 1, 1966

By J. W. Craig

THERE are, broadly speaking, three classes of refractories: acid, basic, and neutral. Fireclay, diaspore, silica, and the sillimanite group of minerals are included in the acid class, which for the most part are not very resistant to basic slags. The neutra! class includes chrome, graphite, and silicon carbide, while most important in the basic class are magnesite and dolomite. Although chrome is a neutral refractory, it has no sharp distinction from magnesitic refractoriness. The two are mineralogically (1) and chemically related, and there is available on the market a complete range of brick from straight chrome to straight magnesite. In many indus trial applications, one. type may be replaced by another. The present paper is confined entirely to such refractories. The following types of basic and neutra! brick, each sold under sorne special trade name, are available for use in Canada: (1) Burned chrome from crude ores (2) Burned chrome from treated ores (3) Chemically bonded (unburned) chrome-magnesite ( 4) Burned chrome-magnesite (5) Chemically bonded ( unburned) magnesite-chrome (6) Chemically bonded (unburned) high-iron magnesite (7) Burned high-iron magnesite (Regular) (8) Burned low-iron magnesite (9) Burned olivine-magnesite (10) Burned magnesitic dolomite-chrome (Magnecon) (11) Chemically bonded magnesitic dolomite-chrome (Magmecom) (12) Dolomitic brick

Jan 1, 1936

By Robert B. Parsons

"A t last the legal red tape which has tied up flow-through share financing has been cut. New rules effective for deals signed after 1986 simplify flow-through financing by removing the necessity f or cumbersome agency relationships. But there is no free lunch-the new rules require increased government reporting. And beware federal tax reform promises to have a good look at the new flow-through share rules. IntroductionFlow-through shares have always worked better in theory then reality as an effective financing tool. The concept is straightforward: a transfer of risks, tax deductions, and potential returns. But the mechanics of the old flow-through rules made the transfer of risk impractical to impossible by placing the responsibility for incurring Canadian exploration expense (CEE) on investors. The new rules are significantly more realistic, shifting that responsibility to the issuing corporation. However, every silver lining must have a few clouds around it. In the case of the new flow-through rules, the more obvious negatives are increased reporting requirements and reductions in CEE eligible for flow-through by amounts of assistance received. The new rules are effective for deals signed after 1986, however, so a few old-style deals are still around. Practical Difficulties with Old RulesThe old rules which applied to investments in flow-through shares were structured so as to make it the responsibility of the investor, rather than the issuing corporation, to perform the Canadian exploration expense for flow-through. Since most investors had neither the expertise nor the inclination to incur the CEE, this requirement necessitated the use of cumbersome arrangements whereby the investors would appoint an agent (usually the issuing corporation) to incur CEE on their behalf. Although the issuing corporation might consequently be the party which actually spends the flow-through share funds on CEE, the awkward legal structure of such an arrangement made the investor the ""principal"" incurring the CEE. As such, the requirements of the old rules were met and the investors could receive their flow-through share s."

Jan 1, 1987

By J. Bouchard, A. Desbiens, M. Maldonado, R. del Villar

ABSTRACT: Despite many years of practical applications in mineral processing plants, the potential of column flotation has still not been fully exploited. The challenge in measuring some key variables is certainly an important contributing factor to this situation. Reliable online measurement of varibles, such as the froth depth, bias, gas hold-up, frother concentration, bubble surface area flux, and bubble size distribution, provides opportunities for the application of various advanced control strategies and real-time optimization based on an economic criterion. For several years, Université Laval’sLaboratoire d’observation et d’optimisation des procédés researchers have been working on these opportunities. This paper describes the most recent advances and current research trends.

Jan 1, 2011

By K. C. Sole, G. Robinson, M. S. Moats, W. G. Davenport, S. Sandoval

Global practice in hydrometallurgical production of copper cathode by electrowinning is reviewed, based on individual plant operating data for 2018. Data from 29 plants were collected, representing 38% of world cathode copper production. Similar surveys were carried out in 1997, 1999, 2003, 2007, and 2013. This survey includes analysis of historical and current data. Evolving trends in operating conditions and performance, as well as equipment design and process technology choices, are analysed and differences in operating practices with location are assessed. Examples of recent technology and operational choices to increase productivity, improve copper quality, and decrease electrical energy consumption are discussed. Significant project expansions, particularly in Africa, and the consolidation of numerous small Chinese operations are also presented. INTRODUCTION Global trends and operating practices in copper electrowinning (EW) in 2018 are reviewed and evaluated. Similar world and African surveys were carried out in 1997, 1999, 2001, 2002, 2003, 2007, and 2013 (Robinson, Davenport, & Jenkins, 1997; Jenkins, Davenport, Kennedy, & Robinson, 1999; Davenport, Jenkins, Robinson, & Karcas, 2001; Robinson, Garbutt, & Davenport, 2002; Robinson, Davenport, Jenkins, King, & Rasmussen, 2003; Robinson, Davenport, Moats, Karcas, & Demetrio, 2007; Robinson, Sole, Sandoval, Moats, Siegmund, & Davenport, 2013). Contributing operations included sites from the USA and Mexico (9), Chile and Peru (6), Laos (1), Kazakhstan (1), and Africa (9). Despite fewer contributions compared with past experience, this survey nevertheless represents 2018 copper EW cathode production of 1.76 Mt, or about 38% of world production of 4.64 Mt (International Copper Study Group, 2017). This drop in permission to contribute is attributed to the more competitive nature of the industry and unprecedented production pressures; furthermore, several operations in Australia have shut down, while large operations that are currently commissioning or ramping up to full production in Africa and Asia declined to participate. Of the Chinese operations, which represent an increasingly important proportion of global electrowon cathode copper, particularly in Africa, only Tenke Fungurume (Democratic Republic of Congo; DRC) participated in this survey.

Jan 1, 2019

By Gui Hua Wang, Xin Chang, Zhong Ying Han, Yuan Fang Cheng

"According to the geometrical characteristics of triangular meshes, Triangular Mesh Split Model (TMSM) based on a finite element method is proposed to simulate cracks propagation of fractured rock. With TMSM, stress intensity factors at the tip of cracks are obtained by far-field contour integral. Meanwhile, vector cross multiplication is adopted to fix the cracking unit, and maximum circumferential stress criterion is used to determine the crack propagation angle. Then crack dynamic propagation simulation is realized through local mesh split or node movement at crack tip. With this method, the crack can split apart a unit or extend along the mesh boundary, so the crack could extend along an arbitrary path and is not restricted by the initial mesh. The applicability of the mesh split algorithm is verified by the crack propagation examples of wing crack and multi-fractured rock mass with holes. The results show that this method not only has higher accuracy of fracture parameters calculation, but also can accurately simulate the crack initiation and propagation of rock under complex stress state such as tension, compression and shear. In addition, the far contour integral is introduced to determine the crack tip stress intensity factor and there is no need to reconstruct a singular element at the crack tip or to intensify the meshes. Compared with the existing mesh reconstruction algorithm, this method significantly improves the computational efficiency.INTRODUCTIONGenerally, rock is neither the full continuum, nor entirely discrete body, but rich in geological defects, such as joints and cracks. A large amount of geotechnical engineering practice shows that most fracture of rock is closely related to the internal joints, cracks and crack expansion (Horii et al., 1985; Wong et al., 1998). Although the classical theory of fracture mechanics established the theoretical foundation of crack initiation, propagation, so far it is still extremely difficult to characterize the propagation of airfoil-typed crack and the interference problem of multiple cracks. Up to now, the micromechanics mechanism research of crack propagation of fractured rocks has still been a hot research topic of rock fracture mechanics."

Jan 1, 2015

By P. Lausch, Z. X. He, J. F. Archibald

"Documented underground fill failures have resulted because of the lack of adequate knowledge concerning fill strength and other physical parameters, as well as to a lack of consistent quality of fill materials being used by operators. On the basis of literature review and correspondence with backfill operators at 18 mines throughout the province of Ontario, non-systematic quality control procedures have been shown to exist, both within different levels of single operations and between separate mining operations, which act to provide inferior engineered fill materials and erratic application response in situ.Assessment of existing procedures set by mine operators for determining backfill physical parameters, and recommendation of optimum fill material testing and manufacturing guidelines are presented in this paper.A series of standard fill characterization test procedures are recommended to provide substantial, though not comprehensive, fill behaviour review. The purpose of these recommendations is to propose industry standards for backfill quality review. Data acquired could be utilized for fill design functions and as a means of comparing fill quality parameters between sites in a regular and more systematic fashion than is presently done."

Jan 1, 1993

By W. W. Cummings

The Mineral King Mine, owned and operated by Sheep Creek Mines is located in the Purcell mountain range of southeastern British Columbia. Production of lead and zinc concentrates commenced in 1954 some 60 years after the initial discovery. Low cost mining methods have been employed to extract 16,0C'O tons of ore monthly from large ore bodies formed by replacement in limestone. Extensive areas in the limestone are yet to be explored and success in the search for new ore bodies is anticipated.

Jan 1, 1960

By M. M. Holgate

"Porosity neutron deflection scales can be derived more easily by cumulative correlation than by the conventional method of plotting corresponding points on a graph. The micro-log can be used as a porosity datum for the neutron log by transforming the permeability cut-off it shows to a porosity cut-off by a permeability-porosity function obtained from core analysis. Porosity footage values calculated in this manner from the neutron log are within 20 per cent of core analysis values."

Jan 1, 1960

By A. M. McKim, J. S. Ambler

"The iron ore of the Scully Mine is upgraded from 36 per cent Fe to 66 per cent Fe through single-stage crushing, wet autogenous milling, sizing by vibrating screens and two-stage spiral separation, followed by a process in which the concentrate is dried and then further improved by high-tension separators. The capacity of the concentrator is 17,000 long tons of concentrate per day. Discussion of the operation will recognize the special problems encountered in handling preponderantly fine ore, relate issues of interest regarding wear and review mechanical innovations found to be advantageous at Wabush. The modern trend toward big equipment, thoroughly instrumented, has been the theme of design. Effects on availability must be a consideration in this choice, and sectionalizing of circuits to minimize these consequences is as important as streamlined maintenance."

Jan 1, 1969

By Yujing Jiang, Xuezhen Wu, Bo Li, Tomomi Iura, Gang Wang

"Yielding bolt has been widely used for rock reinforcement in mining and civil engineering in high stress conditions. However, the interaction mechanism of yielding bolt and matrix mass is still not clear at present, and no analytical model is available to predict its reinforcement effect quantitatively. In this paper, the mainstream yielding rock bolts were reviewed firstly. After that, a coupling model is proposed to account for the interaction between yielding bolt and matrix mass. Based on the plane strain axial symmetry assumption and the incremental theory of plasticity, equilibrium equations and compatibility equations of matrix mass, and also the response of yielding rock bolt are deduced theoretically. The proposed method was programmed in Visual Basic development environment, and a semi-analytical solution for the coupling model is achieved. The reinforcement mechanism of yielding bolt in conventional tunnelling is clearly demonstrated through an illustrative case study. The reinforcement effect of yielding bolt is estimated quantitatively, and the distribution of axial force along the bolt is presented. In addition, the validity of proposed method is verified by numerical simulations. INTRODUCTIONHigh stress in surrounding rock mass can cause serious stability problems such as massive squeezing in soft rock and rock burst in hard rock. It is observed that many conventional rock bolts failed when experiencing large displacement, which implies that they are too stiff to sustain large deformation and dynamic conditions (Stillborg, 1994; Hoek et al., 1995). Yielding bolt, which can also be called energy-absorbing bolt, has been widely used for rock reinforcement in mining and civil engineering for these conditions (Neugebauer, E., 2008). This paper focuses on the static reinforcement effects of the yielding bolts with analytical method and numerical simulations."

Jan 1, 2015

By W. G. Schultz

"Sylvite's potash mine, which produces 8,000 tons of ore per day, probably ranks as one of the most highly mechanized and automated mining operations in the world. Employing, on a normal 10-hour production shift, one supervisor and a crew of seven operators, Sylvite is able to mine at an average rate in excess of 600 tons per hour. The ore is produced by two Marietta miners weighing 258 tons, the largest and heaviest pieces of equipment ever taken underground. The ore produced by these two Marietta miners is conveyed to the shaft area, cycled through a 15,000-ton storage system and hoisted to surface completely automatically. The operation of all equipment in the mine can be monitored and controlled from a central control panel located underground. Because Sylvite's mine is a new operation with equipment of a new design, the full potential of the operation has not yet been realized. The ultimate capability is clearly evident from the success Sylvite has had over the past year as the average mining capability has risen from 100 tons per hour to 600 tons per hour."

Jan 1, 1973

By A. G. Lylie

Introduction At the Britannia Mining and Smelting Company's mill, the equivalent of 2,500 to 2,800 pounds of copper sulphate crystals per day is made from copper which is precipitated from the mine-water. This copper sulphate is used in the mill for the recovery of sphalerite by2 flotation. From 1932 until 1936 it was produced by exposing the precipitate to air for thirty days and then dissolving the oxidized copper with dilute sulphuric acid. In 1936, the flotation of sphalerite was discontinued and, when it was resumed in 1947, steps were taken to try to improve the former method. The present paper outlines the way in which this was done, and describes the plant and procedure by which copper sulphate is now being made, and by means of which an appreciable saving is being effected. Aboratory Tests The previous work had established that the precipitate, which consists mainly of metallic copper, must be oxidized before the copper would dissolve in dilute sulphuric acid. Various methods for oxidizing it were tried but in the early laboratory work the only suitable one found was to heat the precipitate to 600°C. and hold it at this temperature for two hours. When this was done, approximately 90 per cent of the copper became soluble in .acid. This percentage was considered satisfactory for practical purposes, but the cost of roasting was prohibitive because only a small amount of roasted precipitate was required each day.

Jan 1, 1951

By Mike Fontaine

The success of a project is defined by meeting the financial performance objectives of the business case within a stipulated timeframe. Early in design, little information is normally available; the uncertainty introduces risk to the project outcome. Using a range of risk management tools and techniques, a project can be developed from front end loading phases 1 through 3 (FEL1–FEL3), and project implementation (FEL4) and then into operations with an optimized probability of success. For every project element, the risk management framework embodies: establishing a context; assessing risk (identify, analyze, and evaluate); and treating risk. Embedded within design activities, this process mitigates or eliminates risks. Monitoring and control, as well as extensive communication and consultation with stakeholders, is integral to the risk management process.

Jan 1, 2015

By Yin Guangzhi, Song Zhenlong, Li Minghui, Li Wenpu, Deng Bozhi

"Darcy's law is widely used to describe the oil and gas flow characteristics in the multi-pore media reservoir. However, the low-velocity non-Darcy flow of oil and gas occurs in the multi-pore media reservoir under low permeability conditions. Meanwhile, the high-velocity non-Darcy flow of oil and gas occurs in the multi-pore media near the wellbore. The gas flow velocities in coal in different deformation stage under different gas pressure gradient were tested and the relationships between gas flow velocity and gas pressure gradient were discussed, which can help us to investigate the transformation conditions of gas linear flow and gas nonlinear flow in coal. The results showed that the gas flow in the coal under low effective stress environment can be described by Darcy's law. The low-velocity non-Darcy flow of gas gradually occurred and the start-up pressure gradient increased in the coal as the effective stress increased. The low-velocity non-Darcy flow of gas also occurred in the coal at the yield deformation stage, however, the start-up pressure gradient decreased as the effective stress increased in this stage. In post-peak stage, the highvelocity non-Darcy flow of gas occurred in the coal under low effective stress environment. The gas flow in the coal gradually returned to be Darcy flow as the effective stress increased. The mechanism of the phenomenon is discussed based on the experimental results. The research results can be used to guide well test analysis and prediction of oil-gas production. INTRODUCTIONThe oil and gas flow in original multi-pore media reservoir are usually regarded as steady and linear processes and can be described by Darcy’s law. However, the low-velocity non-Darcy flow of oil and gas occurs in the multi-pore media reservoir under low permeability conditions. Meanwhile, the highvelocity non-Darcy flow of oil and gas occurs in the multi-pore media near the wellbore or workface. The gas flow in the multi-pore media even may be unsteady under some conditions such as gas emission and outburst.The phenomenon of underground water low-velocity flow in clays was deviated from Darcy’s law was found in the end of the nineteenth century (King, 1898). The deviation from Darcy’s law was later reported and investigated more (Swartzendruber, 1962; Miller and Low, 1963). These researches revealed that the start-up pressure gradient exists under low permeability conditions. Klinkenberg (1941) proposed that the permeability constant as determined with gases is dependent upon the property of the gas, and is a linear function of the reciprocal mean pressure. This effect can be explained by taking into account the phenomena of slip, which are related closely to the mean free paths of the gas molecules."

Jan 1, 2015

By F. Doxey

Introduction Numerous papers have been written dealing with the construction and functions of, and the environmental conditions created by, Diesel locomotives. Therefore, it is not my intention to attempt to deal with these phases of Diesel transportation other than to make reference to them in ?relation to and in connection with actual operation. The rapid expansion of industry during recent years and the necessity of products being made available at competitive prices in home and world markets has made the demand for cheaper coal a very serious factor for the coal industry. This condition has meant each coal producing country looking into ways and means whereby greater productivity and reduction in cost could he achieved. Surveys made show that, in addition to face mechanization, savings, in some cases substantial, can be made in transportation. Ventilation The most efficient mines are in-variably the well ventilated ones, for it is true that, where there is good ventilation, there are usually good roads. These combined factors are very essential where Diesel locomotives are used. Good roadways and track allow speed, and good ventilation dilutes rapidly any disagreeable exhaust gases. Locomotive Development In the older types of auxiliary rope haulage, coal hauled per haul-age hand is usually very low.

Jan 1, 1951

By C. P. Browning

Copper, as far as we know, was the first metal used by man, and due to the fact that it occurs in many places in the 'native' state, and also to the ease with which it may be shaped, it has played an important part in the evolution of civilization. Copper tools with inscriptions dating back to 6,000 B.C. are known in Egypt, where the metal probably got its start as a useful material in human hands. Just how far back the use of copper in Canada dates is difficult to say, but it was in use by the Indians in the Lake Superior country long before the arrival of the first white man. For many generations the Eskimos also have used copper derived fr0m deposits of the native metal found in the Coronation Gulf district. Due to the metal's many unique qualities, imperishable with age, ancient implements and utensils are apparently as good today as when they were made, having withstood the onslaught of time probably better than objects of any of the other base metals. Copper alloys so well with other metals that today it is second only to iron in its industrial value. Even at the beginning of the eighteenth century the world's production of copper was probably not more than seven thousand tons a year, with Great Britain producing three-fourths of this. One hundred years ago the mines of the United States, Chili, Mexico, Canada, South Africa, Australia, and Tasmania, which now produce about nine-tenths of the copper of the world, were totally undeveloped. Ln 1926 the world production of copper was approximately 1,658,000 tons, which was seventy thousand tons greater than in the preceding year; but growing demand absorbed the increased production, so that the stock of rough copper throughout the world is comparatively small. Of this huge tonnage of the metal, Canada produced four percent, two-thirds of it emanating from British Columbia, nearly one-third from the Province of Ontario, and the balance from Quebec.

Jan 1, 1927

By John J. Laffin

"Nova Scotia Department of Mines and Energy Throughout the history of Nova Scotia, trends in the production and use of its coal resources have resulted in major impacts on the economy and society of the province. Current trends in coal demand locally, nationally and internationally are having and will have an increasing positive effect on Nova Scotia over the next twenty years-in terms of energy supply, job creation and general economic development. Coal for electrical generation is an immediate and key objective of Nova Scotia's energy plan; and, in the long term, coal-derived fuels will meet the province's needs for transportation fuels. Demand for metallurgical coal is also expected to increase, especially if the merchant coke plant currently under investigation becomes a reality.Meeting these coal supply and utilization objectives in the face of increasing environmental, social and economic constraints poses a tremendous technical challenge. Work has begun on projects to expand coal production capacity and to adapt new technologies for coal preparation and utilization to the specific needs of Nova Scotia; much more work will be required in the coming decade in order to succesfully tap this resource.IntroductionThe energy problem facing Atlantic Canada has a few unique features not found in the rest of the country. Canada, as a whole, has access to a diverse mix of energy resources, including crude oil, natural gas, coal, hydro and uranium, with the result that crude oil supplies only about 40 per cent of Canada's primary demand. In contrast, foreign crude oil dominates Atlantic Canada's energy mix, supplying over 70 per cent of the primary energy demand.This results in important differences in various sectors. Nationally, about 5 per cent of the electricity is generated from oil whereas last year in Nova Scotia approximately 40 per cent of the electricity generated was from imported oil. Residential, commercial and industrial space heating, and industrial process heating in Atlantic Canada was almost 100 percent dependent on foreign oil. This is in sharp contrast to the situation in central and western Canada, which have access to secure domestic natural gas, oil and hydro electricity."

Jan 1, 1982