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By R. S. Norman

The objective of this program was to select approximately 100 acoustic materials for flammability evaluation. Noise control programs have been initiated on several types of mining equipment and vehicles which can be used in underground coal mines. Often, the materials which are used in these noise reduction programs have not been tested for flammability properties according to the same reference standard. During this program a variety of materials were selected for measurement according to ASTM E-162 procedures. A radiant heat energy source was used to measure flammability properties of 15.2 x 45.7 cm. samples. In the absorptive materials category, 45 percent of the materials tested had a flame spread index of less than 25. For barrier, damping, and isolation materials the corresponding values were 40, 43, and 9 percent.

Jan 1, 1979

By David W. Houseknecht

Probabilities of encountering coalbed discontinuities during vertical or horizontal drilling in a specific coalbed can be estimated based on analysis of mined-out areas of the coalbed where the size, shape, orientation, and distribution of discontinuities are known. The result- ant probability estimates can be applied to cost-risk evaluations of drilling programs proposed for exploratory, developmental, or methane drainage purposes in undeveloped areas of that coalbed. Data compiled from mine maps of the Beckley Coalbed in southern West Virginia were used to estimate the probabilities that discontinuities would be encountered in two illustrative hypothetical drilling programs--one for drilling vertical boreholes and the other for drilling horizontal boreholes. Analysis based on a mined-out area of the Beckley Coalbed indicated that vertical methane drainage boreholes spaced 1,000 feet apart in a square grid pattern would each have a 29 percent probability of encountering a discontinuity in a geologically unexplored area of the coalbed. It was also determined that exploratory vertical drilling could locate most of the discontinuities if a borehole spacing of 2,500 feet were used. For horizontal drainage boreholes in the Beck- ley Coalbed, the analysis indicated a linear relationship between hole length and the probability of encountering a discontinuity.

Jan 1, 1982

Comparative tests of four coals used industrially for coke production have been made by three laboratories of the Federal Bureau of Mines, each using its standard equipment and procedures for evaluating coal for coking. Two of the coals were blends used in the western and eastern sections of the United States, the third was a strongly coking coal widely used for producing coke in Alabama, and the fourth was a blend typical of those used for producing foundry coke in the Birmingham district. The coals used and the cokes produced from them covered a wide range of chemical and physical properties. The tests used at all three laboratories for determining the physical properties of the cokes were made according to ASTM (American Society for Testing Materials) methods. The excellent agreement found for the physical properties of the cokes indicated that, for the coals tested, the BM-AGA (Bureau of Mines-American Gas Association) 18-inch circular retort used at Pittsburgh, Pa" the 14-inch slot-type oven used at Denver, Colo., and the 17-inch slot-type oven used at Tuscaloosa, Ala., were substantially equivalent for evaluating coals for production of coke. Thus, added value is given to data obtained previously and independently at these three Bureau laboratories. INTRODUCTION Laboratory equipment to produce coke for evaluation has not been standardized by the industry. The results obtained with anyone design of equipment have been regarded as showing only the relative values of coal to produce coke of the requisite quality. Few systematic studies have been made to correlate results obtained in different types of equipment. Results of one, in which the Bureau of Mines participated, were published recently.2/ This

Jan 1, 1961

By George R. Schottler

The objective of this research is to find the extent of the range of applicability of previously developed statistical methods for determining grade and tonnage of ore to bedded uranium deposits. Uranium assays obtained from gamma-ray logs of exploratory drill holes are used to compute grade and tonnage of ore in the deposit by a standard polygonal method and by statistical analysis. The results obtained by the two methods are compared. The uranium-assay frequency distributions are shown to be lognormal and a simple transformation permits the use of standard normal curve statistics. The effects on the assay frequency distributions of stratified sampling, a required minimum mining thickness, and increased assay-interval length are investigated. The addition of low-grade mineralization to make up the required minimum mining thickness results in a distinct change in the skewness of the assay frequency distribution. Any statistical inference regarding grade-tonnage relationships that will be produced, using the minimum mining thickness, should be made on the basis of this "revised" assay frequency distribution.

Jan 1, 1965

By E. C. Lane

[This Is the ninth in a series of reports on properties of commercial motor fuels, made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the interior. The first report gave data on motor gasoline sold during the winter of 1935-36.3/ The Present report presents analytical data for 2,033 samples, representing the products of approximately 80 companies, which, as in previous surveys, include both large and small suppliers. In addition, the Pacific coast is represented by data that were average by the Pacific Coast Technical Group before 'being submitted and are published exactly as they were received. As in previous surveys, the data are divided into the three groups of samples of regular-price, premium-price, and third-grade gasolines, and each group has been averaged separately. The cumber of samples, items, and brands comprising each group, exclusive of those of the Pacific coast, arc as follows: Regular price, 1,066 samples, 208 items, and 49 brands; premium price, 575 tamales, 154 items, and 38 brands; third-grade gasoline, 7;4 samples, 150 items, and 53 brands. The meanings of these terms as used in the surveys tar as follows: Sample: The individual supply of gasoline obtained at the filling station and analysed in the laboratory.]

Jan 1, 1940

By ARCH L. FOSTER

The rapid increase in the mmber of automobiles during the last 25 years has resulted in the insistent and growing demand for better roads of more permanent construction. Some form of State license for the operation of automobiles has been in effect almost from the time of the first "self-propelled" vehicle, and some part of the revenue derived from the sale of these licenses has been applied to the maintenance and construction of roads. However, to obtain funds with which to build their present highway systems, the individual States have resorted to the taxation of gasoline. The first State to adopt a gasoline tax was Oregon, the law becoming effective February 25, 1919. By 1928, all of the States except two had levied taxes on gasoline at rates varying from 2 to 5 cents per gallon. New York and Massachusetts passed gasoline tax laws which became effective in 1929. Regulations governing the quality and the methods of handling gasoline and other petroleum products sold in the States have also been adopted by 29 States; many of these laws antedate the adoption of a gasoline tax. The variations in motor fuel speci- fications and methods of test have been pronounced in the several States. The Bureau of Mines, in making certain technical studies of the rasolines marketed throughout the United States, the results of which are reported in its semiannual motor gasoline surveys and other reports, has had occasion to obtain and compile all of the present (April 1, 1931) tax and pection laws of the several States which relate to motor fuel and other petroleum products. To facilitate the use of this material and to obviate the need in most cases of reading the complete text of the laws as published by the States, the pertinent information was arranged in tabular form for cly reference. 3 Although digests of States gasoline tax laws' are available and copies of the complete laws can be obtained from the State agancies in charge of the enforcement of gasoline tax and inspection laws, it is believed that

Jan 1, 1932

By R. R. Lowery

The Bureau of Mines developed hypereutectic aluminum-silicon alloys which 11.7.d better mechanical properties than the unmodified hypereutectic alloy. A commercial aluminum-20 weight-percent silicon LIr alloy was selected as a ary base for improvement. The primary silicon. grains were reduced from ASTM 4-5 to ASTM 8.5 by the use of phosphorus and phosphorus compounds. The remaining eutectic matrix was refined by sodium metal additions of 0.2 weight-percent. Solid solution strengthening of the alpha aluminum was obtained by adding 2 percent copper and 0.5 percent magnesium. Also, 1 percent nickel was added to harden the alloy. Optimum thermal treatment consisted of a solution treatment for 10 hour:, at 480° C with hot water quench, followed by aging for 6 hours at 175° C. The final alloy exhibited a Rockwell B hardness of 75 ±2 in the heat-treated condition. The ultimate tensile strength was 39,5O0 psi with no recordable elongation. The coefficient of linear thermal expansion was 20.4 x 10-6 per °C in the temperature range 20° to 300° C. No wear resistance data were collected.

Jan 1, 1966

By C. J. Walker, J. S. Miller

This work was done in an attempt to find a simple solution to the problem of simultaneously changing terminal rate and terminal pressure under conditions of unsteady - state flow in porous media . Although the original aim was not realized , a method for encasing a sandstone core that would permit high - pressure ( 200 to 980 psi ) flow tests and the use of electronic equipment to measure pressures at points along the core during unsteady - state gas depletion was found to be feasible . The sandstone core used in this study was from the Bandera formation of Pennsylvanian age , Redfield , Kans . The core , cylindrical in shape with a 3.5 - inch diameter and 6- foot length , had a porosity of 15 percent and a permeability of 9 millidarcys .

Jan 1, 1963

This report briefly describes the broad program of research and technologic work conducted by the Bureau of Mines on coal and related subjects during 1966. In addition to n description of investigations on mining, preparation, and utilization of coal, an account is given of the Bureau's work in mine health and safety, coal resources, mine explosives, and environmental conditions relating to coal mining and utilization. Details of most of the projects are reported in publications cited throughout this report. Centers and laboratories conducting the coal research and related investigations appear in appendix A; organizations, institutions , and companies contributing to the Bureau's coal research and technologic program are listed in appendix B.

Jan 1, 1967

By Patricia J. Leonard - Mayer

A Bureau of Mines surface resistivity method has been used to determine the joint strike and coefficient of anisotropy of jointed , nearsurface formations at five study areas . The field studies demonstrate the use of rotated , or azimuthal , Wenner-Lee arrays for determining the strike of predominant joint sets . The results of the field studies include the following : in a formation having a predominant , vertical joint set , the maximum value of the apparent resistivity ( pa ) occurs in the same direction ( azimuth ) as the joint strike ; the polar coordinate graph of pa for such a formation is approximately elliptical ; the coefficient of anisotropy ( ^ ) can be calculated from the field data , and values of λ for jointed formations are in the same range of values reported for layered formations ; values of λ are higher at mined sites than at unmined sites . The azimuthal resistivity method and horizontal profiling were used at a site in Pennsylvania to delineate a zone of intensely jointed and fractured bedrock that provided a flow path from a surface stream to a mine . Analysis of the data has been based on a simple model of a jointed formation having a single joint set ; the success achieved to date indicates the need for a more complex model and additional field data .

Jan 1, 1983

By W. J. Wiehagen

The Work Crew Performance Model (WCPM) seeks to define performance variability within similar tasks of an underground work crew and relate observed variability to a cost consequence. Performance variability is described using work site observations to determine the adherence to job elements con¬tained within a standard operating procedure. Key components of the WCPM include (1) job definition through task analyses and the ranking of job elements by perceived cost consequence, (2) observational techniques for establishing performance baselines by measuring adherence to safe and proficient job procedures, and (3) cost linkages between adherence to task procedures and measures of consequence for noncompliance. Data presented within this report were obtained through the study of shuttle car operation in an underground mine in Appalachia. Observed adherence to safe and proficient job procedures by opera¬tors matched well with the consensus profiles (measured through a nominal group technique) with min¬ing personnel. It was also found that experienced operators consistently outperformed less experienced, incidental operators. These findings imply potential use of the WCPM as a practical procedure for thinking systematically about the choices available to reduce performance variability. Field application of the model can offer useful data to evaluate training and financially support performance improvement strategies that can be tested for their ability to reduce human error.

Jan 1, 1994

By W. C. McLaughlin

Under a cooperative agreement, the Bureau of Mines, Magma Copper Co., and ASARCO, Inc., tested backfilled ground support systems at t.wo elevations in Magma's San Manuel, AZ, mine. The tests were mainly for guidance in designing the loading crosscuts of the new ASARCO Sacaton underground mine. Two-piece, wide-flange steel sets for 8-by 8-ft (2.44-by 2.44-m) and 11-by II-ft (3.36-by 3.36-m) openings were designed. Set spacing was 3 ft (0.91 m) and 5 ft (1.52 m), respectively. After erection, the sets were lagged with various test materials. The void between the lining and the ground was backfilled with sand and pea gravel. Instruments measuring strain (used to determine changes in stress) were placed beneath the sets and in the backfill. Results indicate the backfilled sets in the smaller drift (2315 grizzly level, panels 6 and 7) of 8-by 8-ft (2.44-by 2.44-m) cross section are a viable permanent support system, lower in cost than the standard formed concrete. Results are inconclusive in 2615 grizzly level, panels 5 and 6, where wide-flange steel sets were used with 5-ft (1.52-m) long concrete gob lagging of T-design.

Jan 1, 1983

By Peter C. Wood

This report describes research directed toward the preparation of chemical oxygen (02) sources which exhibited improved 02 storage and reaction characteristics when compared to potassium superoxide (KO2). The initial focus of the research was the preparation of calcium superoxide (Ca(02)2) by the disproportionation of calcium peroxide diperoxyhydrate. The Ca(02)2) was characterized by chemical, thermal, and x-ray analyses. Several methods for scaling up the Ca(02)2 synthesis process were studied. Next, the reactivity of Ca(02)2 toward humidified carbon dioxide (C02) was evaluated and was compare o that of K02 under flow-test conditions approximating those existing in portable breathing apparatus. The reactivities of mixtures of K02 and Ca(02)2 or lithium peroxide towards humidified CO2 were also studied. Finally, an analysis of two commercial, K02-based, self-contained self-rescuers was conducted to determine the potential weight and volume savings which would be possible if Ca(02)2 or a mixture of K02 and Ca(02)2 were used as a replacement for K02.

Jan 1, 1983

By H. W. Kilau

The Bureau of Mines evaluated synthetic fluorspars as substitutes for natural fluorspar in basic oxygen steelmaking using a high-temperature rotational viscometer and a quarter-ton basic oxygen furnace (BOF). Consider-able variation in stability and BOF slag fluidizing properties were found when using the initial synthetic products, but improved synthesis methods produced synthetic fluorspars that were generally comparable to natural fluorspar in laboratory testing. Trials in the furnace showed the synthetic products to be operationally the equivalent of natural fluorspar. Higher sulfur and phosphorus contents in some of the synthetic materials did not adversely affect the steel chemistry. Analyses of wet scrubber samples showed evidence that the pelletized synthetic fluorspars experienced greater physical and chemical disintegration than did natural fluorspar. It was also found that operation of a BOF without fluorspar is possible when making low-carbon steels because iron oxide is intrinsically generated as the slag fluidizer.

Jan 1, 1981

By Edward E. Johnson

The principal purpose of this study was the development of an engineering and economic model of a hypothetical large-scale open pit gold mining operation. The guiding concept in developing the model was the idea that, through study of a number of such models, it would be possible to evaluate a mineral property and to make reasonable estimates of the benefits to be derived from research in mining and metallurgy. The model by use of a computer is able to produce results easily and quickly when cost factors are varied. Cost factors may be varied as a result of assumptions of improved technology or of assumptions of assuming different approaches or methods to accomplish a particular segment of the mining or processing operation. The discounted cash flow rate of return was used to measure the effect of changes in costs or expected revenue. In this study, assumptions based on past processing practices were made in an effort to reduce costs of processing the ore These assumptions were: (1) Eliminating the low-grade cyanide circuit; (2) reducing the quantity of material to be processed by screening after crushing; and (3) using a combination of assumptions (1) and (2). All three assumptions resulted in reduced capital investment and operating cost that caused substantial increases in the rate of return.

Jan 1, 1968

By W. C. McBee

Technology for the preparation of densifiable sulfur concrete (sulfapave) materials has been devised by the Bureau of Mines. The materials are intended as new construction materials for use in corrosive areas where conventional materials fail. A series of modified sulfur cements were developed, which can be used in combination with dense-graded aggregates to prepare sulfapave materials with excellent corrosion-resistant properties. The materials can be mixed, laid, and compacted into place with conventional hot-mix asphalt pavi.ng equipment. Mixture designs utilizing 5-to 30-pct-modified sulfur cements and dense-graded aggregates gave material properties ranging from rigid to flexible. Laboratory corrosion tests in sulfuric acid showed no material loss or deterioration of physical properties over a 1-year test period in concentrations ranging from 0 to 60 pct at ambient temperatures. Preliminary results on field testing the materials for durability to weathering, corrosion, and traffic have been excellent, with no evidence of failure in the materials.

Jan 1, 1985

Bosworth, T. 0. The Mackenzie oilfield of northern Canada. Petroleum Times, vol. 5, Apr. 30, 1921, pp. 489-491. Jour. Inst. Petroleum Technologists, vol. 7, Oct., 1921, pp. 276-290; discussion, pp. 290-297. Gives location of the field, some of its geology, mode of occurrence and character of the oil. See also Oil Trade Jour., vol. 12, June, 1921, pp. 48-108. Canadian Min. Jour., vol. 42, May 27, 1921, pp. 420-422. Oil and Gas Jour., vol. 20, June 3, 1921, pp. 90-90. Petroleum World (London), vol. 18, June, 1921, pp. 233-2.64, 236-238, 240-241. Bull. Canadian Inst. min. and met., July, 1921, pp. 629-638. Mining and Metallurgy, Oct., 1921, pp. 47-48. Bureau of Foreign and Domestic Commerce. Resources of Balkan and Near Eastern countries. Commerce Repts., Oct. 24, 1921, pp. 488-489. Includes summary of the mineral resources of these countries, mentioning petroleum and allied substances in Roumania, Albania, Anatolia, Mesopotamia, Palestine, Arabia, Persia.

Jan 1, 1921

By F. J. Wiebelt

Production of small tonnages of asbestos has been reported from 18 California counties; 16 additional counties have occurrences of asbestos. The counties in the northern part of California that have had a recorded production are: Alameda, Amador, Calaveras, Contra Costa, E1 Dorado, Napa, Nevada, Placer, Shasta, Siskiyou, Trinity, and Tuolumne. No deposit in the State has maintained consistent production. Serpentinized peridotites (potential chrysotile-bearing rocks) are widely distributed in the coast ranges, Klamath Mountains, and western foothills of the Sierra Nevada.

Jan 1, 1958

By John A. Kost

Previous work performed under Contract H0220003 suggested that the mean incombustible content could be obtained with fewer samples and smaller samples without greatly increasing the sampling error. Under Modification No. 4 additional surveys were made in twelve coal mines, representing six states. Same 2,500 samples were collected, analyzed for incombustible content, and statistically evaluated. The earlier findings were substantiated.

Jan 1, 1975

By N. A. C. Smith

This report on the physical and chemical properties of typical crude oils of southern Louisiana and southern Texas is the seventh in a series of preliminary chapters of a bulletin covering the producing districts of the United States. Preceding reports* may be obtained from the Bureau of Mines on request. The details of the methods used in this survey in collecting samples and making laboratory tests have been discussed in the first three papers. A method of summarizing and interpreting the laboratory data has also been given, but most of the crudes included in the present report differ so radically from those previously reported, that it has been found advantageous to adopt a somewhat different method in making summaries. This method is described in detail later. If any errors or omissions are noted by readers, it is hoped that these will be brought to the attention of the Bureau of Mines, for correction before the appearance of the final bulletin.

Jan 1, 1922