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By Wood W, Bell A

Brown coal production in Victoria's Latrobe Valley Region (Figure 1) continues to rise and currently stands at around 50 Mt per annum. With the exception of around 2 Mt used to produce some 700 Kt of brown coal briquettes, this coal is mined by the State Electricity Commission to fuel large thermal power stations with a total installed capacity of just over 5 000 Megawatts. The moisture content of the coal as mined typically exceeds 60 per cent, making Latrobe Valley coal a markedly low rank fuel. The lack of heating value is, however, compensated for through power station design and by the fact that ash yield is very low, usually within the range of one per cent to four per cent on a dry basis. This means that compared with most other coals, the burning of Latrobe Valley brown coal produces relatively small quantities of waste products and discharges a minimal level of pollutants into the atmosphere. Even so, the inherent quality of Latrobe Valley coal does vary significantly from one area to another (Gloe, 1991; Barton et al, 1992) both on a local and a regional scale. Such variations need to be recognised and understood in order to not only realise efficiency gains in existing power stations but to properly assess resource potential for future utilisation and the application of new technologies. The principal aim of this paper is not to describe coal quality variation in detail or to speculate on the nature of and reasons for such variation. Rather, it is to simply underscore that significant differences do occur and that this is clearly a factor which needs to be considered in any evaluation of Latrobe Valley brown coal as a resource for the future.

Jan 1, 1992

By D. R. Spears

As part of its mission to develop technology to assure a continuing supply of minerals, the US Bureau of Mines has investigated the flocculation of a Stillwater, MT, chromite ore. The ore was flocculated at different solids contents and at different stirring speeds to determine the importance and effect of hydrodynamic factors. In acidic and basic pH, the chromite ore was flocculated with high molecular weight polyacrylamides differing in the degree of hydrolysis. Polyacrylamides were found to bind to chromite ore particles through hydrogen bonding. The anionicity of the polymer and the pH affected the degree of polymer-particle interaction, which in turn affected polymer conformation at the surface. A polymer conformation with many loops and tails was used to explain high flocculation efficiency. It was found that such a conformation could compensate for poor hydrodynamic conditions.

Jan 1, 1992

By Steven M. Rupprecht

"The artisanal mining sector in Central Africa is largely informal, yet provides an essential livelihood for many (directly or indirectly) participants, as well as facilitating an important source for the flow of income into many communities. Artisanal mining varies from site to site, but appear largely well structured despite its informality. The artisanal mining sites in Central Africa have some inherent management structure and the extraction itself is often organised. Artisanal mining is labour intensive and is generally conducted utilising hand digging methods e.g. shovels or hand chisels. Artisanal mining is generally more dangerous than small-scale or large-scale modern mining operations. This is especially true as artisanal operations are generally subsistence activities with artisanal miners focusing more on immediate concerns than the long-term consequences of their activities. When miners have no other source of income, they will usually find ways to evade controls and carry on working. The objective, through proper/dedicated training of artisanal miners is to migrate Artisanal mining to establish a small-scale mining (SSM) industry in Central Africa. Through developing the necessary skills in the fundamental areas of mining it is proposed that Artisanal Mining can become more productive and safer mining operations. The paper reviews the above focus areas, highlighting the skills and tools that are necessary to assist in establishing a sustainable small scale mining industry migrating from manual labour to semi-mechanised mining and processing. The purpose of the transformation process is to create a safe, healthy, environmental and community oriented mining operation with the objective to uplift the skills and wealth of the mineworkers and the general community."

Jan 1, 2015

The plant and processing site at Porgera has been built on a levelled mudstone ridge about lkm E of the mine. Excavation of 7xl06m3 of soil and rock was necessary to achieve the required area. The exposed mudstone belongs to the Chico Formation and is weak, sheared and readily breaks down by slaking upon exposure. Tectonic uplift and subsequent erosion have produced the present landscape of narrow bedrock ridges, with deep colluvium in the incised valleys. The deep excavation to a maximum of 60m, has rapidly unloaded the mudstone, and subsequent stress relief has caused rebound and dilation of the material. The processes of pore pressure equilibration, softening, progressive failure and loosening, combine to deteriorate the newly exposed rock mass. These processes are commonly associated with pre-existing shear surfaces, fissures and a

Jan 1, 1991

By R. R. Klimpel

"SYNOPSISA discussion of the importance of flotation rate in the analysis of mineral flotation is presented. In particular, the highly interactive nature of the flotation ""system"" is emphasized where there are components of chemistry, equipment, and operating conditions simultaneously involved. It is further shown that: 1) flotation rate must be measured in order to economically optimize the performance of an industrial flotation circuit, 2) that consistent patterns exist in both flotation rate and equilibrium recovery when changing various settings of the system components, 3) that knowledge of these patterns is necessary in order to avoid making system changes that are either self-compensating or dramatically re-enforcing in some particular aspect of performance, and 4) the rate related role of the chemistry component (e.g.frothers and collectors) is often much bigger than is sometimes realized (especially in a negative sense involving overdosing of reagents). INTRODUCTIONFroth flotation is widely usedl-6 in mineral beneficiation processes as a method for separating different types of finely divided solids present in a liquid (usually aqueous) suspension. The approach is based on the contacting of solids with upward moving air bubbles in an agitated vessel where the solids are exposed to chemicals (collectors) which create a condition favoring the attachment of a certain portion of the solids to the air bubbles. This selected portion is then removed in a froth stabilized by chemicals (frothers) and subsequently recovered from the flotation vessel. Depending on the settings of the various components of the flotation ""system"" (see Figure 1) it is possible to achieve a wide range of flotation performance."

Jan 1, 1984

Research into the mechanisation of ore winning from the very narrow reefs characteristic of South African gold mines has been conducted from as early as 1964 through the Chamber of Mines Research Organisation (COMRO) but with limited success. However, the Council for Scientific and Industrial Research (CSIR) has recently re-evaluated the potential for the mechanisation for the narrow tabular gold mines. It has been determined that there are approximately 22 000 tonnes of gold left in-situ in channel widths of less than 500 mm in thickness. The extraction of ore from such reefs requires a complete paradigm shift in that the current mining cycle (drilling, blasting, cleaning and supporting) is not feasible since such a stoping width would not allow the workers entry into the stope. Consequently, a non-entry form of mining is required. With this target in mind CSIR has invested in a project called the Nederburg Miner which seeks to identify new technologies for drilling, rock breaking, cleaning, and materials handling, the application of which will enable non-entry mining of very narrow ore bodies. The intention is to develop a fully automated system that will not require human involvement at the stope face. The outcomes of research into this proposed system will not only extend the life of South African gold mines but will also enhance South Africa's reputation for excellence in mining research. This paper presents the new technologies under consideration and potential methods for their application into an integrated non-entry mining system.

Jan 1, 2008

By Ryan L. Veenstra

This paper presents a modelling study of a cemented paste backfill in an underground stope. The model was developed to help provide a better understanding of what is happening in the stope during the filling stage of the stope. In order to do this, the model incorporates the paste rise rate, stope geometry, and time-dependent input parameters. This paper looks at the effect of geometry in two parts. The first part compares a series of simple rectangular stope models. These models differ in size both in two and three dimensions. The second part compares the results of four 2D models together and then to the field instrumentation data. Part of this section introduces the geometry and instrumentation within the test stope.

Jun 1, 2012

The Phoenix mine on the Mararoa Reef at Norseman, Western Australia, provides an outstanding: AUstralian instance of the recurrence of payable ore beneath the bottom of an abandoned mine, and an interesting and instructive example of the development ofideas with regard to ore recurrence in a particular district. The Mararoa Reef is the most productive of several hypothermal goldquartz vains in pre-Cambrian basic volc81olics which strike northsouth and dip on the average, 45 degrees east. The Phoenix minewas abandoned at 500 ft. vertical depth after producing 342,000 tons of 9.9 dwt. recovery grade (equivalent to nearly half of the total production of the Norseman field) from a 2,500 ft.. long, horizontally disposed oreshoot, which is reported to have had an ore outcrop only 30 ft. in length.Interest in the field was revived in 1933, and by 1941 new ore mined and developed on the Mararoa Reef by Central Norseman Gold Corporation N.L. amounted to approximately 700,000 tons of 6.7 dwt. recovery grade. In the same period another oreshoot of similar size and grade was developed by Norseman Gold Mines N.L., south of the old Mararoa company's site. As shown by the plans, the ore occurs in discontinuous shoots. The intervening area of shear is poor in quartz as well as in gold. Geological work on behalf of Western Mining Corporation Ltd., and Central Norseman Gold Corporation N.L. has been in progress in the mine and in the field more or less continuously from 1913 to 1941 and again since 1946. This paper describes the successive advances in the understanding of the exploratory problem up to late 1941, to which several investigators have contributed. It is published by permission of the Board of Directors of Central Norseman Gold Corporation N.L., owners and operators of the Phoenix and other mines.Development of the Prospect.In 1933 Western Mining Corporation acquired an option over the Phoenix property and adjacent leases. H. E. McKinstryl visited the mine and recognised that the ore occurred primarily on the flatly dipping sections of the vein, as distinct from the steeply dippingsections, in a wide shear zone with reverse movement. Many of the flatly dipping fractures were seen to exhibit tension phenomena and to link one shear plane to the next below on the footwall side. The flat links carried much more quartz than the steeper shears.Later, H. J. C. Conolly, assisted by J. D. Campbell, examined the prospect and by contouring the vein with reference to an inclined...

Jan 1, 1950

By Verya Nasri, Scott Thorburn

The City of Toronto and the Toronto Transit Commission (TTC) have conducted an Individual Environmental Assessment (EA) for a 6.2 km, 4-station underground extension of the Spadina Subway from Downsview Station to Steeles Avenue. This Environmental Assessment Study was performed in three phases including routes and general station locations, alignments and station concepts and detailed assessment of the effects of the undertaking. URS Canada Inc. has led the consultant team for this Study. The anticipated total duration of the project is approximately 6 years and its estimated total cost is about $1.4 billion. This paper presents the planning process of the project, the environmental and engineering challenges, and the measures taken to address them.

Jan 1, 2007

By J. E. Johnson

Discussion of the paper of Prof. Henry M. Howe, presented in abstract by Bradley Stoughton at the Cleveland meeting, October, 1912, and printed in Bulletin No. 71, November, 1912, pp. 1181 to 1227. J. E. JOHNSON, JR., Ashland, Wis. :-This material is largely beyond the understanding of most of us practical men, but there are certain portions of that diagram that are of enormous importance. We have been conducting a, very extensive investigation of the quality of charcoal-iron and of all iron, and we have found that this eutectic point here (indicating on chart) is a sort of balance point between the good irons and the bad ones, and I have some slides to show what practical results we have found depending on this point here on the d diagram; and it would be a mistake for men who were -concerned with operation and were getting practical results, to think that these things are of no importance. They are exceedingly hard to understand, and I confess that a great deal of them is beyond me, but there is no doubt that the quality of iron depends to an enormous extent on the location of the carbon content of the iron to the right and left of this point, and the position of that point is dependent upon the silicon, and I wish to make a plea to the practical and operating members of the Institute not to disregard this material on account of its being highly scientific, because I hope to show later that there are matters of the highest practical importance that depend directly upon certain portions of this diagram. HENRY D. HIBBARD, Plainfield, N. J. :-T understand that washed metal, which, is practically pure iron and carbon, does not solidify at one instant, is cast-iron does, but passes through a mushy stage. That has been an enigma as to how and why it did so, and possibly some light might be thrown on it in this connection. BRADLEY STOUGHTON, New York, N. Y.:-If Wittorff's propositions are accepted, washed metal containing more than 4.1 per cent. of carbon would begin to solidify as liquid plus Fe4C

Dec 1, 1912

By Nathan P. Schmidt

Climate and hydrology data are required during all phases of mining projects, including impact assessment, mine planning and design, operational water management and mine closure and reclamation design. In the Canadian north, data sources are spatially sparse and often short-term in nature, and design parameters are often estimated based on data collected at sites far distant. Confidence in such data can be increased by verification or modification using data collected during properly implemented baseline and operational monitoring programs. A data set that accurately reflects conditions at the project is more readily accepted by regulatory agencies during the permitting process, and allows development of more effective and economic water management, mitigation measures and compensation. Data requirements and collection methods for developing an adequate data set for mine development are reviewed. These are illustrated using examples from oil sands, diamond and metal mines in the Canadian north.

May 1, 2004

By William Crowe Kellogg

By now the term AFMAG has been fairly well introduced to the mining industry. Several papers have been presented and published concerning AFMAG (references 1 and 2). However, the term AFMAG remains rather new to the industry, and the exact place which AFMAG occupies in the minerals exploration field is still somewhat uncertain in the minds of many who may have use for this new and interesting method of electromagnetic exploration for conductive minerals. It is the purpose of this paper to again review the basic theory of the AFMAG system, to describe and - illustrate the equipment and data presentation as used in aerial surveying, and to provide some idea of the cost and nature of airborne AFMAG surveys. This paper is primarily of a general descriptive nature and presents AFMAG theory in a schematic rather than mathematical form; emphasis is placed on the equipment, the present method of data presentation and survey operations, since it is believed that such, information will now generally best serve to inform the mining industry of the characteristics of the AFMAG system.

Jan 1, 1960

By Prince Lazarovich, Hrebelianovich

I WAS asked by the chairman of one of the Sessions on Employment Problems to talk about the viewpoint of the foreign workingman. I am not a workingman. I have never done what a work-hand might call an honest day's labor; that is, I have never been in a factory or manufacturing plant or in a mine, though in truth, hard work and I are well acquainted. I was a soldier, am an engineer, have long been actively interested in the most important waterway construction in the near East, have served politics and diplomacy, written books and lectured at universities. My knowledge of the foreign workingman in this country comes from the fact that my own compatriots here at various times came to me and appealed for advice and help, and last year I was asked by the employment manager of a corporation to undertake a welfare job at one of their plants. I went out, saw the plant, talked with the superintendent and outlined certain of my ideas which he personally heartily approved, but which did not find favor with those higher up. I approach the subject of the foreign workman's point of view with the understanding that the industrial employer's effort is for the maximum of efficiency. I am conversant with labor conditions abroad both in industry and agriculture. What I have learned of industrial conditions in America as they affect the foreign immigrant has been chiefly gathered from the cases referred to of foreign workmen who from time to time have come to me with their troubles. In the course of those investigations, in order to give whatever help or advice was possible, I have been impressed with the fact that the great United States industries evidently had- pot yet sufficiently recognized the value of studying the conditions of the workingman in the lands of his origin across the seas. A careful study of that which could be called the moral element in connection with its foreign labor would give industry a knowledge of the man's reason for coming, what' grievances he brings with him, his hopes for a future, and the peculiar character of his capacities. The employer would thereby be enabled to meet the man, to be helpful to him, to aid him and at the same time promote industrial efficiency, inasmuch as a workman who believes that he is being dealt with humanly and squarely is contented and satisfied and will give willingly, and even with pride, the best that is in him; justice and a fair deal is all the man wants.

Jan 4, 1918

By Peter Moser, Mark Ganster, Andreas Gaich

Surveying of a bench face before blasting is a pre-requisite for a proper blast planning and for a satisfying blasting result both in terms of safety and fragmentation. When surveying a bench face, preferably a large amount of measurement points are required in order to determine the geometry and especially the irregularities with sufficient accuracy. Only contact-free measuring systems allow evenly distributed measurements over the whole bench surface. Existing systems such as total station, laser profiler, or laser scanner show significant drawbacks such as that surveying results are just isolated values of the bench geometry such as heights or profiles, that borehole positions have to be defined in advance in order to know where to take profile measurements and that systems require special surveying skills and that they are expensive too. In order to overcome these difficulties and to provide the blasters a simple tool for bench surveying, blast design and layout and the subsequent back-transfer of the blast plan into the quarry, the Department of Mineral Resources& Petroleum Engineering of the University of Leoben, 3G Software & Measurement company and Mineral AB, one of the largest producers of aggregates in Europe formed a joint venture to develop a new system. Based on an existing stereophotogrammetric system for rock surface surveying and joint analysis (JointMetrix), a new tool was developed within a year. Apart from several mines and quarries using that new tool already today in the daily work, both the Department of Mineral Resources& Petroleum Engineering at the University of Leoben and Austin Powder GmbH Blasting Service did a lot of studies to determine the reliability of the new stereophotogrammetric blast surveying and planning system and its precision in comparison to classical laser surveying equipment. After 1 year of testing and comparison with laser based surveying instruments, it can be concluded, that the new technology of blast surveying& design systems based on stereophotogrammetry is suitable for being used in the daily work routine in quarries and mines. The comparison of the precision of laser based systems and stereophotogrammetric systems has shown, that the deviation between these two types of systems is less than 10 cm, in many cases even lower.

Jan 1, 2007

The mineralogy of nickel slags from the flash smelter of Western Mining Corporation Ltd. at Kalgoorlie was studied. Residual magnesium silicates in the sulphide concentrates raise the melting point of the slag and result in the formation of magnesium-rich olivines. Addition of lime lowered the melting point, and, in slowly cooled slags, resulted in the formation of a pyroxene.Magnetite and sulphides were also present in all slags.The converter slags contained an olivine near fayalite in composition, together with wiistite, magnetite, and a little sulphide.Accretions from the hearth of the flash furnace were largely composed of magnetite with subsidiary olivine similar in composition to those of the flash furnace slags.Wall deposits, however, were largely composed of nickel ferrite and nickel-iron olivines.

Jan 1, 1976

Despite limited discussion, Chemistry of Flotation is a good text and reference 1985 by M. C. Fuerstenau, J. D. Miller, and M. C. Kuhn Society of Mining Engineers Caller No. D Littleton, CO 80127 Softcover, $23.50 (member), $18.50 (student member), $28.50 (list) Review by Richard R. Klimpel Chemistry in Flotation, as stated by the authors, is intended as a textbook for students as well as a reference book for practicing flotation engineers. It covers subject matter related to surface phenomena; collectors and collector salts; natural floatability; the flotation of sulfide minerals, insoluble oxide and silicate minerals, semisoluble salts, and soluble salts; and slime coatings. There are no discussions in the book on practical plant implications of flotation chemistry, such as the influence of rate, particle size effects, dosage, flotation equipment, and methods of chemical addition. The book itself is small (only 177 pages), and, as published, is in an easy-to-handle soft cover. Once one accepts the intent of the authors, this book really does represent a very concise and convenient summary of the chemistry of flotation. It is, however, far from complete in its discussion of concepts and implications of data. Very often in the presentation, key prior knowledge (or at least subject matter awareness) not given in the book, is assumed. Thus, depending on one's familiarity with the specific subject matter, some sections can be easily followed while others could be tough going. Some of the discussion is so brief and terse on important subjects that unless the reader already realizes the meaning of the presentation, the conclusions to be drawn are not always clear. Therefore, if one is not expecting a self-contained primer on flotation chemistry, this book is very useful. To this end, the book is recommended to practitioners of flotation chemistry. The presentation of data in figures and tables is good. It helps considerably in the book achieving its conciseness. The authors certainly are qualified and knowledgeable in the subject matter - apparent in the style of presentation. In summary, this reviewer thoroughly enjoyed this book and will use it as a concise review of flotation chemistry. Richard R. Klimpel, member SME, is a scientist with Dow Chemical Co., Discovery Development, 1776 Building, M. E. Pruitt Research Center, Midland, MI 48640. International Symposium on Blast Furnace Ironmaking, 1985, The Indian Institute of Metals, The Tata Iron and Steel Co., Ltd., Jamshedpur 831007, India, 282 pp., papercover, no price given - Papers from this symposium held in Jamshedpur, India, include the following: determination of coal and coke quality; feed to blast furnaces; burden quality and blast furnace performance; operation of blast furnaces on charcoal; review of cast house slag granulation systems; developments in blast furnace engineering and control; process improvements in blast furnace ironmaking; coal injection into the blast furnace; and coke from stamp charged coal. Advances in Materials Technology for the Process Industries, 1985, edited by H.A. Huskins, National Association of Corrosion Engineers, P.O. Box 218340, Houston, TX 77218, 273 pp., softcover, $20-This book is the proceedings of a meeting held in Atlanta, GA in October 1984. It describes innovations in metallurgy, ceramics, glass, composites, and polymeric materials that impact the integrity and economics of operating systems. It covers biotechnical developments, improvements in membrane systems, or beneficiation processes, as well as developments in electrochemical controls, testing procedures, and surveillance techniques. A Reference Guide to Mining Legislation in Canada, 1985, by B. Barton, B. Roulston, and N. Strantz, The Canadian Institute of Resources Law, Room 430, Bio Sciences Building, The University of Calgary, Calgary, Alberta, Canada T2N 1N4, 120 pp., bound, $US28- This guide provides a ready means of finding how the different jurisdictions in Canada regulate mineral activity. It covers the rights required for exploration, development, and production of mineral metallics and industrial minerals. It does not cover placer mining, petroleum and natural gas, bituminuous sands, coal, or structural materials. Dictionary of Geological Terms, 1985, edited by Robert L. Bates and Julia A. Jackson, The American Geological Institute, 4220 King St., Alexandria, VA 22302, papercover, $7.95 plus $1 for postage - This third edition is for geoscience students, teachers, and rockhounds. It defines the core vocabulary of earth sciences, contains 8000 revised definitions, and includes 1000 new terms. It adds recent terms in plate tectonics, hydrology, and permafrost studies. Accurate definitions are given without technical jargon, cross-references are included, and commonly used abbreviations are provided. Processing and Utilization of High Sulfur Coals, 1985, edited by Yosry A. Attia, Elsevier Science Publishing Co. Inc., 52 Vanderbilt Ave., New York, NY 10017, 787 pp., bound, $142.50-These proceedings comprise the majority of the papers presented at the First International conference. Investigators there reported the latest discoveries, developments in commercial practice, and state-of-the-art reviews of scientific principles and applications of various technologies for handling, processing, and use of high sulfur coals. Sessions were held on: characterization of sulfur in coals; environmental problems and impact of high sulfur on coal use; selective mining and blending; coal desulfurization by physical and chemical cleaning techniques; handling of coal fines; sulfur capture during coal combustion; biological desulfurization of coal; and new applications for high sulfur coal. The Economics of Magnesium Metal, 1985, Roskill Information Services Ltd., 2 Clapham Road, London SW9 OJA England, 129 pp., 71 tables, appendices, bound, $750-Despite setbacks in some major magnesium markets in 1985, Roskill's latest forecast for the last half of this decade is for a 4% to 6% annual growth rate in demand. Growth for magnesium metal is expected in the motor industry for use as a possible substitute for aluminum. Some magnesium producers are altering their marketing strategies to cultivate this market. This study also includes a review of the worldwide magnesium industry, its end uses and consumption, and international trade and price trends.

Jan 7, 1986

By R. W. Lawrence

"In the past year, BioteQ Environmental Technologies Inc. have initiated design and construction of new plants to add to an existing list of plants that utilize the BioSulphide® and ChemSulphide™ process technologies for metal recovery and water treatment. In these plants, low cost biogenic sulfide or, in some cases, chemical sulfide reagent is used to selectively remove metals from contaminated water. The process produces high grade, marketable, metal sulfide products even from low grade feed solutions. The revenues generated from the sale of products can allow for water treatment at a profit in some cases, offset treatment costs in others, and generally reduce sludge disposal and management costs. The effluents produced from the process can meet stringent environmental standards. Current plants in operation and under construction range in sulphide demand from 50 kg/day to 3.7 tonnes/day, with the feasibility of larger plants with sulfide demands ranging from 6 to 43 tonnes/day under review.Biogenic sulfide reagent can also be considered for other applications in hydrometallurgy and mineral processing. Uses under consideration by a number of mining companies include: (1) replacement of sodium hydrosulphide in the SART process for cyanide regeneration and copper recovery in the processing of gold-copper ores, and (2) replacement of sodium hydrosulphide for use in the separation of copper and molybdenum in flotation. Biogenic sulphide, produced on demand at site, offers significant cost savings and provides the additional benefit of improved safety due to the elimination of the transportation, handling and storage required for chemical sulphide reagents.This paper reviews the applications of the BioSulphide® and ChemSulphide™ technologies for water treatment and metal recovery, and introduces projects where biogenic sulfide can be applied in hydrometallurgy and mineral processing."

Jan 1, 2007

By M. Veiga

"Mining is an energy and water intensive activity. Increasing energy efficiency and reducing water consumption are two of the key requirements in moving toward a more sustainable mining industry. Water reduction, reuse and recycle options are reviewed, identifying cases where these options have been implemented. Then a novel mine water network design method is described, which analyzes a mine/mill water system in order to identify areas where water requirements and water system energy requirements can be reduced. First, a site water balance is determined and major water consumers and sources are specified. Next, multiple possible combinations of supplying water to mine and mill consumers are compared. Finally, low energy and water combinations are identified.INTRODUCTIONMining consumes vast quantities of energy: The whole mining and metals sector consumes over 12% of the world’s energy (DOE, 2009). Mining also requires large quantities of water, although mining water consumption is a relatively small portion of the overall world water use. Even in relatively dry, mining-intensive countries like Australia and South Africa, mine water consumption is only 2-3% of national water demand (Brown, 2003). However, at the local level, when mining takes place in areas where water is scarce, mine water consumption can severely impact local supplies. In addition, acid rock drainage, leaks from waste impoundments, or direct disposal of tailing into waterways can contaminate surface and groundwater (MMSD, 2002). Mine water systems can be large energy consumers, but better mine water systems can reduce both water and energy consumption. Improving water system design and practice are key strategic requirements in moving toward a more sustainable mining industry.This paper addresses conventional base-metal or precious-metal mine sites, which consist of an underground or open pit mine and a mineral processing plant, or mill. Ore is extracted and processed through the plant to produce a saleable product. Tailing, or waste material, is then deposited in a tailing storage facility (TSF). Any rock removed from the mine with no economic value, or waste rock, is stored without being processed."

Jan 1, 2010

By P Steinier

Most operations, when considering their comminution circuit, are primarily concerned with achieving the desired particle size distribution to obtain adequate liberation for the separation process, at minimum cost. Invariably, the effect the grinding media has on the subsequent separation process (ie flotation, leaching) is not taken into account when selecting the media. This choice is driven by cost rather than metallurgical outcomes. Maximising valuable mineral recovery, with optimum selectivity against gangue minerals, is about good particle preparation. And, particle preparation is strongly related to achieving adequate mineral liberation with the correct pulp chemical conditions. However, the pulp chemistry of a system is largely ignored and relies heavily on pH control and the addition of appropriate reagents (collectors, frothers, activators, depressants). The changes effected by the addition of the various reagents are obtained through conditioning the ground pulp prior to or during the concentration stage, subsequent to grinding. Frequently, reagents are added during grinding with good effect, but the impact of the grinding media on down stream processing is usually overlooked. A number of case studies examining the effect of grinding media on pulp chemistry and subsequent flotation performance were completed on several different sulfide mineral systems (for example, lead/zinc, copper, refractory gold). The evidence suggests that a change in grinding media type from forged to high chrome (ie conditioning the pulp during grinding) resulted in a shift in pulp Eh to less reducing conditions, an increase in the dissolved oxygen content of the pulp and a reduction in the iron species present. The changes have a positive impact on flotation behaviour. The results of the case studies are discussed.

Jan 1, 2004

The Archaeozoic Willyama Complex at Broken Hill has suffered several periods of deformation and metamorphism. New structural and petrological information together with that available from the literature gives a picture of the metamorphic evolution of the Barrier Ranges. Several epochs of metamorphism are recognized, and potassium-argon dating of minerals has been applied with limited success to the resolution of these epochs.INTRODUCTIONAdvancements in the mineral industry at Broken Hill over the past eighty years have been accompanied by a continual striving towards increased understanding of both the geological history of the Barrier Ranges and the environment of the Broken Hill ore deposits. However, although many detailed studies of selected localities and particular-aspects of Broken Hill geology have been carried out recently, the regional geology of the Barrier Ranges as a whole has received little attention from a petrological viewpoint since the pioneer investigations of Mawson (1912) and Browne (1922). There still remains a great need for regional surveys combining field studies of the habits, structures and outcrop relationships of the various rock types with laboratory investigations of their chemistry, mineralogy and microscopic ,fabrics. Recording observations arising from three brief visits to the Broken Hill area during 1959 and 1963 may stimulate further surveys.During one of these visits, the generosity of the Zinc Corporation Limited in providing field transport and geological guidance enabled the writer to collect material and study field relationships and appearance of the various rock types at numerous localities covering most of the Willyama outcrop. A complete study has not been conducted...

Jan 1, 1963