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By C. Chongo, F. X. Paquot, C. Ngulube

"Over the last six years, the Kansanshi copper/gold mine has continued to process significant quantities of complex transitional mixed ores. The effect of the complex mineralogy on the flotation performance is depicted. Initially, ore treated came predominantly from accumulated stockpiles. In the ensuing years, ore treated shifted to primarily freshly mined ore that generally showed less tarnish with better float kinetics but with the downside of producing lower concentrate grades. A number of changes were made to improve the efficiency of the roughing circuit and quality of concentrate produced. These changes were as a result of initial mineralogical studies and laboratory float test work done and discussed at length in a previous paper. Salient among the adopted recommendations from previous work were increasing circuit capacity and modifying configuration to increase the residence time and the number of sulphidisation stages. These modifications were completed and commissioned in 2011. This, however, resulted in significantly low rougher concentrate grades and subsequently below-specification final concentrate product. This was primarily due to higher mass pulls resulting from the extended rougher bank with multiple concentrate discharge streams. This necessitated the need for an enlarged cleaning capability to offset this. The extra cleaning capacity came on-stream in 2014. Of note was the development of a recovery model, based on the strong correlation between the total copper and acid-soluble copper ratio, as a tool for monitoring plant performance. INTRODUCTION The Kansanshi mine, the largest copper mine in Africa, is 80% owned by Kansanshi Mining PLC, a First Quantum subsidiary. The remaining 20% is owned by the state through the parastatal ZCCM. The mine is located approximately 10 km north of the town of Solwezi and 180 km to the northwest of the Copperbelt town of Chingola. The mine has been in commercial operation since 2005. Prior to June 2009, Kansanshi mine treated only two ore types: oxide and sulphide. All transitional ores mined during the period leading up to 2009 were stockpiled. The treatment of the minerologically complex, transitional ores through a third train commenced in June 2009 but with numerous metallurgical challenges. This transitional ore (called mixed ores) could not be previously treated economically due to high gangue acid consumption (GAC) minerals association (making it unsuitable for the oxide float–leach circuit) and poor flotation response ruling out the conventional sulphide float circuit. The new novel circuit involved a conventional sulphide pre-float followed by flotation involving staged controlled potential sulphidisation (CPS)."

Jan 1, 2015

By k. Osei-Boakye

This paper presents the calibration of a real-time aerosol monitor, the TSI DustTrak?, to the NIOSH 5040 method being used by the Mine Safety and Health Administration (MSHA) for compliance enforcement evaluation. The standard NIOSH 5040 instrument for compliance evaluation of diesel particulate matter (DPM) has an inherent time lag of up to two weeks for laboratory processing of sample results. Therefore, providing the underground mines with a means of quantifying DPM conditions in real-time, will enable them to efficiently and effectively manage DPM levels to ensure compliance with the regulated limit.

Jan 1, 2009

By Chen Xia, G. Deschenes, Wan-Tai Yen

"Ammonium thiosulphate is a potential replacement for the cyanide in gold leaching. However, the high reagent consumption hinders its practical applications. In order to reduce the thiosulphate consumption, chemical additives were used. The gold leaching tests were conducted on a sulphide copper-bearing gold ore with 0.3M thiosulphate, 0.03M copper sulphate and 3M ammonium hydroxide solution at 44% solids and pH 10.2. Sulphate, sulphite, amino acid and chelating agents were initially used as additives. It was found that chelating agents (EDTA and NTA) could reduce the thiosulphate consumption from 30 kg/t to 17.8 kg/t with some increase of gold extraction. The improvement from other additives was not significant. Other approaches were also attempted to reduce thiosulphate consumption with some success. The thiosulphate consumption could be reduced to about 17 kg/t by reducing copper sulphate concentration fiom 0.03M to 0.0015M; adding 0.04M of EDTA; replacing copper sulphate with 0.001M of nickel sulphate. The increase of pulp density fkom 44% to 60% solids could reduce the thiosulphate consumption to 17 kg/t as well. Limiting the dissolved oxygen content by sparging nitrogen reduced the thiosulphate consumption further to 10 kg/t. It could be concluded that the regulations of copper and oxygen supply in the lixiviant were the keys to reduce the reagent consumption.INTRODUCTIONCyanidation, as the predominant gold leaching method, has been used in mining industry for more than a century. The low reagent requirement and the high performance are the reasons for its great success. However, cyanidation cannot deal with ores containing large amount of copper, nickel, arsenic and zinc minerals. This type of ore may consume more reagents and result in a poor gold extraction. On the other hand, the carbonaceous materials may preg-rob the gold from pregnant solution and make cyanidation a problem leaching method. Further more, the high toxicity of cyanide represents another challenge to modern gold mines. In the beginning of the year 2000, an environmental disaster caused by an accidental spill in Yugoslavia was broadcasted world-widely (Gurevitch 2000). Gold mine operators are facing higher social pressures and increasing costs on environmental protections. The usage of cyanide in mining industry has been banned in some countries and locations such as Czech Republic, Japan, Turkey, California, Colorado, Wisconsin and Montana States. Thus, a non-cyanide lixiviant is required."

Jan 1, 2002

The National Mining Hall of Fame and Museum (NMHF&M) will induct its the 2014 National Mining Hall of Fame Class on Sept. 13, 2014 during its 27th Annual Induction Banquet and Ceremony at the Westin Hotel in Denver, CO. Representing the domestic and worldwide metal production, education, and health and safety sectors of the industry, this year?s four inductees cover a diverse cross-section of the mining industry. Harry M. Conger III, Günther Franz (Frank) Joklik, Ellen Swallow Richards and Dr. Alfred Weiss will join 223 other mining industry pioneers when they are formally inducted into the National Mining Hall of Fame. They were selected for being visionaries, leaders and ambassadors, both within their own sectors and across the industry at large. Conger was a great role model and strong advocate within Homestake Mining Co. and among his industry peers on behalf of environmentally responsible, safe, profitable and high-performance operations. As chairman and chief executive officer, Conger was instrumental in revitalizing and rebuilding Homestake into an industry leader in technological advances and environmental protection. Through his contributions in exploration, project development and operations management as Kennecott president and chief executive, Joklik did much to strengthen Kennecott as a company and assisted in restoring the competitiveness of the U.S. mining industry. Richards is generally recognized as the founder of ecology. She was the very definition of a pioneer in such diverse fields as chemistry, geology and mineralogy, mining and metallurgy, environmental science, public health, home economics and education. Weiss was a true visionary in using quantitative methods and digital computers to aid mineral exploration, plan and design mines, operate mineral production facilities and integrate the disparate information resources throughout a mining company into a modern management information system. NMHF&M Board of Directors Chairman, Paul C. Jones, said, ?Again this year we are honored to be able to induct an outstanding group of deserving individuals who have made exceptional contributions to the mining industry in the United States. Included are two living inductees who have made significant contributions to management in the industry. One inductee was the first female graduate from the Massachusetts Institute of Technology, its first female faculty member and the first female member of AIME who had an outstanding career as a mineral investigator in the United States. Another inductee was a lifetime innovator in bringing digital technology into common use in our industry. Each of our 2014 inductees made significant and lasting contributions to our industry and are well deserving of becoming a member of the National Mining Hall of Fame.? The Hall of Fame Induction Banquet and Ceremony is a marquee event for the National Mining Hall of Fame and Museum each year. The 27th Annual Induction Ceremony and Banquet will be held at the Westin Hotel in Denver, CO on Saturday, Sept. 13, 2014. For banquet reservations, contact the NMHF&M office at 719-486-1229. More information is available on the NMHF&M website at www.mininghalloffame.org.

By E. G. Davis

This report summarizes an investigation to determine the occurrence and recoverability of heavy minerals in sand and gravel operations in the Southeastern United States. A total of 61 samples from 34 sand and gravel operations in Alabama, Georgia, South Carolina, and North Carolina were studied. Heavy minerals, in amounts ranging from 3 to 400 pounds per ton, were found in all of the samples. Eighty percent of the samples contained 20 to 40 pounds per ton of heavy min¬eral. Valuable heavy minerals, in order of decreasing amounts, were ilmenite, kyanite, zircon, rutile, and monazite. Large-scale concentration tests were made on five samples from four major producers. Gravity concentration by Humphreys spirals and tables resulted in bulk heavy mineral concentrates that graded from 82 to 98 percent total heavy minerals. Mineral recoveries ranged, in percent, as follows: Ilmenite 60 to 95; zircon 96 to 100; kyanite 37 to 77; rutile 89 to 100; and monazite 96 to 100. Separation studies on the gravity concentrates showed they would respond to high-tension and high-intensity magnetic separation techniques to produce individual mineral concentrates. The recovery of each individual mineral from fractionation of the heavy mineral gravity concentrates, in percent, was: Ilmenite 77 to 94; rutile 41 to 68; kyanite 62 to 79; zircon 49 to 83; and rare-earth products, monazite and xenotime, 42 to 96. The grade of each mineral concentrate was: Ilmenite 51.1 to 68.7 percent Ti02; rutile 93.7 to 94.3 percent Ti02; kyanite 55 percent A1203; zircon 58 to 61 percent Zr02; and rare-earth products containing 73.8 to 90.8 percent monazite and 4.8 to 12.7 percent xenotime.

Jan 1, 1971

By James C. Barker

Unverified reports of rare earth element (REE) concentrations in gold placers and radioactive mineral prospects in the Zane Hills were investigated by the U.S. Bureau of Mines as part of the Alaska critical minerals program. REE is reported to occur in dredge concentrates at the Hogatza mine and up to 1.2 pct REE was previously analyzed in alkalic syenite (bostonite) dikes marginal to the pluton. In addition, numerous thorium-rich veins, explored for their uranium content but unevaluated for REE, occur on the western margin of the Zane Hills. The Bureau mapped and sampled all of the reported or suspected REE occurrences. Dredge concentrates contain abundant uranothorianite, a mineral species which incorporates cerium subgroup REE. Bostonite dikes occur in conjunction with a multi-phased zoned alkalic intrusion, however, no significant REE concentrations were found. Thorium-rich veins contain nil to 0.5 pct Y but resource potential is limited by this relatively low grade, the ultimate low tonnage potential, and the lack of uranium as a major economic element. The Zane Hills exhibit attractive exploration targets for uranium deposits, primarily in a sedimentary form. Gold may be found peripheral to the pluton in both placer and lode deposits. Resource potential of REE, however, appears limited to a placer by-product of REE-Zr-Ti that is recoverable only during large scale gold placer mining. Placer exploration of the lower Wheeler and Dakli Creeks is suggested.

Jan 1, 1991

By L. B. Berger

From time to time the Bureau of Mines receives requests for information and advice regarding the safety of using internal-combustion engines operated on butane fuel as prime movers for haulage and other purposes in mining and tunneling. The purpose of this, circular is to discuss the properties of butane and to present data in regard to the possible use of this fuel in underground operations. Published information on the use of commercial butane as a fuel for internal-combustion engines indicates that, insofar as performance is concerned, butane may be utilized satisfactorily and efficiently for this purpose. However, the introduction of a volatile, inflammable material such as butane into confined spares such as mines or tunnels would create potential fire and explosion hazards that should be given due consideration by those concerned with the promotion of safe practices.

Jan 1, 1944

By Kevin Hennings

Screening efficiency models developed to date rely almost exclusively on empirical formulas based upon large amounts of acquired operating data. A screening model was developed using a combination of empirical coefficients and explicit mathematical expressions which quantify screening phenomena. A series of screening tests was run to supply data for purposes of correlation and empirical coefficient evaluation. The model has been implemented as a digital computer program. The validity of the modeling procedure has been established by laboratory testing. Results generated by the model have been used to compile an applications handbook, which can be used to predict screening performance in lieu of using the computer program.

Jan 1, 1982

By Robert W. Bruhn

An investigation was male of ground response to pillar retreat mining in a 1.7 meter thick seam at 108 meter depth at a site in northern West Virginia. This paper describes mining-related stress changes and movements at nine level, displacements within the overburden, ground surface subsidence and groundwater level variations. Subsidence approached 40 per cent of the nine height ad continued more than a year after mining. Water levels declined la certain deep-lying strata.

Jan 1, 1984

This Bureau of Mines report comprises tables listing the name, location, and other pertinent data concerning certain future fuel-related projects. The tables include information on projects involving the proposed or planned development of fuel resources, as well as the development of storage, transportation, and conversion facilities; the report covers the 26 States east of the Mississippi River. Of the total 594 projects for which information is provided, 492 concern coal mines and electric generating plants.

Jan 1, 1976

Open cast mining has been practiced in South Africa since the late1970s under near ideal geotechnical conditions. In the past decade, with the exhaustion of the traditional South African coal fields, geotechnical conditions have deteriorated. In addition, the nature of the open cast coal mining industry is changing from the conventional strip mining of virgin coal seams to the extraction of underground coal pillars by buffer blasted highwalls. These industry changes have resulted in the need to re-examine the manner in which geotechnical engineering is applied to highwall design. This paper proposes a geotechnical design rationale for open cast highwalls. Furthermore, the rationale takes cognizance of the various geotechnical hazards associated with conventional strip mining and pillar extraction by buffer blasted highwalls. The need to use geotechnical domain models and blasting geotechnics, as proactive tools for rock fall reduction, are also discussed.

Jan 1, 2001

By Steve Kral

The mining industry in northern Ontario is known mostly for its huge nickel deposits. Inco’s and Falconbridge’s nickel mines in the Sudbury Basin are the best known. And with nickel prices being what they are, interest in the region continues. And how. Inco and Falconbridge want to merge. Teck Cominco wants Inco, but without Falconbridge. Xstrata made a hostile bid for Falconbridge, which Falconbridge rejected. And, in June, Phelps Dodge trumped them all when it made an approximately US$40-billion friendly offer for Inco and Falconbridge in a two-part deal.

Jan 1, 2006

By Dimitris Pachakis

In this paper, the authors give a brief overview of the current practice guidelines and tools for the seismic design of sheet pile quay walls, emphasizing how the design guidelines are lacking when the existing structure performance evaluation is required to meet performance-based criteria. Relying on recent experience they explain how the existing practices can be amended to focus more on performance evaluation as opposed to design. An example is given of an old sheet pile quay wall analyzed and evaluated for its performance according the recent performance criteria devised for Californian Marine Oil Terminals.

Jan 1, 2011

Distinguished guests ladies and Gentlemen. As many of you know, before I became a Labour Member of Parliament, I had an unusual career path for a politician, in that I spent quite a few years working in the business community. In other words, I was mainstreamed before I was institutionalised. Given that some of this time was spent working for the then Macraes Mining Company Limited, now Gold and Resource Developments NL, I feel that I may have a perspective on how things are seen, on both sides of the fence. In terms of public perception and esteem I am not sure which career option was the step up and which was the step down. So far what I have found very familiar, is that in both roles there is a gulf between the reality and the perception of that reality - a gulf that is both huge and hard to bridge. I think it is a point worth making here amongst another busy industry cluster, that we can all too easily get so embroiled in the day to day activities, that we lose sight of how this might look to those running on a different treadmill. I can still remember scratching my head at the beginning of some days, as I worked to get new mining projects started that I knew were going to bring real jobs and economic benefit to New Zealand, but ending the day feeling like I may instead have been proposing bringing back both strip mining and slavery. If I learnt one valuable lesson out of that time it was this: .... mining has become so publicly demonised on the road to ecological nirvana, that even attempting a lucid dialogue on mining issues, with some, is incredibly difficult.

Jan 1, 2000

Perception has the unfortunate habit of becoming reality. Urban inhabitants unfortunately do not regard mining as a legitimate or desirable business, despite its contribution to Australia's export income (+A $8,000 million, being nearly a third of all exports); share of GDP (it is 4.5%); and the fact that its presence fills up all the empty spaces northwest of the Adelaide-Melbourne-Sydney-Brisbane crescent of inhabitation. The huge economic contribution of Australia's minerals industry, resulting from providing more than half of merchandise exports (Figure 1), is achieved by employing only some 2% of the national work force (Gaulton, 1997). Unfortunately, the minerals industry's critics generally oppose exploration on the basis that what you don't know will not hurt you. It is the 'do-not-confuse-me-with-facts' philosophy or 'ostrich syndrome', which somehow crudely assumes that mining practices have stayed in the style popular circa late 1800s. Somehow ignorance really is bliss for these idealistic believers, who are reminiscent of the members of the Flat Earth Society!

Jan 1, 1997

By K. Ding

The thermodynamic activity of MnO was measured in MnO-CaO-MgO-SiO2 slags that are typically encountered in the production of manganese-containing stainless steels. A gas equilibration-quenching technique was employed in measuring the activities. Activities of Mn in Pt-Mn alloys were redetermined at 1600ºC, which reconfirmed earlier results of strong negative deviations. MnO activities were then measured by equilibrating slags of various compositions based on a statistical experimental design procedure with Pt-Mn alloys under controlled partial pressure of oxygen in MnO saturated platinum crucibles at 1600ºC. Activities of MnO were found to increase with increasing concentration of MnO, basicity and CaO to MgO ratio. Two multi-coefficient regression models were developed to predict the activities and activity coefficients of MnO in slags at 1600ºC. Keywords: activity, MnO, slag

Jan 1, 2005

By Johnston, T. L.

BISMUTH is found as native metal associated with tin, copper, cobalt, silver, gold, or other metals and in a variety of ores. The more important ones are: bismuthinite (bismuth glance), Bi2S3; bismite (bismuth ochre), Bi2O3.3H2O; and bismutite (bismuth carbonate), Bi2O3CO3?H2O. Of lesser importance are the arsenate, telluride, and vanadate. The sulfide is the most common; the others are often oxidation products from this mineral. Bismuth minerals have been found in various places in the United States, principally in Colorado and Utah, but no ores are mined solely for bismuth. In the Granite mining district of Beaver County, Utah, a stratum of limestone about 6 ft. thick has been almost completely replaced by contact minerals in which bismuthinite associated with pyrite and molybdenite was found intergrown with silicate minerals. In the early days a few small lots of ore assaying 7 to 10 per cent bismuth were shipped from this district. Native bismuth has been found in the Clifton and Tintic districts of Utah. Bismuth is produced as a byproduct in the refining of lead, copper, gold and silver ores, it being recovered from the anode mud from the Betts process. Deposits of bismuth minerals exist in Argentina, Aus¬tralia, China, Japan, Germany, Spain, Peru, Bolivia, and Canada, but Bolivia is the principal, producer and could easily supply all of the present world's demand.

Jan 1, 1933

By Godofredo F. Barrios

For years urethane screen surfaces have been used in a wide range of wet screening applications where openings from as fine as 100 microns and coarser have been used. The purpose of this paper is to expose the reader to new developments in both screen surface and screening equipment technologies which allow an end user to consider urethane screen surfaces for fine screening applications. These technologies allow an end user to use the inherent advantages of urethane with regards to wear resistance while also realizing the benefits that a high oper area urethane screen surface can bring. These benefits include non blinding characteristics and feed capacities that which rival that of traditional stainless steel surfaces. The paper will highlight the features of this patented urethane screen surface technology and the screening machines they are used in conjunction with. There will also be a presentation of case studies of commercial installations where these technologies are utilized. These case studies are from the base metals industry therefore relevance to the conference is direct and not inferred. Included in the paper will also be constraints which must be taken into account when considering urethane screen surfaces such as temperature and chemical attacks. This paper will expose potential end users to a possibility of using screens to achieve extremely accurate size separations in applications where screens were previously not considered. The paper will explain and demonstrate that prior concerns of screen surface blinding, high screen surface consumption rates and large screen surface area requirements can be eliminated by proper utilization of high open area urethane screen surfaces.

Jan 1, 2007

By M. Yavuz

Underground mining method selection (UMMS) is one of the most important issues in mining engineering. Underground mining method should be primarily selected to make use of underground resources optimally. It is nearly impossible to change the mining method once selected by the reasons of rising costs and mining losses. Because of these reasons, UMMS process is extremely important in mine designs and economics. The strategy of underground mining method selection has been studied by different researchers in the literature. Boshkov and Wright (1973) proposed a classification system; Morrison (1976) suggested a selection chart; Laubscher (1981) proposed a selection methodology; Nicholas (1981) presented a classification system; Hartman (1987) developed a selection chart and Miller-Tait et al. (1995) modified the Nicholas? system and developed the UBC mining method selection process. In reality, UMMS is one of the important Multiple Attribute Decision Making (MADM) problems and mining engineers have always some difficulties in making the right decision in the multiple criteria environment. To make a right decision on UMMS, all known criteria related to the mining method selection should be analyzed and the problem solved according to suitable decision making techniques. A review of the literature reveals that decision making techniques have been used for UMMS applications. Kesimal and Bascetin (2002), Bitarafan and Ataei (2004), Bascetin et al. (2006), Alpay and Yavuz (2007), Karadogan et al. (2008) and Samimi Namin et al. (2008) used decision making techniques in UMMS applications. In this paper, two different MADM methods: Analytic Hierarchy Process (AHP) and Fuzzy Multiple Attribute Decision Making (FMADM) are applied to select the optimal underground mining method for a chromite mine and final solutions are then compared. THE AHP METHODOLOGY The AHP method developed by Saaty gives an opportunity to represent the interaction of multiple factors in complex unstructured situations (Triantaphyllou, 2000). The method is based on the pair-wise comparison of components with respect to attributes and alternatives. A pair-wise comparison matrix n×n is constructed, where n is the number of elements to be compared. The method is applied for the hierarchy problem structuring. The problem is divided in to three levels: problem statement, object identification to solve the problem and selection of evaluation criteria for each object. After the hierarchy structuring, the pair-wise comparison matrix is constructed for each level where a nominal discrete scale from 1 to 9 is used for the evaluation as shown in Table 1 (Saaty, 1980; Saaty, 2000). The next step is to find the relative priorities of criteria or alternatives implied by this comparison. The relative priorities are worked out using the theory of eigenvector. For example, if the pair comparison matrix is A, then, [Amax=××- [1] ] To calculate the eigenvalue ??max? and eigenvector w=(w1, w2,..., wn), weights can be estimated as relative priorities of criteria or alternatives. [ ] Since the comparison is based on the subjective evaluation, a consistency ratio is required to ensure the selection accuracy. The Consistency Index (CI) of the comparison matrix is computed as follows: [CImax--= [2] ] where ?max is maximal or principal eigenvalue, and n is the matrix size. The consistency Ratio (CR) is calculated as: [CR= [3 ] where ?RI? Random Consistency Index. Random consistency indices are given in Table 2. [ ] Table 2. The consistency indices of randomly generated reciprocal matrices As a general rule, a consistency ratio of ?0.10? or less is considered acceptable. In practice, however, consistency ratios exceeding ?0.10? occur frequently. THE FMADM METHODOLOGY The FMADM methods have been developed due to the lack of precision in assessing the relative importance of attributes and the

Jan 1, 2009

By Sidney Katell

Philippine laterite and serpentine ores can be utilized in an electric furnace operation to produce both a steel ingot and a ferronickel product. Figure 1 is a schematic interpretation of a plant in which laterite and serpentine ores are processed separately to obtain both ferronickel and steel as products. A relationship of estimated capital requirements and probable returns has been established in this study for a plant of this type. No attempt has been made to evaluate the risks involved in commercial operations. At such time that the project might be constructed and placed in operation, changes in the costs of material, labor, and power may materially affect the profitability aspects of this study. One of the uncertainties involved in the economic evaluation is the cost of mining, handling, and shipping the ores. It is on this basis that the cost of ore delivered at the plant is assumed to be variable at $3, $5, and $7 per net ton (dry basis). For all other costs a plant site at Iligan City, Philip-pine Islands, has been assumed in preparing the economic characteristics for a plant that will process 2,000 tons4/ of ore per day. Results of the study, for the 2,000-ton plant, with all monetary values expressed in terms of United States currency (Philippine peso valued at $0.50), are summarized as follows:

Jan 1, 1962