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By CLAYTON C. BALL

In the year 1948, more than ever before, the coal industry established itself on the threshold of a new and exciting future expansion. While production did not equal the wartime and peacetime peaks of 1944 and 1947, it was, in review, a good coal year. During the latter part of the year a combination of mild weather, record stock piling, and general business slackening reduced coal demand to the extent that marginal mines suspended operations, while mines remaining active found it necessary to renew their attention to producing better products at lower operating costs.

Jan 1, 1949

By William R. Yernberg

A conference on coalbed and coal mine methane was held March 27 and 28, 2000, in Denver, CO. The conference, organized by the Strategic Resource Institute, was attended by leaders in the coal mining and gas energy industry. The conference focused on the recovery of methane from coal beds as an energy resource and the removal and utilization of coal-mine methane (CMM) related to underground coal mining. The two-day conference discussed methane resources around the world, methods of recovery, methane markets, underground coal mining, health and safety issues and environmental issues related to methane. The consensus among the presenters is that the future looks promising for coal bed methane (CBM) and CMM.

Jan 1, 2000

By A. W. Gauger

SMELTING of iron ore, manufacture of steel, and the fabrication of ferrous metal products are all processes that require energy. Charcoal was adequate, to supply this energy for the relatively simple processes of the early iron-masters. In the fourth decade of the nineteenth century, anthracite and bituminous coal and later coke supplanted charcoal for the smelting of iron. So far as the chemical phases of the process were concerned, charcoal was an ideal iron-furnace fuel. It had practically no sulphur, and its ash, besides being low in quantity, consisted chiefly of lime and alkalies, thus supplying a part of the flux required for smelting the ore. The ash of coal and coke on the other hand, being largely silica, had itself to be fluxed with bases added to the charge. Physically, however, coke proved to have many advantages over charcoal, which could not be used in the furnaces of today. The chief reason, however, for the change from charcoal to coke was the impossibility of maintaining an adequate wood supply.

Jan 1, 1941

By V. R. Burkhart

Pennsylvania Power & Light Company is an investor-owned public utility which was incorporated under the laws of the Commonwealth of Pennsylvania on June 4, 1920, with general offices at 901 Hamilton Street, Allentown, Pennsylvania. At the present time PP&L is operating five coal-fired steam electric stations, two hydroelectric stations and one steam heat plant which is being converted from anthracite to oil fired. In addition, PP&L is a partner in both the Keystone and Conemaugh mine mouth bituminous coal-fired steam electric stations in Central Pennsylvania and also part owner of a company which operates another hydroelectric station. PP&L plants, other than the two mine mouth stations, are located in Central Eastern Pennsylvania. (Figure 1) The company derives about 99% of its operating revenues from supplying electric service, while the balance is from the one steam heat plant serving the city of Harrisburg. The entire service area covering 10,000 square miles in 29 counties, has a population of approximately 2,300,000 people. The area served is mostly suburban. It includes 109 communities each having a population in excess of 5,000 people. The largest cities served are Allentown, Bethlehem, Harrisburg, Hazleton, Lancaster, Scranton, Wilkes-Barre, and Williamsport which range from 50,000 - 120,000 in population. So you see our service area does not include any major cities. The area has industrial, commercial, residential, agricultural and recreational activities that are linked with the Eastern Megalopolis by an extensive interstate limited-access highway system and railroad networks. We consider this Central Eastern Pennsylvania area we serve as the "heart of the market" -- an area with great growth potential.

Jan 1, 1973

By Steve Kral

Led by a surge in coal production and prices in recent years, Colorado’s mining industry is taking part in the same revival as others states and the world. Not too many years ago, the state’s industry was languishing in the same doldrums as the rest of the mining world. Ironic for a state whose history was based on mining. Now, however, Colorado’s mining can boast increased production in all commodities produced, along with prices that allowed companies to expand, increase work forces and post improved shareholder value. So there was a lot of optimism at the Colorado Mining Association’s (CMA) 107th National Western Mining Conference in February. The conference, held in Denver, attracted more than 500 attendees and 39 exhibitors. The theme was Colorado Mines the World.

Jan 1, 2005

By James F. Kelly

"Research and development on the production of liquid fuels from coal is rapidly expanding worldwide. AImost every industrialized country is engaged in coal liquefaction research and process development. In Canada, the federal government, through CANMET, is actively supporting coal liquefaction research and development in a number of areas.A review of the basic principles and some of the processes in the production of liquid fuels from coal is presented with reference to the characteristics of the Canadian coal resource base. An overview of the CANMET coal liquefaction contract program is presented and specific results from the batch autoclave studies carried out with Saskatchewan lignite and Nova Scotia high-volatile bituminous coals are discussed. The development of a laboratory-scale continuous-flow coal liquefaction unit at the Energy Research Laboratories of CANMET to investigate the co-processing of coal and bitumen/heavy oil is also described.IntroductionThe CANMET coal liquefaction program is made up of two interrelated parts. The first part consists of the research and development work being carried out at the Energy Research Laboratories near Ottawa, Ontario. The second focuses on contracted research and development as part of the Coal Conversion Program of Energy, Mines and Resources Canada. The long-term objective of the liquefaction program is to contribute to Canadian liquid fuels production through the definition, research, development and demonstration of different coal liquefaction technologies for the Canadian marketplace.In coal liquefaction, the main objective is to produce liquid hydrocarbons with a higher hydrogen-to-carbon (HIC) ratio than the coal feedstock while reducing heteroatom (S,O,N) content, removing mineral matter and minimizing gas production. Typical atomic HIC ratios for a variety of Canadian fossil fuels are shown in Figure I. Canadian coals have about 500/0 of the HIC ratio present in tar sand bitumens and heavy oils and only about 20% of the ratio available in methane. In general, the cost of synthetic fuels production is related to the cost of hydrogen and, therefore, to the increase of HIC ratio between feedstock and products. On this basis, the production of liquid fuels from coal would be expected to be more costly than liquid fuels produced from bitumens and heavy oils. However, for mined tar sands and some heavy oils this difference tends to be offset by the large sand content (>90 mass %) of tar sand bitumens and the increased production costs of viscous heavy oils. For example, it can easily be shown that for equal weights of distillate <525°C) yield, current coal liquefaction processes required between two and three times less mined coal by weight than the mined tar sand s required for the most technically advanced processes proposed for bitumen upgrading."

Jan 1, 1981

By R. E. Pennington

My subject this morning is coal liquefaction technology. Actually, coal liquefaction involves a number of technologies in a very complex system. The first slide shows the major components of such a system with arrows to indicate appropriate flows. The components are the facilities for coal feed preparation and handling; the coal hydrogenation or base liquefaction section; facilities for product separation and recovery, and in addition, facilities for the production of hydrogen from coal-based sources. A very rough break- out of the investments involved in these areas is given at the bottom of the slide. Investment is spread about equally among the three areas of operations Another way of looking at it is that the investments in what might be called support facilities are of the same magnitude as the base investment in the hydrogen facilities. Therefore, it is appropriate in a discussion of coal liquefaction technology to treat it as a system composed of a number of technologies. The next slide lists the various functions in the feed preparation section along with an indication of technology status. Storage, crushing, grinding, drying of coal all have been in commercial practice for a number of years. The slurrying and pumping of coal at least in water slurries, is practiced commercially also. The heating of coal slurries in oil to high temperatures under pressure is not in commercial practice and development and testing is going on by a number of people in this area. Some rather complex phenomena occur when coal oil slurries are heated to high temperatures.

Jan 1, 1975

By Paul Wellman

The energy problem of the U. S; was emphasized by the oil embargo of late 1973 and early 1974 and it seemed for a time that the Federal Government, under pressure from the general public, might take some corrective action. However, this was not the case. With the gasoline lines gone and an apparent plentiful supply of petroleum products, public concern quickly dissipated., This country is more vulnerable to an oil embargo today than we were in 1973-1974 and this fact should be of concern to all our people. Since 1968, we have used oil and natural gas at a much more rapid rate than we have been able to find new domestic sources; thus, there is an increasing gap between domestic production and consumption and we have filled the gap with ever increasing oil&apos; imports. These imports have increased at an alarming rate in the recent past, some 58 percent in 1976 compared with 1975. Imports are nearing 8 million barrels per day. Then, by applying some simple arithmetic, at $12 per barrel, the resulting trade deficit is $96 million per day or $35 billion per year. Obviously, this cannot be tolerated by our economy over a long period of time. Historically, we have shifted from one fuel to another as is shown in this slide. In 1850 about 90 percent of our fuel requirements came from direct combustion of wood, by 1900 we shifted to coal for 70 percent of our fuel, and now about 78 percent of fuel requirements comes from oil and natural gas. The difference is that the previous shifts were voluntary and the one facing us now is of necessity.

Jan 1, 1977

By Sarma S. Kanchibotla

In overburden cast blasting the explosive energy is used to move a significant percentage of overburden from the high wall to the spoil pile thus reducing the amount of material to be handled by machinery. However, the obvious trade-off between the extra explosive energy in the cast blast versus reduced dragline effort is complicated by an increased risk of damage to the underlying coal. This damage may not be obvious but inevitably leads to reduced coal recovery and may negate much of the benefit sought from cast blasting.

Jan 1, 1999

By Ronald F. Ayers

The study upon which this paper is based was completed by Battelle&apos;s Columbus Laboratories for the U.S. Army Corps of Engineers in 1974. It is but part of an overall effort by the Corps to evaluate the costs and benefits to the nation of waterway improvements. This study is primarily concerned with future coal markets for production from those counties near the Wabash River in the heart of the Eastern Interior Province. An objective here is to consider a most pessimistic energy (and hence, coal) demand for planning purposes.

Jan 1, 1976

By J. Platt

Debate over acid rain legislation has presented a moving target for coal and utility company planners attempting to figure out how legislation will affect their business environment. In spite of disagreement among experts, the prospect for continued change, and persistent --perhaps even growing --uncertainty, a great deal has been learned about coal market dynamics. This paper reviews progress and describes some of the major problems and controversies.

Jan 1, 1990

Drilling in the south of the Rapahoe Sector at Greymouth Coalfield has demonstrated the existence of thick coal seams in the upper Rewanui Member. Seam correlation is handicapped by complex lithostratigraphy and laterally variable geophysical log profiles. An integrated investigation of coal measure stratigraphy, coal petrology, and proximate analyses, suggests a feasible model whereby most of the major seam intersections belong to a single horizon. Coal properties vary laterally in response to original swamp conditions, which are believed to have ranged from well-drained to ponded. A new model of peat accumulation is proposed for the northern Rapahoe Sector, whereby Upper Rewanui peat accumulation occurred on a flood plain between the levees of a major south southwest-flowing fluvial system in the east and the toe of a western alluvial fan.

Jan 1, 1985

By d&apos, L. R. Fletcher, Andrea. D. V., M. A. Peltier

The Bureau of Mines analyzed coal mine blasting accident data obtained from the Mine Safety and Health Administration (MSHA), U.S. Department of Labor. The data were examined to determine the causes, frequency, and severity of accidents in an effort to point out the most dangerous aspects of coal mine blasting. Accident data for the 14 years from 1971 through 1984 show that there has been a total of 43 fatal and 926 nonfatal blasting accident victims in surface and under- ground coal mining. This is an average of 3.1 fatal and 66.1 non- fatal injuries each year. Underground coal mining accounted for 60.5% of the fatal and 78.7% of the nonfatal accidents involving explosives and breaking agents in coal mining. In addition, since 1970 there have been 53 fatal and 20 nonfatal injuries that occurred when explosives were the ignition source for dust and/or methane explosions in underground mines. Abstracts from 297 accidents that occurred from 1978 through 1984 were also examined to determine accident causes. Most accidents occur during scheduled blasting, and failure of the blast area security system is the leading cause. Blast area security problems in surface mining are failure to clear the blast zone, failure of personnel to follow instructions, inadequate guarding, and failure to retreat to a safe location and/or take adequate cover. Other common causes in surface mining include premature blasts, excessive flyrock, and misfires. In addition to the above causes, accidents in underground coal mining can be due to rockfalls triggered by the blast, unexpected breakthroughs, fumes, and incidents associated with Airdox-type systems.

Jan 1, 1986

By David Newman

In Eastern Kentucky, the Darby seam has had an extensive history of coal bumps and pillar bursts. The combination of high overburden, strong rock and coal, subjacent and superjacent mines, and retreat mining has produced incidences of violent pillar failure. The influence of these factors on pillar stability and the potential to bump is illustrated in two case histories. In the first case history, a bump occurred unexpectedly during the retreat mining of a five heading continuous haulage panel. Alternative cut sequences and pillar dimensions were analyzed to identify a geometry that would reduce the potential for future coal bumps or bounces during retreat mining. The viability of the alternatives was constrained by the reach of the continuous haulage system, the overburden depth, and the presence of thick sandstones in the main roof. Each alternative was numerically modeled cut-by-cut to examine the mechanism of stress transfer, as a pillar row is retreat mined. This approach highlighted which cuts were being made in highly stressed portions of a pillar and therefore more prone to coal outbursts. Validation of the numerical modeling was accomplished by comparing the cuts where bumps and outbursts had occurred underground to the highly stressed cuts shown within the models. Recommendations of the barrier pillar width between adjacent panels, pillar dimensions, and changes in the retreat mining sequence were proposed based upon the overburden thickness, geology, and the result of the numerical modeling. The second case history documents a nine-entry panel 3,600-feet long that was retreat mined a distance of 2,064-feet without a significant roof fall or roof-floor convergence. Mine management became concerned about the potential for a coal bump or a large roof collapse within the gob and the resulting air blast. The stress on the pillar line and within the remnant pillars in the gob was quantified through numerical modeling. Changes in mining practices on the current panel were implemented to avoid a bump in the active panel. A barrier was established between the current and the future panels to protect the future panel against abutment pressures from the void area. A change in pillar centers was proposed in the adjacent panel to absorb the side abutment pressure from the gob of the active panel.

Jan 1, 2008

By Anthony Iannacchione

Coal mine bursts have represented a major hazard for U.S. mining operations for more than 90 years. During this time, many prevention controls have been developed and tested. This paper reviews 11 prevention control techniques. Although coal mine bursts are not common events in most underground coal mines, their occurrence almost always requires a change in mining practice. Over the many years of dealing with these hazards, specialized requirements for layouts and novel extraction sequences have been developed on a site specific basis. The keys to mitigating risks are to properly assess the coal burst hazards and to possess the knowledge and skills to prevent or remediate their occurrence.

Jan 1, 2008

By D Craw, N Newman

Previously published stream quality data and AMD (acid mine drainage) analyses have been collated into a database (DAME û Database for Assessment of Mine Environments) and additional samples including NMD (neutral mine drainage) have been collected from coal mine drainages on the West Coast. Variations in the chemistry of mine drainage samples can be related to four factors: 1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; regional geology (Brunner Coal Measures or Paparoa Coal Measures) 2.&nbsp; &nbsp;&nbsp;&nbsp;&nbsp; mine type (open cast or underground) 3.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; hydrogeology 4.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; local geology &nbsp; In general mines hosted in Paparoa Coal Measures produce NMD whereas mines hosted in Brunner Coal Measures produce AMD with highly variable chemistry. Differences in coal mine drainage chemistry between mines hosted in Brunner and Paparoa Coal Measure sequences can be measured with acid-base accounting geochemistry. Correlation of ANC (acid neutralising capacity) and MPA (maximum potential acidity) analysis of rocks with mine drainage samples is substantially better than correlation of NAG (net acid generation) analysis with mine drainage chemistry. &nbsp; It is likely that NAG analysis over estimates acid generation potential of some samples due to release of organic acids that are not released under environmental conditions. In general, differences in mine drainage chemistry between Brunner and Paparoa hosted mines are attributed to the effect depositional environment and diagenesis on coal measure composition. Exceptions to generalisations relating mine drainage to Paparoa or Brunner host rocks are likely where local geological conditions cause increased deposition of pyrite in Paparoa rocks and additional analyses are required to confirm interpretations. &nbsp; Based on the interpretation of these results a mine drainage chemistry hazard model has been constructed. The hazard model predicts likely variations in mine drainage chemistry based on the four factors listed above. The hazard model has implications for mine related water quality risks. For example, ecotoxicity, human health affects and selection of remediation techniques are all sensitive to mine drainage chemistry.

Jan 1, 2006

By Frank E. Chase

During the past quarter century, coal mine geologists have evolved from providing a qualitative description of drill core and coal reserves into quantitative geotechnical specialists who bridge the gap between geology and engineering. In the late 1970?s and early 1980?s, hazard prediction mapping was in its infancy. At best, hazard maps identified rudimentary structures and conditions such as stream valley locations, sandstone/shale transition zones, and lineaments. A ?technical disconnect? had existed between geologists and mining engineers as each profession operated largely independent of each other. Engineers did not readily integrate geology and geologic conditions, with the exception of coal thickness, into mine planning. Geologists were relied upon for reserve estimates and did not participate in mine planning or design. The employment and market slump of the 1980?s and 1990?s combined with mining more challenging reserves mandated that this gap be bridged and forced geologists to learn to speak more ?numerically? to engineers so they could be understood. The purpose of this paper is to describe the procedures and thought processes used by coal mine geologists when determining various mineability and reserve extraction feasibility issues. The paper will also address underground geologic hazard mapping and prediction techniques. To achieve these objectives, the opinions and experiences of leading coal mine geologists, geotechnical and strata control specialists across the United States were solicited.

Jan 1, 2006

By D. N. Bigby

This paper concentrates on ground control innovation in Europe since the first Morgantown conference, mainly from a UK perspective. In particular, it describes the rock engineering and ground control tools developed to address the mine support and design problems associated with coal mining at great depth in areas influenced by previous workings. The differences in approach across the Western European industries are also examined. Perhaps the most significant change in the period has been in the science of coal mine rock mechanics itself, with support design now based firmly on measurement, analysis and understanding. The ground control innovations described here have played their part in increasing the efficiency with which coal is mined and in increasing safety to the extent that fall of ground accidents are now rare.

Jan 1, 2006

By M. A. Trevits, I. R. Houlison, A. C. Smith, T. P. Mucho

Timely and rapid intervention to underground combustion events (fires, explosions, and spontaneous combustion) is the key to the successful control of the mine atmosphere and restoring of a coal mine to production. The focus of this paper is the utilization of a GAG 3A jet engine system to combat either large out-of-control fires or to render an entire mine inert when access to problem areas is difficult or impossible. This system is based upon a Soviet designed agricultural jet engine which consumes aviation fuel with oxygen (O2) from the intake air and exhausts combustion gases, primarily carbon dioxide (CO2) and water (H2O), along with the nitrogen (N2) from the air and small amounts of carbon monoxide (CO) and hydrogen (H2). The system is designed to approach stoichiometric combustion (ideally, pure burning that scavenges all the oxygen from the intake air). Therefore, these exhaust gases are almost entirely “inert gases”- i.e., gases which do not contribute to, and in fact, can suppress the combustion process due to the lack of oxygen. Other methods to inert mine areas have been used in the US and internationally, but these methods usually use low flow inertisation equipment or methods. Use of these low-flow inertisation equipment and methods has been successful in proactively rendering gob areas inert and has the ability to inert the entire mine workings. Due to the low flow rate, however, a substantial period of

By F J. van Zyl, C A. S Thomson

"Anglo American Thermal Coal conducted a high level study of all of its underground collieriesto determine if there were electrical power saving opportunities at the main fan stations.A systems approach to electrical power savings was used to identify potential savings in the various components of a primary ventilation system. Furthermore, only technological interventions were considered to obtain electrical power savings. From generic technological driven electrical power saving strategies four energy savings strategies were identifi ed, namely potential overall reduction in ventilation volume, improved underground air utilisation, optimisation of fan-set effi ciency and potential fan drift design optimisation. The study indicated the colliery (say Colliery D, Shaft A) that showed most potential in the four technology driven energy savings strategies. A detail study was undertaken at Colliery D, Shaft A to increase the confi dence level and the study confi rmed that up to 45 per cent of the main fan absorbed power can be saved (475 kW) with an estimated capital payback period of 18 months. The study clearly showed that an integrated approach to optimise the entire mine ventilation system has great potential for power saving, and that a clear, well -defi ned methodology will be applicable to similar underground collieries. This paper discusses the background to the study and the process followed to implement the energy savings initiative at Colliery D, Shaft A."

Jun 1, 2012