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By Nirander M. Safaya

Revegetation success on surface mined lands is dependent upon the nature of the plant growth media. Soil physical and chemical properties dictate the needs for specific reclamation and subsequent management practices. Field experiments were conducted at six coal mine sites in Oliver and Mercer Counties, North Dakota to determine the subsequent effects of a single application of selected amendments on spoil and topsoils over the five year period, 1974-1978. Considerable variations in the physical and chemical properties were found in mine spoils from site to site. The texture of spoils ranged from sandy clay loamy at North Beulah I to loamy at Glenharold, and from sandy loamy at North Beulah 3 and South Beulah sites to loamy sands at the Center site. The pH of the sites ranged from 6.5 at South Beulah to 8.2 at North Beulah 3. In many cases, the pH values of mine spoils were not significantly different from the topsoils. The electrical conductivity (ECe) did not exceed 6 mmhos cm-1 at the test sites even though in other studies much higher values were recorded in the same vicinity. The spoils from Glenharold and North Beulah test sites can be classed as moderately saline, and those from Center and South Beulah as non-saline. The sodium adsorption ratios (SAR) varied from less than 1 to 32, with highest values in the spoils of North Beulah 3 followed by Glenharold; all other sites were nonsodic. Lowest SAR values (less than 1) were found in the topsoiled sites at South Beulah and Center. Spoils of North Beulah 3 test site were highly calcareous, followed by North Beulah 2 and Glenharold. Center mine spoils which were the least calcareous of the test sites, showed the calcium carbonate equivalent three times higher than that of the topsoil. The average calcium concentrations in the spoils of North Beulah 3 and South Beulah test sites were -13 and 14 me 100g -l while at North Beulah 2 and Glenharold test sites 25 and 22 me 100-1-1 were recorded, respectively. The overall magnesium concentrations ranged from an average of 4 to 16 me 100g 1. Sodium concentrations in all sites never exceeded 10 me 100g-1. Phosphorus concentrations on the average at North Beulah 1, North Beulah 2, and Center were 10.2, 4.6, and 22.2 µg g -1 spoil, respectively. Concentrations of potassium ranged from 200 ppm at South Beulah site to more than 375 pp in at the Glenharold site. High concentrations of sulfates (239-2778 µg g-1) seem to contribute to the salinity in these spoils. Chloride concentrations of spoils were low and never exceeded 40 µg g-1 spoil. Based on established critical levels of deficiency for micronutrients in agricultural soils, it seems that none of these were deficient. However, controlled environment experiments did reveal increased plant growth responses when some micronutrients were added to the mine spoils. Treatment effects were highly site specific depending on the nature of the soil/spoil characteristics and, of course, the properties of the various treatments. While slack coal amendment to the spoils at North Beulah 2 site affected significant increases in a large number of variables (both major and trace elements), amendment of the topsoils at the South Beulah test site with leonardite resulted in significant decreases in a number of variables, particularly trace elements. Spoils at Glenharold and North Beulah 3 demonstrated the fewest significant changes due to amendments. Calcium, magnesium, strontium, organic matter and nitrogen were consistently increased from site to site with the addition of lignitic materials. Other spoil/topsoil physical and chemical properties (30 variables) as affected by amendments and time are discussed.

Jan 1, 1982

By Jerry A. Wichser

A series of linear programmed instruction modules was developed in the general subject areas of Blasting Technology & Explosives Safety & Electrical Training. The linear programs (modules) were developed in the form of tape-slide plus workbook materials, while the branching format evolved from the LTS teaching machine system from MIT, through several other teaching machines and micro-computers, finally settling on Radio Shack TRS-80 microcomputers, Models I & III. Initial validation figures indicate that essentially the same result, are attained from both methods (based on pre and post test scores), with the most noticeable difference being an approximately 25% savings in study time with the branching modules. In December 1980, the development of modules on High-Voltage Training, Trolley Wireman Training, and Compressed Gas Safety was added to the overall tasks of the contract.

Jan 1, 1984

By Robert S. Dalzell

Following the introduction of roof shields to the U.S. longwall mining scene in 1975, the number of shield faces (faces supported by shields) has increased steadily, and the occurrence of accidents associated with ground control inadequacies at longwall operations has shown a downward trend. However, ground control problems in longwall mining still exist. New mining systems, however efficient, have run afoul of roof control. Shield faces have suffered extended stoppages because of roof cavities. In this report, the Bureau of Mines addresses the problem of longwall roof control. The report presents a review of foreign remedial and strata replacement techniques for longwall faces and evaluates their potential for domestic application. The technology reviewed includes meshing, chemical rock stabilization, cribbing, strain-absorbent modules, inflatables, synthetic foam, and monolithic fills.

Jan 1, 1985

By G. W. Grove

The wearing of self-contained oxygen breathing apparatus, although relatively safe if proper precautions are taken, is dangerous if defective apparatus -is worn, if men with inadequate training, experience, and physical requirements are used, or if improper procedure is followed. This is proved by the fact that at least 26 men are known to have lost their lives while wearing-oxygen breathing apparatus since its introduction in this country about 35 years ago. Self-contained oxygen breathing apparatus, commonly called "mine rescue apparatus" and sometimes improperly referred to as "oxygen helmets," is the only equipment that can be used for respiratory protection against poisonous mine gases, regardless of concentration or against an atmosphere containing little or no oxygen.3/ Apparatus of this type was introduced in this country in 1907, and since that time it has been widely used in conducting rescue and recovery work after mine fires and explosions and in some other work. All oxygen breathing apparatus used in this country before 1918 was imported from Europe, and although this equipment provided safer, more rapid means of conducting recovery work after mine disasters, there were many mechanical deficiencies in the apparatus which resulted in the death of some of the wearers. This led to the research and experimental work by the Bureau of Mines that resulted in the development and manufacture of more reliable and efficient types of apparatus in this country.

Jan 1, 1944

By W. F. Watts

This report describes a statistical analysis of 41,502 respirable quartz dust samples collected from 1974 through 1981 in metal and nonmetal mines and mills. The goal of this Bureau of Mines study was to identify commodities and occupations associated with high quartz dust exposure so that future enforcement and research activity can be focused on the high-exposure areas. For this analysis, the Bureau used its computerized Mine Inspection Data Analysis System (MIDAS), which contains data on nearly 350,000 air samples, including data for 61 contaminants in 45 commodities. The samples analyzed were collected by inspectors of the Mine Safety and Health Administration (MS HA). The data were entered into the MIDAS computer and coded according to commodity, occupation, location, and other categorical information. Occupations an. commodities with high quartz dust exposure were identified by grouping the data by code categories. Workers at sandstone, clay and shale, and miscellaneous nonmetallic mineral mills had the highest quartz dust exposures. Within these mills, occupations with high exposures were baggers, general laborers, and persons involved in crushing, grinding, and sizing operations. Dust concentrations in these mills were not necessarily the highest, but because the dust contained a high percentage of quartz, the health risk from dust exposure was the greatest.

Jan 1, 1984

By M. W. Von Bernewitz

The Bureau of Mines receives frequent requests for information on the treatment of mercury ores, but as its own and almost all other publications on mercury are out of print, the Bureau has prepared this circular on the metal for the prospector and operator of small mines and plants. Mercury, commonly though improperly termed ?quicksilver?, is the only common metal that is liquid at ordinary temperatures. Mercury is used in the amalgamation of gold and silver, in power boilers, explosives, friction-less bearings, laboratory apparatus, lamps, medicine, paint, rectifiers, and for ?silvering.? The last mentioned is being superseded by silvering with silver. The use of mercury boilers may increase when they are thoroughly understood, but amalgamation is -being replaced to some extent by the use of corduroy and other collecting mediums, such as jigs and flotation cells.

Jan 1, 1937

By W. H. Pomroy

This report describes research by the U.S. Bureau of Mines to design and in-mine test a rapid response pneumatic fire detection system for multilevel metal mines. The relative merits of pneumatic detection are discussed in the context of typical multilevel mine layouts and environments. The Bureau's prototype system is described, with emphasis on design features that counter commonly experienced and/or perceived operating problems with pneumatic detection systems. Finally, the results of a 3-year in-mine performance evaluation of the prototype system are discussed.

Jan 1, 1990

By James W. Reil

A test series of small, precisely-controlled and thoroughly-monitored production blasts was conducted at two quarries. In each series, all variables except delay were kept constant, as much as practically possible. The first aim of the study was to determine the effect of local geology on ground vibration. The second aim was to test several hypotheses relating the effect of millisecond delay intervals to fragmentation and ground vibration. A resonant frequency of ground vibration was shown to be related to the thickness of the overburden, in accord with a model proposed by Gupta (1961). Since the overburden geology creating this resonant vibration cannot usually be changed, two methods were tested to choose delays such that blast vibrations would destructively interfere. These were shown to be effective in modifying both the peak particle velocity and response spectra of ground vibration. The delay interval chosen also affects fragmentation, primarily in massive rock, with an optimum relief between holes of 2 ms/ft. Strain gage records indicate a possible mechanism consistent with this information.

Jan 1, 1985

By Franklin H. Persse

The Bureau of Mines estimated reclamation costs for 13 surface coal mines in nine States west of the Missisisppi River. With the exception of the Pacific Coast coal province, at least one mine in each of the western coal provinces was studied. Cost estimates were, made using standard estimating procedures from data obtained from company records, interviews with industry personnel, and onsite observations. Estimated costs are presented in four categories which represent the four phases of mined-land reclamation: (1) Design, engineering, and overhead; (2) bond and permit fees; (3) backfilling and grading; and (4) revegetation. Estimated costs as of the first quarter of 1976 are expressed as averages and ranges in terms of per acre, per ton of coal produced, and per million Btu. Total reclamation costs ranged from $860 to $7,200 per acre, from 6 to 84 cents per ton, and from 4 to 35.3 mills per million Btu. A mine in the Northern Great Plains coal province (Region D) showed the highest per acre cost whereas mines in part of the western region of the Interior coal province (Region A) experienced the greatest per ton and per million Btu cost. The high cost of reclamation in the Western United States is reflected in the backfill in and grading category, particularly in the cost of topsoil removal and subsequent replacement as required by individual State reclamation regulations.

Jan 1, 1977

By Mark Flower

A 20L ignition test chamber has been used to test suspensions of 7 UK and world traded coals in air and O2/CO2 mixtures typical of oxy-combustion conditions. The coals varied in rank from sub-bituminous to bituminous and were tested in varying concentrations from the ignition limit to 400g/m3. Following each successful test the combustion residue was collected, weighed and analysed within a thermogravimetric analyser, allowing Q factors to be estimated. The ignition limit varied slightly in air, but was mostly around the 200g/m3 level. With the exception of Coal C, which was much harder to ignite, it correlated roughly with coal rank. The ignition limit changed significantly with O2 concentration when in mixed O2/CO2 gases. Only a few high volatile coals ignited in 21% O2/CO2 v/v, and then only with a 2500 J, rather than a 1000J, igniter. An increase in O2/CO2 levels to 30 or 35% gave ignition patterns similar to those carried out in air with a further increase to 40% having little additional effect. In addition the minimum ignition concentration decreased with increase in O2. Heterogeneous combustion or gasification of the coal by CO2 appears to be confirmed by comparing weight loss results for air and O2/CO2 mixtures respectively for an equivalent peak pressure rise.

Jan 1, 2009

By Sabri Ergun

Cost estimates and technical feasibility are compared for six chemical coal cleaning technologies. The comparison is based on conceptual application of the chemical cleaning methods for removal of pyritic and organic sulfur from a utility grade bituminous coal. The process layout includes receipt of 8,000 tpd ROM coal, fine coal pulverizing, desulfurization, and preparation of a compacted clean coal suitable for storage and shipment. The methods are: the Magnex iron pentacarbonyl process, the KVB dry oxidation process, the Battelle hydrothermal caustic leaching precess, the TRW Meyers ferric ion leaching process, the Ledgemont oxygen/water leaching process, and the Bureau of Mines/Energy Research and Development Administration air/water leaching process. Capital costs estimated for the desulfurization operation alone, scaled to 8,000 tpd, range between $14 MM and $122 MM, while estimated operating costs for desulfurization alone on the same scale of operation range between $7 and $17 per ton clean coal produced. Relatively little is known about the chemical cleaning of coal, and present cost estimates indicate that the method might not be competitive at its present state of development when used alone to clean utility grade coals for sulfur removal. The principal attractiveness of chemical coal cleaning lies in its potential for combination with physical cleaning to produce cost competitive compliance coals in a combined process with high-Btu yields.

Jan 1, 1977

By Gordon R. Sima

This contract is concerned with feasibility studies, design and fabrication of a prototype hand-held test instrument and a machine-mounted test Instrument for measurement of electrical shock hazards of mining machines. This report presents the proposed and detailed design of the hand-held test instrument and the machine-mounted test instrument. Theory of operation of each instrument is discussed and includes the operating parameters.

Jan 1, 1976

Data released by the Commerce Department's Bureau of Economic Analysis show continued gradual change in the real GNP's rate of growth in 1984, which has eased from an annual growth rate of 10.1 percent in the first quarter lo 7.1 percent in the second quarter, and then to 2.7 percent in the third quarter. The automobile industry strike in the last half of September had only a small effect, estimated at less than a 0.1 percentage point reduction in the growth rate. Among the components that comprise the GNP, personal consumption and fixed investment grew at lower real rates in the third quarter than in the second quarter, while net exports decreased. Personal consumption expenditures increased $0.4 billion in the third quarter, compared with an increase of $20.1 billion in the second quarter. Nonresidential fixed investment increased $3.9 billion in the third quarter, compared with $9.6 billion in the second quarter. The other component of fixed investment--residential investment--increased from $60.8 billion in the second quarter to $61.2 billion in the third quarter. Real net exports of goods and services decreased $1 1.3 billion in the third quarter, compared with a $3.1 billion decrease in the second quarter. Although exports increased from an annual rate of $144.7 billion to $150.2 billion, imports increased much more, from an annual rate of $1 56.2. billion to $172.8 billion (table 1).

Jan 1, 1984

By F. W. Wessel

Manganiferous carbonate slates of the Cuyuna range, which are part of the unoxidized thin-budded iron formation, represent a large potential source of manganese. This report details recent bench-scale research by the Federal Bureau of Mines in applying mineral-dressing techniques to these materials in order to investigate their potential uses. Work outlined in the report was directed toward the production of concentrates usable as iron-blast furnace feed, but an equally important objective might have been to furnish an enriched feed for extractive processes for recovering manganese. Flotation concentrates were prepared that contained 11.1 percent manganese, 27.8 percent iron, and 12.2 percent silica, with recoveries of 73 percent of the manganese and 48 percent of the iron. Calculated analysis for a simulated sinter suggests a product containing 16.0 percent manganese, 40.2 percent iron, and 17.6 percent silica, with 31 percent recovery of the dry weight of the ore. The silica in the flotation concentrates was due to quartz and iron silicates. Substantial quantities of the iron silicates (stilpnomelane and smaller amounts of minnesotaite) were present in the slate, and the need to reject these minerals limited the recovery of iron. The sintered flotation concentrate would be usable as ferruginous manganese ore for iron blast-furnace feed because of its favorable manganese silica ratio. The unsintered flotation concentrates, representing 45 percent of the feed weight and containing manganese enriched in the ratio of 1.6 : 1, also could be used as feed to processes for extracting manganese.

Jan 1, 1961

By E. Chin

The countries of Asia and the Pacific, with their large mineral resource base, are significant suppliers of a wide variety of minerals to both regional and world markets. Australia, China, and India dominate the commercial mineral exploitation in the region. Australia has known reserves of major minerals, which are adequate for both domestic demand, and for exports, and is a significant producer of bauxite; copper; diamond; gold; iron ore; lead; manganese; mineral sands (titaniferrous minerals, monazite, and zircon); nickel; salt; silver; tin; uranium; and zinc. China is the world leader in proven reserves of antimony, barite, ilmenite (titanium), magnesite (magnesium), molybdenum, rare earths, and tungsten. China also has large resources of low-grade iron ore and significant resources of other mineral commodities, such as coal, based on its production and export capabilities. India has significant resources of bauxite, barite, graphite, iron ore, and mineral sands.

Jan 1, 1995

By A. C. Fieldner

The Sectional Committee on Classification of Coals, functioning under the sponsorship of the American Society for Testing Materials and the rules of the American Standards Association, in its 1934 report recommended to the American Society for Testing-Materials5 that Specifications for Classification of Coals by Rank be adopted as tentative. These specifications, slightly modified as recommended by the Sectional Committee, in its 1935 report,6 wore approved as tentative standards by the society in 1935. The specifications rover the classification of coals according to their degree of metamorphism, or progressive alteration, in the natural eerie s from lignite to anthracite. The basic scheme of classification is according to fired carbon and calorific value (expressed in B.t.u.) calculated to the mineral-matter-free basis. The higher-rank coals are classified according to fixed carbon on the dry basis, and the lower-ran]: coals according; to B.t.u. on the moist basis, that is, containing its natural bed moisture but free of visible surface moisture. Agglutinating and weathering indices arc used to differentiate between certain adjacent groups.

Jan 1, 1935

By Chas. F. Jackson

This paper is one of a series dealing with mining methods and costs, prepared and published under the sponsorship of the United States Bureau of Mines and made possible through the cooperation f many mining companies in the United States and foreign countries. The preparation of this paper follows a field study of top-slice mining during which the author visited and discussed with operating officials a large number of iron mines in the Lake Superior region. During this study special note was made of changes in top-slicing practice during the past decade, prior to which the author had acquired several years experience with the method through active connection with a number of mines employing top slicing.

Jan 1, 1931

By James R. Boyle

The value of mineral production increased 6.2% in 1976. With the exception of coal, practically all commodities registered an increase in production and value; most had an increase in unit value. Total value exceeded $1 billion for the first time. The increase in nearly all nonmetallic mineral production was a complete reversal of the 1975 experience. Alabama led the Nation in the production of crushed marble and was second in bauxite and scrap mica, third in oystershell, third in kaolin, and fifth in dimension limes-tone and dimension marble. International Trade.-The international trade passing through the Mobile customs district was valued at $2,524 minion in fiscal year 1976, up 20% from that of the previous year. Of the total value of trade passing through the district, 52% of the value of experts and 89% of the value of imports were handled through the port at Mobile. The major export Commodity was coal through McDuffie Coal Terminal which amounted to nearly 2.9 million tons, up from 2.4 million tons in 1975. Coal exports were to Japan, Italy, Turkey, the United Kingdom, and Brazil. Other exports were cement (114,000 tons) and [ ]

Jan 1, 1979

"Status of the Mineral Industries" provides a written and graphic view of the Nation's mineral position and its mineral industries. The report, issued annually by the Bureau of Mines, U.S. Department of the Interior, describes recent activities in mineral production, consumption, imports, exports, and uses of significant minerals and mineral raw materials. Charts profile trends for the past 28 years in supplies and uses of iron, steel, major nonferrous metals, primary nonmetallic construction raw materials, fertilizers, and plastics. Also included are current and historical financial data on the mineral industries, such as debt-equity ratios, asset-to-liability ratios, and plant and equipment expenditures.

Jan 1, 1979

By C. R. Sponsler, O. C. Blade

"INTRODUCTION This report on the properties of motor fuels sold through service stations in the United States is a continuation of a series of reports made in accordance with a cooperative agreement between the Coordinating Research (CFR) Committee of the Coordinating Research Coouncil (CRC) 4/ and the Bureau of Mines of the United States Department of the Interior. The first of these reports presented data on motor gasolines sold during the winter of 1935-36. 5/ Further reports were issued describing motor gasolines sold during the succeeding summers and winters to and including the summer of 1941. 5/ reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed. 5/The present report presents analytical data for samples, representing the products of approximately 100 companies. Most of the samples represented in this report were obtained during December 1)55 and January 194o. As in previous surveys, the companies covered by the survey include both large and small suppliers. Conforming to former reports, the data cover three groups of samples - regular-price, premium-price, and third-grade gasolines.As the number of analyses submitted for samples of third-grade gasoline are not considered adequate to represent this type of motor fuel, data for the analyses have not been averaged, but the individual items are tabulated. The number of samples, items, and brands comprising each group is as follows:Regular-price, 1,958 samples, 317 items, and 96 brands; premium-price, 1, samples, 292 items, and 85 brands; third-grade, 58 samples, 22 items, and 14 brands. The meanings of these terms as used in the surveys are as follows;"

Jul 1, 1946