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By C. A. Herbert

This paper sets forth the hazards of accumulations of explosive mixtures of methane and air due to inadequate ventilation, the causes of which are discussed as follows: 1. Lack of well-maintained air courses. 2. Air losses due to leaky stoppings, trap doors, and overcasts. 3. Faulty mining methods. 4. Poor supervision. A modified plan of room-and-pillar panel mine development is suggested, which, it is believed, will eliminate many off the hazards of gas accumulations inherent in the present method of mine development. It is also suggested that some water-proofing agent be used on the roof of permanent air-course entries in conjunction with roof bolting to eliminate the detrimental effect of the moisture-laden atmosphere during summer and thus prevent serious roof falls.

Jan 1, 1953

By T. G. Mayhew, A. A. Bergeron, R. J. Mahany

This report describes an operational communications system which provides remote intra-terrestrial wireless transmission of environmental information. Design and modification specifications of requisite equipment are included along with a detailed description of system operation

Jan 9, 1976

By G. B. Shea

"In 1928, there were 47 fatal accidents in the California petroleum industry, 14.6 per cent more than occurred in 1927 when 41 men lost their lives in the drilling, producing, manufacturing, and marketing divisions of the industry. This increase in the number of fatal accidents for 1928 has caused the first upward trend in the fatality curve of the California petroleum industry since 1923. In no other year during the 6-year period have the fatalities in any one year been greater than those for the preceding year. This fact should be given serious consideration and study by the petroleum industry, and an endeavor should be made to cause the number of fatalities again to decrease and conform to the previous gradual declining trend of the fatality curve.The following chart shows the trend of fatal accidents during the past six years:Of the 47 fatalities in 1928, 30 occurred in the drilling and producing division, 1 in the pipe line and transportation division, 14 in the refining division, and 2 in the sales and marketing division. A comparison of the number of fatalities in each division for 1927, and 1928, is given in the following table:3"

Sep 1, 1929

By Richard J. Mainiero, James Q. Wheeler, Lewis H. Kopera, Yael Miron

The research reported here was part of the effort to evaluate the safety of a process to recover TNT from MK-9 depth bombs by the autoclave melt out process. In this process the depth bombs are heated to 121°C so that the TNT will melt and run into a vat. Unfortunately, asphalt lining the inside surface of the bomb also melts and flows out with the TNT. It is not known what effect the asphalt contamination and the higher than normal process temperatures (12°C) would have on the sensitivity of the TNT. Testing was conducted on molten TNT and molten TNT contaminated with 2 pct asphalt at 90, 100, 110, 120, 125, and 130°C. In the liquid drop test apparatus with a 2 kg weight, the molten TNT yielded a 50 pct probability of initiation at a drop height of 6.5 cm at 110°C,decreasing to 4.5 cm at 130°C. Asphalt-contaminated TNT was somewhat less impact sensitive than pure TNT at temperatures of 110 to 125°C, but became more sensitive at 130°C; 50 pct probability of initiation at a drop height of 7.8 cm at 110°C, decreasing to 3.3cm at 130°C. In the card gap test, the molten TNT detonated at high velocity for a gap of 0.25 inches at 90 to 125°C and detonated at high velocity for a gap of 0.5 inches at 130°C. For gaps of 0.5 to 3 inches at 90 to 125°C and 0.75 inches to 3 inches at 130°C, the TNT did not detonate at high velocity but produced a violent explosion that caused significant damage to the test fixture. For gaps of 4 inches the TNT did not react. In the gap test there was no significant difference between the pure and asphalt-contaminated TNT. The thermal analysis test results showed that when asphalt is present in TNT, it greatly accelerates the exothermic decomposition of TNT, starting at temperatures near 200°C. The research demonstrated that asphalt-contamination of recovered TNT does not appear to have a significant effect on TNT shock sensitivity, but does adversely affect impact and thermal sensitivity. The results also showed that molten TNT seems to be more shock sensitive than previously suspected. It appears that at relatively low shock stimulus levels, the molten TNT may be undergoing a low velocity detonation, wherein the shock wave traveling through the gap test pipe cavitates the molten TNT, greatly increasing its sensitivity.

By Michael L. Clar

The U.S. Bureau of Mines contracted a study to determine the feasibility of water diversion and overburden dewatering for underground coal mines in the Appalachian Region. All relevant published literature pertaining to the occurrence and control of surface and groundwater in underground coal mines was reviewed and organized into a bibliography. The impacts of mine water with respect to health and safety, production, environment, and costs were assessed. Sources of water inflow into underground mines were described. A summary description and evaluation of techniques that can be used to reduce the amount of water entering underground coal mines was prepared. A review of engineering practices currently used by operating coal mines in the Appalachian region to prevent the movement of ground and surface water into active coal workings was conducted. Major emphasis was placed on the identification of the geologic and hydrologic con¬dition of the site, onsite inspection of the methods used and an evaluation of their technical and cost effectiveness.

Jan 1, 1981

By Lowell B. Moon

The Stange and Byrnes Heirs manganese mines, adjoining properties in Bland and Giles Counties, Va., have produced at least 20,000 long tons of concentrates containing 8,000 long tons of manganese. They were selected as the site for a strategic-mineral development project because of the existence of geologic possibilities for extensions of the known ore body. In plan, the long dimension of the ore body parallels the axis of a major anticline. Localization apparently is due to longitudinal and transverse fracturing incident to two-way folding. That the manganese oxides were deposited by downward-moving solutions is suggested by the fact that mineable concentrations are confined to a coarse, porous sandstone under-lain by impervious silt and clay. Bureau of Mines project work began on January 15, 1941, and was completed on April 23. The work sampling the faces of the pit, bulldozer trenching, and churn drilling. Pit sampling consisted of 132 channel samples usually 5 feet long and taken at 20-foot intervals. Seventeen trenches aggregating some 4,500 feet in length were dug by the bulldozer. Trenches averaged 12.6 feet in width and 5 feet in depth. A total of 1,978 feet of churn drilling was done in 33 holes. In preparation for churn drilling it was necessary to construct roads to 21 of the 33 sites. A total of 2,867 linear feet of road averaging 13 feet in width was built.

Jan 1, 1950

By R. S. Dean

[During t!~c past f isc.~l y~:-.r the Xetzllvz-gicd 3ivi oion has made im- portant contribution-, don,- tlie lines rlictnteil by the Bureau policy of con- servation of domestic rnker~l rcsoul-ces throui;h use. During t!~c past f isc.~l y~:-.r the Xetzllvz-gicd 3ivi oion has made im- portant contribution-, don,- tlie lines rlictnteil by the Bureau policy of con- servation of domestic rnker~l rcsoul-ces throui;h use.]

Jan 1, 1940

By R. S. Dean

[During the past fiscal year the Metallurgical Division has made important contributions along the lines dictated by the Bureau policy of conservation of domestic mineral resources through Its investigations include determining of fundamental data of metallurgically important materials improvement of standard ore-treatment method to eliminate waste and improve the grade or recovery of the products; and development o new metallurgical processes.]

Jan 1, 1940

By J. W. Thompson

BURYING DEAD MINERS. BURYING BODIES OF DEAD MINERS. REVISED STATUTES (HURD) 1874, P. 263. SEC. 22. LIABILITY OF RAILROADS, ETC., FOR BURIAL EXPENSES.-When any railroad company, stage or any steamboat, propeller, or other vessel engaged in whole or in part in carrying passengers for hire, brings the dead body of any person into this State, or any person dies upon any railroad car or in such stage, steamboat, propeller or other vessel in this State, or any person is killed by cars, or machinery of any railroad company or by accident thereto or by accident to or upon any such stage, steamboat, propeller, or other vessel, or by accident to or in or about any mine, mill or manufactory,* the company or person owning or operating such cars, inachinery, stage, steamboat, propeller, or other vessel, mine, mill or manufactory shall be liable to pay the expenses of the coroner's inquest upon and burial of the deceased and the same may be recovered in the name of the County in any court of competent Jurisdiction. NOTE--The original Act of February 15, 1855 (Laws 1855, p. 170), makes no reference to the dead bodies of persons killed" by accident to, in or about any mine."

Jan 1, 1919

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions5/ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1961

By NIOSH Publications

In 2004, 14,478 mining operations reported employment statistics to the Mine Safety and Health Administration (MSHA). Almost half (48.9%) were sand and gravel mines, followed by stone mines (30.4%), coal mines (13.9%), nonmetal mines (5.1%), and metal mines (1.7%).

Sep 1, 2007

By W. H. Ode

Because trade increased among various nations after World War II, the Coal Committee of the Economic Commission for Europe established a Classification Working Party in 1949 to develop an International system for classifying coal. Although national classification systems existed, they had been developed in accordance with characteristics of domestic coals without reference to coals of other countries. Terms for describing similar or identical coals differed in each nation. This caused confusion in evaluating coals shipped in international trade and also hampered exchange of technical information on problems of coal utilization. Experts4/ participating in the classification project early in their work agreed that two systems should be formulated, one for the higher rank coals or so-called "hard" coals in European terminology and the other one for the lower rank coals, the latter designated mainly as brown coals and lignites in the various countries. Rank refers to the degree of metamorphism (progressive alteration) in the natural coalification series from lignite and brown coal to anthracite. The system for classification of hard coals was published late in 1956 as a document of the United Nations.5/ Results of a study for applying this system to American coals were published in 1958.6/

Jan 1, 1960

By W. A. Calhoun, M. M. Fine

"One of the most important wartime activities of the Bureau of Mines was the search for new sources of mineral necessary to the prosecution of the war. Part of that effort was in the form of metallurgical service extended to other government agencies engaged in purchasing and stock piling some of the more critical and strategic materials.Fluorite was one of the materials stock piled by the Metals Reserve Company. The fluorite was usually in the form of coarse metallurgical con¬centrate purchased in the United States and abroad. The material was stock¬piled to insure an adequate reserve of fluorite for the metallurgical industries. The domestic production of metallurgical fluorite containing a minimum effective calcium fluoride content of 55 percent,4/ however, gradually increased until production was at least equal to consumption. The stock-piled metallurgical fluorite, therefore, soon became a surplus commodity.On the other hand, the supply of acid-grade fluorite, containing a minimum of 97.5 percent calcium fluoride and n maximum of 1.5 percent silica,5/ was never entirely adequate. Increased consumption of acid-grade material in the aluminum, petroleum, and chemical industries kept that material on the critical list during the war.Under the circumstances, it was felt that a study of the possibility of producing acid-grade fluorite from the metallurgical stock piles would be of some benefit to the war effort. Consequently, samples of fluorite from several of the Metals Reserve Company stock piles were tested by the Bureau of Mines at the request of the War Production Board.Two groups of samples were submitted for testing. One consisted of metallurgical fluorite purchased from Mexico and stock-piled in the El Paso and Laredo, Texas, stock piles of the Metals Reserve Company. The second group of samples was from the stock piles at Gila, N. Mex.The sample submitted from the El Paso stock pile consisted of about 5,000 pounds of minus 4-inch material. Mineralogically, the sample consisted of fluorite contaminated by calcite, chert, quartz, and small amounts of iron and alumina. Although some of the fluorite was reasonably free from gangue at minus 1-inch, much of it remained locked in sizes as fine as 65-mesh.The Laredo sample was about 5,000 pounds of material from five different piles. The samples from each stock pile, A to E, inclusive, were analyzed separately to determine whether the grade of the material in the piles varied markedly. As there was little difference in the analyses, the samples were combined in proportion to the tonnage represented to make a composite sample for testing. The composite sample consisted of fluorite with small amounts of quartz, calcite, and barite. Most of the fluorite was the dark-colored, opaque variety. A small amount of iron-oxide staining was present, and traces of muscovite, clay, pyrite, and tourmaline were noted. The quartz was present as crystals in vugs, and as finely disseminated grains in the fluorite. The druzy quartz and the calcite were free at minus 10-mesh, but the disseminated grains, some of which were 1 to 15 microns in size, were not entirely free at minus 270-mesh. A petrographic estimate indicated that 65 percent of the silica was locked in the 150- to 200-mesh."

Jun 1, 1946

By William F. Jahn

Because of the' situation in Europe during the summer of 1939, with the possibility of war and consequent curtailment or loss of supplies of tin to the United States, the Bureau of Mines undertook an investigation of domestic tin resources. This was permitted by the Strategic Minerals Act of 1939, which authorized investigation of possible domestic resources of strategic minerals necessary in a national emergency. The minerals selected were in short supply, and the United States depended almost entirely on imports to meet normal requirements. The Black Hills of South Dakota were selected for investigation as one possible source of tin because of the occurrence of the mineral there has been known since 1876, although production had never been important. The Tinton area, in the northern part of the Hills, had received the most attention and contained some minor indicated and inferred tin deposits.

Jan 1, 1949

By R. L. Rough

The Bureau of Mines analyzed rotary-coring-operations data to compare mud and air as coring mediums, and to compare core recoveries, penetration rates, and cost data for the respective mediums as part of an investigation of the susceptibility to secondary-recovery techniques of petroleum reservoirs in Ohio, Pennsylvania, and West Virginia. This report describes the rotary-diamond coring equipment and operations employed while coring 20 wells--10 cored using mud, and 10 cored using air. Data relevant to the draw works, rotary-table power, drill pipe, drill collars, core barrel, core head, mud pumps, or air compressors are tabulated. Average bit weight and rotary speed, core recovery, and penetration rates are listed for each formation cored. In general, core recoveries were better from the mud-cored wells, whereas penetration rates were faster for the air-cored wells. Coring costs were about the same for single-formation wells cored with either mud or air; however, costs increased considerably when multiple-formation wells were cored with air.

Jan 1, 1969

By W. A. Grosh

In 1951 the Federal Bureau of Mines became interested in the reports of copper-nickel mineralization in northern Minnesota. Several outcrops on the north side of the Duluth gabbro in the Kawishiwi River area were sampled by the Federal Bureau of Mines and George M. Schwartz of the Minnesota Geological Survey. Because these samples showed appreciable amounts of copper and nickel, a 100-pound sample of an un-altered outcrop was obtained for metallurgical testing. Results from this preliminary work were all favorable; therefore, in the fall of 1953 the Bureau of Mines diamond-drilled three holes near the outcrop of the con-tact between the Duluth gabbro and the Algoma granite. A total of 686 feet of NX size hole was drilled, and 100 percent of the core was recovered. Each hole intersected the contact, and the strike and dip for that locality were established. The core was split, and half was used for analyses and further metallurgical tests; the remainder was retained for permanent record in the Bureau of Mines core-storage warehouse.

Jan 1, 1955

By C. W. Van Noy

The procedure suggested in this report is intended for the use of engineers, esters, accountants, etc., in estimating the cost of chemical-type operations. It is intended to over operating costs, not investment costs, as the latter have been covered numerous other publications. However, as capital investment costs are reflected to a high degree in operating costs, it is important to point out that accuracy of investment costs is highly essential. Therefore, all factors that might be included under plant -capital costs should be considered, such as requirements of shops, employees' housing, etc. The procedure is designed primarily for use in types of chemical oper¬ations, such as the production of synthetic liquid fuels, anhydrous ammonia, and others of like or similar nature. Yet, no attempt has been made to cover the entire chemical industry.

Jan 1, 1949

By W. W. Staley

This paper discusses the design of small head frames that will fill the needs of prospectors and small operators whose operations are conducted through shafts. The head frames considered were designed to handle relatively small tonnages. It was assumed that the shafts in which buckets are used would not exceed 300 feet in depth and that not over 60 tons of rock would be hoisted, in, 14 hours. In the design of the larger head frames, a hoisting capacity of about 250 tons per 6 hours from a depth of 300 to 500 feet was assumed. Under these conditions, hoisting speed, rate of acceleration, and weight of rope have a negligible effect on the head frame design and, therefore, have been ignored in the following, discussion. Because timber is relatively cheap and easily obtained in most mining areas, the discussion has been confined to timber construction.

Jan 1, 1937

By C. A. Mehring

[This paper, which describes the milling practice at the San Guillermo concentrator of the Compania Industrial "M Potosi", S.A., located at Chihuahua, Chihuahua, Mexico, is one of a series of similar papers being prepared by the United States Bureau of Mines. The concentrator treats lead-zinc-silver ore at the rata of 2,300-2,400 tons of dry material daily and produces lead concentrate and zinc concentrate by selective flotation methods. The lead concentrate is smelted at the Chihuahua plant of the American Smelting & Refining Co., and the zinc concentrate is shipped to various European smelters.]

Jan 1, 1933

By H. S. Auvil

[Coals of low-volatile rank cannot be coked without admixing large proportions of high-volatile cod in the used type of byproduct-coke oven, because they expend excessively and. exert side thrust, which ruins the oven wells. Some medium-volatile coals also give trouble. Since high-rank coals produce a strong, blocky coke, it is desirable to have the rank as high as practicable, particularly in the manufacture of foundry coke. Accordingly, it has become the practice to mix or blend high-volatile shrinking coals with as much low-volatile coal as possible and still have a mixture that mill not deform the walls or cause difficulty in pushing the coke. Occasionally, the safe limit of low-volatile cool has been exceeded and ovens have been damaged. It is desirable, therefore, to have a reliable method of determining the expending tendencies of mixtures before they are charged into the ovens. Furthermore, coal changes somewhat in its properties as mining progresses, end therefore, mixtures found to be safe at one time may cease to be so subsequently, particularly if nearly the maximum allowable percentage of low-volatile coal is being used. ]

Jan 1, 1938