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By R. G. Gürtunca, J. A. Breslin

This paper briefly describes the progress in mine safety in the United States, with emphasis on recent events that have followed since the explosion at the Sago Mine in January 2006. Legislation following the mine accidents last year and areas of work carried out by the National Institute for Occupational Safety and Health (NIOSH) related to the accidents are discussed. American coal production in 2006 was 1,150 million short tons. Most of this coal is consumed domestically, with annual exports of coal about 50 million tons. One third of annual production is produced at surface mines and the rest from underground. This coal is produced by about 82,000 miners working at 1,400 coal mines. Major improvements in coal mine safety have been made in the US since the Federal Mine Safety and Health Act of 1977. The fatal injury rate in underground coal mines between 1977 and 2004 was reduced by 47.8% to 0.036. The annual number of fatalities dropped from 112 to 14 during that period. Likewise, the non-fatal days-lost injury rate was reduced by 42.6% from 10.87 to 6.24. The improvements in mine safety during this period can be seen in the graph of underground coal mine explosion fatalities and injuries from 1980 to present, which is shown in Figure 1. Between 1984 and 1993 (9 year period) there were 5 explosions and one major mine fire, for a total of 55 fatalities. Over the seven year period from 1993 to 1999 there were no fatalities from coal mine fires and explosions. However, in the six years since 2000 there have been 5 explosions and one fire, which have caused 37 fatalities. [ ]

By Takahide Wakamatsu

In Japan all the complex sulfide ore deposits of base metals have been developed as underground mining. The underground mining cost is extremely high as compared with open pit mining case. Therefore, in milling section of base metal mines, technical advance for maximum recoveries of valuable constitutents in ore has been required all the time to utilize as much ore mined as possible. At present, in mill plants treating "Kuroko", complex sulfide ore, concentrates of copper, lead, zinc, pyrite and barite are produced, with gold and silver contents in the copper, lead, and zinc concentrates being estimated as extra profit. As in the case of Kuroko milling plants, gold and silver contents in the lead and zinc concentrates of lead-zinc ore milling plants are also varuable from an economical viewpoint. Silver content is very high in Kuroko crude ore as well as lead-zinc ore.

Jan 1, 1982

By James Wm. White

Computer based dispatching in open pit truck haulage operations yields many benefits of current interest to mine management. The key tangible benefit is a substantial productivity increase with a given fleet of equipment or, alternately, a significant reduction in equipment required to meet production quotas. Other tangible benefits, depending on the operation, include minimizing rehandle, meeting several blending constraints simultaneously and ensuring a target plant feed rate. Intangible benefits include production forecasting, performance comparisons of trucks or shovels of different manufacture and extensive on-line report generation. Recent advances in mini and micro computer hardware and software and solid state electronics permit design and implementation of system features not feasible even a few years ago. Here we discuss many of these recent developments with emphasis on system aspects and dispatching algorithms.

Jan 1, 1983

Today computers are accepted as a standard item in industry and they perform a variety of tasks over a wide spectrum of activities from mine planning and CAD to data processing and spreadsheet work. However many problems particularly in the. area of decision making where there are no clear mathematical models available and usually the output or answer is dependent to some extent on a heuristic approach, don't lend themselves to conventional solutions using standard procedural algorithms. Recently a number of techniques have evolved primarily from the enhanced capabilities of modem equipment, which are capable of solving these problems. This paper is a brief overview of these rather unconventional developments of computer technology in the area of artificial intelligence with reference to their application in mining.

Jan 1, 1993

By P. H. Derbyshire

The use of continuous flight auger piles has increased significantly in the U.K. to such an extent that it is now the most widely used method of constructing small diameter bored piles. This paper describes the improvements in equipment, techniques and particularly monitoring that have led to this growth. A review of the equipment in use describes how purpose built self erecting machines have been generally adopted. Improvements in ancilliary equipment are described. Concrete has almost completely replaced grout and techniques have been developed to extend the length of reinforcement that can be placed. Leading specialist contractors have developed instrumentation to monitor the construction of the pile (in terms of time, depth, torque, concrete pressure and flow) and keep a record for checking. A further significant development of this monitoring by means of sensors at various levels in the auger stem is described. The results obtained from this monitoring are reviewed and future developments discussed.

Jan 1, 1989

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By John O. Marsden

The past fifteen years have seen a number of important developments in copper hydrometallurgy, including the commercial application of biological heap leaching of secondary (chalcocite-dominant) copper ores, the commercial demonstration of chalcopyrite concentrate leaching technology using pressure leaching and biological processes, and the application of novel configurations of solution extraction circuits. Significant emphasis is now being placed on the development of effective stockpile leaching practices for primary ores (chalcopyrite and bornite-dominant mineralization). Some of these developments have been highly successful, and will pave the way for further development and commercialization. Others have been less successful. These developments are reviewed in the context of the metal price cycle and trends for the future are identified.

Jan 1, 2006

By R. Robertson

Dense medium cyclones are the preferred means for cleaning 112 in. x 14 Mesh to 28 Mesh (12.7 mm x 1.0 mm to 0.6 mm) raw coal and are becoming a common choice for cleaning raw coal from a nominal top size of 2-1/2 in. to 3 in. (63.5 mm to 76.2 mm) down to 14 Mesh to 28 Mesh (1.0 mm to 0.6 mm). During the last ten years, dense medium cyclone circuitry design has undergone changes which have combined to improve process efficiency. This paper describes these improvements and compares present day design with the design used prior to the mid 1980's. Improvements in the following areas are described: Raw coal desliming, cyclone configuration, drain and rinse applications, dilute medium circuitry, and instrumentation and control.

Jan 1, 1997

By L. Watters, R. Terry, D. Placha

Dense medium cyclones are the preferred means for cleaning 1/2 in. x 14Mesh to 28Mesh (12.7 mm x 1.0 mm to 0.6 mm) raw coal and are becoming a common choice for cleaning raw coal from a nominal top size of 2-1/2 in. to 3 in. (63.5 mm to 76.2mm) down to 14 Mesh to 28Mesh (1.0 mm to 0.6 mm). During the last ten years, dense medium cyclone circuitry design has undergone changes which have combined to improve process efficiency. This paper describes these improvements and compares present day design with the design used prior to the mid 1980's. Improvements in the following areas are described: Raw coal desliming, cyclone configuration, drain and rinse applications, dilute medium circuitry, and instrumentation and control.

Feb 24, 1997

Robertson Diasol have developed a spectral gamma-gamma tool fully able to withstand borehole conditions. Spectral data is digitally recorded across 256 channels depending on energy levels of the photoelectric effect. Data processing is being developed with the objective of calibrating channel amplitudes to mineral type which will lead to a direct log of selected mineral grade as a continuous trace with depth.

Jan 1, 1990

By R. B. Hyde

"Severe drilling conditions and difficult mud problems are briefly out-lined as the major cost items in all production operations. The chief problems discussed are abnormal pressures, high temperature, trouble-some shales, and low rates of penetration. These problems have been eliminated or greatly reduced in many areas by• the proper application of recently developed drilling mud products and techniques. These severe problems and their solutions are discussed generally: the application of high-density weighting materials to overcome abnormal pressures; surfactant muds with sodium polyacrylate as a solution for deep and high-temperature drilling; shale control muds and new dispersants for severe shale problems; and low-solids emulsions and •extreme-pressure lubricants for greatly improved rates of penetration."

Jan 1, 1959

By L. C. So, S. Faucher, S. Mostaghel, D. Sauter, S. -Y. Oh, S. K. Lee

"Molten material from pyrometallurgical furnaces is tapped at high temperature, carrying a large amount of heat. Traditional handling methods of slow air cooling or water granulation do not allow for the recovery of heat from slag and matte. Furthermore, water granulation adds an inherent safety risk of explosions. Recently, there have been numerous studies into processes attempting to recover waste heat. However, most of them have never been commercialized due to numerous challenges including scalability, cost, low heat recovery efficiencies, and difficulties in heat utilization. Ecomaister-Hatch has recently developed and commercialized a reliable and simple dry atomization system that allows for heat recovery while eliminating the use of water. Comparisons of pilot and commercialized dry atomization and heat recovery technologies will be presented and challenges of these technologies will be highlighted.INTRODUCTION Slag has traditionally been regarded as an undesired waste product from smelting operations with slag management focused on removal and disposal of “waste”. Over 500 million tonnes of slag are produced per year, carrying with it ~220 TWh of energy (Barati, Esfahani, & Utigard, 2011). Depending on the process, the energy content of slag ranges from 10-90% of the total energy input (Barati, 2011, Rodd, 2010). There has therefore been great interest in recovering energy from slag. Slag handling methods can broadly be classified into three categories: (1) dumping and slow cooling, (2) wet granulation and (3) dry granulation. As discussed below, only dry granulation routes are amenable to heat recovery. Slag dumping involves the slow cooling of molten material and crushing of the resulting solid. In this process, slag is dumped on the ground directly from furnaces or transferred to slag pots that are moved by rail or haulers and then dumped on the ground. The molten material is left to cool and solidify until it can be broken and handled by heavy machinery."

Jan 1, 2017

By C. Kleine

Coal sorting with an x-ray-transmission (XRT) sensor has experienced a lot of development since first described by Jekinson et.al. in 1974. Powerful computers and increasingly sensitive X-ray scintillation counters enabled the development of high-performance sensor-based sorting machines. The first industrial installation of a belt-type XRT-sorting for coal is in operation since 2004. It is upgrading high quality coal from 1% ash to 0.7% ash for cathode production. In comparison to the high quality coal which is treated with a belt-type sorter, the chute type sorter has been successfully optimized for high volume coal treatment of lower quality coals. This project was funded by the German Environmental Fund (Project Nr.244444). In cooperation with the RWTH Aachen University and Isambane Processing, CommodasUltrasort(now Tomra Sorting Solutions) conducted extensive pilot test work under production conditions in 2010 for the destoning of power station coal at Arnot Power Station in South Africa. The experience gained during this pilot test phase led to an optimized, redesigned PRO Secondary XRT Chute sorter which is now in operation at a South African coal mine. This flexible semi-mobile modular destoning plant is treating a size range of -120 mm +30 mm at a throughput of 150 tph. The implementation of this plant not only reduces the ash content, abrasiveness index and sulfur content significantly, but also reduces royalties, water treatment and transport costs.

Sep 1, 2012