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By C. Patrick, D. Puckett

The feasibility of monitoring the locations and vital statistics of equipment and personnel in surface and underground mining operations has increased with advancements in radio frequency identification (RFID) technology. This paper addresses the use of RFID technology, which is relatively new to the mining industry, to track surface equipment in mine pits, loading points and processing facilities. Specific applications are discussed, including both simplified and complex truck tracking systems and an automatic pit ticket system. This paper concludes with a discussion of the future possibilities of using RFID technology in mining, including monitoring heart and respiration rates, body temperatures and exertion levels; monitoring repetitious movements for the study of work habits; and logging air quality via personnel sensors.

Jan 1, 1999

A linear programming model with integer sequencing variables is developed to schedule limestone production for a quarry in Central Japan. The model is used to optimize raw material production from the quarry supplying limestone to cement, quick lime and aggregate plants. Typically, the mining in the quarry takes place in four to six different areas each area having 3 or 4 mining increments. Each mining increment contains different quality of limestone. The limestone production from the quarry is transported to the plants byway of 3 ore passes. Each plant requires a given quantity of limestone per period meeting certain quality constraints. This paper will describe development of the scheduling optimization model and how it is used to schedule production by period within the quarry to meet the capacity and blending requirements of the plants.

Jan 1, 2003

By Kai Nielsen

In underground mining coarse muck and large boulders lead to ineffective utilization of costly mining equipment, and extra expenses and delays caused by secondary blasting. Cost analysis in some Norwegian mines shows that these extra expenses may amount to 10% or more of total mine operating costs. A computer model has been developed for sensitivity analysis of underground longhole stope blasting. The basic idea of the model is : When increasing the blasting energy input and fragmentation costs, the fragmentation will be better. This will lead to cost savings for loading, hauling, secondary blasting and primary crushing. The blasting design giving the lowest overall costs will indicate the optimal practice. The model has been used with data from several underground operations in Norway. An example run with typical costs shows that the costs for drilling, blasting and secondary blasting are the most significant parameters in the optimization process.

Jan 1, 1986

By P. Venkatsubramanian, D. R. Maneval

An insufficient hydrologic data base exists for most large and small coal basins in Alaska owing to the lack of need in the past to collect data. The runoff process is insufficiently understood which is complicated by specifically northern phenomenon, and the lack of understanding of hydrologic relationships in permafrost environment. This paper presents an understanding of the hydrologic effects of frozen ground and presents methods by which the influence of surface mining upon the hydrologic balance can be analyzed.

Jan 1, 1987

By Regina N. Tempel, Laurie S. Balistrieri, Lisa L. Stillings, Maggy F. Lengke

The Dexter pit lake, within the Tuscarora volcanic field in Elko County, Nevada, formed after closure of the Dexter mine. Mineralogy at the Dexter mine is related to widespread feldspar, silica, and chlorite alteration. Major mineralogy includes quartz, alkali feldspar, albite, phlogopite-biotite, hornblende, iron-titanium oxide, chlorite, kaolinite, smectite, illite, and sericite, with lesser amounts of calcite, zircon, apatite, and rutile. Trace element geochemistry is characterized by high levels of As, Ba. Cr, Cu, V, Zn, B, Zr, Li, and U. Detailed mineralogy and geochemistry are required for geochemical models to accurately predict trace element concentrations in pit lake waters.

Jan 1, 2000

By S. Yang

Based on an analysis of the features found in Chinese surface coal-mining areas, including areas that have already been developed and areas that are in the process of being developed, this paper discusses some rational coal-haulage systems. An optimal decision-making model, which includes a geological model, a mining model and an economic estima¬tion model, was developed for the selection of a coal-haulage system. A case study is presented.

Jan 1, 2000

By L. Laage, R. Greur, W. Pomroy

MFIRE is a mine ventilation and fire interaction computer simulation program. It allows transient state ventilation simulation and features mass based flow rates, natural ventilation, air recirculation, fan curve fitting, airflow reversal and product of combustion tracking. MFIRE was designed to accommodate the needs of the mining industry, for routine ventilation calculations and mine emergency planning. This paper describes recent work by the US Bureau of Mines and Michigan Technological University to improve MFIRE by incorporating humidity in the mass flow and heat exchange calculations, a data file preparation program, and variable reference density in the network calculations. Recent bug fixes are also discussed.

Jan 1, 1995

By K. V. S. Sastry, A. J. Hunt, K. D. Lofftus

Sol-gel processing is rapidly becoming an important process for producing such advanced materials as high activity catalysts, fiber optics and ceramic precursors. These materials can be tailor made with properties unique to sol particles as well as the gel aggregates by controlling production of the sol, the formation of the gel, and the removal of the interstitial fluids. This paper presents colloidal and kinetic principles of sol generation and gel formation. Hydrolysis of alkoxides provides the best means of controlling sol production and electrostatic stabilization enables the formation of the most homogeneous gels. Gelation occurs by hierarchial aggregation which produces inhomogeneities much larger than the sol particles. Colloidal and kinetic principles can be applied to reduce the size of the inhomogeneities and obtain high performance transparent insulation and new ceramic composites.

Jan 1, 1990

By Lynn B. Hales, Randy A. Ynchausti

Object-oriented technologies have been developed to more closely model the way we think about the world and our natural approach to solving problems. Higher levels of abstraction, generalization and classification are benefits of an object-oriented approach. Object-oriented programming, design, and expert systems are part of this technology which is shaping the future of real-time supervisory control. Goals of real-time supervisory control systems include: minimizing variations in process operations, improving efficiency, maximizing production, and implementing procedures for starting and stopping the process. Incorporating object-oriented technology in design, development and implementation of real-time supervisory control systems provides new opportunities for these tasks. This paper discusses some of the opportunities and challenges of implementing real- time supervisory control using an object-oriented expert system for a rougher flotation circuit

Jan 1, 1993

This section is addressed to the computing needs of corporate (top) management which are less specialized than the computing needs of operating or divisional management described in the previous sections. It is essential that the computer be used as a tool to serve corporate management and that information and results are presented in a succinct form. A key responsibility of the manager of computer applications is to communicate well with corporate management. A common trap for computer management is to allow the development and implementation of sophisticated and academically interesting computer applications which do not enlighten corporate management in its decision-making task. Thus it is essential to devote sufficient time and effort to designing and specifying a computer system before developing and implementing the system.

Jan 1, 1979

By Barbara Maren Winkler

For mine production problems in mines with varying qualities, both open pit and underground, the linear programming method (LP) has been used successfully. By this method it is possible to keep the total production blend for each period within a required range of qualities while optimizing objectives like production costs, net return, ore grades, other qualities, or a combination of these. Technical restrictions like constrained capacities can be added to the model. This makes LP a flexible and powerful tool for mine production planning. Practical experiences have shown the major influence fix costs have on the actual economic result of a planning decision. It can be proven that fix costs cannot be included in LP models. We describe a way to address this fix cost problem by using mixed integer linear programming (MILP) as an extension to LP in the optimization of a mine planning problem. This raises the issue of complexity. We discuss the computational complexity of the resulting models and the enhancement of model flexibility for the user of a planning system. We demonstrate the method embedded in a practicable everyday planning system for a complex underground coal mine. By computational examples we show how the method improves the economical results of the planning.

Jan 1, 1996

By Donald A. Dahlstrom

If you have ever driven on the Autobahns of Western Germany, you are well acquainted with the "fast lane." There is no speed limit; there are only two lanes in the direction you are going, and if you choose to drive in the fast lane, you had better be prepared to drive faster than anyone or someone will tailgate you with a constant screeching horn until you move to the "slow lane." The prize for this mastery of the fast lane is some kind of a "macho" feeling and getting to your destination sooner than your competitor. This has some comparisons with today Is liquid-sol id separation. We've certainly had our moments in the fast lane but we've also had other countries forcing us into the slow lane at times. It can be very embarassing when someone almost runs over your back and then shakes a fist at you as you shakily scatter to the much slower and overcrowded lane. Because of necessity, there will be many new improvements and added requirements in the next decades into the 21st century and beyond. Those countries and industries that can maintain the pace in the fast lane will be successful while the others may well be relegated to the non-competitive lane. Before considering what will be the challenges in the future for competitive liquid-sol id separation performance, it would be wise to review progress over the past forty years in this area. The author has to admit his ancient age and believes he can act as an evaluator of these many advances. To place the beginning of the 40 years (the author predates his initiation into liquid-sol id separation by one more year), the United States was still building smelters and operating them with little or no sulphur dioxide removal , practically

Jan 1, 1989

By R. R. Klimpel

The efficiencies of plant-scale comminution processes are often evaluated by various indices calculated and/or measured somewhat independently of the performance of any associated downstream froth flotation processes. To compare specific comminution factors, such as energy utilization, media consumption and equipment utilization time, comparisons of comminution efficiency independent of flotation behavior are appropriate. However, as increasingly detailed plant-level information is gathered on the joint and highly interactive nature of comminution and froth flotation, it is becoming even more obvious that knowing and using simple efficiency indices are not enough. What is needed are more performance-related measures of the efficiencies of the combined size reduction froth flotation system for effective plant-level economic optimization to occur. The purpose of this paper is to present examples of some of the important interactions that influence the joint efficiencies of size reduction and froth flotation processes.

Jan 1, 1999

By B. K. Baird, P. C. Satchwell

The application of cutoffs during and after pit optimization is examined for a lower-grade multimetallic copper deposit. Pit optimization requires calculation of the net revenue associated with each mining block. The calculation incorporates parameters such as metal prices, grades and expected recoveries, mining and processing costs, smelting and refining charges, and penalty element and royalty charges. Sensitivity analysis during pit optimization reveals which parameters have significant effects on the total contained resource tonnage and total contained nondiscounted revenue in the optimized pit. The cumulative effects of changing several of the more-significant parameters are investigated The application of a copper cutoff grade to a block inside the optimized pit could result in the less-than-optimal extraction of the resource. A block with a copper grade below the applied cutoff could be economic due to the presence of other metals. Conversely, a higher-copper-grade block may be subeconomic. Also discussed are the merits of applying a copper-grade cutoff, an "equivalent-grade" cutoff and a dollar-per-ton cutoff to blocks inside the optimum nit.

Jan 1, 2002

By John D. Grothe

Laboratory experiment as a basis of commercial plant design has been the subject of much analysis and thought and on which a large number of articles and papers have been published. We would be forced to choose between an unduly brief exposition if we wanted to cover it completely, or no exposition at all. We must therefore concentrate upon the essentials without ignoring at the same time too many of the qualifying factors which, by the choice of what we want to examine, may become side issues. In doing so, we do not imply that these side issues are therefore any the less important. In every case, what is said here applies with almost equal force to the pilot plant which may be necessary as it does to the commercial plant. In discussing a recent paper by Derek C. Shelton on the Santa. Barbara Mill in Chihuahua at a meeting of the Inst. of Mining & Metallurgy (London), D. J. Ottley said on the matter of relating laboratory results and small scale tests to full scale plant results that he would like' to draw the attention of members to the great difficulty of scaling up mineral dressing plants and processes. He felt that this was an important yet neglected subject which merited considerable fundamental scientific attention from mineral dressers and plant design engineers in particular. How much of this fundamental scientific attention has, as a matter of fact, been accorded to the subject, mainly by our sister profession, Chemical Engineering. The close similarity to chemical engineering problems that we meet, particularly in hydrometallurgical operations, suggests that Chemical Engineering publications offer a rich source of information and discussions of methods useful to us. We have only to think of pressure leaching, ion exchange, liquid-liquid extraction, precipitation and so on, all problems in chemical engineering unit processes or of the new Freeport Sulphur Nickel plant in Cuba or the Sherritt Gordon plant and many others.

Jan 1, 1960

By David J. Maguire, Ken Alexander, Maya Scherbakov

As conveyor systems continue to improve in reliability due to improved design, installation, maintenance, and operation, one of the more common modes of failure is the rubber carry cover being abraded away to the tension member. Various types of abrasion are discussed as well as current laboratory methods for measuring wear. New lab methods to mimic types of abrasion in service are presented and data from current and improved rubber covers will be presented. Actual wear performance of current and new cover compounds in multiple applications (coal, limestone, granite) will be compared to the new lab test methods and cost benefits shown.

Jan 1, 2002

By C. Ptacek, D. Hiller, J. L. Janbor, H. Mccreadie

Between 1991 and 1994, metallurgical residues from a pressure-oxidation autoclave at the Campbell Au-quartz mine at Red Lake, northern Ontario, were neutralized with dolomite-rich flotation tailings and were deposited in a polyethylene-lined disposal area. Mineralogical analysis indicates that most of the As occurs as a crystalline ferric sulfarsenate, and some is associated with Fe oxides and with K-H3O jarosite. Field pore-water geochemical data from 1994 and 1995 showed increases in Fe(II) and As(III) concentrations, suggesting that the sulfarsenate and jarosite are dissolving; none of the discrete As phases included in a thermodynamic database limit dissolved-As concentrations, and these concentrations may continue to increase. These results demonstrate the potential for Fe and As loading through groundwater systems.

Jan 1, 1998

By S. Chunhui, W. Anbin, R. B. Cook

The Xicheng is one of China's largest lead-zinc (Pb-Zn) districts with known minable reserves in excess of 10 Mt (11 million st). The centrally located Changba-Lijiagou and nearby deposits are representative of the district. They consist of stratiform and stratabound zones of pyrite-sphalerite-galena mineralization within deformed, moderately metamorphosed Middle Devonian clastic and carbonate units. When considered with other similar districts that extend for several hundred kilometers to the east, a major episode of Devonian sedimentary exhalative mineralization is indicated.

Jan 1, 1992

By R. Sawyer, M. Sadler, M. Holdworth

Greens Creek is a high grade Ag/Au/Pb/Zn deposit located in southeast Alaska. Maximizing the Net Smelter Return revenue from the fine grained mineralization is a dynamic process given changes in metal prices, smelting terms, ore grades and flotation characteristics. This paper discusses the evolving concentrate production strategy, and how it is affected by such factors as ore and concentrate specifications and by market conditions. Also described is the development of an on-line computer program that provides the mill operators with real time NSR data and a means for optimizing Net Smelter Return.

Jan 1, 2002

By R. M. Cox

Pneumatic coal loading and conveying systems provide alternative methods for the safe and efficient mining of the thin, high-grade coal seams found in the Southern Appalachians. Pneumatic systems eliminate most of the health and safety hazards associated with the operation of conventional mining and haulage equipment in small low-coal mines by removing powered mobile equipment from the mine. Ventilation is also improved by the coincidental removal of gas and respirable dust from the mine by the operation of the pneumatic loading and conveying system. Other significant advantages of pneumatic coal recovery systems are relative simplicity, operating flexibility, low capital cost, quiet operations, environmental benefits and ease of automation. The design considerations and field evaluations of experimental prototype pneumatic coal loading and conveying systems installed and operated in small thin-seam mines are presented in this paper. In addition, fundamental design criteria and recommendations for the installation and operation of a variety of pneumatic coal loading and conveying systems that offer alternative coal-recovery systems that alleviate the serious health and safety concerns of current small mine operations are proposed.

Jan 1, 2000