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By A. E. Boudreau

Abstract-It has long been recognized that platinum-group-element (PGE) deposits in layered intrusions preferentially occur in intrusions that crystallized from high-Mg parent magmas. Recent studies suggest that evaluation of any given intrusion for economic PGE potential should also include assessment of the PGE, sulfur and chlorine concentrations in the cumulates and potential parent liquids. PGE: Magmas that contain relatively abundant Pt and Pd are the best candidates for forming economic deposits. Although analyses of coeval sills and dikes are the best indicators of primary magmatic PGE concentrations, analysis of the cumulates themselves is also valuable. For example, within the Stillwater complex, background PGE values in cumulates from the ultramafic sections of the complex contain, on average, several 10s of ppb Pt and Pd. Background concentrations of this order are suggestive that the magma was not depleted in the PGE. Sulfur: Conventional petrogenetic models for the formation of PGE deposits in layered intrusions require the PGE to have been concentrated during a magmatic sulfide-saturation event. In contrast, some hydrothermal models suggest that sulfur and the PGE were mobilized from footwall cumulates by upward- migrating, high-temperature hydrothermal fluids. Both models suggest that significant PGE deposits are likely to occur at and below the level where stratigraphic increases in whole rock sulfur concentrations occur. Chlorine: In both the Stillwater and Bushveld complexes the cumulate sequences below the major PGE-bearing zones contain anomalous Cl-rich apatite. The chlorapatite component of apatite in these rocks may exceed 40% and, in the Stillwater complex, typically exceeds 90%. It is stressed that pristine igneous mineral analysis and not whole rock data be used, as whole rock Cl concentrations may be affected by very localized (grain boundary), low-temperature alteration. Intrusions that crystallized from high-Mg, high-Cl magmas appear to have the best potential to host significant PGE deposits.

Jan 1, 1995

By Sylvain Picard

"RESUMELe gisement Silidor représente la dernière découverte effectuée dans le camp minier de Rouyn-noranda (fin 1985). Située à 5 km à I' ouest-nord-ouest de Rouyn-Noranda, ce gisement aurifère doit être mis en exploitation au cours du mois d’avril 1990. 11 est constitué par plusieurs facies minéralises comprenant une tonalité, un dyke mafique, une brèche carbonatée et par une veine de quartz. L’or se présente en particules très fines associées ou non à la pyrite. La zone d’altération hematitisee se développe sur une largeur de 30m environ de chaque cote de la veine. Une première étude structurale montre que la minéralisation s’est mise en place le long d’une zone de tension, orientée NNW, résultant de I' interaction de deux zones de cisaillement dextre orientées N270° et N300°. Les réserves diluées sont évaluées jusqu’ à 700 m de profondeur, à 4,78 Mt à 5,4 g/t Au. ABSTRACTThe Silidor ore deposit, located 5km WNW of Rouyn-Noranda, is the latest discovery made in the Rouyn-Noranda mining camp. Discovered at the end of 1985, this gold deposit will begin production in the spring of 1990. The deposit comprises several facies including a tonalite, a mafic dyke, a carbonated breccia and quartz vein. Gold is present as very fine grains, associated or not with pyrite. A 30m wide hematized alteration zone is developed on both sides of the structure. A structural analysis shows that the mineralization took place along a NNW oriented tension zone that resulted from the interaction of two dextral shear zones, oriented N270 and N300 respectively. The diluted ore reserves are estimated at4,78 Mt at 5,4 g/t down to a depth of 700m."

Jan 1, 1990

By L. Avramovic, B. Han, R. Jonovic, Z. Stevanovic, K. Haga, S. Dimitrijevic, A. Shibayama, L. Godirilwe, Y. Takasaki

Pyrite (FeS2) and chalcopyrite (CuFeS2) which could not be recovered, are present in mine tailings discharged from Bor copper mine. About 0.3% of copper (Cu) is contained in these tailings, therefore it can be considered as a useful copper resource. At the same time, pyrite is known to promote acid mine drainage, therefore it is necessary to detoxify the tailings. An efficient method has been proposed to recover copper and reduce the environmental impacts of tailings by a combined hydrometallurgical process of high pressure leaching (HPL), solvent extraction (SX) and electrowinning (EW) process. HPL process yielded high copper leaching rate (>95%) when water (H2O) was used as a leaching media. On the other hand, pyrite contained in the tailings was converted to iron oxide by high pressure leaching. Stability evaluation of the residue obtained from high pressure leaching, confirmed almost no elution of metal ions. The percentage of copper extracted and stripped from the Cu-loaded organic phase reached 97.4%. Moreover, it was confirmed that a low iron concentration in the electrolyte of copper electrowinning, resulted in the improvement of current efficiency of copper electrodeposition. INTRODUCTION Mine tailings are a by-product obtained from the flotation process and there are billions of tons of already existing tailings all over the world. Moreover, several billion tons of additional copper tailings will inevitably be produced in the coming years (Onuaguluchi & Eren, 2012). With the declining average copper ore grade, alternative sources of copper are highly sought, mine tailings have a comparable copper grade to that of low-grade ores (0.2–0.3%) therefore, it can be said that copper mine tailings present a very important source of secondary raw material for copper production (Antonijevi´c et. al., 2008). Consequently, it is necessary to confirm the possibility of the valuable metals (such as copper) recovery from mine tailing in which copper content is about 0.2–0.3%. Our group investigates the flotation and high pressure leaching processes for recovering of copper from mine tailings. Previous work on related samples include copper and nickel flotation tailings from Botswana, and a low–grade copper ore sample from Chile. Impurities, which are associated metals in mine tailing such as iron (Fe) and aluminum (Al) co-dissolve into the solution during the HPL treatment process. Therefore, separation of copper from impurities is necessary for selective extraction of copper from mine tailings and upgrading the copper concentration in the leachate to enable further purifying of Cu by electrowinning. Thus, it is important to investigate the possibility of applying solvent extraction for concentration of copper from leachate solutions of mine tailings (Onuaguluchi & Eren, 2012; Antonijevi´c et. al., 2008). In this study, LIX-84I was used as an extractant of copper from the leachate of high pressure leaching of mine tailing. As a fundamental solvent extraction investigation, the extraction behavior of copper was studied using a simulated solution of the leachate from the high-pressure oxidative leaching of mine tailing. The effects of; solution pH, extraction time, extractant concentration and phase ratio on copper extraction and sulfuric acid (H2SO4) concentration on stripping were investigated.

Jan 1, 2019

By Marcel Vallée

"Abstract - Traditionally, the emphasis in ore and reserve inventory has been to provide fairly simple definitions and presentations for reporting to shareholders and the investing public. The recent introduction of the mineral resource category aims to take into account the "part of the deposit that cannot yet be produced or extracted legally and profitably." Recent proposals still place insufficient emphasis on relating resource/reserve reporting definitions more closely to the needs of mining and exploration operators for the estimation and inventory of these basic material assets.In most schemes, significant ambiguities and shortcomings remain. These concern the potential economic interest of resources, the concept of continuity which is fundamental to the estimation of volumes, mass and grades, the objectives of the production feasibility study and the requirements of the geology, engineering and economic appraisals leading to it, and the "availability" of the permits required to start mine development. Up to now, no industry-wide formal consensus has yet been reached for any of these steps, nor for reconciliation between successive statements.A resource/reserve inventory scheme is presented here that is based on ISO 9000 principles and the Australasian system. Explicit criteria and transition points are proposed to define resource and reserve. Similarly, appropriate criteria are proposed to classify the three mineral resource and two ore reserve categories, based on geological and value continuity and on the objectives of the feasibility study. This scheme offers a way to develop ISO 9001 certification of resource/reserve estimation procedures for mining operations and supply exploration companies with an appropriate inventory system, to allow better information for the shareholders and the investing public.Résumé - L’objectif des inventaires des minerais et des réserves est, depuis le début du siècle, de fournir des définitions simples et d’ordre général visant les actionnaires et le public investisseur. L’introduction d’une catégorie de « ressources minérales » fournira un cadre tenant compte de la "portion d’un gisement qui ne peut encore être extraite ou exploitée légalement et à profit." Cependant, les propositions récentes de systèmes d’inventaires ne comportent pas des définitions des ressources et réserves qui tiennent compte suffisamment des besoins des opérateurs en exploitation et en exploration minière.La plupart des systèmes comportent des ambiguïtés et des carences. Citons la susceptibilité d’exploitation commerciale des ressources, la continuité qui est au centre de l’estimation des volumes, masses et teneurs, les objectifs de l’étude de la faisabilité de la mise en production, le niveau requis des travaux de géologie, d’ingénierie et d’économique qui y mènent, ainsi que la disponibilité des permis dont dépend la mise en production. Il n’y a jusqu’à maintenant aucun consensus dans l’industrie sur ces points, ni sur des procédures de réconciliation entre les estimations successives.Le système d’inventaire des ressources/réserves proposé ici s’appuie sur la structure ISO 9000 et le système australien. Des critères et des points tournants explicites sont établis pour définir les ressources et les réserves. De même, les définitions des trois catégories de ressources et deux catégories de réserves, s’apparent sur la continuité de la géologie et des teneurs et sur les objectifs de l’étude de la faisabilité. Ce projet offre une voie pour développer les critères de la certification ISO 9001 pour les opérations minières, tout en fournissant un système approprié d’inventaire aux compagnies d’exploration, pour mieux informer les actionnaires et les investisseurs potentiels."

Jan 1, 1998

By Ronald C. Schimmel

In 2006, the Corus IJmuiden pellet plant produced approximately 4.6 mln tonnes of pellets. Corus IJmuiden is about to increase its pig iron production to 6.4 mln tonne HM per annum. The burden of the Corus IJmuiden blast furnaces consists of approximately 50% high basicity sinter and 50% acid pellets, both produced in-house. To enable an increased iron production, the capacity of the pellet plant needs to be raised to 5.0 mln tonne per annum. The capacity is increased by modifications to the plant layout, which were implemented during the 2006 cold maintenance stop. In addition, the composition of the ore blends is optimised to gain productivity.

May 1, 2007

By G. Chi, W. J. Davis, S. Watters, D. Hoy, S. Castonguay

"The Poplar Mountain gold occurrence in western New Brunswick is hosted in the Poplar Mountain volcanic complex (PMVC), which is located along the southern segment of the regional Woodstock fault zone. The PMVC consists of three principal units including, in ascending order, a porphyritic felsic volcanic unit, a volcaniclastic unit, and a mafic volcanic unit. U-Pb dating of zircon indicates that the age of the volcanic rocks is younger than 459 ± 3 Ma, and 40Ar/39Ar dating of mineralization-associated sericite indicates that the age of mineralization is 411 ± 3.7 Ma. Gold-mineralized zones occur in all the lithologic units but mainly in the porphyritic felsic volcanic unit. Gold zones are not controlled by individual faults but are characterized by high-density brittle fracturing, thin carbonate-quartz veining, and intensive ankerite-sericite alteration, superimposed on an earlier chlorite-calcite- quartz alteration. Gold is associated with arsenopyrite, which mostly occurs as disseminations in the host rocks, and to a lesser extent with quartz-carbonate-sericite veins and quartz-cemented breccias.Geochemical data indicate that mineralization-associated alteration is characterized by enrichment of K, Rb, Cs, Ca, Sr, Ba, As, Sb, W, C, and S. Fluid inclusion data indicate that the mineralizing fluids are composed of H2O, salts, and CO2 with variable amounts of N2 and CH4; salinities range from 2.3 to 10.6 eq. wt.% NaCl, but mainly from 2.3 to 5.6 eq. wt.% NaCl, and homogenization temperatures lie mainly between 220° and 270°C. Fluid pressures at the site of mineralization are estimated to have been 770 to 1200 bars, corresponding to a depth of 2.9 to 4.6 km at lithostatic pressure. The d18OSMOW and d13CPDB values of mineralization-related ankerite range from +14.5‰ to +16.5‰, and -6.8‰ to -8.3‰, respectively. The d18O values of the ore-forming fluids are estimated to be 6.4‰ to 8.3‰ at a temperature of 250°C. These carbon and oxygen isotope data fall in the field of magmatic fluids and in part the field of metamorphic fluids.Considering the geological setting of the region, abundant granitic intrusions, the similarity between the age of mineralization (411 ± 3.7 Ma) and the nearby Pokiok batholith (402-415 Ma), and the enrichment of granophile elements in mineralization-related alteration, the ore-forming fluids were probably derived from a granitic intrusion underneath the PMVC. These fluids were focused along structures related to the Woodstock fault. The Poplar Mountain gold occurrence might be compared to some granitic intrusion-related gold systems based on the geochemical data presented herein. L’indice aurifère de Poplar Mountain dans l’ouest du Nouveau Brunswick est contenu dans le complexe volcanique de Poplar Mountain (CVPM), lequel est situé le long du segment sud de la zone de faille régionale de Woodstock. Les trois unités principales du CVPM sont, de la base au sommet, une unité volcanique felsique porphyrique, une unité volcaniclastique et une unité volcanique mafique. La datation U-Pb de zircons indique que les roches volcaniques sont plus jeunes que 459 ± 3 Ma, et la datation par la méthode 40Ar/39Ar de séricite associée à la minéralisation assigne à la minéralisation un age de 411 ± 3.7 Ma. Bien que les zones minéralisées en or soient présentes dans toutes les unités lithologiques, on les retrouve surtout dans l’unité felsique porphyrique. Les zones aurifères ne sont pas contrôlées par des failles individuelles mais sont caractérisées par une grande densité de fractures cassantes, de minces veines de quartz-carbonate, et par une altération en ankérite-séricite intense qui se superpose à une altération antérieure en chlorite-calcite-quartz. L’or est associé à l’arsénopyrite, laquelle est principalement présente à l’état de disséminations dans la roche hôte, et à un moindre degré avec des veines de quartz-carbonate-séricite et des brèches à ciment de quartz.Les données de géochimie indiquent que l’alté"

Jan 1, 2008

By G. Morin, S. Amira, F. Chiesa, B. Duchesne

"The effect of heat treatment on the stress corrosion cracking (SCC) resistance of A206 aluminum alloy was studied using the breaking load test according to ASTM G139 standard. This method uses the residual strength measurement from tensile test specimens previously stressed axially while exposed to the 3.5% NaCl alternate immersion test according to ASTM G44 standard. The residual strength after exposure is used as a measure of SCC degradation. The performed heat treatments were conventional natural aging T4 and artificial over-aging T7 tempers in addition to artificial aging T6 temper added for purpose of comparison. These tests showed that A206-T4 has a good resistance to SCC at pre-loads up to 100 MPa while A206-T7 was prone to SCC for pre-loads of 0 and 50 MPa, and showed total loss of ductility for pre-load of 100 MPa. Both A206-T4 and A206-T7 pre-loaded at 150 MPa showed poor resistance to SCC. A206-T6 showed the worst susceptibility to SCC as it lost all mechanical resistance at the end of the alternate exposure to 3.5% NaCl solution, even without any applied pre-load. Metallographic analyses showed that the resistance of A206 alloy to SCC is mainly affected by the transition from pitting to intergranular corrosion attack. The initiation and the propagation of intergranular corrosion attack might be assisted by high stress concentrations in the pits, particularly for pre-loads higher than 100 MPa. The transition from pitting to intergranular corrosion can also be promoted by hydrogen evolution from growing pits, which supports crack propagation by hydrogen embrittlement.INTRODUCTIONA206 aluminum-copper casting alloy offers ones of the best mechanical properties among the aluminum foundry alloys. This alloy belongs to the 206 alloy family developed in 1970s as an alternative to the highly resistant and ductile but more expensive Ag containing 201 alloy (Tiryakioglu, 2009). A206 showed also good low cycle fatigue strength (Sigworth, 2002). These properties made A206 alloy a strong candidate for some vehicles lightweighting applications. In spite of its interesting properties cited above, A206 alloy was rarely used in critical applications due to its tendency for hot tearing and stress corrosion cracking (SCC). Studies of A206 hot tearing behavior showed that this tendency can be reduced by improving castability and by grain refinement (Sigworth, 2002). The optimisation of the casting design can also prevent the tendency toward hot tearing. The SCC of aluminum-copper alloys arises from their susceptibility to localised corrosion, especially in chloride containing media. The localised corrosion in Al-Cu alloys is caused mainly by their heterogeneous microstructure, where the presence of many phases leads to the formation of micro-galvanic coupling with the matrix. However, most of the studies aimed at investigate the SCC of Al-Cu alloys concerned the wrought ones, especially the AA2024 alloy tempered in the T3 (or derivative) condition and few studies concerned the 206 and cast alloys in general (Alexopoulos, 2009 and 2016; Campestrini, 2000; Vogt, 1998; Talamantes-Silva, 2008; Zhang, 2003). Jean et al. (Jean, 2009) studied the effect of heat treatment on SCC behavior of B206 alloy using alternate immersion technique and grain boundary attack method and did not find direct correlation between the two methods. Another study showed that aging of 206 alloy may make a casting susceptible to SCC (Sigworth, 2002). However, these studies did not provide detailed information about the mechanisms of SCC of 206 alloy, as well as the effect of the stress intensity. The present work investigates the effect heat treatments and the stress intensity on the morphology of the corrosion attack and the SCC behavior A206 aluminum alloy. This study uses the breaking load test according to ASTM G139. This test utilizes direct tensile specimens and was developed to give a more quantitative measure of the SCC performance of resistant aluminum"

Jan 1, 2016

By A. C. Halferdahl

The Granby ores may be divided into three groups or classes. The No. I ore is a heavy pyrite, chalcopyrite, pyrrhotite, sulphide carrying some free silica, and calcite. No. 2 ore carries the same general group of sulphides as does No. 1, but in a lesser amount. The gangue is an altered greenstone. No. 3 ore has a smaller amount of sulphides than either of the others. Analyses of these ores is as follows: Cu. Si02 Fe. CaO S. Al 203 MgO No. I. Per Cent. 1.8 17.5 33.0 5.7 34.5 2.3 1.3 No. 2 Per cent. 2. 0 35. 6 23. 9 4. 3 I .5. 0 9. 2 6 .. 0 No. 3, Per cent. 1 . 5 40. 9 21 . 7 3. 0 I 1 . 3 11 . 0 5 . 4 The sulphide minerals in No. 2 and No. 3 ores occur largely in bands in the gangue, and for these portions comparatively coarse grinding serves to release the gangue. Drill cores show a certain dissemination of sulphides in portions of the rock, so that grinding to 5 per cent. + 65 mesh with 65 per cent.-200 mesh liberates the sulphide minerals very completely. The association of the sulphides is fundamental. The pyrite was probably deposited first and was followed by a portion of the chalcopyrite, or these two portions of the sulphide minerals were deposited together.

Jan 1, 1924

By Gunther F. Leichtle, James A. Finch, Colin A. Hardie, Cesar O. Gomez

"The recycling of wastepaper has become an important and common process worldwide. Techniques similar to those used in the mineral processing industry are used to produce high quality recycled fibers for use in newsprint. The mineral processing group at McGill University in conjunction with the Pulp and Paper industry (Mechanical and Chemi-mechanical Wood Pulp Network) has adapted one of these techniques, column flotation, for the purpose of deinking wastepaper. This article describes the typical process of recycling wastepaper from a mineral processing point of view. It also presents results from McGill University's flotation column test work at a Quebec wastepaper recycling facility.IntroductionThe recycling of wastepaper has become an important and common process worldwide, including Canada which is now the world's largest importer of wastepaper (CPPA, 1996). Much of the current drive to increase the utilization rate of recovered paper is a reaction to the solid-waste disposal problem that faces many Canadian and U.S. municipalities. The real problem in the disposal of solid waste is not the absolute amount of garbage that must be disposed of each year but this amount in relation to available disposal capacity.Environmental restrictions on the creation of new landfill sites and incinerators (the two main options for disposal of municipal solid waste) have tightened the demand/supply balance in the solid waste disposal market. This shrinking availability of waste disposal sites in the face of increasing population with greater disposal requirements defines the Developed World's solid waste crisis. Not only are there fewer disposal sites available, but the costs of using them is skyrocketing. These factors have increased government regulations mandating recycled paper content in newsprint. Conservation and environmental issues make the current drive for wastepaper recycling a real issue and business opportunity.A key to the success of producing quality recycled fibers from wastepaper is the deinking technology. The production of tissue papers, paper towels and newsprint requires regenerated fibers which are substantially free of ink particles. Of the various options available, mineral processing techniques can offer the most economical, environmentally acceptable and versatile strategies (Yoon, 1993). Today, it is recognized that flotation is one of the most effective processes for removing ink particles in the production of a high quality product. In a collaborative program with the Pulp and Paper industry, the mineral processing group at McGill University has adapted column flotation technology for this purpose. This article will describe the typical process of deinking from a mineral processing point of view (Part A). It will also present some results from McGill University's flotation column test work at a nearby paper recycling facility (Part 8)."

Jan 1, 1998

By Debasis Deb, Ankur Narang, G. P. Raja Sekhar, Kamal C. Das

"The stability of underground structures made (especially) in jointed rock mass is of the utmost important to designers, engineers and operators. Rock bolting is generally being practised to reinforce excavation walls and roofs by minimizing the movement of rock joints. This study proposes a new analytical model for the prediction of displacements, axial load and shear stress of a fully grouted rock bolt intersected by single or multiple rock joint(s). The governing equations for rock bolt are derived based on the assumption that shear force generated by slippage along the bolt-grout interface has a linear relationship with respect to the relative displacement at the interface. The proposed model is novel compared to the existing literature in the sense that it accounts for rock kinematics as an enriched sum of a continuous part (elastic) and a discontunous (jump) part due to the presence of joint planes. The complete solution of the bolt displacement, axial load and shear stress is derived as a function of the rock displacements, and, it comprises of Heaviside and/or Dirac delta functions in the solution space due to the jump at the intersection point(s) of bolt(s) and joint(s).Our novel solution is able to predict the elastic behavior of a grouted bolt, subjected to opening of the joint planes in pull-out test and also in excavated tunnel. These two cases also serve as benchmarks for grouted rock bolts with multiple joints and can be used for validation of numerical and experimental models. Further, the solution is applied to analyze the behaviour of grouted rock bolt as well as cable bolt installed in circular tunnel, with variations in rock joint(s) opening displacement, shear stiffness in the boltgrout interface and locations of the joint planes. Results indicate that for a specified grout stiffness, the maximum axial load developed in the bolt for discontinuous distribution of rock mass displacement is significantly higher than that of the continuous distribution of rock displacement. This paper provides an analytical interpretation of bolt beaviour considering multiple joint planes with variable joint opening displacements. The results obtained via the analytical method are in line with the corresponding investigation done by other authors. Thus, our analytical treatment can be used to understand bolt behaviour in realistic situations."

Jan 1, 2015

By Jean Fortin

In order to remain competitive, the search for excellence has been and will remain the only viable option facing the Mount-Wright operations. Safety and environment, process and technology as well as cost performance have been the focus points on which the operations have concentrated their efforts in order to meet and exceed our company's "Vision 2000" plan. Some of our mine's accomplishments have been a new work organization, a world class maintenance and a new collective agreement. The concentrator, maintenance and production departments have evaluated their processes and implemented various improvements in areas such as power supply, dewatering, blasting, implementation of service centers for large and small vehicles, fleet standardization, crusher, mills and silos improvements... etc. Safety and work environment for personnel have been our driving force in order to achieve this plan.

May 1, 2003

By J. W. Matousek

"Computer modeling of smelting processes requires internally consistent equations for calculating the compositions of mattes and slags. That is, the sum of the calculated assays must total 100%. One set of equations that satisfies this requirement for copper produced under oxidizing conditions (pSO2>one atmosphere pressure) is given by the following:%[Fe] = 62.0 – 0.775%[Cu]%[S] = 28.0 – 0.00125%[Cu]2%[O] = 10.0 – 0.225%[Cu] + 0.00125 %[Cu]2Mattes containing nickel in appreciable quantities do not have the defined “white metal” end point of approximately 80 percent copper and 20 percent sulphur that is found in the copper system during the converting process. The above equations, however, are readily extended to nickel and nickel/copper mattes for any desired end product composition."

Jan 1, 1996

By Margarete Kalin

Mine Waste Management ?Reduction of Sulphideoxidation or inhibiting weathering of rocks Geologist - broken or ground rocks Hydrologist - sources of contaminants Mining engineer - waste sites Consulting companies - income units People - Ugly, bad, dead Ecological Engineer Landscapes which contain building blocks of an emerging ecosyste

May 1, 2013

By Trent Hamilton

Cameco ? McArthur River Operation is a high-grade uranium mine in northern Saskatchewan. Average grades mined are nearly 20%, more than 20 times higher than other operating uranium mines in the world. The significant risks involved with mining this grade has been effectively mitigated using innovative and unique controls, implemented from development and production mining through to ore processing. The types and sources of radiation are presented and protection measures are discussed. McArthur River?s strong radiation culture is evidenced by continually low radiation exposures while transitioning to new mining zones.

Aug 1, 2010

By Rashid Bashir

The presence of groundwater in the form of large aquifers can have an important influence on investment decisions for underground mines. The design for such mines requires development of special mining methods, and mine dewatering infrastructure to avoid hazards during shaft sinking and underground development. The costs associated with mine drainage control and Mine Dewatering Systems (MDS) are relatively small compared to the huge consequential losses that can occur in case of an uncontrolled inflow and subsequent flooding of the mine. The design of MDS needs consideration of accurate prediction of the maximum uncontrolled inflow rate, availability of the system during an uncontrolled inflow while the inflow is mitigated, and decision on pumping system technology to have capability to operate under water. The research presented in this paper provides a theoretical framework for a reliability based design procedure which takes into account the uncertainty in the estimate of the maximum uncontrolled inflow, performance of the system during the period of an uncontrolled inflow and a methodology to decide on appropriate pumping technology considering the reliability of the system and available underground storage. The reliability based mine design procedure integrates the ideas of Effective Reserve and Hydraulic Reliability Index to come up with a unified methodology for design of Mine Dewatering Systems.

Aug 1, 2010

By G. Chung, W. Petruk, D. Doyle

"A series of tests was conducted on Carol Lake iron ore, which contains about 38 wt % hematite and 19 wt % magnetite, to establish a flowsheet for high weight yield by spirals. A pilot plant was run in parallel with the IOC concentrator to simultaneously test two flowsheets on the same feed material. The IOC concentrator processes the ore by treating it directly in a spiral circuit, whereas the pilot plant used a laconite flowsheet which had a low intensity magnetic separator (LIMS) at the front of the circuit. The LIMS produced a non-magnetic (hematite-rich) product and a magnetic (magnetite-rich) product prior to treating the ore in two separate spiral circuits. The results from about 150 tests were evaluated by chemical assays and materials balancing techniques, and a selected test was evaluated by the image analysis and materials balancing technique.The image analysis and materials balancing evaluation showed that a higher hematite recovery was obtained by the hematite spiral circuit than by the IOC concentrator spiral circuit, and a slightly lower magnetite recovery by the magnetite spiral circuit than by the IOC concentrator spiral circuit. Furthermore the hematite recovery by hematite spirals was higher than the magnetite recovery by magnetite spirals. The better hematite recovery was achieved because a higher liberation is obtained for hematite than for magnetite, and the hematite in the Carol Lake ore has a narrower grain size range than magnetite. Consequently, better spiral control can be maintained when processing a hematite-rich spiral feed, than when processing a magnetite-rich spiral feed. Since the feed to the IOC concentrator spiral is a mixture of hematite and magnetite, an intermediate hematite recovery is obtained by the IOC concentrator. INTRODUCTIONA study of characteristics that affect recoveries of hematite and magnetite from the Carol Lake ores of the Iron Ore Company of Canada (IOC), was carried out in connection with a project on designing a flowsheet for maximum weight yields. A pilot plant using a taconite flowsheet was run in parallel with the existing IOC concentrator which uses a classical iron ore flowsheet. About 150 tests were run to compare iron recoveries and weight yields by the spirals in the two flowsheets. Better iron recoveries were indicated for the taconite flowsheet, but the results were not consistent and the reasons for the observed differences were not apparent. The material from one test (Test 61), which gave better iron recoveries for the taconite flowsheet, was evaluated by the image analysis and materials balancing technique. A suite of samples was taken from 5 points in the IOC concentrator and from 8 points in a pilot plant (taconite flowsheet). The samples were analyzed to compare the behaviours of the Carol Lake hematite and magnetite in the spirals of the two flowsheets. The results provided a sound basis for further tests in designing a high weight yield flow sheet."

Jan 1, 1993

By Grant Arnold

Le Camp Minier de Matagami est situé dans la ceinture volcano-sédimentaire Harricana- Turgeon appartenant à la Province du Supérieur, sous-province de l?Abitibi, au Québec. Les gisements de métaux de base polymétalliques sont retrouvés exclusivement dans les deux domaines lithotectoniques comprenant l?association basalte-rhyolite (Matagami-Brouillan et Joutel-Raymond). Tous ces dépôts, à l?exception de ceux de Selbaie, sont de type exhalatif et représentent des dépôts volcanogènes à Zn-Cu, typiques de l?Archéen. Le complexe volcanique de Matagami est constitué principalement de deux phases de volcanisme tholéïtique. Les dacites et les rhyolites du Groupe de Watson, représentent la phase la plus précoce et celles-cis sont recouvertes par la seconde phase qui est constituée majoritairement de roches intermédiares à mafiques intercalées d?horizons felsiques, formant le Groupe de Wabassee. Un sédiment chimique sulfuré, la Tuffite Clef, marque le contact et l?hiatus entre ces deux groupes. Cette tuffite est reconnue à la grandeur du flanc sud du camp minier et représente l?horizon favorable à explorer puisque sa déposition a correwspond à une période d?intense activité hydrothermale. Le complexe volcanique de Matagami est limité au nord et au sud par des bandes sédimentaires orientées est-ouest, connues respectivement sous les noms de Groupe de Matagami et Groupe de Taïbi. Le Complexe intrusif de la Rivière Bell, qui occupe la base du Groupe de Watson, est un complexe lité consistant en une séquence stratifiée gabbroïque avec localement des niveaux stratiformes à concentrations d?oxydes magmatiques, la bordure de ce complexe est marquée par la présence d?un horizon granophyrique. Cette intrusion synvolcanique prétectonique, représente probablement la source de chaleur étant à l?origine de l?activité hydrothermale observée dans les roches volcaniques sus-jacentes. Suite à un levé aéroporté, le camp minier de Matagami a vu le jour en 1956 lors de la découverte du dépôt de Mattagami Lake, un gisement volcanogène de 25.6 millions de tonnes. Depuis ce temps, un total de neuf gisements ont été exploités et un dixième, Bell Allard, est présentement en production. En date du 31 décembre 1999, la production historique du camp s?élevait à plus de 41 millions de tonnes. Cette présentation mettra l?accent sur la géologie des récentes découvertes dans le prolifique camp minier de Matagami. Les ressources publiées pour le dépôt Persévérance sont de 947,000 tonnes titrant 19.12% Zn, 1.37% Cu, 32 g/t Ag et 0.40 g/t Au. Deux autres découvertes, Équinoxe et Persévérance Ouest contibueront à la ressource globale. Les trois dépôts sont situés au niveau de la Tuffite Clef même si les roches sus-jacentes ne sont pas celles typiquement observées dans les autres dépôts du flanc sud. Ces découvertes sont le résultat d?un programme d?exploration ciblé et soutenu, démontrant ainsi la possibilité de découvrir de nouvelles ressources même dans les camps miniers comme Matagami qui ont été explorés intensivement depuis plus d?un demi-siècle.

May 1, 2001

By R. Lodha, C. Oprea, G. Oprea, H. Zargar, T. Troczynski

"The basic refractories used in non-ferrous industry contain chrome ore for improving the thermal shock resistance, thus reducing the penetration of molten metal and fayalite-type slags into the lining. The current study aims to replace chrome ore with Me4+ ions along with Fe3+ ions in order to form MgO-Al2O3- FeOx-Me4+O2 based complex spinel systems that could perform similar to the complex chromia-bearing spinel in the magnesia-chrome refractories. This system allows for lower temperatures of synthesis and sintering. In our study, compositions with 60% MgO were fired below 1500°C and resulted in complete formation of complex spinel, and open porosity less than 5%. The in-situ formation of the complex spinel from the fine mix of oxides in the MgO-Al2O3-FeOx-Me4+O2 system offers a suitable alternative of binding system to produce basic refractories at lower temperatures and of similar physical and mechanical properties with magnesia-chrome bricks fired above 1750ºC. INTRODUCTIONThe synthesis of magnesium aluminate spinel (MgAl2O4) (Maschio, Fabbri, & Fiori, 1988) or magnesium chromate spinel (MgCr2O4) from their respective oxides is diffusion controlled resulting in a sluggish reaction even at high temperatures. For instance, the diffusion of Mg2+ and Al3+ ions in the intermediate spinel layer during reaction is slower than the diffusion of Mg2+ in corundum and Al3+ in periclase. The interfacial layer of spinel formed during the reaction increases the diffusion path for the spinel forming cations. This accompanied by ~8% volume expansion retards further reaction resulting in incomplete spinel forming reaction during sintering and hence densification during the reaction cannot be achieved. In order to assess sintering studies with fine particulate oxides that would result in a lower diffusion path, a mechanical mixture of the hydroxides of aluminium and magnesium calcined at 1400ºC to 1600ºC for 1 hour does not result in complete spinel formation (Sarkar, Das, & Banerjee, 2003), which indicates that reaction sintering of stoichiometric magnesium aluminate spinel is retarded by initial reaction forming the interfacial spinel layer. The basic bricks used as linings in non-ferrous pyro-metallurgical convertors are manufactured using magnesia and chrome ore, the sintering of which produce spinel solid solution. This solid solution is a mix of both normal and inverse spinel structures that sinters at temperatures in excess of 1800ºC in air."

Jan 1, 2012

By Pingchao Ke, Zhihong Liu

Fe(III)-As(V) precipitates were synthesized from the Fe(II)-As(V)-SO42--H2O system at 90°C in initial Fe(II)/As(V) molar ratios of 4.0 and 5.0, respectively. The synthesis were carried out by introducing oxygen gas into the system to oxidize Fe(II) ions into Fe (III) ions, and at the same time, adding aqueous sodium carbonate solution into the system to neutralize the acid released by the hydrolysis reactions, with the purpose of keeping the pH constant at 1.5±0.05. The precipitates obtained were characterized by XRD, chemical composition analysis, SEM, XPS, and Raman spectrum. The results indicated that the particles in the precipitates were in the morphology of irregular aggregation with their sizes in the range of about 1–4 µm. The precipitates consisted of scorodite, ferric arsenate and amorphous hydrated ferric oxide, of which amorphous hydrated ferric oxide formulated as Fe(OH)x(SO42-)y. The characteristic XPS peaks of Fe-AsO43- and Fe-O in the precipitates located at 711.8 and 713.3 eV, separately, and the existence of amorphous hydrated ferric oxide led to two series of shake off lines developed over the end of high binding energy of Fe2p XPS. The precipitates were stable in TCLP tests at pH 4.93 for 60 hours with the arsenic concentrations in the leaching solutions being 0.27 mg/L and 0.59 mg/L for the precipitates prepared in the initial Fe(II)/As(V) molar ratios of 4.0 and 5.0, respectively. The tests for the long-term stability of the precipitates were carried out by leaching them for 40 days at 25°C under various media in the pH range from 9.50 to 10.57, and the results showed that the precipitates synthesized in this study were much more stable than those by previous researchers.

Jan 1, 2017

By K. K. Mamyrbayeva, G. Z. Guseinova, V. A. Luganov

This paper presents the results of theoretical and technological studies on leaching ore of Bozshakol deposit. The major oxidized copper mineral of Bozshakol ore is atacamite, and the content of malachite, azurite, cuprite, copper sulfide minerals is insignificant. The chemical composition of the test sample, with mass, %: 0.9 Cu; 55.00 SiO2; 22.40 AI2O3; 9.00 Fe2O3; 2.24 CaO; 3.56 MgO. Technological studies on leaching the ore were carried out with sulfuric acid 5, 15, 25 and 50 g/dm3 in one and multistage (up to 4 stages) countercurrents. Size of ore 1 mm, the ratio S : L 1: 4. It was found that with increasing of acid concentration from 5 to 50 at one-mode leaching the copper extraction reaches 55 %. At multistage leaching the copper recovery reaches 73 %, a productive solution containing g/dm3: Cu - 4; Fe – 1.2; Al – 1.1 at a pH of 2.8. When leaching the cinders obtained by ore roasting in an atmosphere with limited value of oxygen, with increasing of the roasting temperature from 650 up to 750 °? the extraction of copper from the Bozshakol ores reduced from 31.5% down to 24.4%. The rate of filtration is markedly increased compared with the crude ore. When leaching the cinders obtained by roasting in a nitrogen atmosphere a marked increase up to 87.2-88 % of copper extraction from Bozshakol ores is observed. As an extractant for the extraction of copper from the pregnant solution used LIX984N extractant in kerosene. On the basis of the calculations it was built extraction isotherm and modeled processes of copper recovery with the circuit 2E + 1P, allowing up to 93 and 96% extraction. The through extraction of copper from the ore in the electrolyte was 67 %. Technology is recommended for semi test.

Jan 1, 2016