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By D. R. Willmer

An understanding of how health and safety management systems (HSMS) reduce worksite injuries, illnesses and fatalities may be gained in studying the behaviors of health and safety leaders. These leaders bear the accountability for identifying, understanding and managing the risks of a mining operation. More importantly, they have to transfer this knowledge of perception, recognition and response to risks in the mining environment to their workers. The leaders’ efforts to build and maintain a mining operation’s workforce that consistently executes safe work practices may be captured through more than just lagging indicators of health and safety performance. This exploratory study interviewed six leaders in occupations such as site-level safety supervisors, mine superintendents and/or general managers at surface and underground stone, sand and gravel and metal/nonmetal mine sites throughout the United States, with employee populations ranging from 40 to 175. In exploring leaders’ perspectives on how they systematically manage health and safety, examples such as approaches to task training, handling near-miss incidents, identifying future leaders and providing workers with feedback offer insights into how leaders translate their knowledge and management of site-level risks to others.

Jan 1, 2018

By D. R. Willmer

An understanding of how health and safety management systems (HSMS) reduce worksite injuries, illnesses and fatalities may be gained in studying the behaviors of health and safety leaders. These leaders bear the accountability for identifying, understanding and managing the risks of a mining operation. More importantly, they have to transfer this knowledge of perception, recognition and response to risks in the mining environment to their workers. The leaders’ efforts to build and maintain a mining operation’s workforce that consistently executes safe work practices may be captured through more than just lagging indicators of health and safety performance. This exploratory study interviewed six leaders in occupations such as site-level safety supervisors, mine superintendents and/or general managers at surface and underground stone, sand and gravel and metal/nonmetal mine sites throughout the United States, with employee populations ranging from 40 to 175. In exploring leaders’ perspectives on how they systematically manage health and safety, examples such as approaches to task training, handling near-miss incidents, identifying future leaders and providing workers with feedback offer insights into how leaders translate their knowledge and management of site-level risks to others.

Jan 1, 2017

By J. A. Halt, E. Larsen

"The Sydvaranger magnetite mine closed in 1996 due to low iron ore prices and was reopened in 2009. The flowsheet has remained more or less as in the old plant, based upon two grinding steps followed by magnetic separation. The magnetite is free of harmful elements and should be attractive on the high quality market. This requires a concentrate containing less than 2% SiO2, which previously was achieved by amine flotation. Amine was preferred because it could be used with sea water. The use of amine is now restricted by the Norwegian Climate and Pollution Agency. Therefore, testwork to replace cationic with anionic flotation was done. Activation of quartz with Ca or Mg ions prior to anionic flotation was shown by research from 1960 to 1980 to be effective under laboratory conditions. The old research results have been followed up in order to make a commercial process for Sydvaranger. Calcium activation works excellently with all Sydvaranger ores, including the ones containing amphibole minerals, but Ca activation requires the high and not environmentally friendly pH of 12.4. Magnesium activation at pH 10.5 is a little more challenging, because the maximum concentration of MgOH+ is about 100 times lower than that of CaOH+. Fortunately, the major impurity in the main Bjornevatn orebody is quartz, which responds well to Mg activation. The process does not appear to depend much upon water quality, as the silicates may already be activated during grinding and magnetic separation in recycled water. The new process is environmentally friendly, as only well-known household reagents are used; oleic acid or tall oil, dextrin, sodium hydroxide and magnesium chloride at pH 10.5.IntroductionThe processing plant of Sydvaranger Gruve AS (SVG) is located in the port town of Kirkenes in the northernmost part of Norway, 10 km by rail from the high-grade deposit of Bjornevatn. This plant has been able to beneficiate magnetite ore to up to 99.5% purity, as described by Sandvik and Malvik (2001). Using the magnetic properties of the ore and making the most out of its enviable liberation characteristics, the original plant consisted of ball mills and 600-mm magnetic separators. The plant was shut down due to market conditions in 1996 but reopened in 2009."

Jan 1, 2015

By Johann Steynberg

The design and construction of a Concentrator based on initial pilot plant work is rarely perfect. Palabora's plant was no exception although the basic objective to produce copper in a safely conservative manner was certainly achieved in a profitable manner. identification of the metallurgical and mechanical deficiencies of the plant through operating experience and a better concept of the minerology of the orebody enabled the development of a more efficient process both in terms of the metallurgical performance and cost effectiveness. To maintain and improve this level of efficiency, continuous inspection and revision of the plant metallurgy and engineering standards is required. In this presentation a few of the investigations and changes are described: 1.0 Alternative methods to restrict and eliminate the detrimental effect of critical size material on the performance of an autogenous mill. 2.0 An analysis of the environmental condi¬tions in Palabora's grinding circuit and the introduction of high chrome balls as grinding media. 3.0 The role of magnetite in the beneficiation process at Palabora. 1.0 Alternative methods to restrict and eliminate the detrimental effect of critical size material on the performance of an autogenous mill.

Jan 1, 1985

By D. M. Avant, A. J. Solomon, S. M. Pickering, W. R. Fox

Introduction Most high purity silica is produced from crystalline quartz, generally from sand. However, there is a small area of southern Illinois where a porous, friable white chert rock is found that is very different in physical form from quartz sand. This microcrystalline material, commonly referred to as tripoli, is more easily ground to micron sizes than sand. Although of similar Moh's hardness, microcrystalline tripoli is less abrasive than either ground quartz sand or many synthetic abrasives. Location The southwestern corner of Illinois is underlain by extensive deposits of very porous chert; in some places the material is quite white. Two companies, Illinois Minerals Co. and Tammsco Inc., mine and process this white material. The Illinois Minerals plant is located at Elco, and the Tammsco plant is in Tamms, IL. Both companies mine from various locations within a 10-mile truck haul of their plants. Production from this district has been continuous since at least 1915. Malvern Minerals Co. mines and processes a generally similar microcrystalline, friable novaculite near Hot Springs, AR. Geology The southern Illinois white tripoli area is on the southern flank of the Illinois Basin. The commercial silica zone is a facies of the Clear Creek chert of Lower Devonian Age. To the north, where it occurs deep in the basin, the Clear Creek is a siliceous limestone. In the mining area, thin overburden has allowed access by surface ground water, which has leached away the carbonate content and left a quite pure silica residue. Fossils characteristic of sea bottom deposition, such as brachiopods and trilobites, are occasionally encountered in mining. The structure of the mining area is poorly known, due to infrequent outcrops. Strata in most mines are inclined at dips of 5° to 20°. There appear to be occasional high angle normal and reverse faults, but these are seldom of any significance in mining. The friable white silica zone mined in the Clear Creek chert is overlain by dark brownish-red chert and siliceous shale. Exploration drilling to date has not encountered the base of the microcrystalline tripolitic zone. Chemical content Leaching by ground water solution has removed virtually all the carbonate from the original siliceous limestone. Impurities encountered are red to yellow iron oxides, aluminous clays, and occasional black manganese oxides. The silica has no detectable formula water. A typical chemical analysis and physical properties are listed in Tables 1 and 2. Mineralogy and crystallinity Southern Illinois friable tripoli appears amorphous under the polarizing microscope. No crystal structure and only occasional, vague, patchy anisotropism is evident. However, the material gives an excellent quartz X-ray diffraction pattern. Thus, so far as X-ray mineralogy is concerned, the material is clearly

Jan 12, 1986

By Roy A. Grancher

?The Horn of Plenty seems to have sprung a leak?.? anonymous For the first time in the Nation's peace-time history, shortages have become a way of life for the United States. Such words as scarce, tight, and critical are used in regard to supply, leading to priorities, allocations, and possible rationing as make-shift attempts to satisfy demand. Almost every day a new type of shortage appears in another product area that has traditionally been taken for granted as being in perpetual abundance. The range of coverage extends from basic commodities such as oil, chemicals, cement, steel, copper, cotton, etc., through to machine tools, motors, bearings, electronic components, etc. , to those finished outputs that satisfy our fundamental requirements for food, clothing and shelter. Signs of the times appear in cancelled airline flights, unfilled lines at gasoline stations, no available home freezers, lengthy delays in any furniture deliveries, or to that little old lady seen walking out of a local supermarket clutching her hoard of twenty rolls of toilet paper. What a sad commentary to have to make about our Land of Plenty, so long the envy of the World for its material wealth -- and today with its initials "U. S." seemingly standing for ?Unlimited Shortages.?

Jan 1, 1974

By A. Noble

"A supply of sustainably sourced rare earth elements (REEs) is critical for several high-tech industries, renewable energy technologies, and defense applications. Recent studies have shown that REEs exist in coal and coal combustion byproducts at elevated concentrations and in quantities that could meet domestic demand. Despite these promising findings, declines in rare earth prices, volatile commodity markets, and challenging geo-metallurgical conditions have jeopardized this potentially valuable REE resource. While the dilute REE concentrations inherently necessitate low-cost separation technologies, the ultimately operating cost threshold for economic extraction must be based on commodity price projections and market demand. In this paper, the micro-pricing principle is used to develop a rigorous economic model assessing the inherent value of REEs in coal materials. This model is based upon basket pricing of individual elemental oxides, and elemental distributions of coal samples from various basins. These results may be used to assess the economic viability of potential REE concentration and refining technologies INTRODUCTION Recent efforts by US Department of Energy (DOE) and the National Energy Technology Laboratory (NETL) have suggested that rare earth elements (REEs) may exist in coal and coal byproducts at concentrations suitable for economic extraction and processing. While the knowledge of REE occurrence in coal material dates back over 50 years, recent supply restrictions and material criticality considerations have prompted a national interest to establish a sustainable domestic supply of REEs. REEs are not “rare” in the sense of crustal abundance; however, few natural processes lead to concentrated ore deposits. As a result, the elevated concentrations found in coal material may provide a potentially promising resource for these materials. While the term “rare earths” is often used to describe a singular concept, the 15 rare earth elements actually have varying and sometimes contrasting scarcity and cost profiles. Various authors have proposed classification systems to provide information on REE criticality (e.g. Seredin and Dai, 2012, Zhang et al., 2015). The most straightforward classification is provided on the basis of geochemistry with designations for “light”, “medium” and “heavy” rare earths. Light rare earths (those to the left of the periodic table: Ce, Pr, Nd, and Sm) tend to be more common and less valuable when compared to their medium (Eu, Gd, Tb, Dy, and Y) and heavy (Ho, Er, Tm, Yb, and Lu) counterparts. While light rare earths are often found in traditional ore deposits at economic concentrations, the heavier rare earths are almost exclusively found as ion-absorbed clays (Seredin and Dai, 2012)."

Jan 1, 2016

By C. M. Brinckerhoff

Much has been written in the mining technical magazines about the caving system. Many of these articles were published in the Transactions of the American Institute of Mining Engineers prior to World War II. In recent years little has been written on mining methods or on the detailed planning always required. Block caving had primarily been used to mine deep copper ores in Africa, the United States and in Chile, although other ores had been mined by this same system. Asbestos ore had been caved in Canada, tin ore in Bolivia, molybdenum ore in Colorado, iron ore in Wyoming and Sweden, and limestone in California.

Jan 1, 1984

By J. A. Dos Santos

High angle conveyor (HAC®) systems in open pit mining offer many advantages over the traditional, truck only, haulage systems, including: (1) superior energy efficiency, (2) less dependency on petroleum products, (3) less sensitivity to inflation, (4) less labor, (5) less excavation for the amount of ore recovered, and (6) less ramp construction and maintenance costs. Previous studies had revealed the technical and economic feasibility of high angle conveyors. This paper presents the Sandwich Belt HAC® as the vital link to optimization of in-pit conveying systems. HAC development to date is discussed, beginning with studies in 1979, to the first large scale prototype in 1983, to the first commercial unit in 1984, into "the latest commercial installations. Discussion continues with the HAC systems to suit the various open pit mining operations and the corresponding characteristics of the system components, particularly the high angle conveyor. The range of HAC systems from the low capacity (up to 1,814 t/h), low lift (10.7 to 36.6M), highly mobile to the moderate capacity (1,814 to 3,629 t/h), moderate lift (36.6 to 76.2M), intermittently mobile to the high capacity (greater than 3,629 t/h), high lift (greater than 76.2M), semi-mobile, are discussed along with some possible combinations of these.

Jan 1, 1989

By J. Kretschmann

Southeast Asian countries cannot maintain their economic growth rate without the development of their mining industries. To make this development as sustainable as possible requires sound fundamentals securing not only economic progress and environment protection but also improvements in occupational safety and health (OSH) for the miners. Mining in South East Asia is still very labor intense and dangerous. Tremendous achievements from world class mining operations in advanced mining countries can be used as role models to improve the status quo of the Southeast Asian countries in OSH management. Know-how transfer, therefore, is a key factor for major improvements. Effects of this transfer based on a multi-level approach will be discussed based on a case study. It describes the transfer from German to Vietnamese hard coal mining industry. Crucial requisites for excellent achievements in OSH in Southeast Asian mining countries are also mentioned.

Feb 23, 2014

By Gustavo G. Pilger, Jair C. Koppe, João Felipe C. L. Costa

Information for mine planning requires to be close spaced, if compared to the grid used for exploration and resource assessment. The additional samples collected during quasi-mining are frequently located in the same pattern of the original diamond drill holes net but closer spaced. This procedure is not the best in mathematical sense for selecting a location. The impact of an additional information to reduce the uncertainty about the parameter been modelled is not the same everywhere within the deposit. Some locations are more sensitive in reducing the local and global uncertainty than others. This study introduces a methodology to select additional sample locations based on stochastic simulation. The procedure takes into account data variability and their spatial location. Multiple equally probable models representing a geological attribute are generated via geostatistical simulation. These models share basically the same histogram and the same variogram obtained from the original dataset. At each block belonging to the model a value is obtained from the n simulations and their combination allows one to access local variability. Variability is measured using an uncertainty index proposed. This index was used to map zones of high variability. A value extracted from a given simulation is added to the original dataset from a zone identified as erratic in the previous maps. The process of adding samples and simulation is repeated and the benefit of the additional sample is evaluated. The contribution of an extra sample was evaluated locally, globally and in terms of variation in total measured resources. The procedure showed to be robust and theoretically sound, mapping zones where the additional information is most beneficial. A case study using coal seam thickness illustrates the method.

Jan 1, 2002

By D Beahm

Introduction The Energy Metals Corporation (EMC) holds numerous mineral properties in the northern portion of the Great Divide Basin including the JAB Property, one of several potential properties being planned for development as a satellite facility to the greater Antelope Uranium Project. A National Instrument 43-101 Technical Report has been completed for the JAB property. This report estimates total measured and indicated mineral resources on the property totaling 3,555,022 pounds U3O8 contained in 2,400,875 tons at an average grade of 0.073 % U3O8 at a .25 GT cutoff in accordance with CIM Standards on Mineral Resources and Reserves. The JAB Property is located in Sections 13, 14, 15, 16, 21, 22, and 23, Township 26 North, Range 94 West, approximately Latitude 42o 14’ North and Longitude 108o 00’ West (Figure 1, Location Map). This property consists of unpatented mining lode claims and Wyoming State mineral leases comprising approximately 2,100 acres.

Jan 1, 2007

By Jacques Bernazeaud

Rouez is a recent discovery of a major low-grade sulfide body (± 100 m, 0,6 % Cu, 0.3 % Pb, 1 ,5 % Zn, 21 g/t Ag, 1.5 g/t Au) in a populated farming area of Brittany, France, some 30 kilometres northwest of Le Mans. The discovery is the result of an airborne electro- magnetic (INPUT) survey. It is the first time that the INPUT method has been used in France. The survey Gas successful in spite of the numerous interferences normally found in populated areas. The lack of a good drainage system would not allow the discovery of Rouez using stream sediment geochemistry alone. Ground geophysical surveys confirmed the airborne work and gave sufficient information to make the first hole a discovery hole. The deposit is Proterozoic in age and sediment-hosted. The metamorphism is low grade.

Jan 1, 1983

By Rudolf E. Greuer

Modeling a mine ventilation system is a formidable mathematical problem requiring the solution of twice as many equations as there are airways with half of these being quadratic equations. The addition of a mine fire to the problem adds many more complexities. The U.S. Bureau of Mines and Michigan Technological University attacked this problem in stages. During the 1970's and 80's, a series of computer simulation programs were developed which offered progressively increasing levels of modeling capability and accuracy. The current version of this software, MFIRE 2.0, was released in 1993. This programs provides for full dynamic state mass flow-based modeling of a mine ventilation system, and includes natural ventilation, mechanical ventilation, air reversals and recirculation, methane and fire contaminant spread, and moisture condensation and evaporation in the mass flow and heat exchange calculations. This program is a useful tool for routine ventilation planning and can significantly improve mine safety by enabling detailed quantitative analysis for mine emergency preplanning. This paper reviews the evolution of the MFIRE program from its infancy as a simple digital network simulator replacing analog computers to the present version.

Jan 1, 1994

By J. S. Bays

Industries are challenged to meet increasingly stringent regulations for selenium and metals. Cost-effective treatment is required to minimize the economic impact of environmental compliance. Low-cost biological treatment of selenium can be achieved passively using biochemical reactor cells composed of natural organic media components such as wood chips, sawdust, hay, composted manure, and peat. The reactor cells create an anaerobic microenvironment for biological reduction and sequestration of selenium and other metals. Biochemical reactors can be combined with constructed wetlands for flow equalization and to remove the organic byproducts in reactor cell outflow. Passive treatment reduces capital cost and operational effort compared to more expensive and complex physical and chemical treatment. Recent pilot and full-scale projects by mining companies and by the US Bureau of Reclamation demonstrate that passive treatment can achieve compliance with selenium concentrations over a range of flows and environmental conditions. Case histories of passive selenium treatment systems and their key findings are provided, and prospects for future applications are summarized.

Feb 27, 2013

By G. Wahl, H. Danilkewich, T. Mann

Developers of advanced mining projects face the challenge of how to craft a “Request for Proposal for a Feasibility Study” that will result in bids that are comparable and will lead to a successful execution of the study. Mining engineering consulting firms are challenged by “Request for Proposals” that may consist of a limited description of the Scope of Services and other items, which could present difficulties in the subsequent financing and/or development of the project. Changes in international disclosure requirements have also changed the landscape on how resources and reserves are reported by introducing new disclosure requirements and concepts such as qualified persons. This paper lays out a strategy for preparing a Feasibility Study “Request for Proposal” based on the experiences of a mining engineering consulting firm working on a diversity of projects around the world, and in light of the recent changes in international reporting standards for reserves.

Jan 1, 2002

By I. Y. Bausov, L. G. Stolarczyk, R. E. Pillmore, A. J. Hillard, J. T. Duncan

"Prevalence of lung disease in younger miners surprised industry regulators, congressional members, researchers and black lung clinic staff members. Mitigation researcher focused on low-coal mining in the Appalachian regions until Miners Colfax Medical Center (MCMC) Black Lung Clinic examinations discovered 25 of 72 Wyoming coal miners with lung disease. To reverse recent upward trend in lung disease, research programatic have been directed at reducing exposure to respirable “float” dust. This paper suggests broadening the scope of research to include boundary detection in efforts to improve outcomes. Beginning with a better understanding of biochemistry of anaerobic bacteria methylation processes precipitating sulfur and heavy metals into thin seam boundary layers. Expanding research and development objective to focused on minimization of bit-pick crushing cone volume and preventing mining thin boundary coal layers and out-of-seam dilution. Black lung clinical evaluations of miner will confirm outcomes directed towards reduced occupational disease and smoke stack emissions. INTRODUCTION Miner exposer to bit-tip crushing cone volume, fragmentation and auger movement generated respirable “float” dust and boiler emissions are related science-technology –engineering-mathematics (STEM) problems. Formidable but not intractable problems are driven by oxidation of upper flood plain elements in the periodic table and biochemical metabolic presses occurring in coal basin. Because of burial compaction, quartz and trace heavy metals (Fe2+, Mg2+) are concentrated in thin seam boundary layers. By not cutting through thin boundary coal layer and out-of-seam into hard quartz containing rock layers, miner lung disease and smoke stack emissions are minimized. Cutting bit-pick elastic wave hydrodynamic principle force vectors in the coal layer must be aligned to minimize respirable dust generation, constrained by fragmentation size. Dust abatement by water spray and machine design are effective; but for, failure to address cutting cone dust volume generation and its distribution along run-of-mine (ROM) transportation systems the boiler. Real-time precision thickness measurements by integrated cutting drum (icDrum) sensor, machine man-interdiction from a dust free control room, is a cost effective way to prevents respirable dust exposure. The recommended STEM research and demonstration initiative addresses issues raised by discoveries of increased rate of lung disease discovered in young miners and concerns over emissions from coal-fired electric generation stations (Global Warming). In-mine demonstrations must be validated by on-site MCMC mobile Black Lung Clinic data acquisition and analysis."

Jan 1, 2016

By A. L. Miller, A. J. Chambers, P. R. Griffiths, D. A. Parks

"Diesel engines are one of the primary contributors to the presence of nano and ultrafine aerosols in ambient air and occupational environments. Exposure to diesel emissions has been shown to contribute to various adverse health outcomes of the pulmonary system and cardiovascular system. Currently diesel emissions in the workplace are monitored by way of collecting the aerosol onto filters, which are then sent to a lab for thermal-optical analysis using the NIOSH 5040 method, which measures elemental and organic carbon explicitly. This process can take days or even weeks, and workers can potentially be exposed to excessive levels of diesel particulate matter (DPM) before the problem is identified. To remedy this, researchers from the National Institute for Occupational Safety and Health (NIOSH) are seeking to develop a field-portable method for measuring elemental and organic carbon in DPM aerosols. In the current study, we investigated the use of Fourier transform mid-infrared (FT-IR) spectrometry, which lends itself more readily to implementation in a real-time system than do the thermal-optical analysis methods. We have demonstrated a method for measuring organic and elemental carbon in DPM for a broad range of organic carbon (OC) to elemental carbon (EC) ratios (from 50.3 to 0.8). The ability to handle a wide range of OC to EC ratios is critical given the evolving diesel technology. INTRODUCTION Respiratory illnesses are common in mining industry workers [1] and exposures to toxic aerosols such as DPM can result in serious respiratory illness [2]. Health studies show a correlation between workplace exposure to diesel exhaust and an increased risk of lung cancer [3-8]. The International Agency for Research on Cancer (IARC) has characterized diesel exhaust as a human carcinogen [9], and similar classifications have been made by the World Health Organization and the California Air Resource Board. A recent study [10] suggests that the risk of lung cancer is approximately three times greater for heavily exposed workers. When compared to other aerosols in the mine environment, the settling time of DPM is significantly longer than that of dust due to their small particle size (typically < 1 µm) [11]. Additionally, submicron particles (such as DPM) are deposited in the lungs much more efficiently than their larger counterparts such as dust [12]. Previous studies focusing on particle morphology [13] show that the largest mass contributor to lung disease in mining is elemental carbon, which provides a solid core onto which hydrocarbons are adsorbed. In accord with those findings the Mine Safety and Health Administration (MSHA) decided on submicron total carbon as a surrogate for monitoring diesel particulate matter in the mining environment."

Jan 1, 2018

By James L. Patton

Automation of mining increases the productivity of labor, thereby reducing the unit cost of labor. Such cost constitutes the largest portion of the direct or variable costs of producing coal. Therefore, any increase in productivity directly reduces variable cost. The large investment in mechanical equipment carries with it the burden of increased fixed charges. As the proportion of fixed cost to the total cost increases, the effects on the cost of production changes are amplified. Therefore, equipment must be fully utilized at all times. Averaged fixed costs rise with any decline in production. Such a situation forces coal companies to seek every means of main¬taining full production. Figure I will reflect the story on the relationship of production to cost.

Jan 1, 1962

By L. Westerstrom

Supply and Demand After a dismal first half, the industry saw a marked improvement in its markets during the final six months of 1983. Domestic consumption was 17.6% higher in the second half of the year, primarily due to a surge in electric power requirements. The sharp increase in demand for electric power during the third and fourth quarters afforded utilities the opportunity to lower stocks that had accumulated to record levels during 1982. Consumer stocks were reduced from 179 Mt (197 million st) at the end of June to 153 Mt (169 million st) by the end of the year. That is the largest inventory drawdown on record during a six-month period without a major coal strike. Despite the huge depletion in inventories, coal production in the second half of 1983 rose 1.3% above output in the second half of 1982. However, because of the disappointing first half, production in 1983 totaled only 712 Mt (785 million st), 6.4% less than the 760 Mt (838 million st) produced in 1982. Demand The extent to which the economic recovery affected coal markets in 1983 varied: • total domestic coal consumption increased 4.2%; • electric utility coal consumption increased 5.3%; • exports declined by about one-fourth; • coal consumption at coke plants declined 9.5%; and • coal consumption in the other industrial sectors increased 2.9%. Domestic coal consumption totaled 667 Mt (737 million st) it 1983, 27 Mt (30 million st) more than 1982. Electric utility consumption increased from 539 M1 (594 million st) in 1982 to 567 M1 (625 million st) in 1983. Coal consumption at coke plants declined from 37 Mt (41 million st) to 34 M1 (37 million st). Residential and commercial use increased 181 kt (200,000 st) - from 7.4 to 7.6 Mt (8.2 to 8.4 million st). Electric Utilities: Electric power generation increased 3.1% in 1983. Demand for electric power increased in all major consumer categories. Residential and commercial use rose 2.7% and 3.3%, respectively. The most striking increase, however, and indicative of the economy&apos;s strong upturn, was the increase in industrial electric power use. Industrial power requirements, which declined 9.8% in 1982, rose 4.1% in 1983. The electric utility sector continued to expand its use of coal last year while lowering its requirements of oil and natural gas. In 1983, electric generation from coal increased 5.7%, while genera-

Jan 5, 1984