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"In an environment of rising energy prices and mining at greater depths, cost-efficient loading and hauling equipment is essential. Conducted at an underground mining operation, this study analyzes the energy consumption and gas emissions of diesel and electric load-haul-dump machines (LHDs) with similar bucket capacities. Based on energy prices from the first quarter of 2014, results of discrete event simulation show that energy costs for diesel and electric LHDs are US$0.24/t and US$0.07/t, respectively. Also, diesel LHDs emit 2.68 kg CO2 per litre of diesel fuel, whereas using electric machines reduces the need for ventilation to mitigate engine heat and emissions and reduces energy costs.RÉSUMÉ Dans un contexte de croissance des prix de l’énergie et d’exploitation minière à des profondeurs de plus en plus grandes, il est essentiel d’avoir des équipements de chargement et de transport les plus rentables possible. La présente étude, effectuée dans une mine souterraine, analyse la consommation énergétique et les émissions de gaz de chargeuses-navettes (LHD) au diésel et à l’électricité ayant des capacités de godet similaires. En se basant sur les prix courants de l’énergie, les résultats d’une simulation d’événements discrets montrent que les coûts énergétiques pour les LHD au diésel et à l’électricité sont respectivement de 0,24 $US/t et de 0,07 $US/t. De plus, les LHD au diésel émettent 2,68 kg CO2 par litre de combustible diésel alors que les machines utilisant l’électricité réduisent le besoin de ventilation pour atténuer la chaleur des moteurs et les émissions en plus de réduire les coûts énergétiques."

Jan 1, 2015

By Alfred W. G. Wilson

In this paper is presented a review of the changes that have taken place in certain Canadian non-metallic mineral industries since 1909. The fifteen-year period 1909 to 1923, inclusive, has been selected for two reasons. In the first place, statistical treatment of the subject under review has been nearly uniform throughout the period. In the second place, this decade and a half is itself further subdivisible into three well marked quinquennial periods, the middle one covering the period of the great war when industrial conditions were greatly disturbed. It then becomes possible to institute certain comparisons between equal periods before and after the war disturbances. The items selected for inclusion in this review are certain of the more important members of that class of minerals usually grouped together under the heading of non-metallics. They are all minerals of which Canada is known to possess important resources, and which are indispensable to many of our greatest manufacturing industries.

Jan 1, 1925

By S. Banisi, J. Marois, A. R. Laplante

"This paper compares the behaviour of gold and ore in the grinding circuit of Hemlo Gold Ltd. Particular attention is given to grinding kinetics, classification behaviour, and liberation. For grinding kinetics, laboratory grinding of gold flakes and silica, 840-1200 um in size (14/20 mesh), was also performed to provide a standard for comparison and to study in a controlled environment the mechanisms of breakage, folding, smearing and impacting.Grinding kinetics were characterized at laboratory scale with breakage and selection functions. The breakage function showed that 75% of gold disappearing from the 840-1200 um class reported to the 600-840 um; this figure is much higher than for silica ( 46%) or most other minerals, and implies that comparatively fewer fine fragments are produced from the breakage of gold flakes, on account of gold's malleability. The selection function of silica was four times that of gold. At plant scale, the ratio of the selection function of ore and gold increased from 6 for at 50-100 um to 20 at 500-1000 um.Observation of original flakes and their fragments with the scanning electron microscope showed that the main mechanism of ""grinding"" from the 840-1200 um to the 600-840 um class was folding rather than actual breakage. This was confirmed by a measure of individual flake weight. The postulated breakage cycle is that relatively globular flakes become increasingly serrated through grinding; they can then regain their original shape through folding and reflattening into cylindrical and spherical shapes, as the majority does; however, some fragments will at this point undergo actual breakage. Photographic evidence is presented to support the proposed mechanisms.Smearing of gold unto silica was observed when silica was ground after a gold, and embedding of silica into gold flakes when gold was ground after a silica. Both mechanisms occur whenever gold and harder minerals are jointly ground, and result in ""unliberation"" of gold. It is postulated that smearing of gold onto other minerals plays an important role in explaining how gravity recovery can increase overall gold metallurgy, especially when used ahead of flotation.Classification of gold in the primary hydrocyclones takes place at a much finer cut-size than ore, 20 vs. 57 um. This and the slower grinding kinetics result in high gold circulating loads in the primary loop, 6700%, and a gold content in the primary cyclone underflow (PCUF) is twenty four times that of the ore. The gold size distribution for primary cyclone overflow is much finer than that of the ore, although they are essentially similar in the PCUF.Liberation, or more accurately ""gravity recoverability"", was assessed with a 7.5 cm (3"") Knelson concentrator. It varied between the thirties for the primary mill discharge and two cyclone overflows, to highs of 89 to 92% for the PCUF and secondary mill discharge, 89 and 92%, respectfully."

Jan 1, 1991

By Steve Cole

"The economic and strategic importance of PGE bearing deposits is fuelling renewed exploration and development efforts in the precious metals mining sector.This paper presents a review of the various techniques used in the processing of PGE bearing ores, from primary benificiation to processing routes for the different flowsheets that have been developed amongst current producers. Recent innovations such as preconcentration of ore using gravity separation, recent trends in flotation circuit design and the development of hydrometallurgical routes for the direct treatment of flotation concentrates without the need for smelting will be discussed. Data from recent projects will be presented to illustrate common characteristics of PGE ores and concentrates.INTRODUCTIONThe six platinum-group elements (PGE): ruthenium, rhodium, palladium, osmium, iridium and platinum, together with gold and silver, are considered to be ""precious"" metals. The recent spike in platinum and palladium prices coupled with the projected increase in demand for the metals has fuelled a spate of exploration and new projects in the PGE sector. Historically primary producers of PGE metals have controlled the flow of information relating to the mining and processing of these ores into the public domain. Very little published information relating to individual operations and processes is available in comparison to the abundant literature relating to other metals.The purpose of this paper is to provide a general overview of the issues relating to the processing of PGE ores. Each topic discussed could easily be the topic of a paper or book and so in many cases only the surface of the topic will be scratched. An attempt has therefore been made to provide as many references as possible.This paper discusses the classification and location of PGE ores, the mineralogical factors that affect recovery of PGE's, methods currently used for recovering PGE's and process trends in PGE metallurgy."

Jan 1, 2002

By S. Mostaghel, S. Nicol, M. Y. Solar

Once upon a time, the process engineer developing the design criteria for a new saprolite ferronickel smelter had it easy: most ores were around 2.5% Ni, with a Fe/Ni ratio of 4 to 5 and a SiO2/MgO ratio of about 1.6; to use the French word: garnierites. The ferronickel grade selected was the conventional 20 to 25% Ni and the impurity levels could be predicted from well established [C], [Cr] and [Si] vs (FeO) graphs. However the process engineer can no longer depend on statistics to design smelters: Ni grades are decreasing while the goethite contents are increasing; SiO2/MgO ratios vary from 1 to 3; and Al2O3 concentrations are reaching levels that cannot be ignored. Mechanistic models must be developed to select or predict essential parameters such as kiln and furnace reductions, ferronickel grade, slag losses, metal and slag liquidus, operating temperatures, etc. But these models must be simplified so that they can be used on a routine basis; and they must be calibrated against a wide range of commercial operations in order to yield the most realistic predictions possible. The present paper proposes one possible approach, using FactSage as a basic source of thermodynamic data. The predictions thus obtained are compared to actual performance for two well documented operations, as well as to the predictions made with other tools that might be more accessible.

Jan 1, 2014

By James A. Finch, Stéphanie Somot

"The self-heating facility developed at the Noranda Technology Centre [Rosenblum and coworkers, 2001; 1995] has now been established in the Department of Mining, Metals and Materials Engineering at McGill University. A research program into mechanisms has been initiated (with support now from four industrial partners under Camiro). The first investigation is into the role of pyrrhotite (Po), the most commonly suspected mineral to trigger self-heating. Following a standard experimental protocol, self-heating was assessed on samples of Po mixed with sand as an inert material. With increasing Po content, self heating progressively increased but, interestingly, the samples visually appeared less and less oxidized. A high Po content, it was hypothesized, may give a more reducing environment favouring formation of H2S. The presence of this gas could be significant as it has a high exothermic heat of reaction with oxygen. The system was modified to test the hypothesis by including copper pieces and copper sulphate to react with (and therefore reveal) the gas as copper sulphide. Evidence is presented in support of H2S production, which to our knowledge has not been shown before and introduces a potentially important avenue of investigation into self-heating mechanisms.INTRODUCTIONSelf-heating of sulphide minerals poses potential environmental and safety hazards in mining of ores, and storage and transport of concentrates. While some conditions are known to be critical, the reactions remain poorly understood making self-heating difficult to predict and control.A major advance in measurement was introduced by Rosenblum and co-workers [Rosenblum et al., 2001; Rosenblum and Spira 1995]. A self-heating assessment method was developed and applied to various sulphide-bearing materials The method is based upon automated calorimetric cells with data acquisition, now available to McGill researchers and which have been used for the study reported here."

Jan 1, 2006

By L. Shasko

Deliberative mapping is a method of public engagement designed to bring citizens and specialists together to inform policy decisions in conflict-laden areas of science and technology (Stirling and Davies 2004a). Citizens and specialists participate in the process both separately and together. A deliberative mapping study was held in Regina, Saskatchewan in October and November of 2019. Participants in the study assessed options for reducing greenhouse gas emissions in small, remote or off-grid communities, including assessing the role of small modular nuclear reactors (SMRs) in climate change mitigation. Deliberative mapping is designed to facilitate direct, two-way conversations between citizens and specialists through both formal and informal discussions. The relationship building component of this process may increase trust. Public consultation processes that lack two-way dialogue or are seen as obligatory rather than meaningful can worsen public opposition or lead to negative public perceptions. Public education alone is not enough to change public opinion. Providing people with more information on topics they already hold opinions on can work to reaffirm previously held biases, but building relationships can provide new pathways to overcome divisions and turn close-mindedness into open-mindedness.

Jan 1, 2020

By S. Rivard

"This paper demonstrates the selection of grinding circuit technology for a number of recent projects including discussion of the key drivers and the role of energy efficiency. Decreasing head grades combined with a strong and sustained increase in operating costs has forced miners to examine increased project size, increased equipment capacity and efficiency improvements in order to reduce their unit operating costs and improve overall project economics. Comminution energy consumption, safety and capital cost considerations play a critical role in the success of projects. This paper presents some key guidelines for a successful and cost effective comminution circuit design and includes a case study on three projects, outlining the issues and the drivers which led to the ultimate circuit selection and the critical role that energy efficiency played.IntroductionComminution circuits for minerals processing are selected based on their suitability and efficiency in reducing run-of-mine ore to the desired feed size for the downstream process. The input material (ore) properties and downstream process requirements are the key determinants and there are standard approaches for each circumstance.The minerals processing industry has been a fast adaptor of efficiency improvements based on increasing capacity of equipment (e.g. trucks, crushers, mills, pumps) but less successful in adapting radically new technologies that disrupt incumbent flowsheets or processes.The installed power of grinding mills has increased linearly over the past 25 years (Meka & Lane, 2010) and pumps and classification equipment have kept pace. The autogenous grinding (AG) and semi- autogenous grinding (SAG) mills displaced stage crushing as a dominant method of coarse rock breakage in many applications causing crusher manufactures to increase the capacity of cone crushers to meet the competitive demand.Examples of new comminution technology in the 20th and 21st centuries are the development and adoption of cyclone classification in the 1940s (Newtech, 2016), AG milling in the late 1950s, vertical grinding mills in the 1980s, high pressure grinding rolls (HPGRs) also in the 1980s and ultrafine milling technology in the 1990s (Meka & Lane, 2010)."

Jan 1, 2017

By M. F. Almeida

"Due to the randomness of all factors influencing the sintering operation, a two-stepped procedure is proposed to find the best way of using stocked fines at a plant producing Fe-Mn alloys for the steelmaking industry. The approach is based on the following: (1) predict the result of the sintering operation by establishing the best multilinear regression model using some of the characteristics of the loaded material; and (2) find the best solution under a minimizing cost criteria by solving a linear optimization problem using the regression equation plus constraints on the feed and product. IntroductionSome tests carried out using 20% to 30% of sinter in the material loaded into a 60 000 KVA Tysland-Hole electric furnace producing Fe-Mn alloys for the steelmaking industry indicated: (1) a meaningful decrease in the off-gas temperature and, consequently, a better energy use due to the material higher porosity; (2) more uniform heat distribution as a consequence of the electrode reaction zone enlargement; (3) an improved furnace control resulting in a smoother operation; and (4) a decrease in gas production facilitating the off-gas treatment. For some years, this plant used only the coarse fraction of the Mn ores, thus stocking all the received and own-generated fine particles. In view of the mentioned results, a strategy for increasing the use of stocked fines was formulated, including a step where it was necessary to decide which components and respective quantities should be used in the blends to be sintered (Almeida, 1984).It is well known that several factors affect productivity and energy consumption in sinter production, also influencing the product quality. Raw materials characteristics, namely chemical and size composition, affect permeability to gases and may or may not allow a deeper bed. In general, finer ores decrease permeability, increasing electricity consumption by fans, but due to their higher specific surface area, react more completely with other components in the mixture. For coke granulometry, a compromise must be obtained in order not to burn it too quickly nor to widen the flame front, therefore decreasing productivity. Decreasing coke in the blend also acts in sinter bonding, decreasing its consistency and increasing crushing and return fines. Moisture addition also influences components mixing, pre-agglomeration, bed permeability and, consequently, sintering productivity. Therefore, optimum conditions must be established for both a given sintering plant and the components in the feed (Dawson, 1993)."

Jan 1, 1998

By Nick Hazen

Many successful actions are required to bring a profitable extractive metallurgical operation into production. Competent process development performed within the project development schedule increases the chances of obtaining project financing and decreases the risk of engineering design errors being built into the commercial plant. The general sequence of steps in process development is well known: technology review, desktop studies, scoping studies, prefeasibility, and so on, with an increasing requirement for experimental evidence as the studies advance. This paper suggests principles for guiding process development work so that the efforts stay on track toward a smooth startup and a profitable commercial operation. It emphasizes closely aligning the research with the corporate goals of the mining company management, understanding the mineralogy and variability in the deposit, and guiding by flowsheet and material balance. Examples of hydrometallurgical process development leading to the early use of solvent extraction in the mining industry are given.

Jan 1, 2014

By Colleagues from Process and Operation departments, Guy Chevalier

"QCM's pellet plant, located in Port-Cartier, Quebec, produces up to 8.6 million tons of iron ore pellets annually. Four different types are produced: three for blast furnace operations and one for direct reduction furnaces. The paper presents the scientific approach that led to the installation of new process equipment to improve the reducibility of direct reduction pellets (DR pellet). The findings, the equipment selection and some post start-up modifications are presented.This low silica DR pellet is used in Midrex and HyL shaft furnaces. A good DR pellet has to meet strict chemical, physical and metallurgical specifications. An important metallurgical property is its ability to release oxygen when exposed to reducing gases. Considering that the market for DR pellets is expanding and being aware that reducibility is critical for our clients, a program to improve the latter was undertaken. Test work showed that one factor which has a negative effect on reducibility is the proportion of particles larger than 75 microns. Knowing that the best way to reduce the amount of coarse particles was to close our open grinding circuits, we began evaluating the most suitable classification equipment applicable to our process operations. We settled on hydro-classifiers based on their very sharp cut and their low operating costs. In light of the hydro-classifiers performance it was also decided to replace the hydro-cyclones of an already closed circuit.INTRODUCTIONAt the Québec Cartier Mining pellet plant, continuous improvement programs are aimed at increasing levels of consistency and improved chemical, physical and metallurgical properties. This is being accomplished while still maintaining pellet plant production volumes to satisfy market demands.QCM produces three types of pellets for blast furnace use: acid pellets, designated as ""BHF"", fluxed pellets, designated as ""BAF"", and low silica fluxed pellets, designated as ""BSA"". For direct reduction, a low silica acid pellet or DR pellet, designated as ""BBS"" is produced. This low silica DR pellet is used in Midrex and HyL shaft furnaces.The demand for DR pellets has been increasing during the last few years and is believed to continue so in the future. Wanting to be present in this growing market QCM found that it would be essential to work at improving its DR pellets quality. Efforts have been focused on improvements in three areas: SiO2 reduction, elimination of sticking and increasing reducibility. Improvement programs have begun with laboratory research followed by plant trials and full-scale implementation as a cooperative effort among QCM, COREM, and key customers."

Jan 1, 2002

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

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

Jan 1, 1992

By L. Drisdelle, S. Gendron

"Survival in today's business climate requires participation of all employees in a Total Quality Management Program encompassing everything - ""safety, quality of products, quality ofet1ch and every job done, and of course production "". We all know what needs to be accomplished, but struggle with how to do it, especially in an industry which has not always experienced management/union cooperation, and mistrust is still present.This paper describes a process to improve team work and employee involvement in Inco's nickel carbonyl refinery at Copper Cliff The process involves facilitatorship training for all employees, and a system for reinforcing and accomplishing the required behavioural change. The system is described in detail and a number of examples are presented. At the refinery, the staff is starting to understand as Max DePree recently wrote ""Without Quality Behaviour, you cannot have Quality Product"". IntroductionThe Copper Cliff Nickel Refinery (CCNR) is Inco's largest and most modern nickel refinery, which celebrated its twentieth year of successful operation in April 1993.The heart of the refinery is the Inco pressure carbonyl (IPq plant which produces high purity nickel pellets and specialty powders by refining an approximate 80% nickel granule feed. The carbonyl plant is a modem chemical plant with very special and demanding requirements for safety and environmental protection due to the toxic nature of the refining gas.Since 1987, there has been an emphasis at CCNR on a comprehensive Total Quality Improvement (TQI) Program which was designed based on recognizing customers' needs for improved systems for quality management. This program is customer oriented and comprises such elements as team organizational concepts, customer audits, process assessment and internal quality auditing.A detailed review of progress was made in early 1991 and it became apparent that the ""ownership"" of the TQI program was not broad based. In fact, the program was very much a staff driven effort and fell far short of total employee involvement and relentless continuous improvement that are now considered essential to remain competitive and stay in business.Inco staff has now come to regard that early phase of our TQI program as ""the technical aspects of total quality improvement"".The safety experience was also puzzling. Even though the safety statistics were good with an average lost time frequency of 1.6 for the last five years, the perfonnance improvement had plateaued and remained pretty much the same. Clearly a new approach was required if significant progress and continuous improvement was to be made."

Jan 1, 1994

By James F. Archibald, H. Jame Hackwood

"Research was performed to assess the feasibility of barrier membrane substances, for use within mining or associated high risk environments, in restricting the diffusion transport of radon gas. Specific tests were conducted, both within laboratory and in situ environments, to determine radon gas concentration ratios across a barrier of interest and emanation rate variation resulting from application of such materials. Several materials have been demonstrated to be effective in restricting the emanation of radon gas into initially radon-free environments. One liquid material shows particularly good promise upon consideration of ideal radon barrier criteria.IntroductionIt has long been known (I.2.3) that inhalation of the short-lived, alpha particle-emitting daughters of radon gas can result in irradiation of lung tissue with the potential for causing lung cancer. Control measures are necessary to maintain concentrations of airborne contamination at a minimum to protect miner health and safety. Typical control practices in mines have been through the application of systematic ventilation and backfilling of excavated opening. As mines become deeper, however, and additional workings become exposed, increased ventilation capacity requirements are needed. As an alternative to other radiation control measures, the use of sealants to prevent radon migration from walls into mine atmospheres may provide a suitable engineering alternative."

Jan 1, 1987

By Sydney C. Mifflen

COAL MINING, with its some 15,000 employees, is directly responsible for the livelihood of one-fifth of the population of the Province of Nova Scotia and indirectly so for that of possibly another fifth. Deposits of coal are known and worked in four counties of the Province, from which is being produced yearly tonnages as noted below: Cumberland County 750,000 tons Piccou County 400,000 tons Inverness County 100,000 tons Cape Breton County 5,250,000 tons TOTAL FOR NOVA SCOTIA 6,500,000 tons Production in Cape Breton county is entirely from the one source, the Sydney coalfield, and not only is this field the most important in respect to output, as is disclosed above, but it is also the largest presently known deposit in the Province and holds the greatest tonnage yet in reserve for future mining. In the light of the above more or less generally known facts, it is trite to remark on the importance of the Sydney coalfield in the internal economy of the Province. On the other hand, not nearly as well-known nor as frankly recognized is its significance in the national life of Canada, for from this field is produced not only 80 per cent of the Nova Scotia coal but over 40 per cent of all coal mined in the Dominion. Another noteworthy comparison can be made from the fact that the Sydney field contributes 22 per cent of all the bituminous coal consumed in Canada, the remainder being made up of 7 per cent mined elsewhere in Nova Scotia, 27 per cent from other parts of Canada (British Columbia and Alberta, principally), while the remaining 44 per cent is imported, practically wholly, from the United States of America.

Jan 1, 1941

By B. K. Gorain

"The Air-Metabisulfite (AMBS) process has been developed to treat complex copper, molybdenum and precious metals (gold, silver) bearing ores using brackish and sea water. This process was able to produce significantly better copper concentrate grades and higher recovery than possible using conventional lime and/or cyanide based processes for certain complex ores with high sulphide gangue minerals. The AMBS technology in now used commercially following a rigorous evaluation process emanating from laboratory curiosity to plant applications. In addition, many projects have embraced this technology at a feasibility level involving various complex ore bodies.This paper presents a summary of the findings from testing the AMBS technology on various ores types. Experiences gained from this successful development from bench to piloting and then to plant applications are also presented in this paper.INTRODUCTIONProcessing of sulphide copper, molybdenum and precious metal ores typically involves flotation of copper bearing minerals while depressing non-sulphide and other non-copper sulphide minerals such as pyrite, pyrrhotite and sometimes arsenopyrite. Though in many precious metal ores, the values are in these sulphide minerals as well. The conventional method employed in the industry to produce a saleable copper concentrate requires depression of these non-copper sulphide minerals using an alkaline pH above 9.5, though 10.5 to 11.5 is more common. Alkalinity is controlled by the addition of a pH modifier. Lime is normally employed as a pH modifier due to its relatively low cost; however, the costs associated with adding lime can be significant and the effectiveness of lime as a depressant could be drastically reduced when the process water supplied to the flotation circuit contains high level of dissolved salts. In some cases, a small amount of cyanide is used along with lime to depress non-copper sulphide minerals especially when its proportion to copper sulphide minerals in the ore is higher than three."

Jan 1, 2016

By A. J. Monhemius

"The paper reviews the history of modern iron control processes in hydrometallurgy. Particular attention is paid to the processes developed in the 1960s by the electrolytic zinc industry for the removal of iron from zinc sulphate leach liquors - namely the Jarosite, Goethite and Hematite processes. Problems faced by the industry in the safe disposal of the iron residues produced by these processes are discussed. The lessons learnt over the past half century by the zinc industry are projected on to the current efforts to develop hydrometallurgical processes for the treatment of copper sulphide concentrates. It is argued that any attempt to create a “hydrometallurgical copper smelter” is doomed to ultimate failure, unless and until methods are developed that can recover iron from solution in a form that can be directly utilised by the steel or pigment industries.INTRODUCTIONYou suddenly realise that age is catching up with you and that technology is moving on apace when you are asked to talk about the history of a process or a technology that you’ve grown up with. Such was my reaction when, out of the blue, I received an email last year from the chairman of the CIM’s Historical Metallurgy Committee, asking me if I would give a talk on the early developments of iron control in hydrometallurgy. Once I’d got over the initial shock of realising that I had now become living history, I was of course flattered that the invitation was to give a talk at the prestigious IMPC, a conference series that has been going for as long as I have been in the business. That this particular IMPC was to include the 4th Symposium on Iron Control in Hydrometallurgy, made the invitation even more appealing and appropriate, because I was the co-chairman of the First Symposium on Iron Control, together with my old friend, John Dutrizac (known by many as Dr Jarosite), which was held 30 years ago in Toronto.first became involved with iron at the very start of my career in hydrometallurgy – the research topic for my Masters degree thesis at UBC, back in the mid 1960s, was “Reductive leaching of Goethite with SO2”. My thesis supervisor was the late Professor Ian Warren, who himself was a protégé of Professor Frank Forward, one of the founding fathers of modern hydrometallurgy. Little did I realise at that time, now 50 years ago, that the problem of iron and how to deal with it in hydrometallurgical processes would be a theme that followed me throughout much of my 40-year career in academia."

Jan 1, 2016

By D. S. Flett

"The current state-of-the-art of chloride hydrometallurgy for treatment of complex sulphide bulk concentrates is reviewed. General considerations regarding the various flowsheet steps are examined and options discussed. Then, individual flowsheets are presented and discussed. Finally, the forward prospects for chloride hydrometallurgy for treatment of complex sulphide bulk concentrates is considered and conclusions drawn concerning the likely application of this technology in the future. IntroductionHydrometallurgical processes for treating sulphide concentrates, in general, have received considerable attention over the last three decades or more. Many flowsheets have been developed, many pilot-plant studies have been undertaken and several processes are now successfully operating. For example, direct ammoniacal pressure leaching has been used by Sherritt Gordon Mines since the 1950s to extract nickel from pentlandite concentrates, the roast-leach-electrowin route is widely used to recover zinc from sphalerite concentrates and direct sulphuric acid pressure leaching of sphalerite concentrates has been successfully commercialized. Also, Duval Corporation operated a direct cupric/ferric chloride leaching process (Schweitzer and Livingston, 1982) with electrowinning to recover copper from chalcopyrite concentrates, this process (now closed) being the only chloride process which has been commercialized for a sulphide flotation concentrate. Despite these developments, it has long been considered, particularly for copper sulphide concentrates, that direct hydrometallurgical processes are in the main unlikely to be able to compete successfully with smelting for large-scale operations of simple high-grade single metal concentrates. As long as such concentrates can be produced commercially, smelting is likely to remain the principal processing route (Flett, 1981). This view is being challenged nowadays through pressure leaching developments made by Dynatec and CESL in Canada and the recent start-up of the Western Metals Gunpowder plant at Mt. Gordon in Queensland (Flett, 2000). Complex sulphide ores offer even greater opportunities because of the ability to produce a bulk sulphide concentrate from the complex sulphide ore with considerably higher metal recovery than is often possible from the production of individual metal sulphide concentrates from differential flotation. Interest continues to focus on hydrometallurgical solutions to these processing problems, particularly with regard to chloride hydrometallurgy. This paper, therefore, reviews current state-of-theart with respect to chloride hydrometallurgy"

Jan 1, 2002

By Paul Krivokuca

Outline Quinsam Coal Mine ?? Location ?? Mine History ?? Safety ?? Production ?? Hiring 4S Mine ?? Depillaring design ?? Structural mapping, Risk assessment ?? Rock Bolt Design Selection ?? Training

May 1, 2008

By Brian Danyliw

"Dust control is an increasingly important consideration for all mining operations from a health, safety, environmental and maintenance perspective. Modern mining operations incorporate a variety of mechanical dust control techniques into design however in many cases these engineered systems are unable to meet desired fugitive dust level targets. In these cases a variety of chemical dust suppression options are available to operators to assist in meeting their targets. This paper provides an overview of available chemistries, discussion of application techniques and equipment requirements and available performance monitoring technologies. This paper will also include a number of case histories discussing the treatment approach chosen, challenges encountered, chemical feed, storage and application equipment, monitoring techniques employed and results achieved.INTRODUCTIONDust FundamentalsFugitive dust by definition is an aerosol consisting of particulate matter suspended in a gaseous medium. Aerosols can include suspensions of particulate (solids) or sprays (liquids) or a mixture of both. Of particular concern from an occupational health and safety perspective are aerosols of particulate matter due to their involvement in classical occupations lung diseases such as silicosis, poisoning through chronic exposure to compounds such as lead and beryllium and expected involvement in more modern identified conditions such as cancer, asthma, and a host of other respiratory and non-respiratory conditions which may be caused or influenced through exposure to dust.According to the ""Glossary of Atmospheric Chemistry Terms"" (IUPAC, 1990), ""Dust: Small, dry, solid particles projected into the air by natural forces, such as wind, volcanic eruption, and by mechanical or man-made processes such as crushing, grinding, milling, drilling, demolition, shoveling, conveying, screening, bagging, and sweeping. Dust particles are usually in the size range from about 1 to 100 µm in diameter, and they settle slowly under the influence of gravity."" It should be noted that the behavior of particulates with respect to settling rate in air is a function of particle mass and shape and therefore the geometric size of the particle can be misleading. Occupational hygienists utilize the concept of particle aerodynamic diameter as a more representative reflection of particle size. Particle aerodynamic diameter, is defined as ""the diameter of a hypothetical sphere of density 1 g/cm3 having the same terminal settling velocity in calm air as the particle in question, regardless of its geometric size, shape and true density."" The expression of particle size as aerodynamic diameter allows for a more consistent understanding of particle behavior both from a settling perspective as well as from the perspective of how dust particles will behave in the respiratory tract. Figure 1 illustrates settling rates for particles of various aerodynamic diameters. The relationship between particle size and settling rate is important for understanding what size of particles must be addressed by dust control strategies as well as what particle sizes represent the most danger from an exposure and occupational health perspective."

Jan 1, 2015