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By J. D. Bosman, L. J. Gardner

"The Bushveld Complex is a large layered igneous intrusion, located in the northern parts of the Republic of South Africa. The complex hosts the largest known reserves of Platinum Group Metals in the world. On the western limb of the complex, mining of the Merensky economic horizon and UG2 chromitite layer has been conducted for many years by several mining companies, including Impala Platinum Limited. Over the past decade, Impala has planned a new generation of greenfield vertical shafts, commencing with comprehensive geological and geotechnical studies. As part of the geotechnical studies, numerous tests have been conducted to quantify the mechanical properties of the various near-reef rock types. These tests include point load tests conducted in the field, as well as uni-axial compressive strength, triaxial compressive strength, and Brazilian disc tensile strength tests conducted in specialist laboratories. The authors have compiled an extensive database containing a large number of tests for different rock types, ranging from felsic Anorthosite to mafic Pegmatoid. The database was analysed to quantify the mechanical properties and values for Mohr Coulomb and Hoek Brown failure criteria for each rock type typically exposed by mining. The paper will provide a data set of rock mechanical properties typically used in numerical modelling and other design processes. Using the significant number of tests available, data describing the variability of the various parameters will be included."

Jan 1, 2015

By Yoginder Paul Chugh, Jason E. Tinsley

"Over the last five years, the authors have compiled a database of Short Encapsulation Pull Test (SEPT) evaluations from Interior Basin (Basin) coal mines. Typically, SEPT data are analyzed to obtain peak load carrying capacity per unit length of resin encapsulation designated as the ""Grip Factor,"" or GF. In a previous paper, ""An Analysis of Short Encapsulation Bolt Pull Test (SEPT) Data From Interior Basin Coal Mines,"" authors analyzed tangent value of the load-displacement curve as Anchorage Stiffness at 50% (AS-50) of the peak load, or GF value, to assess reinforcement potential of an installed bolt system. This paper attempts to correlate the secant AS VALUES (of SEPT on 6 ft (1.8 m) long installed bolts at a lower load of about four tons from several different mines in the Basin with their MSHA-approved primary support requirements. Since the current regulatory environment requires plan changes dynamically to ensure that roof falls are minimized, the authors hypothesize that the practiced roof control plan must meet the minimum requirement of adequately supporting immediate roof strata. The analyses are based on 181 SEPT studies performed by Minova professionals. Analyses indicate a macrolevel correlation for both roof support density and roof support cost that may have the potential to be used by mine operators to compare their performance with other mines in the area. Limitations of the analyses include ignoring mining depth, mining height and required secondary supports as part of the requirements for a roof control plan. The authors recommend additional analyses to develop this concept further to develop guidelines that can be confidently used by coal companies.INTRODUCTIONPartially- and fully-grouted bolts are extensively used in coal mines for roof support as part of MSHA-approved roof control plans. Since grouted bolts have a larger area of contact with the rock, they can develop much greater anchorage capacity than conventional expansion shell (point-anchored) bolts. Load transfer characteristics and interaction mechanics between steel rebar, grout and rock mass around the bolt hole for grouted bolts are generally assessed in the laboratory or field though short-encapsulation pull tests (SEPT), which have been extensively researched by Aziz and Jalalifar (2005), Aziz (2004a), Serbousek and Signer (1987), Signer (1990), and Mark et al. (2002), among others. In a SEPT, about 12 in. (30 cm) of bolt length is typically encapsulated in resin and a pull test is performed to collect load-displacement data prior to failure and, in some cases, post-failure. A typical load-displacement data set for a bolt is shown in Figure 1. SEPT characteristics are designated by peak load carrying capacity, or grip factor, which is the peak load carrying capacity per unit length of resin encapsulation. SEPT is routinely used to assess anchorage performance characteristics of different lithologies overlying a coal seam to identify type of bolt, bolt diameter, length and spacing across and along an excavation. Anchorage stiffness, or AS, at any load may also be calculated as the tangent or secant value of the slope of the load displacement curve at a particular load level. Anchorage Stiffness characteristics of bolts from SEPT data have typically not been considered in any depth until recently (Chugh et al., 2014; Chugh et al., 2015)."

Jan 1, 2016

By Kenneth K. Humphreys

Over the past four years, the Coal Research Bureau of West Virginia University has presented a number of papers on operations research in the coal industry before various AIME meetings and meetings of other societies. These papers have been followed up by further presentations in the technical press. The emphasis of all of these papers has been to demonstrate applications of operations research to the solution of numerous types of coal industry problems. In each case, effort has been made to demonstrate that operations research does not require extensive knowledge of computer science or use of sophisticated higher mathematics. In fact, for most applications, satisfactory results can be obtained by a single individual in a minimum of time with no aids other than a pencil and paper and a knowledge of basic arithmetic. The most recent efforts by the Coal Research Bureau have been directed toward the continuing industry problem of optimizing the location of mining facilities. Preliminary work in this area was presented before the Central Appalachian Section of AIME and subsequently published in the May, 1972, issue of Coal Age. This initial presentation illustrated techniques for determining optimum locations of facilities based upon material transport effort under the assumption of constant cost per ton mile of haulage effort. The present paper will expand upon this earlier work and introduce economic factors. In the design of a mine or mining system, careful consideration must be given to the sites selected for each element of the system. Optimum placement of facilities is vital to minimize capital and operating cost. Thus, barring unfavorable geological conditions or other exceptional factors, facilities should be located at those points which represent the minimum cumulative cost over the life of the property. Most cost factors are independent, or essentially independent of the location of fixed facilities. Thus, for example, regardless of the location of the shaft, the direct cost to mine any given ton of coal is essentially constant. The major 1

Jan 1, 1972

By A. F. Cohen

When location guidelines are followed in choosing sites for fixed point velocity transducers for use in underground coal mine monitoring, mine air turbulence intensities <11% are generally expected at those sites. The objective of this Bureau of Mines investigation to determine the effect of turbulence intensities <11% on vortex shedding sensors and transducers. Measurements were made at velocity levels of interest for underground coal mine monitoring use (?200, ?500, ?1,000, ?1,500 ft/min). The effect of grid-produced turbulence intensities (2% to ?14%) on the output of vortex-shedding air-velocity transducers was less than ±10%.

Jan 1, 1985

By P. C. Thakur

In Part I of this paper, it was established that the width of longwall faces in highly gassy mines is primarily limited by the volume of air reaching the tail-end of the face. The ventilation air reaching the tail-end of the face should be not only enough to keep methane concentrations below the statutory limits (generally 1 percent) but also enough to prevent any gas layering. The air volume leaking from the longwall face into the gob should also be able to push the explosive methane-air mixture away from the gob area immediately behind the longwall face where active roof-fall is taking place (typically 30-45 m). The second group of variables that also controls the width of the longwall panel consists of (a) the rate of advance, (b) bleeder air quantities, (c) specific methane emissions for the gob area and, (d) efficiency and cost of gob gas capture. This paper will discuss the second group of variables and its impact on the optimum width of longwall faces in highly gassy coal mines.

Jan 1, 2009

By W. Song, C. Richards, B. Q. Li

"This paper presents a two-phase flow numerical model for spouting gas-particle flow reactors used in chemical vapor deposition processes for manufacturing heart valves and other biomedical implants. The model is developed based on the Eulerian-Eulerian formulation of gas-particle flows, with the k-e engineering model modified with the presence of particles for the description of turbulent gas flows. In parallel with the numerical model development, physical models are set up, where the particle image velocimetry is used for visualizing the particle flows and spout shapes and heights and optical probes are used to measure the particle velocities. The numerical model predictions are compared reasonably well with the experimental measurements.IntroductionVarious biomedical implant components, such as bone joints, dental components and heart valves, are coated with bio-compatible thin films by chemical vapor deposition in particle-laden chemical reactors [l-5]. In these reactors fine particles are used as packing and supporting media. During the coating operation, these packed particles are fluidized by an upward gas jet from the nozzle, reach a certain height and fall back on the top of an annulus region. These recirculating particles are mainly for levitating the implant components (usually one or two in a reactor at one time) so that every portion of them is equally exposed to the gaseous atmosphere. An equal exposure is critical for forming a uniform, mechanically strong and corrosion-resistant coating on implants. Plant experience shows that the quality of the coating is directly related to a stream of operating parameters such as temperature, particle size and loading, and gas flow rates [6]. Optimization of these operating parameters for improved reactor performance depends crucially upon our fundamental understanding of the physics governing the gas-particle flow, heat, and mass transfer phenomena taking place in these reactors."

Jan 1, 2004

By M Scoble, C Hughes, M Roberts

At 14 per cent, the representation of women working in the mining industry is the lowest among primary industry categories in Canada. Despite an increase in research and industry commitment to advance and retain women in the mining industry, the gender gap in mining organisations persists.This paper is based upon a recent Canadian survey of 163 highly qualified women (HQW) working in the mining sector. For the purpose of this research, HQW were defined as women with a BachelorÆs degree or higher. This research sought to identify career progression and retention patterns of women who in theory have the educational qualifications to advance into positions of leadership in mining operations. We considered why womenÆs advancement in mining organisations has stalled; examined the career development pathways of HQW; and investigated the interactions of mining workplace culture on HQWÆs career development and retention within the Canadian mining industry. Results?indicated two distinct career pathway trends for HQW. æThe specialistÆ; a career characterised by multiple professional scientific and technical positions, and æthe corporateÆ; a career characterised by professional administrative roles and roles in mid-level management. It was found that neither æcorporatesÆ nor æspecialistsÆ systematically progressed into senior management and executive roles. These findings suggest that HQWÆs careers in mining are stalled, despite a strong indication by respondents of interest in their professional career advancement. With regards to?workplace?culture, respondents indicated that blatant forms of gender discrim-ination have been reduced in mining workplaces; however, exclusion from informal networks, implicit bias and subtler forms of workplace discrimination persist. Consistent with previous mining sector research, improving work-life balance, work flexibility and mentorship were found as key drivers for HQW to advance and remain in the industry.CITATION:Hughes, C, Scoble, M and Roberts, M, 2012. Where are the women? Highly qualified women in the mining industry, in Proceedings International Mine Management 2012, pp 23-34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By R C, K L. Rees, J S. J van Deventer

In contrast with previously published models for the carbon-in-pulp (CIP) process, the model proposed in this paper incorporates film transfer, intraparticle diffusion, simultaneous leaching, preg-robbing, the loading of multicomponent species, and the effects of fouling and changing cyanide levels. The rationale behind this comprehensive model is that changes in fouling and competitive adsorption along a CIP cascade affect the profiles of gold loading. As it is impossible to quantify all these non-ideal factors, a method is proposed whereby an imaginary species is postulated so as to combine all the competitive effects. A plant survey at the Telfer mine has shown that the mass loss due to a gravimetric analysis of the fouled carbon could be used directly to quantify this competitive effect. The degradation and consumption of cyanide along the Telfer CIP cascade enhance the loading of copper on to the carbon, which should be taken into account when modelling the gold profiles. It appeared that the effect of cyanide itself on the loading of gold was negligible compared with its effect on the copper. Evidently much more research is required on this topic in order to optimise CIP operations exposed to constantly changing conditions.

Jan 1, 1998

By C. L. Schaidle

Computers and communications technology have revolutionized many industries. In earthmoving, this revolution has just begun. The major changes are still to come, but they are just around the corner. This paper presents a vision of this up-coming revolution in our industry. This vision is comprehensive. It includes basic communication, machine monitoring and diagnostics, job and business management, planning and operations, and machine control. For our industry to realize maximum benefits from the information age, we must have a vision of the future that is shared by technologists, machinery producers, and miners.

Jan 1, 1994

THE discussion at the annual meeting of the paper on "Devices for Detecting Dangerous Gases in Mine Air" (published in. MINING AND METAL-LURGY, February 1, 1927, p. 69) was prefaced by the following description of a new portable methane indi-cator, presented by D. C. Ashmead: Two comparatively recent disasters in Utah are directly responsible for the perfection of the new methane detector. The first of these occurred on May 1, 1900, when 200 work-men lost their lives. The second disaster did not occur for more than two decades, when, on March 8, 1924, at the Castle Gate Mine No. 2, 172 workmen were killed. A dis-sembled safety lamp was later found at the seat of the ex-plosion. This indicated, as a possible cause, that the safety lamp had gone out and the fire boss had tried to relight it. These two disasters brought, the mine operators of the State of Utah to the concentrated attempt to end the loss of life through mine explosions. The Governor of the State appointed a committee, known as the Utah Mine Op-erators Committee, to study the phases of the problem, and this Committee in turn enlisted scientists all over the country in cooperative research. One group, under the direction of E. K. Judd, of the Union Carbide and Carbon Research Laboratories, of Long Island City, New York, concentrated its efforts on develop-ing a methane detector which would be completely ade-quate. This is now successful, since in laboratory as well as actual coal-mine tests the apparatus has instantaneously and accurately detected the presence of extremely small amounts of methane.

Jan 3, 1927

By George M. Fowler

MINING geology is a progressive study, so we must look to the future for the solution of many of its most significant problems. These problems, world-wide in scope, offer ample opportunity for the exercise of the utmost skill and intelligence by all that attempt to solve theta, as it is generally recognized that many ore deposits of the future will he found only by months or years of combined intelligent effort by the several engineering groups. Renewed appraisals are continually being made to better understand the relationship of physical-chemical processes to ore deposition and other mineralization and to interpret the findings of the geophysicists and others in terms of economic results. A study of current geologic activi¬ties clearly reflects the growing tendency for cooperation between the different branches of geology in order to appraise their united efforts. In line with these activities arrangements have been made to transfer the geophysical section of the U. S. Bureau of Mines to the Geological Survey.

Jan 1, 1936

By S. E. Kesler, C. M. Moore, J. C. Van Loon

The possibility that chlorine and fluorine form complexes with ore metals, thereby having a strong effect on the mobility of these ore metals during late magmatic and hydrothermal processes, suggests that the abundance of chlorine and fluorine in igneous rocks could be used to distinguish intrusions that have generated ore deposits. The simplest and most economical measure of this chlorine and fluorine is the water-leachable chloride and fluoride that is released from fluid inclusions in the rock during crushing of the sample. In order to evaluate the possible use of this technique, measurements of water-leachable chloride and fluoride were made with selective ion electrodes on samples from nine intrusive complexes. There does not appear to be any simple relation between the abundance of chloride and the presence of mineralization. Fluoride values in mineralized intrusions appear to be higher than those in barren intrusions.

Jan 1, 1973

By G Danckert

The key technical theme of ‘orebody knowledge’ has been applied by Rio Tinto in the Pilbara iron ore precinct from 1966, when operations first started there. It forms the basis of present day application, as well as planning for the future.This paper will review how the early towns and mines commenced and how they formed the basis of Rio Tinto’s early operations, on which the Pilbara precinct has been based. A profile of the last decade of Pilbara growth will be highlighted, together with the current integrated network of mines, rail and ports and the next generation of expansions.The paper will specifically describe the Rio Tinto process of significant resource evaluation, including comprehensive drilling programs and the conversion from resource to reserves. It will also describe the overall mine planning process, both from the strategic view, as well as for short-term mine plans.The ability to innovate in resource development will be discussed. This will include not only the technical dimension of changing cut off grades, use of low-grade ores and managing low-grade stockpiling and beneficiation, but also the broader application of new technology and innovation in the iron ore business.

Jul 11, 2011

By B. DANIEL MARJAVAARA, I. A. SOFIA LARSSON, ANNA-LENA LJUNG

One way to upgrade iron ore is to process it into pellets. The pelletizing process is multifaceted, involving complex fluid dynamics with highly turbulent, high-temperature flow in intricate geometries. This makes it hard to perform measurements during operation, so a useful tool for better process understanding is computational fluid dynamics (CFD), where the challenge is to perform efficient and trustful simulations of complicated problems. A validated simulation model can be valuable for increased process control and development. In this paper, the flow field and coal combustion process in a pilot-scale iron-ore pelletizing kiln is simulated using a CFD model. The objective of this work is to apply a coal combustion model to enable an investigation of thermal effects from the flame on the surrounding flow field.

By M. Reda

Inorganic oxidizing agents of the type MeOx-z such as Chromate, Vanadate, Tungstate, and Molybdate... etc. are widely used as corrosion inhibitor. In non acidic solution these oxidizing agent are reduced on the surface of the meta, according to OX + m e + p H20 Red + n OH" In which y = (n-m)/m. The purpose of this publication is to show that for many metals the value of y for any oxidizing agent determines the possibility of that oxidizing agent being an inhibitor or activator for the corrosion process. The inhibition efficiency for other ions such as Pertecnetate and Tellurate which have not been extensively studied can be predicted. A mathematical, equation was derived to express the relationship among the concentration of oxidizing agent, degree of retardation of the corrosion process I cord cor ° (ratio of corrosion current in the solution containing inhibitor to the base solution) , ionic strength of the solution and the coefficient y. The validity of y and the mathematical, equation were verified by many experimental, works on various metals such as zinc, aluminum and steel. Al, the above research works are based on the published research works of Prof. Mikhailoviskii (from 1979 til, 1998) from the Russian Academy of Science.

Jan 1, 2010

By M. R. Stokes, A. J. Ross

As a result of higher levels of production and greater depths the underground mining industry in the UK is encountering hotter climates in some workplaces. It is widely known that high heat and humidity in an underground workplace will result in reduced performance and may also seriously impair the health and safety of the workforce. It is therefore of paramount importance that the underground environment can be effectively predicted in order that sound decisions can be made to reduce the effect of climate on working personnel. Over the years numerous computer programs have been developed to predict the climate in underground mines. One such important program, developed by McPherson, is CLlMSlM TM which is a prediction model of heat and mass transfer along a single roadway. This paper describes the development of a computer model, called DRIVE, to predict the climate in single entry drivages. This program incorporates the theory established by McPherson for the development of CLlMSlM TM. This involves the algorithm for unsteady state heat transfer. Throughout the development of DRIVE underground measurements have been taken to correlate the program. DRIVE will predict the changes in psychrometric and thermo- dynamic conditions along the drivage depending on a number of parameters. Firstly, the type of auxiliary ventilation system employed such as forcing, exhausting, overlap. Secondly, the addition of heat and moisture due to autocompression, machinery, strata, fissure water, oxidation, broken rock, fallen rock, refrigeration equipment, lighting, personnel, service water. Thirdly, due to the velocity of the air.

Jan 1, 1997

By M Graham, R Brunning, C Andringa-Bate, S Westergren

In 2010, Rio Tinto Iron Ore’s operations commenced the planning and design of a sampling and analysis system for the new 50 Mt/a Cape Lambert Port B (CLB) facility. Current sampling systems at the ports consist of automated robotic, mass-based sampling protocols employed at Dampier, and semi-automated, time-based sampling systems operating at Cape Lambert Port A.The new sampling system at CLB has brought together a fully automated sampling and analysis system utilising time-based sampling, with the capacity to sample ore products of medium quality variation as defined in ISO 3082 (ISO, 2009). The CLB system is required to sample at shiploading rates from 6000 t/h to 13 440 t/h and provide full load-port analysis. The sampling approach is to proportionally extend primary increments (of varying mass relative to shiploading rate) to a standard length using variable speed aero-belt conveyor systems. This enables a fixed number of secondary cuts to be achieved for all primary increment masses and to be delivered to the automated cell. The cell is required to be capable of concurrently processing four individual shipments, each containing multiple cargoes.Achieving the target sampling precision for all export cargo sizes has culminated in the planning, design and construction of the largest automated iron ore port laboratory in the world. The CLB sampling and analysis cell was commissioned in Q3 and Q4 2013. This paper discusses the sampling philosophy and commissioning outcomes.CITATION:Brunning, R, Andringa-Bate, C, Graham, M and Westergren, S, 2014. Cape Lambert Port B shiploading, sampling and analysis, in Proceedings Sampling 2014 , pp 79–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By Paul C. Merritt

Chrysotile asbestos producers in Quebec may soon experience a unique situation-i.e., strong competition from American ore sources for the short fiber market west of the Mississippi River. This com- petition will be forthcoming from Copperopolis and Coalinga, two deposits now being developed on opposite flanks of the San Joaquin Valley in central California. The combined output now planned from both deposits is 100,000 tons annually, equivalent to about 50% of the annual market demand in the western, central and Gulf States, and more than twice the tonnage sold in 1960 by all other American asbestos producers combined. The principal companies involved in these new undertakings are Jefferson Lake Asbestos Corp. (subsidiary of Jefferson Lake Sulphur Co.), Hidden Splendor Mining Co., Coalinga Asbestos Co. (Johns- Manville Corp. in conjunction with Kern County Land Co.), Union Carbide Corp., and Asbestos Corp. Ltd. Jefferson Lake&apos;s principal interest is at Copperopolis where the company&apos;s new 70,000-ton per yr mill recently went on stream. The company also holds some claims at Coalinga, but this latter area is better known as the site where Hidden Splendor, Coalinga Asbestos Co. and Todd Industries (a local company) have established operating mines and mills capable of turning out 30,000 tons of fiber each year. Coalinga is also the site of exploration by Union Carbide Nuclear and Asbestos Corp. Ltd.

Jan 9, 1962

By J. L. Eakin

Systematic flooding was introduced into Nowata County, Okla., in May 1931. The results of this means of stimulating the nearly depleted Bartlesville reservoir in the county has been the subject of four Bureau of Mines Reports of Investigations.2-5/ This report presents a discussion of four full-scale water-flooding projects in the Delaware-Childers field and 1 pilot project in the Curl Creek field (fig. 1). All five plants have been in operation for only a few months. Although substantial increases in the rates of oil production have been obtained 1 by the injection of water, the projects are of particular interest at this time because of the novel methods of operation and new equipment that are being employed. One project utilizes a portable "package" plant designed for a pilot operation. All of the controls for this project are centrally located. The design makes it possible to remove the test plant to another location if the project is unsuccessful or if the unit is to be replaced by a larger plant. This project also utilizes diatomaceous-earth filters successfully for the first time and makes use of plastic pipe. Another novel feature of the operation is the aeration of Arbuckle limestone water through an airlift in the supply well.

Jan 1, 1955

By Paul L. Russell

Introduction As the US and world population increases, so does the problem of supplying expanding energy needs. Early requirements worldwide were mostly met by abundant forest vegetation. Man&apos;s large scale use of minerals-energy resources is a fairly recent development. It occurred only during the past 200 years. Coal was the first mineral fuel to be used extensively. It was not a large factor in US energy production until the beginning of the 19th century. Petroleum and natural gas use is about 125-years-old. Electricity generation by falling water is about a century old. Atomic energy is only about 30-years-old. Extensive use of it is still in the future. Solar energy is in its infancy. Other energy sources such as wind, peat, and geothermal energy are minor and primarily of local importance. There were three main features of the fuel supply picture during the past 125 years. By 1900 coal replaced wood as the principal energy source. Since 1900, oil and gas have captured many coal markets. And after the mid-1970s, there was a resurgence of coal usage. (Figs. 1 and 2). Wood Until the advent of mineral fuels for energy, the major global energy source was wood. But populations increased and became centered in towns and cities. The problem of a sufficient energy supply first developed as nearby, easily obtained wood was exhausted. This problem became more acute as industries such as shipbuilding, smelting, and pottery making, became more widespread. Results of wood use as an energy source and building material are starkly evident in areas of the world where civilization is oldest. Entire forests were consumed and have never been replaced. In the US, wood supplied 90% of all fuel requirements until about 1850; and more than 50% until after 1880. By 1900, wood still supplied 20% of all energy uses. In the mid-1970s, energy costs increased, due largely to the oil embargo. This increase resulted in an increased wood demand for domestic heating. While large quantities of wood were being used, its share of the total energy market was still less than 3%. By 1983, wood was becoming increasingly scarce and more costly near most large US cities. Wind Wind powered ocean vessels for many centuries. Sailing ships were still common in 1900. Windmills provided an early, cheap energy source and continue to be used today on farms. Design and development of windmills for electricity generation is being conducted. Interest in wind power is growing worldwide where availability of wind currents warrants the investment. Also, US regulation requires power companies to "buy back" electricity generated by windpower in excess of that used by the windmill owner. Coal By the 1600s, England was producing, 900 kt/a (1 million stpy) of coal for heating and other uses. The first coal-fired blast furnace for iron smelting was developed in 1621. Coke-making was developed in 1755, and Watt invented the steam engine in 1769. Illuminating gas made from coal was introduced in London in 1800. During this same 200-year period, France and Germany developed coal production, but on a smaller scale than England. US, bituminous coal was mined near Richmond, VA, as early as 1748. Major bituminous coal-producing states in the early period were Pennsylvania, Virginia, Ohio, Kentucky, Illinois, and Maryland. West Virginia replaced Virginia as a major producer, when that state was formed in 1863. As the US expanded west, new coal deposits were found and exploited. Indiana, Alabama, Tennessee, Iowa, Kansas, Missouri, Washington, Colorado, Wyoming, Arkansas, Oklahoma (Indian Territory), Montana, New Mexico, and Texas had significant coal mining operations by 1900. Today the eight major coal producing states are Kentucky, West Virginia, Pennsylvania, Illinois, Ohio, Virginia, Wyoming, and Montana. These states accounted for about 80% of all coal (lignite, bituminous, and anthracite) produced in the US during the past several years.

Jan 8, 1984