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By T. F. Torries

Market data commonly perceived as being useful to industry for decision making include prices, production and trade quantities, production and transportation costs, stocks, customer's needs, and competitor's qualifications. Costs and factors affecting costs are particularly important in determining competitive positions and possible future prices. These costs include relative cost of production as well as cost experienced by the buyer in making the final product. Care must be taken to calculate costs in a consistent manner to achieve meaningful analyses.

Jan 1, 1987

By K. F. Jakob

Sustainable development is a principle for the way we should act in the present. It ensures also options for the future to achieve a balance between social, economic and ecology development. The efficiency of raw material utilisation is being enhanced through technological developments, starting from extraction through all the following stages of the value creation chain. The use of domestically produced resources helps to assure the technological know-how. Additional indicators being collected and published by individual companies are questionable in countries with a tightly regulated legal framework such as in Germany, but make sense in developing and threshold countries. Sustainability in terms of efficient use of raw materials will manifest itself at the next stages of the value creation chain. Examples for efficiency improvement can be found in the steel, the power generation and agriculture industries. The approval procedures for German mining operations entail an internationally extremely strict assessment of the potential impact on the environment. All the mining activities include remediation and recultivation where the practise in Germany has become model character by international levels.

Jan 1, 2005

By J. J. Schwoebel, M. J. Mavor

Rapid coal extraction techniques in gassy mines may strain a ventilation system if a degasification approach is not utilized. Design of mine ventilation systems requires estimates of gas emission rates from unmined coal into the existing mine workings. A degasification system for a specific property can be properly engineered to improve mining economics if the proper geologic and reservoir information is collected. This paper describes methods to determine the degasification rates for horizontal boreholes and vertical (stimulated and unstimulated) wells and the rate of gas emissions into the mine workings. The methodology is demonstrated by a specific example. Horizontal boreholes drilled in advance of mining are demonstrated to be the most effective means of coal seam degasification and reduction of gas emissions into mine workings. The significance of the paper is that few published methods for these estimates are available

Jan 1, 1991

By J. A. L. Campbell

Peabody's Camoy mining system is a truly continuous conceptual method of underground mining of coal. The system solves the three factors which limit coal from being mined continuously. Camoy's principal features are improved productivity and increased recovery. A conservative retreat production rate of 2 1/2 times normal continuous miner room-and-pillar mining rates are projected for a 6-7' seam. Overall mine productivity will be 2 times normal, with a potential for considerably higher rates. Major incremental production increases can be achieved by partial implementation of the system. Total mine recoveries of 75% are expected. The system includes both advance and retreat mining. The retreat half of the approach encompasses many of the features of short wall mining. A central panel is prepared for retreat mining by driving entries using room-and-pillar mining to the left and right of it. The room-and-pillar mining encompasses the advance features of Camoy. In the retreat phase, the roof of the face is supported by self advancing chocks or shields. All mining is done under the chocks by a continuous miner. As the miner advances the chocks continuously move forward behind it. Thus, as in a typical short wall system, continuous roof support is attained. Ventilation is unidirectional, another characteristic of short-wall type systems. Fresh air is brought in and passed over the working personnel. It moves to the face where the continuous miner is operating, picks up the generated dust and released methane, and is exhausted away from all personnel. Exposure to respirable dust and ignition hazards due to methane build-ups are almost totally eliminated. Thus, the second limiting factor is overcome and continuous ventilation is attained. Coal mined with the continuous miner is passed to a surge car and then to a Serpentix conveyor. The Serpentix, a Peabody invention, is a flexible conveyor capable of going around corners.

Jan 1, 1976

By D. W. McGlashan

[Becaune ad ;the extennive nwrgace anea od u.X chopRex2 in emmiom, emuhion dRokdtiun oddeh poaaibWa don ;the necove/ry ul; BinQey divided minmcd pa~LL&a, Swr~aC;tavu% mu2 akab&ze ;the emu-bion and poan an an ad~i&y don ;the dahed mina&. OZhm hpohtant acto oh me ;the naAwre od ;the em&iun inghedied, ;the nQRaLLve volwna 06 the colz;tinuoun and dincon;tinuoun phaa, ;the change aign bonne by the dnuplm ad the o.X phae, ;the z&a pu;tenticd od ;the dahed minmd, the ~olubRe am curdent 06 khe wcr;ten-pulped and gnuund onu. AX on nem ;the AoQRec;trtic point on ZPC, ;the doubRe Raym about ;the minW-&den oil dnopR& i~ neduced in ;tkichnaa and the dn_opR& wU codace and continue to aggnegate into agglommaka . Invetmion dnom O/U ko W/O can UCCWL depending upon a nwnbm a 6 in;tmQeaked daotuh~. EReothokin&Lc inn&wnenta;t/iun to meanwre ;the ZPC, QReckProphonQkic mobilXty z&a pokeW and hakerning cuttrtent me invcduabte in ;the appficatiun ud emu-bion dRo;tat;iun ;to m&~c and nonm&~c minu.&. ] INTRODUCTION Recent interest in emulsion flotation can be ascribed to the necessity of selective separation and concentration of extremely fine minerals. That which follows is an elucidation of the many factors-in emulsion technology in application. In applied surface chemistry for solid-particulate separation and concentration, emulsion flotation is one of the intermediate processes between froth flotation, in which the continuous phase is water (99.5 to 99.999% by volume), and particulate extraction, in which the continuous phase is almost entirely an organic-fluid. Another intermediate process is particulate exchange (or partition) in which immiscible or very limitedly miscible phases are in controll¬ed but appreciable volumes. Surfactants are common to all of these

Jan 1, 1968

By Slobodan Vujic, Goran Cirovic, Dragan Radojevic

Mine production systems (MPS) are characterized, more or less, by the following properties: uncertainty, subjectivity, impreciseness, polysemy, instability, indefiniteness and lack of data. From modern study aspect these MPS mathematically belong to the class of fuzzy systems. With this in mind, the usage of fuzzy sets is recommended as a methodology that treats impreciseness, indefiniteness and complexity of mine production systems in a satisfactory manner. Fuzzy modelling, discussed in this pa- per, is applied as a mathematical implement. The objective of the paper was to show production optimization in practice on the ex- ample of bauxite open pits where fuzzy linear programming (FLP) was used following the criterion per income. The variables in criterion function are linguistic variables while both variables and variable restrictions are presented by triangular fuzzy numbers (TFN). The term "satisfactory income" presented through triangle fuzzy numbers was introduced instead of "maximizing the income". sensitivity of the obtained solutions has been analysed

Jan 1, 1996

By P. Verhoeven, G. Hefter, P. M. May

The dissociation (ionisation) constant of hydrogen cyanide, pKa(HCN), has been measured by high precision glass electrode potentiometric titrations in saline solutions containing up to 5 mol/L sodium chloride. The dissociation constant of water that is necessary for the calculation of pKa(HCN) has also been measured. In saline solution, and in contrast to literature values, pKa(HCN) changes considerably at both high and low ionic strengths as a result of changes in activity coefficients. In addition an equation is presented, using literature data, that describes the variation of pKa(HCN) with temperature up to 150°C. The significance of the changes in pKa(HCN) for optimising the pH of alkaline cyanide gold recovery streams is briefly discussed.

Jan 1, 1991

By D. B. Gentzler, J. L. Kohler

A method of monitoring production information (raw tonnage and machine state) from each working section has been developed. The method is based on the sensing of electrical parameters in each section load center, and the reporting of this information through the existing mine-wide monitoring system. A decision-theoretic type of pattern classification technique has been used to define the machine states. The basis of the method is presented in this paper, along with a proposed hardware and software implementation scheme. Information issues central to the development and use of the proposed production monitoring system are also discussed.

Jan 1, 1990

By Deepak Malhotra, Linda K. Baltich

The minerals business is dynamic and competitive and the economic viability and/or profitability of any mineral company depends on maximizing recoveries while minimizing costs. In order to achieve this goal, it's essential that you have a clear understanding of the current status, including strengths and weaknesses, of the operation. The authors have developed a systematic approach to plant auditing which we have used successfully at several operations. The strategy presented in this paper can be tailored to fit a wide range of audits. This flexibility is a key feature of the approach.

Jan 1, 1989

By Patrick Ph. D. Kennedy, Osvaldo A. Ph. D. Bascur

With the revolutionary progress in information and computer technologies, applying the latest information technologies in metallurgical complexes has become a serious challenge to both a major opportunity and a serious challenge to both management and technical teams. The emerging component and object technologies are changing the way everyone can beneficially use their computer and networks to add to their corporate bottom lines. Most mining and metallurgical plants use predictive maintenance policies based on statistical analysis and special techniques, like vibration analysis and oil and lube analysis for critical equipment. Process control strategies are installed in several metallurgical sites. All process equipment and control strategies require maintenance from local personnel at the mine. Integrated use of existing and emerging technologies is making it possible to implement an overall process effectiveness control index. This index is based on key indices such as losses due to plant availability, performance efficiency and rate of quality. The availability of real time and process history to identify the most critical part of the processing system from mechanical integrity is highlighted. An emerging plant integration paradigm is described to simplify the implementation of business enterprise resources management and distributed plant management systems.

Jan 1, 1998

By W. H. Andrews

DEFINITION OF BAUXITE The term "bauxite" (1) dates back to 1821, when it was assigned to a deposit of red earthy material outcropping near the village of Les Baux in Southern France. Chemical analysis indicated the presence of aluminium oxide, iron oxide and water. Deposits of bauxite are widespread throughout the world although the major developments occur within 30 degrees of the Equator. Essentially bauxite is the product of weathering and leaching of a variety of sediments or rocks, generally in a high-rainfall tropical or sub-tropical climate, resulting in the enrichment of the aluminium oxide content. It is characterised by the presence of one or more of the minerals, gibbsite, boehmite, and diaspore. The other constituents are usually clay, (typically kaolin), hematite and/or goethite (iron-oxides), anatase (titanium oxide), and possibly silica as quartz. A variety of minor elements may be present, such as calcium, magnesium, phosphorus, vanadium, gallium, manganese, and many others in very small quantities. Organic compounds are normally present from development in association with a soil horizon where vegetation may be encouraged by the high rainfall necessary for bauxitisition. The physical form depends upon the geological history of the deposit and correlation also exists with the mineralogy. Older deposits which have been subject to burial are invariably hard and compact with the alumina predominantly occurring as boehmite or diaspore, while the more recent, surface deposits are frequently less compacted and gibbsite is the dominant alumina mineral. In these later deposits, the physical form can vary from the fine red soil (terra rosa) of Jamaica to the Weipa pisolites to the cemented Arkansas type. The presence of concretionary structures is an important aid in identification in the field.

Jan 1, 1984

By R. S. Rickard, B. Ball

INTRODUCTION Pyrite responds to the flotation reagents normally used in sulfide flotation systems. For example, it is well known that xanthates are good collectors for pyrite, and cyanide, sulfide and hydroxides are depressants. The particular response of pyrite to these and other reagents is used to advantage in several areas. By careful control of depressant and collector additions, pyrite can be separated from other sulfides by flotation. This is of obvious importance in base metal sulfide flotation where pyrite depression is often required to produce a marketable grade concentrate. Flotation of pyrite has long been employed in gold ore processing, and it appears that pyrite flotation from coal may become important in the future (1). It is probably a direct consequence of this relative ease of separation, plus the low economic value of pyrite, that detailed investigations on the chemistry of its flotation and depression are relatively limited. Gaudin (2,3,4) and others, in the mid-1950's published data on the flotation of pyrite, but detailed or consistent mechanisms were lacking. In 1955, Sutherland and Wark's book (5) was published, in which a large amount of empirical information, especially earlier work of Wark and Cox, was presented. More recently, in 1968, significant contributions have been made by Fuerstenau et al. (6,7) and Majima and Takeda (El. These papers introduced electrochemical explanations of the effects observed with xanthate and cyanide ions.

Jan 1, 1976

By David B. Campbell

INTRODUCTION This submission was made to the Royal Commission of Inquiry into uranium mining in British Columbia. It discusses the stability of waste rock piles that might be developed in conjunction with uranium mining and the control of leachates that might be generated within these waste rock piles over the short and the long term. Short term refers to the interval during which a waste rock pile undergoes either continuous, or alternatively intermittent development, and in general can be considered to extend over the operating life of the mine. Long term refers to the postmining period, i.e. after the ore-body has been exhausted, and mining operations have ceased. Two major classes of waste material are generated in the course of mining and milling operations. Tails, which are the solid waste materials produced by the milling operations commonly exit the mill in slurry form and are stored in tailing retention ponds. Management and control of these slurried wastes are the subject of other papers to the Commission and this conference. In the course of the mining operations, it may be necessary to remove rock materials that are below cut-off grade. That is, ore concentrations within some of the mined rock may be lower than the concentrations which on the basis of economic considerations justifies milling the material. Rock which is removed in the course of the mining operations, but which is below cut-off grade is referred to as waste rock. This waste rock is commonly consigned to a specific area for disposal where it is placed in a mound or pile, i.e. a waste rock pile. Ore concentrations within the waste rock may vary from zero to just below cut-off grade. Since an increase in the market value of uranium could at some time in future result in reduction of the cut-off grade, it follows that waste rock containing ore concentrations slightly below today's cut-off grade could become ore grade rock at some time in future. For this reason, the mine operators may deem it advisable to separate waste rock according to grade, and to consign the waste rock to two or more individual waste rock piles. For purposes of clarity and simplicity, this submission treats the stability of waste rock piles and leachate control in a manner which assumes that these potential problems are isolated and separate from other aspects of the mining and milling operations. For many site specific cases, the problem of potential leachate control might be integrated with the tailings management aspect of the project, thereby realizing economic benefits while at the same time reducing the potential for adverse environmental impact.

Jan 1, 1980

By Georgios Kafantaris, Carsten Bonde, Nataša Katic

Within the investigation works for the Copenhagen Cityring metro, Geo/CMT have carried out 90 geotechnical boreholes. Together with the previously available investigation, this resulted in more than 15 km of vertical drillings and several thousands of laboratory tests. The design is made for 17 stations, four shafts and two parallel 16 km long tunnels. The geotechnical investigation and design have been carried out in several stages comprising appropriate refinement of structural design and design of excavation operations, including TBM break-in and launching operations at each station shaft. Acceptance of the solution and / or refinement of the investigation and design schedule in the next stage were based on the geological conditions, area availability at surface level, planning and cost-control criteria. The applied recursive design refinement is presented herein with an example of the Østersøgade shaft location.

Jan 1, 2016

By Thomas H. Koenning

The number of spontaneous combustion incidents in the U.S. is expected to increase as the consumption of lower rank coals and the use of longwall mining becomes more prevalent. A spontaneous combustion incident holds the potential for substantial loss of life from a mine fire or explosion if not prevented or controlled at an early stage. Laboratory tests have been developed which are useful in ranking the susceptibility of various coals to spontaneous combustion. Ventilation circuits and mining methods can be designed to minimize the risk of spontaneous combustion. Early detection of spontaneous combustion is possible with the combined use of continuous monitoring, periodic gas sampling, and inspection.

Jan 1, 1989

By Clark Woodland, William E. Stanley

Mining companies have been required to enter a "new era of management" in the 1980's as they strive to become more efficient in an increasingly competitive market place. One response for many companies has been to modify their mine accounting systems to make them more effective for cost control and decision-making. This paper discusses some of the major issues in developing and implementing a standard costing system as part of improved management reporting and cost control procedures. It describes the key features and benefits of a computerized standard costing system with particular emphasis on budget-setting and variance analysis. It also identifies important factors to be considered in order to achieve successful project planning and Implementation.

Jan 1, 1987

By William P. Blacutt

This paper examines Bolivia's General Environmental Bill recently passed by Congress: a multi-purpose law with two primary objectives: a) the protection and conservation of the environment, and b) the promotion of sustainable development. In this law, environmental benefits are emphasized by stating general principles, not by attempting to define the means. Regulations are left to the writing of subsequent complementary codes. This paper shows that much of the controversy surrounding the legislation disappears when it is seen as guide rather than an operational part of Bolivia's industrial policy. In essence, the law addresses recent environmental awareness in a region more anxious than ever to speed economic growth.

Jan 1, 1992

By Barrie W. Sullivan

The New Celebration Gold Mine near Kalgoorlie in Western Australia was commissioned in late 1986 and the CIL treatment plant currently processes 1.7 million tonnes of gold ore annually. The 1988 geological resource was 13.2 million tonnes grading 2.37 g/t Au in several open pittable deposits with the bulk of gold mineralisation occurring as a stockwork in Archaean quartz feldspar porphyry intrusives along a major regional shear zone. Mine planning, scheduling and operating techniques have focused on minimising open pit dilution whilst maintaining production requirements. This paper describes the successful achievement of this aim in extremely variable ground conditions and orebody widths.

Jan 1, 1989

By Jorma Miettunen, Reijo Kalapudas, Pertti Koivistoinen

A new method for measuring the mill filling was developed by Outokumpu’s Pyhäsalmi concentrator during 1989-90. The method utilizes the power draw oscillation which is caused by the mill lifters. Each lifter bar causes a peak in the power draw and thus a continuous oscillation results. In a fixed time scale, the oscillation peaks will shift as the lifter bare hit the mill charge sooner or later depending on the volumetric filling of the mill. Thus the measuring method is based on the phase shift of the power oscillation. So far the measurement is utilized for maximizing throughput of the primary mills at Pyhäsalmi and Enonkoski concentrators and at Harjavalta slag concentrator. The paper describes the new method and the results achieved.

Jan 1, 1992

By J. W. Merks

Spreadsheet software is an effective tool for simulating dynamic stochastic systems such as mineral processing plants. The two-product formula is used to show how to set up a Monte Carlo simulation in a spreadsheet template and how to calculate variances of dependent variables. The key to a reliable and realistic simulation model is to obtain unbiased estimates for all independent variables and variances in the set that defines the stochastic system. Monte Carlo simulation is also a powerful tool for optimizing sampling procedures, for applying sensitivity analysis and for designing and evaluating experiments.

Jan 1, 2000