Small Coal Mines Research Articles

Concentration and distribution of sixty-one elements in coals from DPR Korea

Fifty coal samples (28 anthracite and 22 lignites) were collected from both main and small coal mines in DPR Korea prioritized by resource distribution and coal production. The concentrations of 61 elements in 50 coal samples were determined by several multielement and element-specific techniques, including inductively coupled plasma atomic emission spectrometry (ICP-AES), and inductively coupled plasma mass spectrometry (ICP-MS), ion chromatogram (IC), cold-vapor atomic absorption spectrometry (CV-AAS), and hydride generation atomic absorption spectrometry (HGAAS). The ranges, arithmetic means and geometric means of concentrations of these elements are presented. A comparison with crustal abundances (Clarke values) shows that some potentially hazardous elements in the coals of DPR Korea are highly enriched Li, B, S, Cl, Zn, As, Se, Cd, Sn, Sb, W, Te, Hg, Ag, Pb, and La, Ce, Dy, Tm, Ge, Mo, Cs, Tl, Bi, Th and U are moderately enriched. A comparison of ranges and means of elemental concentrations in DPR Korea, Chinese, and world coals shows the ranges of most elements in DPR Korea coals are very close to the ranges of world coals. Arithmetic means of most elements in DPR Korea coals are close to that of American coals. Most elements arithmetic means are higher in Jurassic and Paleogene coals than coals of other ages. In DPR Korea coals, only seven elements in early Permian coals are higher than other periods: Li, Zn, Se, Cd, Hg, Pb, and Bi. Only five elements B, As, Sr, Mo, W in Neogene coals have arithmetic means higher than others. SiO 2 and Al 2O 3 in ashes are more than 70% except six samples. The correlation between ash yields and major elements from high to low is in the order of Si>Al>Ti>K>Mg>Fe>Na>Ca>P>S. Most elements have high positive correlation with ash ( r>0.5) and show high inorganic affinity.

Economic analysis of reform policies for small coal mines in China

Over the last three decades, China’s coal industry has achieved dramatic increases in coal production, both in absolute terms and relative to the world as a whole. This achievement is due largely to its coal policies. Yet facing increasing pressures of environmental sustainability and market transition, the Chinese government was forced to make deep reforms and adjustments to regulate the coal industry effectively. This paper presents an historical overview of China’s coal economic policies, paying particular attention to the current reform policy of closing mines and restricting the yield for the small coal mines (SCMs) in the context of economic theories and methods. We argue that the SCM closure policy would not likely be efficiently enforced if a feasible market mechanism were not built up. The failure of closure policy is due largely to problems of property rights, coal pricing, ownership, and objectives.

The influence of seam height on lost-time injury and fatality rates at small underground bituminous coal mines.

Due to variations in the thickness of U.S. coal seams, there is great variability in the height of the roof where underground miners work. Restrictions imposed by low seam heights have important safety consequences. As the height of their workplace decreases, miners must stoop, duck walk, or crawl, and their vision, posture, and mobility become increasingly restricted. Low seam height also places important restrictions on the design of mobile equipment and other mining machinery. Using the employment and injury data reported to the Mine Safety and Health Administration (MSHA) from 1990 to 1996, small underground bituminous coal mines with less than 50 employees were stratified by average coal seam height according to the following categories: low (< or =42"), medium (43"-60"), and high (> or =61"). Injury rates for both nonfatal days lost and fatality cases were examined by seam height and leading type of injury incidents. The leading types of incidents associated with fatalities were roof falls and powered haulage equipment. In comparison to high-seam mines, miners working in low or medium seams are at higher risk of being killed by powered haulage equipment, roof bolting machines, and falls of unsupported roof. The leading types of incidents associated with nonfatal injuries were handling materials and powered haulage. As mining height decreases, miners are at increasingly higher risk of having a nonfatal injury from incidents involving roof bolting machines, load-haul-dump equipment, personnel carriers, and powered haulage conveyors. As mining height increases, miners are at increasingly higher risk of having a nonfatal injury from slips and falls and incidents involving shuttle cars and roof and rib falls. Knee injuries are a particularly severe problem in low-seam mines. The rate of injuries to miners while crawling or kneeling is 10 times higher in low seams than in high seams.

Geological and geochemical characteristics of high arsenic coals from endemic arsenosis areas in southwestern Guizhou Province, China

Southwest Guizhou Province is one of the most important areas of disseminated, sediment-hosted-type Au deposits in China and is an important area of coal production. The chemistry of most of the coals in SW Guizhou is similar to those in other parts of China. Their As content is near the Chinese coal average, but some local, small coal mines contain high As coals. The highest As content is up to 3.5 wt.% in the coal. The use of high As coals has caused in excess of 3000 cases of As poisoning in several villages. The high As coals are in the Longtan formation, which is an alternating marine facies and terrestrial facies. The coals are distributed on both sides of faults that parallel the regional anticlinal axis. The As content of coal is higher closer to the fault plane. The As content of coal changes greatly in different coal beds and different locations of the same bed. Geological structures such as anticlines, faults and sedimentary strata control the distribution of high As coals. Small Au deposits as well as Sb, Hg, and Th mineralization, are found near the high As coals. Although some As-bearing minerals such as pyrite, arsenopyrite, realgar (?), As-bearing sulfate, As-bearing clays, and phosphate are found in the high As coals, their contents cannot account for the abundance of As in some coals. Analysis of the coal indicates that As mainly exists in the form of As5+ and As3+, perhaps, combined with organic compounds. The occurrence of such exceptionally high As contents in coal and the fact that the As is dominantly organically associated are unique observations.

An Appalachian New Deal: West Virginia in the Great Depression

An Appalachian New Deal: West Virginia in the Great Depression. By Jerry Bruce Thomas. (Lexington: University Press of Kentucky, 1998. Pp. x, 316. Acknowledgment, introduction, illustrations, photographs, notes, bibliography, index. $36.95.) Great Depression is the central event shaping American life in the twentieth century. More dramatic than industrialization in the nineteenth, the Depression left a political legacy still controversial today. For far too long the event has been treated as a national phenomenon, although each region of America was affected differently. When state boundaries crossed regions, anomalous conditions defying easy analysis resulted. In the twentieth century West Virginia has suffered from bipolar depression. One pole was its coal miners. Coal mining arrived in the late nineteenth century in competition with the established fields of Pennsylvania. West Virginia led the way in developing that system of southern industrialization popularized by Mississippi and copied in Arkansas that promised lower costs by being union-free. Soon absentee mine owners controlled the state government, owned most of the press, and dominated many counties through their deputy sheriffs. New Deal experienced real troubles in coping with the over-production of coal, though its labor legislation allowed John L. Lewis of the United Mine Workers to carry on a successful campaign of union recruitment. other depressed pole of West Virginia was agriculture. Mostly of the small, self-sufficient variety, West Virginia farmers had to endure the Drought of 1930 and then faced collapsing prices. When the Depression cut off the outside income from timbering or working in small coal mines that had helped sustain life on worn out, eroded land, West Virginia agriculture became a disaster area. Compounding the problem, thousands of ex-residents returned to their former homes, and the number of farmers actually increased during the Depression. Agriculture, too, was not well served by New Deal programs. Some experimental communities were set up, but the day of subsistence farming had already passed. In probably no southern state did the Rural Electrification Agency lose more battles to power companies. Indeed, the entire sorry saga of Depression-era West Virginia ranks as the worst in the South. state's geography created isolated communities, and in-grown politics, and generally retarded modernization. dominant coal companies prevented the adoption of severance taxes and starved government services generally. Arkansas readers may take some solace that The Wonder State ranked above West Virginia in public libraries and other signs of progress. …

Accounting for energy use in China, 1980–94

This study contains quantitative methods to account for national energy use. Based on these models, an analysis has been made of energy consumption, efficiency and savings in China in the period 1980–94. Our study supports the conclusion that the energy efficiency has improved since China's economic reform. However, the statistical system used in China is not sound. Greater attention must be paid to the management of small coal mines.

Rural Energy Resources: Applications and Consumption in China

Abstract This paper introduces rural energy resources (including firewood, crop straw, manure, small hydropower, small coal mines, solar energy, wind energy, ocean energy, geothermal, and human and animal power) and their present applications and consumption in China. Rural energy resource applications and development, and consumption situations as well as potential energy savings, are analyzed. Finally, the present government policies and suggestions for rural energy development are discussed.

Transport injuries in small coal mines: an exploratory analysis.

Mine Safety and Health Administration (MSHA) surveillance data were analyzed to elucidate mine characteristics or injury characteristics that distinguished mines with high rates of transport-related injuries from mines with lower transport injury rates. The results showed that most high-rate mines are small, high-rate mines have a disproportionate number of injuries involving young and less experienced workers, and injuries in high-rate mines are proportionally more severe. Further analyses of the MSHA injury data showed that smaller mines have a greater share of fatal and permanently disabling injuries, whereas larger mines have a greater share of injuries involving no lost time. Based on these results, we explored two explanations for the small mine injury risk: (1) a suggestion that differences in injury reporting between large and small mines may contribute to an apparent small mine injury risk, and (2) identification of factors contributing to a true difference in transport-related injury risk between small and large mines. Whereas it was true that most high injury rate mines were small, most small mines were actually zero-rate, having reported employment but no injuries to MSHA. An analysis employing binomial probability theory showed that a substantial proportion of small mines reported zero injuries when it was statistically probable that injuries would have occurred. This indicated that small mines may underreport injuries relative to larger mines. The possibility that reporting bias affected the associations found in this study was explored by eliminating the least severe injuries from the data set and evaluating changes in associations. This "adjustment" for reporting bias did not change previously observed relationships. Finally, MSHA injury data were analyzed in concert with mining population data collected by the Bureau of Mines. With such denominator information, the results indicated a disproportionately high risk of injury among workers in their first year at a mine and indicated that higher injury risk in small mines might be explained by the fact that workers at small mines have substantially less experience than workers at large mines. An effect of age was not found in these analyses. These results suggest the potential importance of targeted training programs for newly hired miners. Results also point to the need to explore specific factors contributing to the small mine injury risk, and to the necessity for complete and accurate reporting of injury data.

Tailored safety training for miners in small Pennsylvania surface coal mines.

Tailored safety training for miners in small Pennsylvania surface coal mines.

The strategy for China's rural energy development

This paper presents a strategy for China's rural energy development at the turn of this century. It proposes the establishment of a three-dimensional and open system of rural energy engineering proceeding from an analysis of China's rural energy resources, the state of rural development, the supply of energy in the countryside and other exogenous variables. The system should consist of lateral and vertical networks of energy supply encompassing all rural areas, i ts mainsray being small hydroelectric power stations, small coal mines and biogas pits on farms. By using the word ‘mainstay’, the author does not intens to describe these as being able to satisfy all energy demands and, instead, means to regard them as the majot sources of energy for China's countryside since they are reliable and easy to set up and require short development cycles while great in sheer numbers. The networks of energy supply cover solar energy and wind power as well as commodity energy supplied by the State. Nevertheless, it will be difficult to significantly raise the proportion of commodity energy to the total rural energy consumption by the end of this century due to the limited scale of its production and the inadequate technical resources for developing new energy sources. This ‘mainstay’ described in this paper can, in an indirect manner, help improve the country's ecological balance and boost the development of ecological energy.

The optimization of coal mine production schedules using linear programming: An example that determines the effects of reclamation costs and interest rates

Reclamation expenditure on coal mine properties is now a fundamental business expense for that industry. A mine owner or manager will attempt to keep this expense to a minimum subject to a given level of production. One of the most important variables that can be manipulated to help keep costs down is the production schedule. Production schedules can be shifted forward or backward depending on the current economic situation. A common method of determining optimal production schedules is to utilize a linear-programming model. These models simultaneously take into account all the variables associated with a project so that an optimal production schedule can be derived. This study involves work with a computerized linear-programming model to examine how optimal production schedules will change for a typical small coal mine due to reclamation requirements and a variable discount rate. The purpose of this paper is: (1) to demonstrate how linear programming can be used to incorporate nonlinear relationships in a profit maximization problem involving mining; (2) to show how, through the use of a heuristic model involving reclamation cost requirements, linear programming can contribute worthwhile information to the mine planner; and (3) to examine how interest rates can (a) be used to estimate future uncertainty, and (b) be used as a policy tool to promote conservation.

Memories of the Herrin Massacre

Herrin, a small coal mining town in southern Illinois, has earned an infamous reputation because of its bloody family feuds, KKK presence, and perhaps most famously, for being the site of the “Herrin Massacre.” After union mineworkers went on strike over wage disputes in 1922, the owner of Lester Mine replaced them with non-union employees. This led to a deadly, violent exchange between the union and non-union mineworkers. My primary research interest in this massacre is to understand the historical trauma and present-day impacts this tragedy has had on the community. Through interviews with relatives and friends of those who took part in the Herrin Massacre, I have discovered the beginnings of a healing process taking place in Herrin, Illinois. The memories of the massacre are still foremost in the community’s minds; nevertheless there is some indication that the intensity of the conflict is lessening as a communal memory.

Oil-bearing paparoa coal measures near Rewanui, Greymouth coalfield

Abstract An oil seepage of moderate size in Paparoa Coal Measures has recently been discovered in a small coal mine near Rewanui, Greymouth Coalfield. The accumulation of this oil, and of the oil and gas reported in several drill holes in the region, appears to be structurally controlled. Because of the appreciable stratigraphic and geographic separation of the oil bearing beds and the nearest marine sediments, and from a consideration of the tectonic history of the area since the petroliferous beds were deposited, it is suggested that the oil and gas are of non-marine origin.

Private Coal Mining in South Wales

A LT HOUGH the British coal-mining industry was nationalized in 1947, nationalization did not mean the complete disappearance of private coal mining in Britain. From the beginning the National Coal Board has licensed the private operation of small coal mines employing underground thirty men or fewer. One area where private coal mining has been particularly successful is the western part of the South Wales coalfield. There the small mines not only have survived nationalization but have flourished, expanding in numbers and output, making a profit in an area where the nationalized collieries have continued to lose heavily. Today private mines produce more than 10 percent of the total local coal output. By providing employment and exploiting a resource that would otherwise remain unused, the private industry performs a valuable service. Its success during the past sixteen years in competition with the nationalized industry, and the continued availability of readily accessible good-quality coal reserves, suggest that the private mines will continue to be an integral part of the geography of this part of the South Wales coalfield for many years to come. The purpose of the present study is to examine the factors that have contributed to their success and to comment on the part they play in the geography of the area.