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By Ing. Alois Adamus, Ing. Václav Pošta, Ing. Lubomír Hájek

This paper reviews experiences connected with the use of nitrogen in the Czech coal industry. Special attention is focused on the first use nitrogen In the Czech Republic, it is probably the first case of fighting a mine fire using nitrogen in all the World. Discussion dwells on the present-day use of nitrogen, its sources, consumption, technological equipment, and the theoretical evaluation of nitrogen flushing.

Jan 1, 1995

By A. A. Sonntag, I. Szanto, D. A. Goodman

This paper presents the most recent developments in mixer-settler technology directed towards treating higher throughputs, increasing efficiencies and providing further improvement in SX technology with a new concept: the submerged launder. Industrial plants built in the last past few years and using these improvements are described.

Jan 1, 1993

By Raymond A. Bradbury

Martin County Coal Corporation operates three underground mines and two surface mines on Wolf Creek in Martin County near Inez, Ky. The original underground development was begun in March of 1970. The property being developed is leased from Pocahontas Land Corporation. The A. T. Massey Coal Company, whose offices are located in Richmond, Virginia, is the parent company and sales agent for Martin County Coal. Duke Power Company is the customer who will take all the production from the mines which ultimately are scheduled to produce 2,500,000 tons annually. The Norfolk and Western Railway Company built a 24-mile railroad into this huge reserve of low-sulfur steam coal. Four coal seams, all above drainage, are included in the lease. The Middle Coalburg and Stockton seams are being deep-mined now and it is in three mines that the diesel haulage equipment is used. Those of you who attended the AIME meeting in Birmingham last October or the Diesel Symposium in Pittsburgh in January of this year are familiar with the introduction of trackless diesel-powered haulage equipment into our Martin County mines. I made a presentation at each of those meetings which dealt with our first experience with Wagner Mining Equipment haulage units. These machines are sold exclusively by Lake Shore, Inc. whose offices are in Iron Mountain, Michigan.

Jan 1, 1973

By L. Berwick, A. Karunanayake, D. Skutt, H. Heath, J. Wang

Thallium (Tl) is a highly toxic heavy metal, soluble over a wide pH range. Tl levels may exceed discharge limits in mining-influenced water associated with processing gold, lead, cadmium, zinc, and copper ores. In this work, the effect of sodium permanganate (CARUSOL® C liquid permanganate) on Tl removal from mining wastewater was studied. Factors influencing Tl removal, namely permanganate dosage/demand, coagulant and flocculant use, order of chemical addition, and co-existing metal ions were examined. The results show that permanganate addition is very effective at removing Tl to below target limits and can provide a unique solution for improving wastewater quality and optimizing overall treatment costs. In addition, several on-line monitoring techniques were evaluated for process optimization. The Hach DPD Free Chlorine method was optimal, allowing plant operators to rapidly and easily spot check effluent samples for excess permanganate dose.

Mar 2, 2022

By Yoginder P. Chugh

The Department of Energy is presently sponsoring the development of automated miner-bolter machines in an effort to increase production and productivity in the continuous room-and-pillar mining sections. This study is concerned with the production potential of these machines in three different mine layouts. The Underground Material Handling Simulation (UGMHS) computer model was utilized in the study. The effect of variables such as bolt installation delay, shuttle car capacity, and equipment availability on production are analyzed.

Jan 1, 1979

By H. B. Weaver

The development of a method to manufacture diamonds has been rated as one of the out- standing scientific achievements of our time. The story is both interesting and significant. This paper will quickly review history of diamond and manufactured diamond. Next, it will discuss manufactured diamond as a product -- how good is it -- and what is the significance of this scientific achievement. And finally, present a few thoughts about the future of this technology and this product. For centuries, diamond was found only in alluvial deposits, primarily in the Golconda fields of India. As a result, man knew nothing of the process by which the stones were formed. In 1860, diamonds were found in South Africa under completely different conditions. Here, for the first time, they were found in volcanic pipe -- their mother ground. These volcanic pipes are roughly cylindrical columns of rock which go deep within the earth. The theory as to the formation of diamond was presented by the geologists in that era. The theory states that molten rock was thrust up through a layer of carbonaceous shale where it picked up the carbon necessary for diamond formation. It was generally agreed that diamond was formed approximately 240 miles below the surface of the earth, thus indicating that extremely high temperatures and pressures were involved.

Jan 1, 1964

By R. D. Hutchinson

I consider it an honour to be the opening speaker in this afternoon's session on "Canadian Exploration". I also think it most appropriate that this joint meeting of the MMIJ and AIME should consider this subject, because Canada is a major exporter of mineral products and Japan and the United States are our two largest customers. Clearly, therefore, both countries have a valid interest in developments on the Canadian minerals scene. I represent the Mineral Development Sector of the Canadian Department of Energy, Mines and Resources. I will therefore speak from the point of view of the Federal Government. At this point I would like to acknowledge the help and constructive criticism I have received from several of my colleagues in Mineral Development Sector in the preparation of this paper. In any discussion of exploration in Canada, it is essential to emphasize at the outset that Canada has a federal system of government, with powers shared between Ottawa and the provinces. Under our constitution, the federal government has jurisdiction over the north, and over offshore areas, while the provinces own the natural resources within their boundaries. They control the systems of land acquisition for exploration and the terns under which mining titles are issued, and are therefore able to determine the rate and conditions of exploration and development of these resources. It follows that the Federal Government can influence the exploration and development of the provincial resources only indirectly by consultation with provincial authorities. However, once the resources are developed and begin to flow to market, the Federal Government can exert a much stronger influence because of its constitutional right to control both inter-provincial and international trade, as well as through its general fiscal and tax powers.

Jan 1, 1976

By André Vien, Robert Edwards, Rob Perry

A metallurgical control application can only succeed if the system's lowest common denominator, its instrumentation and regulatory control is implemented and maintained correctly. This paper describes the basics of regulatory control implementation including some practical guidelines for instrumentation installation, operator interface design, loop tuning, and continuous loop performance analysis. Tuning and analysis techniques are illustrated by step-by-step industrial examples. A small investment in basic control pays dividends in better overall plant performance and provides a solid foundation for advanced control efforts such as expert systems.

Jan 1, 2000

By Gary Buchan

During several months in 1996 and 1997, Cyprus Twentymile Coal Co. (TCC) set world production records at its Twentymile Mine in northwestern Colorado. These records were due to the company's implementation of a state-of-the-art longwall mining and conveyance system along with a -highly dedicated work force. This article is a case study of the design of long panels at the mine from conception to implementation. Obstacles that needed to be overcome included subsidence engineering, environmental regulations, conveyance, ventilation, equipment design and continuous miner (CM) development timing.

Jan 1, 1998

By I. F. Walder

Mill tailings from skarn-type base metal deposits were studied in order to ascertain potential element mobility in response to weathering. Hypogene ore minerals are sphalerite, galena, and chalcopyrite, showing minor supergene oxidation to smithsonite, cerussite, and covellite. Gangue minerals are pyrite, pyrrhotite, magnetite, hematite, andradite and grossular gamet, hedenbergite, calcite, ankerite, and quartz. Foremost of the eleven tailing piles studied, the hypogene sulfide minerals show no or only incipient post-mining oxidation. Iron oxides and hydroxides form the main oxidation products in the tailings and are enriched in heavy metals. A distinction between pre-and post-mining oxide phases may be obtained based on petrographic observations which distinguish whole-grain versus partial grain replacement. Zn and Cd do not appear to be enriched in the weathering derived oxidation minerals and will be more easily leached from the tailings than other metals.

Jan 1, 1994

By Harrison R. Cooper

Composition data is needed as input for executing process control and management of particulate separation for flotation control. While requirements for composition data can be satisfied in many cases by manual sampling and analysis, automatic sampling and assay systems are now viewed as justified for all but the simplest or smallest processes. On-stream X-ray fluorescence analysis (XRFA) has satisfied requirements for the main portion of metalliferous sulfide ore flotation processes as XRFA technology evolved in reliability and sophistication from its beginnings in the late 1950's. In recent years, advanced on-stream analysis technologies have reached levels of development suitable for use in process control to increase efficiencies of important processes in mining and minerals industries such as coal fines flotation and industrial minerals beneficiation (particularly phosphate beneficiation) where XRFA methods have been inapplicable. Recent technical developments pertinent to use of advanced technologies as well as improvements to established on-stream composition analysis methods are discussed.

Jan 1, 1989

By W. Petruk

Imaging is a fundamental requirement when characterizing minerals, ores and related products. Images are used for presentation, texture analysis, characterization, image analysis, identification, etc. The image mode that is utilized is dependent on the application, mineral properties and available instruments. Different instruments produce images that display different features. In order of increasing complexity they are: hand specimens, a non-polarizing microscope, polarizing optical microscope, scanning electron microscope (SEM), low vacuum SEM, microprobe, secondary ion mass spectrometer, staining, cathodoluminescence, tomography and others. Image analysis uses images produced with either an optical microscope or a SEM, but the SEM images are superior in this application. Key words: Mineralogy, Imaging, Mineral characteristics, Scanning electron microscopy, Optical microscopy, Cathodoluminescence

Jan 1, 2003

By James F. Albus, Vincent C. Grimshaw

High pressure fluid energy grinding, or jet milling, is a versatile method of continuously fracturing solids into fine particles to gain substantial increases in exposed surface area Applications in industrial minerals grinding include calcium carbonate, talc, barytes, mica, diatomaceous earth, bauxite, rutile, coal, kaolin, sepiolite, diamonds, etc The basic principles can be extended to provide continuous drying and delivery of discrete par¬ticles from a wet process slurry The main design and operational features of jet mills and dryers are described, relating energy consumption for both air and steam milling and hot air drying techniques Mean particle sizes in the order of 1 micron are achievable from pre-milled feeds, or maintained from similar slurries in the drying mode Aspects of feed preparation and multi-stage processing are discussed

Jan 1, 1983

By Yi Luo

Bolting the mine roof is one of the noisiest underground mining operations. The main contribution to the high noise is the drilling of the roof bolt holes, especially in hard rock. A previous research shows that the specific energy consumed in drilling the bolt holes is inversely proportional to the bite depth (i.e., penetration per drill revolution). Less specific energy at a reasonably high bite depth means less energy is wasted in the drilling process to produce heat, bit wear and noise. Therefore, control of drilling operation to achieve a higher bite depth can provide an opportunity to reduce drilling noise from its sources as a proactive noise control approach. In order to explore the feasibility and to develop the proactive technology for reducing drilling noise, drilling tests have been conducted in laboratory settings. The preliminary results show significant reduction in noise dose can be achieved by drilling in medium hard rock at a reasonably high bite depth. This paper presents the findings from the laboratory experimental studies conducted so far.

Jan 1, 2013

Iron ores may be upgraded by flotation of iron oxides or siliceous gangue using either cationic or anionic collectors. The electrostatic mechanism of adsorption can account for the complex chemistry involved. In industrial practice, only cationic silica flotation is used at present in North America. Some of the seemingly paradoxical phenomena of cationic silica flotation behaviors in meeting the demand for low silica concentrates are reviewed.

Jan 1, 1989

By Johannes Wageneder

As a reaction to the fire accidents in tunnels in Europe Designers nowadays have to demonstrate the integrity of underground structures such as metro systems, railway and road tunnels in case of fire load wherever as a consequence of a lining collapse surface infrastructures or residential areas could be affected. To respond to this FLAMDOCS allows to calculate the stability of reinforced concrete structures during fire load for a series of prede?ned time steps. Elementary theories of non linear material properties and reinforced concrete structures are used.

Jan 1, 2003

By J. W. Gunnett

Abstract. The Surface Mining Control and Reclamation Act of 1977 (PL-95-87), Section 522, establishes requirements for state regulatory authorities to designate lands unsuitable for all or certain types of surface coal mining. Any party having an interest in an area that may be affected can petition for it to be designated unsuitable for mining. Section 522 could present major obstacles to the mining industry by typing up an area in an endless round of petitions. The program under development for Kentucky is examined and analyzed as an example for determining the hidden impacts of Section 522.

Jan 1, 1980

By B. G. Long

Coastal States Energy Company (Coastal), a wholly-owned subsidiary of The Coastal Corporation of Houston, Texas, owns coal mining operations in Utah and Kentucky. One of the Utah operations, Southern Utah Fuel Company (SUFCo), located 30 miles west of Salina, Utah, has been operated by Coastal since 1974. This operation is a single-seam, six-section mine operated from one portal area. It produces 2.2 million tons of coal per year and has a payroll of approximately 300 employees, Coal is mined by continuous miners, hauled by diesel-powered haulers and transported by belt conveyor to outside crushing and screening facilities. Sized coal is hauled by contract truckers 80 miles to a unit-train facility located at Levan, Utah.

Jan 1, 1983

By B. M. Flohr

Railroads are cost competitive with trucks for hauls greater than 500 miles - WRONG. Today I will tell you about many rail movements of less than 100 miles throughout the country. Rail is a short haul transportation alternative you must consider. Transportation today is the largest controllable cost in the total cost of production of goods. In fact it is the one cost area where aggressive management, using new tools, can achieve significant reductions. You can't control the price of metals in the world market, you can't control labor rates since they are tied to industry norms, and the price of raw materials are relatively insensitive to specific price reductions to your firm. Transportation is the one area where major savings are now being realized. Sample Movements First, I will give you several examples of short haul rail moves to make you a believer that they do exist. Then I will show you the reasons why railroads suddenly "like" short hauls.

Jan 1, 1986

By Bruce Kennedy, Dan Nilsson

Mining means drilling and blasting in order to break down the rock, loading and transport, and often also crushing the ore down to a suitable size. These operations can be done in open pits or in underground mines, and also, to a lesser extent, in marine mining. The same operations are also used in various types of construction, i.e., for roads, water power stations, etc. Before beginning a detailed economic analysis of the factors which enter into deciding whether to mine by open-pit or underground mining, and at what point a change should be made from open-pit to underground mining, or vice versa, it is of interest to consider some general factors.

Jan 1, 1982