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By William C. Hood

A leaching column technique that produces effluent similar in quality to coal mine drainage in the Eastern Interior Basin has been developed. The columns are charged with 1000 grams of crushed overburden and cycled through the leaching process once a week for twelve weeks. Inter-relationships among the important chemical constituents are very similar to those present in actual mine drainage waters, but the overall concentrations of ion are more dilute in the leachates. Multiplying the leachate concentrations by a factor of 4.5 gives values similar to mine waters. Available data suggests that each of the leaching cycles represents about three years of natural weathering, so that the leaching technique can predict the evolution of the mire drainage water over a time span of nearly 40 years. Use of the leaching technique with drill core samples should provide a method of approximating mine drainage quality in advance of mining and should be quite useful in identifying potentially toxic units in the overburden. However, the results should he considered to be a 'worst case' situation because the technique' does not consider the effects of reclamation.

Jan 1, 1984

By Paul L. Michael

Roof warring signals from eleven underground coal mines (principally in the Pittsburgh seam) were studied and analyzed. The character of individual acoustic warning signals is shown to be dependent on spectral distribution of energy. Reverberation tires (pulse decay rates) were found to be usually between 0.1 and 0.5 seconds. Listening tests were conducted to assess the miner's ability to discriminate speech and roof talk signals in noise and in quiet, with and without ear protectors and with various levels of hearing loss. The ability to detect roof talk is shown to be generally degraded while wearing car protection in quiet, although, if car protectors are worn only when required by high noise levels, the ability to detect roof talk will be preserved at its maximum.

Jan 1, 1972

By H. A. Doerner

"The pure mineral chromite, FeO.Cr203, consists of ferrous and chromic oxides, chemically united in equal molecular proportions. Unfortunately, pure chromite as defined above appears to be a rare exception. In most chrome ores the mineral may be considered a combination of spinel, MgO.Al203, and chromite, with the latter predominating. The ratios between the four common constituents Fe0, Mg0, Cr203 and A203 vary greatly, and other minor constituents such as TiO2 and. Fe203 may also be present.In the mechanical concentration of chromite ores the maximum grade of concentrates that can be produced is thus limited by the composition of the chrome minerals present. Pure chromite contains 68 per cent Cr203, but the Cr203 content of the chrome minerals in commercial ores varies between 45 and 60 per cent and the average is not far from 55 per cent.Chromite is usually associated with serpentine. Other silicates, quartz, dolomite, magnetite, ilmenite and other iron Minerals are frequently present.The amenability of a chrome ore to concentration, depends upon the kind and amount of the various gangue minerals present and the amount .of crushing necessary to separate the chromite from them.A relatively small amount of chrome ore is concentrated by milling. In most cases the mine product is simply hand-sorted. Such chrome deposits as are known in the United. States can not be worked in this way on account of one or both of the following conditions: High cost of labor and finely disseminated impurities. There are, however, several deposits in the United States, Canada, and Alaska which may be able to compete with imported or by efficiently utilizing modern ore-dressing and milling methods."

Nov 1, 1930

By R. L. Blake

The crystal structure of hematite, a-Fe203, has been refined as part of a continuing study of the behavior of phases in the Fe-O system during reduction and oxidation. Three-dimensional diffraction intensities were collected on two spherical single crystals of hematite with a semiautomated Buerger single-crystal diffractometer. The first crystal refined was a natural Elba hematite with minor impurities. The other, a synthetic crystal, was refined at the request of Mossbauer spectroscopy investigators concerned with impurities in the natural crystal. The structure has been refined with a least-squares program and the final structure for the natural crystal irradiated with CuKa-radiation gave a discrepancy factor (R) of 3.65 percent using 49 unrejected reflections of the 51 measured. For the synthetic crystal, using MoKa-radiation, the discrepancy factor converged to 2.8 percent using 95 unrejected reflections and was 3.3 percent for all 109 reflections. The structure model of Pauling and Hendricks has been confirmed with essentially no change in the iron coordinates and approximately a 5-percent change in the oxygen coordinates. Selected interatomic distances and angles were calculated as were anisotropic temperature factors.

Jan 1, 1970

By Lon A. Williams

This appendix contains drawing lists and drawings of components and assemblies designed for the prototype portable and machine mounted lighting systems per Tasks II & IV of Contract No. H0220065.

Jan 1, 1976

By Jon G. Bredeson

The electromagnetic noise that exists in a mining environment is quite severe and was shown to have been reasonably well documented by a number of researchers in the Phase I Report. The noise levels are such that prudent communication design requires the careful use of all the electromagnetic noise data available. A comprehensive survey was undertaken to determine techniques used in various industrial environments to achieve secure communications in the presence of electromagnetic interference. The techniques were given in the Phase I Report and are rudimentary, but have produced reasonably good results. A number of these techniques could be applied to the mining environment.

Jan 1, 1980

By H. F. Yancey

Although a general relationship exists between the two criteria used to measure sharpness of separation -error area and probable error -they sometimes give quite different appraisals of a particular washing operation. Error area takes into account how the entire raw coal was treated, whereas probable error reflects only how the material of intermediate density was separated, ignoring completely the recovery of clean coal and the rejection of heavy impurity. Error area is thus more reliable for general use. In heavy-medium cleaning, sharpness of separation decreases with increase in separating density, but ordinarily the change is not great enough to affect the yield and ash content of washed coal measurably. Therefore, distribution curves for heavy-medium units can be transposed from one separating density to another, at least in the range of separating densities ordinarily used in the United States.

Jan 1, 1955

During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and the results are described in this report.

Jan 1, 1983

By Arel B. McMahan

The U.S. Bureau of Mines investigated mines, prospects, and mineralized areas in the Owlshead Mountains Wilderness Study Area (WSA) in 1982. Within the WSA, subeconomic manganese, iron, zinc, and lead resources were identified at two mines; sample analyses indicate five other mines and prospects may have gold, silver, iron, manganese, and copper resources. Three mines examined adjacent to the WSA have identified manganese and iron resources; and sample analyses indicate manganese, iron, and gypsum resources may exist at two prospects. Greatest likelihood for future identification of mineral reserves is for manganese at the Black Magic Mine in the southeast part of the WSA. The southern half of the WSA contains nearly all identified mineral resources, and properties at which sample analyses indicate additional resources. The most significant are manganese and iron resources at the Black Magic Mine in the southeastern part of the WSA; and the Ellie, New Deal, and Owl Hole Mines adjacent to that part of the area. Manganese and iron minerals filled fractures and replaced limestone in brecciated and faulted contacts with intrusive granitic rocks. In the southwest corner of the WSA, sample analyses indicate four prospects may have gold and silver resources. These precious metals are in gouge zones along contacts where diorite has intruded volcanic rocks. A small identified resource at the Kennedy Boys Lead Mine in the western part of the WSA consists of quartz veins with zinc and lead minerals along a brecciated contact between granite and limestone roof pendants.

Jan 1, 1985

By Seth T. Reese

THE INJURY DATA and experience at coal mines in the United States for 1951 are presented in this bulletin under the following general heads: (A) General injury experience: Tables 1 to 18: Contain current data on number of fatalities and nonfatal injuries, frequency and severity rates, average severity, major and detailed injury agencies, and distribution of injuries by part of body and days of disability. (B) Selected injury data: Tables 19 to 43: Contain current data on various selected factors of operating and physical conditions that contributed to the occurrence of injuries at bituminous-coal, lignite, and anthracite mines. These factors include extent of hand and machine loading, size of mine by employment and production groups, thickness of bed or vein, duration and number of work shifts, rating of mine as gassy or nongassy, types of cap lamps, explosives, and combination of factors that influence mine safety. (C) Injury experience by States: Tables 44 to 50: Contain current data on number of fatalities and nonfatal injuries, frequency and severity rates, average severity, major causes and principal agencies, injury records of all coal-producing States, and the relative standing by States according to injury-frequency rates. (D) Major disasters: Table 51: Lists the coal-mine disasters that occurred during 1951, giving location, source, and cause. A major disaster in coal mining is defined as a single accident in which or as a result of which five or more men lost their lives. (E) Historical coal-mine injury experience: Tables 52 to 86: Contain data on injuries, injury-frequency rates, employment, and production at bituminous-coal, lignite, and anthracite mines from the earliest records through 1951.

Jan 1, 1955

By Kay E. Goldberg

The Bureau of Mines conducted a study to develop and evaluate a training workshop for mine safety training personnel. The workshop was based on the Instructional Development Institute (IDI) which has been used for nearly ten years to train educators and administrators in the application of a nine-step model for defining, developing, and evaluating instruction. The Mining Instructional Development Institute (MIDI) was developed by investigators at the University of Southern California as a two-phase project. Phase I involved the modification of the six-day IDI program (including audiovisual presentations, workbooks, games, and exercises) for use by mine safety trainers as a workshop lasting three and one-half days. Phase II involved the evaluation and validation of the prototype MIDI workshop by means of a two-stage jury of experts and a prototype field trial. On the basis of data collected in the validation process it was determined that the institute provided an effective and useful method of instruction in mine safety training and that the institute would be especially valuable for mine safety training administrators and supervisors.

Jan 1, 1980

By B. P. Martinez

In response to a request from the President, the Department of the Interior joined with other agencies in a comprehensive study of the land and water resources of the New England-New York region. As part of this study, chemical engineers of the Bureau of Mines have visited 1,025 mineral-industries plants to inventory the waterborne wastes of mineral origin, discharged by the mineral industries of the New England-New York region. Four-hundred and sixty-two of these plants disposed their wastes to a public sewer of some type, but waste control remains a problem for moat of them. The 1,025 plants are discussed in main industry groups according to their production: Chemical and allied products. Stone, clay, and glass products. Iron and steel and their products (except machinery). Nonferrous metals and their products. Electrical machinery. Machinery (except electrical). Transportation equipment. Miscellaneous mineral industries.

Jan 1, 1956

By E. J. Gleim

A list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1942, was published in Bureau of Mines Information Circular 7207.3/ The list of that date was complete as to equipment then available and in current use. Information Circular 7240,4/ published as a supplement thereto, listed equipment approved curing the calendar year 1943. The present list is another supplement covering approvals issued during the calendar year 1943. The items are numbered to indicate the consecutive order in which each type of machine or device was approved in its particular classification. Thus, Information Circular 7207 gave 19 drills and drilling machines on the Bureau's active list. No additional approvals were given in 1942, but the three issued in 1943 bring the total to 22. Item 102, under Loading Machines and Conveyors, also appeared in Information Circular 7207, and items 120 and 124 appeared in Information Circular 7240. These numbers are repeated here to show that approvals were granted during 1943 for additional voltages on machines previously listed for one voltage only. Equipment listed in these circulars is approved by the Bureau of Mines only when found upon inspection and test to comply with minimum standards of safety as outlined in schedules prepared on the basis of many years of experience in dealing with safety problems of the coal-mining industry. The use of such equipment in mines known to be gassy, as well as in those that may become so, is earnestly recommended in the interests of safety. This circular is published so that the industry may be kept

Jan 1, 1944

By Mark R. Pettitt

The development of fire hazard criteria for noise control products in underground coal mines are presented. Qualifying requisites of the criteria include maintaining miners' safety, allowing for maximum use of noise control products, and economic feasibility. The burning process is analyzed for its relationship to fire hazard criteria developed by NASA and the FAA, and the mine environment is analyzed in conjunction with the end-use applications of noise control products. Also, the interim fire hazard specification developed by MSHA is appraised as it applies to end-use applications of noise control products. From these analyses and a literature survey, fire hazard criteria are developed. They include an initial screening procedure that evaluates the level of flammability testing required. Fire tests that may be indicated are the Vertical Flame Test, the Ignition Temperature Test, and the 25-Foot Tunnel Test.

Jan 1, 1983

By Edward W. Parsons

The transverse force developed by expansion-shell rock-bolt anchors on the wall of a drill hole as the bolt is tensioned was measured by the Bureau of Mines using a device specially designed and fabricated for attachment to a universal testing machine. Load cells equipped with electrical-resistance strain gages provided the data from which the transverse force, in pounds, was calculated. Seven different expansion-shell anchors were tested, and the ratio of transverse force to bolt-tension load was found to range between 0.98 and 1.94 to 1.0. The drag load appeared to be the major cause of the transverse-force variation, but the relative effects of individual factors that affected the ratio between the transverse force and the bolt tension were not determined.

Jan 1, 1968

By M. A. Schellhardt

In recent years development of instruments and equipment for determining subsurface pressures and temperatures in. gas and oil wells has made it feasible to obtain information that eras not available in the past on many gas-production problems. The material presented in this report illustrates particularly the value of subsurface-temperature data in the study of subsurface leakage from gas wells. An abnormal decline in the shut-in pressure of the Lone Star Gasoline Co. A. Jones No. 1 gas well in the southern part of the Buffalo (Tex.) field was observed during an interval when a negligible volume of gas bras being withdrawn from the reservoir. Wellhead-pressure readings indicated that the shut-in pressure of the well declined from 2,295 pounds per square inch gage on February 3, 1937, to 1,445 on February 12, 1935. Tests conducted by engineers of the Lone Star Gas Co. suggested that the subnormal pressure gaged on February 12, 1938, probably was not caused by a head of liquid in the well.

Jan 1, 1940

By Forrest T. Moyer

INJURY experience and related employment information are presented in the chapter for the coal-mining, coking, oil and gas, peat, and native asphalt industries in the United States for 1964. No attempt has been made to combine these data and present injury-frequency rates reflecting the mineral-fuel industries because the hazards of the separate industries are not comparable. All rates in the text are calculated separately on data before rounding, hence component rates may not add to the total rates shown in the tables. Tabulations showing the trend of injuries and employment for all mineral industries are presented in Volume III. COAL Injury experience of the coal mining industry was improved in 1964, as measured by the declines of 1 and 14 percent, respectively, in the frequency and severity rates. Although the total number of injuries increased in 1964, a slightly greater proportional increase in man-hours worked caused the frequency rate to drop to 44.65 per million man-hours. The injury-severity rate in 1964 was 7,832 days lost per million man-hours of exposure. Employment and injury data for 1964 are based on final data for anthracite mines and preliminary data for bituminous coal and lignite mines. Fatality experience improved significantly with a record low number of 240 deaths in 1964. This total was 44 less than in 1963. The Nation's coal mines during 1964 were free of major disasters (a single accident resulting in the death of five men or more) for the first time since 1956. The

Jan 1, 1965

The selective placement of coal stripmine overburden is examined. Physical and chemical properties of spoil detrimental to revegetation and groundwater are detailed. The United States is divided into regions or similar problems. Five mining methods already used in the industry, that are capable of selectively handling waste are examined in detail. Technical and economic comparisons are made for the systems when applied to realistic mine settings. The same analysis is conducted for five novel methods capable of selectively handling waste. Comparisons are made between novel and existing methods. Suggestions for new and modified equipment are outlined. Recommendations for further research are provided. This volume contains all Appendices to the report.

Jan 1, 1981

By Michael Rieber

The increase in f.o.b. mine prices of coal from $5/ton to over $18/ton in five years [1] has increased the significance of transportation costs. Coals produced in the vicinity of the consumer bear a much lower transport cost than those produced in the west. This differential may be used for flue gas desulfurization, other cleaning, or further processing of local coals. To the extent that western coals are cheaper to produce and have a lower sulfur content, they offset the locational disadvantage. To the extent that they have a lower heating value, the disadvantage is exercabated. Given the other conditions, an accurate analysis of transport costs will help suggest the location of coal mining and the moue of transport both transport costs and tariffs have risen. Together they have increased delivered coal prices, altered the balance between the use of coal and other fuels, helped to alter the location of mining activity, and put pressure on consumers to examine the cost effectiveness of alternative transport modes. Transportation options for long distance coal movements include rail, barge, pipeline, and EHV transmission lines. A summary of system parameters is shown in Table 2.1. Barge transport, pneumatic and slurry pipelines are discussed elsewhere in this report. Together with EHV, they have been the subject of previous studies [2,3,4]. Slurry pipelines have been shown to be especially useful where rails are not available [2] but the technical problems of dewatering, handling, and utilization of lines [5] remain unresolved. They are discussed in Section 3. Barge transportation depends on the location of the mine and consumer with respect to the waterway system. One drawback of barge shipment is interruptions due to winter, and low or high water conditions. Mine mouth power generation followed by EHV transmission of over 500 miles has been shown to be the most expensive means of delivering an equivalent amount of energy to consumers [2].

Jan 1, 1977

This section of Minerals and Materials analyzes the following three factors affecting the recent performance of the U.S. and world mineral industries: 1) the health of the U.S. and world economies, 2) the level of interest rates and 3) the performance of productivity in both the U.S. mineral industry and the general economy. While these indicators do not exhaust the possible critical factors, they represent an initial attempt to probe some of the considerations underlying the performance of the U.S. minerals and materials industry. The U.S. and World Economies It is essential to analyze the state of the U.S. and world economy because the demand for minerals and materials is a derived demand; that is, since minerals and materials are used in the productive process, the demand for them is a direct function of the demand for the finished products of which they are a basic input. Thus, the demand for minerals and materials is directly affected by changes in present and planned consumption and investment expenditures. The past two issues of this publication have highlighted the generally discouraging performance of the national and inter-national economies. Briefly, the world economy is in the third year of the first long recession in recent history where inflation rates have remained above 5 percent. With many countries either unable or unwilling to support domestic spending while inflation continues, there has been a growing tendency to institute trade-restrictive policies to support domestic demand. The resulting weakened demand conditions in exporting nations have had a direct effect on the mineral industry.

Jan 1, 1982