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By O. Mejia

"As study was undertaken to investigate the relationship between mill liner wear and grinding energy efficiency and to assess the opportunity to control mill speed to improve energy performance as mill liner wears. The study involved analysis of plant operating data and liner wear profiles over time. The operating work index was found to be an effective tool to identify the decrease of grinding efficiency along the liner service. The plant data show that the mill grinding efficiency as determined by monitoring the operating work index, and throughput decreases as liner wears. However, efficiency and throughput can be maintained by either changing the liner more frequently or by increasing the mill speed. Two scenarios for increasing mill throughput were analyzed. The first one involves changing the liner before the efficiency drops and the second one requires increasing the mill speed from 75% to 79%. Both scenarios show financial benefits that can be used in mill operations.INTRODUCTION The analysis of the mill power draw is used in this study as a key parameter for comparing mill liner profile and its effect on mill performance. Current technology and simulation software used in the mining industry do not factor in the impact of liner wear profiles in grinding efficiency and mill throughput (Toor, 2013). To address this gap, this study provides an analysis of key factors affecting mill throughput and grinding efficiency: mill speed, ball loading, and liner profiles. Several years of plant mill operating data, published research papers, and MillTraj® simulation results are used to demonstrate that face angles impact grinding efficiency and throughput and that mill speed can be used to overcome this problem. Moreover, the liner profile wear analyses clarify a mismatch between actual and estimated power draw calculations."

Jan 1, 2019

By Esteban M. Domic

"T.L. Leaching ProcessCommercial PerformanceSociedad Minera Pudahuel Ltda. (SMP) has been innovating in the copper producing field with the commercial application of the Thin Layer (T .L.) leaching process in its two operating division s: Lo Aguirre and La Cascada. Since November 1980, SMP' s Lo Aguirre Division has been producing high-purity copper cathodes at a nominal rate of about 16,500 metric tonnes / year, by mean s of the new route of T.L. leaching, followed by solvent extraction and electrowinning (TLlSX/EW). This has been the first commercial application on T .L. technology in the world, and the only commercial application in Chile for solvent extraction and electrowinning.By mid -1980, SMP acquired Sagasca Mining Co., renaming it as La Cascad a Division. The existing vat leaching facilities were modified to apply T.L. in the same old vats. The existing scrap iron cementation recovery circuit was kept running for the continuing production of copper precipitates. The modifications in the leaching circuit allowed shorter treatment cycles with a lower acid consumption and consequently, copper product ion increased from a previous historical high of 12,000-13,000 metric tonnes /year to a new level of about 22,000 metric tonnes/ year . These changes have been in operation since March 1981.T.L. Leaching commercial performance, both at Lo Aguirre (TL / SX /EW) and at La Cascada (TL/cementation), has been presented in several recent publications. Real operating parameters and process requirement s were reviewed in detail. A breakdown for TL / SX/ EW economics was also published based on Lo Aguirre' s performance during 1982(41."

Jan 1, 1986

By P. Fleming, W. Pascheto

"Rod mills processing nickel and copper ore experienced recurring failures of liner bolts. In some cases failures became very frequent, requiring constant mill intervention and consequently impacting process stability and operating costs. Investigation related to the causes of bolt failures involved a multidisciplinary approach with the participation of engineering, maintenance and operation. It included the determination of bolt failure mechanisms as well as the assessment of mechanical properties, fabrication quality and handling and installation procedures. In addition, other parameters affecting bolt performance such as mill and liner design, operating parameters and maintenance practices were studied. This paper reports the failure investigation results and proposed solutions for failure prevention. INTRODUCTIONOccasional liner bolt failures are common in rod mills. However, chronic bolt failures developed in rod mills processing nickel and copper ore caused frequent shutdowns for bolt replacement to an extent that affected process stability. At first, it was thought that the cause of recurring failures was related to bolt quality. The operation then submitted several failed bolts to failure analysis. However, it became apparent that bolt quality was unlikely to be the main cause of failures. The determination of root cause (s) then became more complex, requiring a multi-disciplinary approach to failure investigation, requiring the assessment of bolt installation methods, mill design, operating conditions and maintenance practices. The results of the metallurgical failure analysis and investigation of other possible causes of failures are reported here."

Jan 1, 2016

By G. Fuentes, J. Viñals

"The nature and basic kinetics of the hydrothermal reactions of bornite, covellite pyrite and enargite with copper sulfate solutions were investigated, as a previous study on the behavior of the bulk Chilean copper concentrates. The reaction of bornite produced digenite at 160 °C and djurleite above this temperature. Covellite was transformed to digenite at < 200 °C and to chalcocite (Q and M) at > 200 °C. The pyrite reaction was significant at > 200 °C and extensive at 240 °C, enargite reacts only above 240°C and produces digenite. The hydrothermal treatment of Chilean Codelco-type copper concentrates with hydrothermal reactions was similar to those obtained from pure mineral samples.INTRODUCTIONStudies on the hydrothermal enrichment of chalcopyrite concentrates were begun by MacGauley and Roberts (1951), Roberts et al. (1953) and MacGauley and Schaufelberger (1956). In the 1970's these processes were reexamined by McKay et al. (1972), and Johnson and Coltrinari (1976), but it not was until the 1990s when the kinetics, mechanisms and full engineering aspects were studied by Barlett, (1992), Jang and Wadsworth, (1994) and Peterson and Wadsworth (1994). The main objectives were to solve some important problems in the copper pyrometallurgy: The increase of the smelting capacity, the reduction of the iron slag – and associated copper losses – as well as the reduction of sulfur emissions. The present rise in copper demand and price implies the production and subsequent treatment of very impure concentrates. Thus, a significant increase of environmental problems can be expected in the copper pyrometallurgy. The previous purification of concentrates can reduce the processing of wastes containing hazardous heavy metals in the copper refineries and the hydrothermal treatment can be an alternative which combines both enrichment and purification. On the other hand, Chuquicamatatype concentrates (Viñals et al., 2004a) contains digenite (Cu1.8S), pyrite (FeS2), chalcopyrite(CuFeS2), b ornite (Cu5FeS4), covellite (CuS) and sphalerite (ZnS) as the main mineral components, with minor amounts of enargite (Cu3AsS4), galena (PbS) and molybdenite (MoS2)."

Jan 1, 2012

By Simon Houlding

"Part 1 (CIM Bulletin, August 1991) of this article identified the limitations of the traditional modelling methods and demonstrated the approximations and errors introduced by their application to complex mining situations. The objective of Part 2 is to describe the evolution of new, proven technology which eliminates these deficiencies and provides precise and practical alternatives. These promote the use of realistic geological and mining shapes and eliminate altogether the rectangular approximations of traditional methods. Limitations of the Traditional MethodsThe limitations of the traditional modelling method s (viz. simple block modelling, gridded modelling and their more recent variations) were discussed in detail in Part I . These methods are all based on the use of rectangular discretization to represent the boundaries and volumes of ore deposits and mining excavations. As a result they are unsuited to the representation of nonrectangular geological complexities such as folding, faulting and irregular surfaces . They are equally unsuited to the representation of realistic excavation limits, particularly in the case of underground mining.Recently these methods, with limited variations in technique, have been applied to increasingly more complex geological and mining situations. The resulting potentials for error and conflict within the modelling pro cess were demon strated in Part I . The effects can be summarized as follows:• volume and boundary approximations introduced by therepresentation of irregular three-dimensional boundaries andvolumes by rectangular modelling elements ; • geostatistical errors and conflicts caused by neglect of the relationships between grade estimates and the geometric/ spatial aspects of irregular volumes and associated observations (samples), including an inability to produce precise estimates with meaningful confidence limits;• a compounding of these effects by using rectangular element sizes other than the geostatistical optimum, and by using differentelement sizes within a model; and• general inefficiencies introduced throughout the modelling pro cess by the requirement to represent geology, grade distribution and excavation limits with a singular modelling method and model."

Jan 1, 1991

By H. Sato, Y. Sato, T. Ooishi, K. Sakamoto

"Sumitomo Metal Mining Co., Ltd.(SMM)'s Niihama Nickel Refinery(NNR) produces high quality Nickel cathode, Cobaltcathode and other by-products using hydrometallurgical refining process called “MCLE”(Matte Chlorine Leach and Electro-Winning). In 2005,NNR started to use nickel and cobalt mixed sulfide (MS) produced by one of the SMM’s subsidiaries Coral Bay Nickel Corporation(CBNC)’s HPAL plant in Philippines, although its main and the only raw material until then was nickel matte. With start-up of the second HPAL plant at Taganito in 2013, NNR expanded its production capacity of nickel cathode from 41,000 to 65,000 tpa and finally achieved its target in 2015 by producing 65,980 tpa. SMM developed the technologies to improve poor reactivity of MS and installed new facilities to cope with increased Cobalt and Sulfur production at that time. This paper describes the technical approach to increase MS treatment with high efficiency.INTRODUCTIONThe Sumitomo Metal Mining Co., Ltd.(SMM)Niihama Nickel Refinery(NNR) produces Nickel cathode, Cobalt cathode and other by-products using Matte Chlorine Leach and Electro-Winning (MCLE) process technology. SMM uses nickel matte and nickel & cobalt mixed sulfide (MS) as raw materials for the MCLE process. Table 1 shows typical composition of these raw materials. Nickel matte had been only raw material until 2005, and with start-up of Coral Bay Nickel Corporation (CBNC) operation in the Republic of the Philippines, MS became major part of it. In 2009, when CBNC doubled its production capacity, NNR also expanded its plant capacity of electrolytic nickel from 36ktpa to 41ktpa, keeping an eye on the possibility of 65ktpa with oncoming SMM’s second HPAL in Philippines. Poor reactivity of MS was the prime concern at that time because our intention was to increase production with MS. Nickel extraction rate deteriorated with increasing usage ratio of MS in raw materials. To keep high nickel extraction rate under high ratio of MS, NNR developed a new leaching technology. Another concern arising from treatment of MS was Cobalt and Sulfur contents that are much more than those of nickel matte as shown in Table 1.NNR introduced new technology of solvent extraction process as to Co/Ni separation process in order to keep cost competitiveness instead of the conventional cobalt oxidation–neutralizing method. As to sulfur products, new sulfur productive facility was installed to improve the exposure to sulfur dust and the hot working conditions for workers. As a result of process development and installation of new facilities against the problem with MSusage,65 ktpa production was achieved in 2015."

Jan 1, 2017

By Yan Jie

The oxygen-enriched bottom-blowing continuous converting process for copper matte was recently developed by the China-ENFI Engineering Corporation. The first commercial plant based on this technology was successfully commissioned at the Yuguang smelter in China in March 2014. The present paper describes this new continuous converting process and compares technical characteristics with other continuous converting processes including: Kennecott-Outokumpu flash converting, the Mitsubishi Process, the Noranda Converter and TSL continuous converting. The bottom-blowing oxygenated continuous converter with competitive capex and opex costs is seen as an attractive alternative to the Peirce-Smith converter.

Jan 1, 2014

By J. E. Nesset

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

Jan 1, 2009

By Jerry Z. Lu

Belt conveyor design involves the evaluation of belt tensions, drive selection, pulley configuration and other technical issues. The conveyor belt tensions vary with conveyor layout, drive pulley configuration, belt selection, and idler selection. The decisions for the belt conveyor construction always take all technical, commercial and maintenance issues into consideration. A good conveyor design shall provide required operational features and at the same time be cost effective. The common issues for an engineer to face during belt conveyor design include: (1) Conveyor drive selection ? drive with fluid couplings or variable frequency drives; (2) Drive system configurations - single pulley large drives or dual pulley smaller drives, if intermediate tripper booster drives shall be applied, what power ratio should be adopted for a multi-drive conveyor; (3) Gear reducers ? shaft mount drives, right angle gear reducers or parallel gear reducers; (4) Drive pulley lagging - ceramic lagging or rubber lagging; If ceramic lagging, what type should be used. (5) Conveyor speed variation ? If conveyors run at variable speeds, faster speed/lower percentage loading or slower speed/higher percentage loading. In many cases the decision maker find themselves in a dilemma ? technical benefits vs. financial benefits, capital cost vs. operational cost, and capital and operational cost vs. maintenance effort. Although many conveyor design topics above have been discussed in numerous technical papers and design reference books, management executives and inexperienced engineers may be confused and feel lost. The consultation of people around them may lead to different opinions since experiences tend to vary, making the decision making process complicated. The purpose of this paper is to simplify these complicated issues and provide useful guidelines for belt conveyor design. This paper focuses more on providing simple and practical answers and solutions instead of discussing each topic academically and theoretically in depth.

Nov 1, 2011

By Y. T. John Kwong

Abstract - To exploit an ore deposit without unduly impacting the environment is a challenge that can only be met by the concerted efforts of traditionally independent teams working on a mining project. Not only is detailed geology required of geologists to help mine engineers to develop a mine plan that assures generation of the least possible amount of mine waste, but metallurgists also have to select the most environmentally friendly mineral processing schemes, and communicate with environmental engineers with regard to complications that process chemicals may pose on proper mine waste management. Traditional ore deposit models typically emphasize the geological and mineralogical aspects of ore genesis to facilitate exploration for similar deposits. Recent research has shown that potential environmental liabilities such as acid mine drainage and metal leaching can readily be predicted according to deposit types. The choice of mining methods, mineral processing schemes, and decommissioning options are also largely dictated by the composition and setting of an orebody to be mined. Integrating such related information into traditional ore deposit descriptions would lead to the development of comprehensive environmental ore deposit models. The latter would facilitate communication among staff of the varied components of a mine project and aid with the selection of a combination of methods and strategies that would assure minimum environmental risks and impacts, reduce the overall project cost, and enhance sustainable development.

Jan 1, 2003

By Patrick Andrieux

Numerous rock blasting design methodologies have been developed over the years, relating either to the primary objectives of blasting, such as the size distribution of the blasted material, or to its undesirable side effects, such as damage to the remaining rock mass. All existing methodologies, while of use, do have serious shortcomings. The question remains whether further improvements can be achieved in the field of practical rock blasting engineering. One approach that seems to hold promise is the relatively new matrix-based rock engineering systems (RES) methodology. It has been conceptually demonstrated that RES could be efficiently adapted to blasting. A brief overview of rock blasting design techniques and their main shortcomings is followed by the basic concepts governing rock engineering systems and a discussion on their pertinence to blasting. The paper concludes with a review of current efforts to develop a useful practical blast design tool using RES. SOMMAIRE Le potentiel d?application des systèmes d?ingénierie du roc aux tirs à l?explosif. De nombreuses méthodologies de conception d?abattage du roc à l?explosif ont été développées au cours des années, qui ont adressé soit les principaux objectifs des tirs, comme par exemple la granulométrie du matériel dynamité, soit ses effets secondaires indésirables, tels les dommages au massif rocheux. Toutes les méthodes existantes fonctionnent dans une certaine mesure et sont utiles - elles sont cependant pour ainsi dire toutes affectées par des limitations ou défauts plus ou moins sévères. La question demeure quant à savoir si des améliorations supplémentaires peuvent être apportées dans le domaine de la conception pratique des opérations d?abattage du roc à l?explosif. Une approche alternative qui semble prometteuse est celle relativement récente des systèmes matriciels d?ingénierie du roc (?Rock Engineering Systems?, ou RES). Il a été démontré de manière conceptuelle que les RES ont le potentiel d?être adaptés aux opérations de sautage. Une brêve revue des principales techniques de conception des tirs à l?explosif est suivie d?un énoncé des principes de base gouvernant les RES, ainsi que d?une discussion sur leur pertinence aux opérations de tir. Cet article conclut avec la revue d?un projet de recherche axé vers le développement d?une méthodologie de conception des tirs à l?explosif basée sur les RES.

May 1, 2002

By H. J. White

Haynes International, a world leader in the manufacture and production of nickel, and cobalt base alloys has invented and developed a low cost high temperature material, with a unique combination of superior oxidation resistance and weldability/ fabricability. HAYNES® HR-224TM (Ni ? 27.5Fe ? 20Cr ?3.8A1 ? 0.3Si ? 0.3Ti) forms a planar/ continuous/ adherent aluminum oxide film at high temperatures which has been shown to effectively limit chromium poisoning in solid oxide fuel, cell, systems. A 20,000 pound vacuum induction melted (VIM) + electroslag remelted (ESR) heat has been melted and converted into various product forms: sheet, plate, bar, welded tubing, wire, etc. The alloy was designed for service in severely oxidizing environments recuperators, automotive catalytic converters, wire strand annealing furnace tubes, etc. and has been of great interest to solid oxide fuel, cell, manufacturers as a materials of construction in balance of plant (BOP) design. This manuscript presents the physical, properties, mechanica, properties, and oxidation resistance of the alloy compared to other materials being considered for solid oxide fuel, cell, design

Jan 1, 2010

By K. D. Card, K. Howard Poulsen

Abstract - The Archean Superior Province craton and the Paleoproterozoic Penokean Orogen are major geological sub-divisions of the southern Canadian Shield and account for much of the metallic mineral production of North America. The Superior Province experienced a mainly Archean history involving several cycles of volcanism, plutonism, and tectonism, primarily in the Neo-archean but also including Meso-archean and Paleo-archean cycles as well. Superior Province consists of northern and southern high-grade gneiss sub-provinces and a broad central region of alternating greenstone-granite and metasedimentary belts. The sub-provinces may represent tectonic terranes assembled in the Archean by accretion processes similar to those of some Phanerozoic orogens. Most of the mineral deposits, including VMS, intrusion-related, and lode gold deposits occur in the greenstone- granite sub-provinces where they were formed in an interval of 100 million years or less around 2.7 Ga. The Paleoproterozoic Penokean Orogen comprises supracrustal sequences deposited in fault-controlled epicratonic and rifted margin settings developed on and about the Superior craton. Deposition of the ~2.4 Ga Huronian Supergroup and its paleoplacer uranium deposits in the eastern Penokean Orogen, and their pre-2.2 Ga deformation, were probably unrelated to the deposition of the ~2.1 Ga Marquette Range and Animikie groups and their major taconite iron formations in the west. However, these sequences were deformed together during the ~1.85 Ga Penokean Orogeny which resulted when an assembly of island arcs containing VMS deposits, the Wisconsin magmatic terrane, collided with the Superior block and its Paleoproterozoic cover. The Sudbury structure with its world class Ni-Cu-PGE ores was also formed at this time, possibly triggered by meteorite impact. Metallogenic patterns in the Paleoproterozoic rocks were controlled by a complex interplay of factors including tectonically controlled variations in deposition and deformation, distribution of mineralization in the Archean basement, and oxyatmoversion, the transition from anoxic to oxygenic atmospheric conditions that occurred during the deposition of these sequences.

Jan 1, 1998

By M. N. Collison

"In 1960, with the opening of the Chisel Lake mine near Snow Lake, Manitoba, the Hudson Bay Mining and Smelting Co., Limited, commenced a new phase in their mining operation -that of bringing ore to Flin Flon over 100 miles of railroad.The schedule of operations required to accomplish this, together with an outline of some of the problems of handling ore at 40° and 50,0 below zero, are discussed. The facilities required to thaw and unload from twenty to fifty cars per working day are also described."

Jan 1, 1966

By J. Gillies

"Those of you who were at last years C.M.P. meeting are aware there was discussion at that meeting concerning the best method of assisting the assayers of metal mines to exchange new ideas and methods of assaying. The opportunity to advise you of what came of that discussion is very much appreciated.There are several societies, including the Chemical Institute of Canada, the Spectroscopy Society and others that could be of some assistance to assayers. However, since these societies cover a rather broad field and not many mine assayers have the opportunity to attend their meetings, it was felt that an organization oriented to the specific needs of the mine assayers would be of more value to them.Several years ago an attempt was made to hold meetings for the benefit of assayers in conjunction with the Conference of Metallurgists held each year by the Metallurgical Society of the C .I.M.M. This did not work because very few of the mine assayers attended the meetings.With the very evident success of the type of meetings the C.M.P. have and the excellent groundwork done by your secretary, Mr. Stevens, in talking about this to mine management and assayers at many mines across the country, it was decided to hold a meeting at Noranda on October 8 to discuss how best we could help ourselves solve our problems.For the initial meeting it was felt that perhaps it would be better to start with a smaller group, so invitations were sent to mines in Ontario and Quebec that were geographically fairly close to Noranda."

Jan 1, 1970

By Zhan Zhang, Hiromi Nagaumi, Zhen Li

"Recently, the remarkable strengthening effect of ??-Al(Mn, Fe) Si dispersoids at both ambient temperature and elevated temperature were found by several researches. A large amount of dispersoids can be formed by applying special heat treatments and within a suitable range of chemical composition of AA3xxx alloys. In the present work, the influences of Cr addition on the mechanical properties and microstructures of the Al-Mn-Mg-Si alloys were investigated. The mechanical properties at ambient and elevated temperatures were evaluated by micro-hardness and yield strength. Moreover, the microstructures in as-cast and heat-treated conditions were quantitatively analyzed by optical and electron microscopes. Results revealed that Cr also had effect on the number density and volume fraction of dispersoids. Micro-hardness and yield strength at ambient temperature increased with the increasing content of Cr, and the Cr addition increased the yield strength at elevated temperature as well. Moreover, the creep resistance at 300°C improved dramatically with the increasing content of Cr.INTRODUCTION Traditionally, AA3xxx aluminum alloys were widely used in packaging, automobile and architecture industries, because of its good formability, excellent corrosion resistance and weldability. And AA3xxx alloys were considered as non-heat-treatable alloys. However, the strengthening effect of dispersoids in AA3xxx alloys was discovered recently (Li & Arnberg, 2003;Li, Muggerud, Olsen, & Furu, 2012; Li, Zhang, & Chen, 2016; Liu & Chen, 2015).Alarge amount of dispersoids could precipitate by a proper heat treatment.In order to further improve AA3xxxalloys, the composition of the alloys should be optimized. A few previous studies were reported to investigate the influence of compositions on AA3xxx alloys. Adding Mn element could enhance the precipitation of ??-Al(Mn, Fe)Si dispersoids and improve the yield strength(Muggerud, Mørtsell, Li, & Holmestad, 2013), as long as the concentration of Mn was under the solid solution limit. Fe decreased the solubility of Mn and accelerated the precipitation rate of ??-Al(Mn, Fe)Sidispersoids(Li & Arnberg, 2003), the yield strength and creep resistance at elevated temperature could increase with an optimized content of Fe(Liu & Chen, 2016). Mg element would affect the nucleation process of ??-Al(Mn, Fe)Sidispersoids by forming metastable Mg2Si(Hirasawa, 1975; Li, Zhang, & Chen, 2017a; Lodgaard & Ryum, 2000), metastable Mg2Si precipitated during heating process and promoted the precipitation of ??-Al(Mn, Fe)Sidispersoids, moreover, Mg provided solid solution strength for AA3004 alloys(Li et al., 2016). Si increased the volume fractionof ??-Al(Mn, Fe)Sidispersoids(Muggerud et al., 2013)and decreased the size of ??-Al(Mn, Fe)Sidispersoids(Li, Zhang, & Chen, 2017b). With the addition of Mo, the size of dispersoids became finer with a higher volume fraction, the volume percentage of dispersoid free zones was reduced. Elevated temperature yield strength and creep resistance improved due to Mo addition (Liu, Ma, & Chen, 2017).However, the effect of Crelements on microstructure and mechanical properties of AA3xxx alloys were rarely reported."

Jan 1, 2018

By Marcel M. Djivre

The paper will outline the destructive test methods and test procedures including the evaluation criteria currently used at the Materials Testing Laboratory (MTL), Sudbury, Ontario, Canada, a laboratory approved by the Ontario Minister of Labour for the purpose of testing or examining mine shaft ropes or other hoisting appliances. For the evaluation of the mechanical properties of rope samples used in "ultra-deep" single-lift shafts, additional discard criteria used in Ontario, Quebec and South Africa shall be presented. Most of the methods and test procedures currently used at MTL can also be found in the current CSA G4-00 Standard, Steel Wire Rope for General Purpose and for Mine Hoisting and Mine Haulage, published in November 2000. In this latest or sixth edition of CSA Standard G4-00, a new Clause 14 has been added outlining the requirements for in-service destructive testing of steel wire ropes for mine hoisting applications. The CSA G4-00 Standard is also intended for the manufacturing of new ropes, and includes requirements for raw materials and construction features for round strand and flattened strand rope, and locked coil rope in bright and galvanized finish. To-date the Ontario Mining Regulations require only that destructive test of new ropes be performed in accordance with CSA Standard G4-00, but does not require conformity to the Standard, and on the other hand the inservice wire ropes are required to be tested in accordance with CSA G4 and thus require conformity. The author recommends that the Ontario Mining Regulations (and regulations of other mining jurisdictions) be improved in order to ensure quality control in the manufacturing of wire ropes destined for mines in Ontario (and Canada). Also, the author recommends the revision of the CSA G4-00 Standard by the technical committee in order to address manufacturer?s concerns with respect to compliance, and harmonize the Standard with Internationally recognized Standards.

Apr 1, 2005

By J .. R. Brown, G. Deschenes

X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD) and Electron Probe Micro-Analysis (EPMA) were used to characterize chemically the gold complex adsorbed on activatedcarbon from a solution containing 102mglL Au and 0.5 giL thiourea. This paper also considers the gold chloride and the gold cyanide systems. The results indicate gold is adsorbed on activated carbon from the thiourea solution as the gold (I) thiourea complex, i.e. Au [CS (NH) 2];&apos; Other gold species such as metallic gold were not detected on the carbon support. These results also suggest the elution of the gold (I) thiourea complex can be performed with high recovery.

Jan 1, 1993

By G. Heinrich

Size by size recoveries and pentlandite liberation data from image analysis were used to evaluate plant tests of pentlandite flotation and pentlandite/pyrrhotite middlings flotation from pyrrhotite in a circuit treating low grade magnetic intermediates at the Strathcona Mill. Raising the pH with lime gave improved selectivity for liberated pentlandite but there were major losses of middlings unless the circuit was pulled hard indicating the need for finer regrinding. However, size by size recoveries at the normal regrind showed that, while the pentlandite recovery improved in the finer ranges, the pyrrhotite recovery also increased leading to little selectivity in any size range. A much finer regrind gave greatly improved selectivity in all size classes suggesting that 'surface polishing' as well as liberation effects were being seen. Using liberation data from image analysis of the products, surface polishing accounted for over 99 % of the improvement in selectivity. Unreasonable recoveries of more highly liberated particles were observed for liberation analysis by volume fraction but showed the expected trend in recovery when the analysis was based on surface liberation. The surface liberation data showed that the improved pentlandite recoveries after finer regrinding were to more than 90 % caused by improved liberation with the remainder contributed by surface polishing effects. The practical implications of this work are that i) the comparison of particle grades with product grades allows to estimate the effect of regrinding on co-flotation/entrainment, ii) surface liberation models should be used for evaluating recoverabilities by flotation and iii) regrind circuits may be set up to ensure that all particles go through the mill or that only the coarse fraction is reground depending on the surface scrubbing found to be required.

Jan 1, 1993

By w. w. Fraser

"In late 1985, Hudson Bay Mining and Smelting Co., Limited announced the Namew Mine/Mill project. Environmental baseline monitoring and planning began in early 1985 while a major drilling program was under way to delineate the ore deposit. This paper overviews the environmental assessment work conducted for the mine/mill operation, and outlines the tailings and water management practices.Planned environmental works and approach were affected in late 1988 when a massive water problem was encountered in the mine. The requirement to depressurize the rock surrounding the underground workings led to the need to develop, on short notice, an environmentally-acceptable procedure to dispose of a large volume of slightly-saline water.Biological toxicity tests performed on the depressurized effluent proved the effluent to be non-toxic and thus allowed resolution of the disposal problem. This resolution includes the conversion of a large water body from native fish species to a rainbow trout fishery."

Jan 1, 1991