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By L. T. Grose

The Bureau of Mines conducted a comprehensive study of the Kanab, Kolob, Kaiparowits, and Harmony coalfields of southwestern Utah to obtain additional information and to determine the potentials of these coalfields as sources of energy for steam-electric power-generating plants. Field examinations were made to ascertain the geologic structure and the stratigraphy of the coalfields, the accessibility of the coal-bearing strata, and the general nature of the coal-bearing strata and the terrain. Many mines, both active and abandoned, were examined, and key personnel in the coal industry in the area were consulted. Available analyses of southwestern Utah coals were compiled, and tentative conclusions regarding the rank and quality of the coals were drawn. Coals have been classified by rank according to the standards established by the American Society for Testing and Materials in 1964. The Parr formula for moist, mineral-matter-free British thermal units has been used to calculate the rank of each sample, except as otherwise noted. Water resources related to the areas of the coal reserves also were investigated. Existing literature and maps pertaining to the geology of the areas were reviewed. Production potentials of the coalfields and economic conditions affecting the possible utilization of the coal reserves as sources of energy for steam-powered electricity-generating plants were investigated and analyzed. The data obtained and the conclusions reached as a result of this study are included in this document. The total reserves of subbituminous A and high-volatile bituminous C coals in the fields of southwestern Utah are estimated to be at least 8 billion short tons at depths generally less than 2,000 feet. It appears likely that this estimate will be increased as additional data are made available through exploration and other investigations. Sufficient coal is available in four southwestern Utah counties to supply three or four large steam-electric plants. If the States involved grant water rights to companies planning to build steam-electric plants, the cost of producing power with coal might be attractive and might justify the construction of one or more of these plants.

Jan 1, 1967

By F. B. Petermann

The Bureau of Mines conducted electric furnace smelting tests on sintered flotation concentrate and siliceous log-washed are. The flotation concentrate was derived from the Maggie Canyon deposit of the Artillery Mountains area, Mohave County, Ariz., and contained, before sintering, 35.6 percent Mil and 19.4 percent Si02 + A1203. The log-washed ore was from the McGregor deposit of the Artillery Mountains area, Mohave County, Ariz., and contained 31.2 to 33.6 percent Mil, 19.5 to 27.6 percent Si02 + A1203, and 2.5 percent Pb. This work was undertaken to determine the most effective smelting technique for producing standard products from such nonspecification ore and concentrates. The objective was to collect data, using a small furnace, which would be reasonably accurate and permit extrapolation to large-scale practice for comparing with results on specification-grade are.

Jan 1, 1962

By M. L. Wang, S. R. Short, E. M. Daniloff, E. L. Petsonk, D. M. Mannino, G .. R. Wagner

"Background—It has been suggested that health related job selection is a major cause of the healthy worker effect, and may result in inaccurate estimates of health risks of exposures in the working environment. Improved understanding of self selection, including the role of airway hyperresponsiveness, should improve accuracy in estimating occupational risks.Methods—We evaluated symptoms of the respiratory tract, lung function, occupa¬tional and smoking histories, and airway responsiveness from a cross sectional sur¬vey of 478 underground bituminous coal miners and non-mining controls. Workers with abnormal spirometry were excluded from methacholine testing.Results—Methacholine responsiveness (= 15% decline in forced expiratory volume in one second) was associated in both miners and controls with reduced ventilatory lung function and an increased risk of respiratory symptoms. Miners with the longest duration of work at the coal face had a low prevalence of methacholine responsiveness, compared with miners who had never worked at the coal face (12% v 39%, P < 0.01). Throughout their mining careers, miners who responded to methacholine were consistently less likely to have worked in dusty jobs than miners who did not respond to methacholine.Conclusions—These results provide evidence that workers who are employed in dusty jobs are less likely than their unexposed coworkers to show increased non-specific airway responsiveness, pre-sumably as a result of health related job selection. Surveys of workers in which responsiveness data are unavailable may underestimate the effects of dust exposure on respiratory health."

Dec 1, 1996

By Wing G. Agnew

[This report presents the results of tests made by the Mining Division, Bureau of Mines, on the relative durability of manganese-steel drill rods and carbon-steel drill rods for use with detachable bits.]

Jan 1, 1941

By Wing G. Agnew

[This report presents the results of tests made by the Mining Division, Bureau of Mines, on the relative durability of manganese-steel drill rods and carbon-steel drill rods for use with the detachable bolts]

Jan 1, 1941

By T. M. Barczak

The term "resultant load vector" is defined as the representation of the forces applied to a longwall roof support element by strata activity through a single, quantifiable measure of support resistance. The relatively complex kinematics of the shield structure prohibits determination of support resistance simply from the summation of leg forces. In the research reported in this Bureau of Mines study, the mechanics of the shield structure were evaluated, and a technique was developed whereby the resultant shield loading could be determined by instrumenting supports with pressure transducers and strain gauges to measure leg, canopy capsule, and lemniscate link forces. This technique has been laboratory tested in the Bureau&apos;s Mine Roof Simulator. Functional relationships among variables were assessed, and confidence intervals were established for prediction of the resultant load vector parameters. Resultant load measurements were taken on five instrumented shields on an active longwall face in Colorado. Results were analyzed and found to be consistent with shield mechanics and anticipated roof behavior. Benefits to be derived from this research, future efforts, and long-range goals are discussed.

Jan 1, 1986

By R. L. Grant

The principal official test performed by the Bureau of Mines to determine the permissibility of coal-mine explosives, commonly referred to as the gallery test, has been in use at the Bruceton station for many years (2, 16).4/ In this test the explosive under study is loaded into the borehole of a steel cannon and fired into a flammable mixture of natural gas and air or natural gas, air, and coal dust. To meet the requirements for permissibility, the explosive must not ignite the gas mixture under the conditions of the test. There is little doubt that these tests have succeeded in the main objective, namely, to screen the relatively safe from the relatively hazardous explosives. It has been generally conceded that adoption of permissible explosives by the coal-mining industry in the United States has substantially reduced the frequency of disastrous underground explosions caused by blasting. In recent years, however, research workers planning programs for improving the safety of coal-mine explosives have felt the growing need of a more quantitative method for measuring the incendivity of explosives based on a better understanding of the role of the important variables in the gallery tests, Accordingly, it was decided to apply certain statistical methods and techniques to the gallery test to develop it into a more precise tool for evaluating permissible explosives. One of the first and more important methods applied for this purpose was the up-and-down technique (6,7,17), It was demonstrated (14,15) that the weight of the explosive charge directly affects the ignition probability of the natural gas-air atmosphere and that the curve of ignition probability versus charge weight is a cumulative normal curve. Following these experiments, a program, still in progress, was set up to study how the addition of sodium chloride to various permissible-type ex-plosives affects their incendivity. This program resulted in 3,294 shots,

Jan 1, 1961

No noticeable international economic recovery occurred during the first half of 1982. Industrial production continued to fall in the United States, Canada and Italy and to hold steady in France. Modest increases in production occurred in Japan, England and Germany, although some decline took place from March to April. The U.S. mining industry has been more severely affected by the world recession than the U.S. economy. This is not immediately obvious when comparing the U.S. mining industrial production index from 1981 to 1982, which decreased 8.5 percent, as compared to a 7.1 percent decline for total domestic industries. However, "mining" industry statistics in the U.S. national economic accounting system include petroleum and natural gas as well as minerals. When metal mining is isolated, the decrease in production from 1981 to 1982 is 19.3 percent. If metal mining production continues to perform at the same rate during the third and fourth quarters of 1982 as during the first half of the year, declines from 1981 levels will be quite severe. Aluminum will have declined 22 percent, copper 18 percent, iron ore 24 percent, lead 3 percent, steel 29 percent, titanium 2 percent and zinc 25 percent.

Jan 1, 1982

By Cleo G. Rall

The method for determining the effective porosity of oil- and gas-bearing sands described in this report is a development of earlier methods (28)3/ devised by the Bureau of Mines. The apparatus bas been improved and made more convenient to use, but the procedure is essentially the same as that which has been in use for maw years. A tabulation at the end of the report gives the results of more than 4,800 porosity determinations for oil sands4/ in the fields of 13 States, A selected bibliography of references to articles containing descriptions and evaluations of various methods of&apos; determining porosity is included in this report. The method was devised and developed at the Petroleum Experiment Station at Bartlesville, Okla., as part of the Bureau&apos;s research on fluid-energy relationships and on methods of improving the recovery of crude oil from underground reservoirs.

Jan 1, 1954

By J. B. Littlefield

[At B. meeting of the Subcommi ttce on Chemica.l _ et.lOds of Air Ant:..1ysis of-the American Public Health Ascociation in October 1937, the llse of the impinger for collectinG lcs.d fu.l1e wa:., discussed. The Bureau of \~nes de-cided to obtain infornw.tion on the efficiency of the lerge and midget im-pingers for this purpose y using the electric recipitator as a r?ference ]

Jan 1, 1938

By R. L. Brown, H. G. Berger, E. F. Pohlman

"The Bureau of Mines in cooperation with the American Gas Association investigating the relation of properties of gas oils to the gum-forming properties of carbureted water gas. The present report deals with the effects of operating practice on the composition of the light oils from carbureted water gas. A general outline of the gummy meter problem has been presented in a previous paper.*Carbureted water gas is a mixture roughly of 80 per cent water gas by volume and 20 per cent oil gas. The latter, though small in relative volume, supplies more than half of the heating value of the gas under the present-day standard. Therefore, it is logical that the oil used in the carbureting process and the operating practices involved should be subjected to scientific study. Many investigations***** bearing on the aspects considered in this paper have been carried out in the past."

Oct 1, 1923

By John C. Machisak

INJURY data and experience, with related employment statistics, at coal mines in the United States for 1958 are presented in this publication under the following general sections: (A) General injury experience: Tables 1 to 6: Current data on number of injuries, degree of injury, frequency and severity rates, average severity, and related employment and production data by work location. (B) Selected injury experience: Tables 7 to 38: Current data on principal agencies of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation&apos;s coal mines. (C) Injury experience by States: Tables 39 to 43: Current data on injuries, their causes, rates of occurrence and severity; employment and production data by work location, by States. (D) Major disasters: Table 44: Data on major disasters from 1949 to 1958. A major disaster is defined as a single accident in which, or as a result of which, five persons or more are killed instantly or die at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 45 to 49: Data on fatalities and their causes at bituminous coal, lignite, and anthracite mines from the earliest records through 1958.

Jan 1, 1961

By Scott W. Hazen

This report describes the design, analysis, and results of a special experimental mine-sampling project conducted as part of the Bureau of Mines continuing program on sample-methods research. The experimental project was conducted at the Bureau?s Denver Mining Research Center and at the Climax molybdenum mine within the framework of a cooperative research agreement between the Bureau and Climax Molybdenum Co., Division of American Metals-Climax, Inc. The primary objective of the project was to investigate the interrelation-ship between sample volume, number of samples, the standard deviation of an assay distribution, and the precision required for an estimate of grade of ore, and to develop this interrelationship into a relatively simple method of application for use in mine sampling.

Jan 1, 1962

By R. D. Berkenkotter

This report describes a weighted method for evaluating the mean and variance of assay data from samples of different length . The method , which produces unbiased estimates from which valid confidence limits can be computed , is appropriate for bedded deposits of variable bed thickness and for vein deposits of variable vein width . Assay data from the bedded Florida phosphate deposit is used to illustrate the procedure .

Jan 1, 1964

By Jon K. Ahlness

The Bureau of Mines conducted laboratory and field experiments to determine tne amount of permeability reduction in uranium sandstone after its exposure to different drilling fluids. Seven polymer and two bentonite fluids were laboratory-tested in their clean condition, and six polymer fluids were tested with simulated drill cuttings added. Sandstone cores cut from samples collected at an open pit uranium mine were the test medium. The clean fluid that resulted in the least permeability reduction was an hydroxyethyl cellulose polymer fluid. The greatest permeability reduction of the clean polymers came from a shale-inhibiting synthetic polymer. Six polymer fluids were tested with simu-lated drill cuttings added to represent field use. The least permeability reduction was obtained from a multipolymer blend fluid. A field experiment was performed to compare how two polymer fluids affect formation permeability when used for drilling in situ uranium leaching wells. For this test, the polymer fluid with the best laboratory results (multipolymer blend) was compared with a commonly used polymer fluid (guar gum) that gave poorer laboratory results. When fluid injection rates for the four wells drilled with the guar gum were compared with those for the four drilled with the multipolymer blend, no statistically significant difference was found.

Jan 1, 1984

By D. R. Tesarik

To ensure the stability ofa tailings pond embankment, the height of the phreatic surface must be kept at or below a safe level. In this investigation, the Bureau of Mines analyzed various horizontal drain designs for tailings embankments to determine their effects on location of the phreatic surface. This report describes the investigation, and it includes 21 dimensionless graphs that can be used to estimate the drain spacing and length dimensions necessary to ensure the stability of embankments of various configurations. Analyses were based on the use of two computer codes, a three-dimensional finite-element code and a two-dimensional finite-difference code. The computer-generated results were compared with results obtained from a laboratory embankment model, other laboratory test results, and piezomet-ric data from two actual tailings embankments. Nearly the same phreatic surface locations were predicted using either of the computer codes. For one of the actual embankments studied, the predicted phreatic surface location was slightly higher than the measured location; for the other, the predicted location closely followed the actual surface trend. Phreatic surfaces of the laboratory model were slightly higher than the code-gener-ated locations, and the differences grew larger as drain length increased or drain spacing decreased.

Jan 1, 1984

By Carl Fisher

A microseismic roof fall warning system was field tested in Western and Eastern coal mines in the United States to better define the capabilities and limitations of the microseismic method in predicting roof fall Microseismic event and energy type data were obtained and documented for twenty-three coal mine roof falls. Field test results indicate that both the microseismic event and energy methods, as applied in this development effort, have a high probability for successful application in a commercially practical roof fall warning system. Based on the results and experience obtained during field testing, a commercial prototype microseismic roof fall warning system was designed and constructed. Although it was the intent of the program to field test the commercial prototype system, delays in equipment fabrication and contract time limitations did not permit field testing.

Jan 1, 1980

By J. B. Littlefield

[Ata. meeting of the Subcommi ttce on Chemical _ et.lOds of Air Ant:..1ysis of-the American Public Health Ascociation in October 1937, the llse of the impinger for collectinG lcs.d fu.l1e wa:., discussed. The Bureau of Mnes de-cided to obtain infornw.tion on the efficiency of the lerge and midget im-pingers for this purpose y using the electric recipitator as a reference method. &apos;I&apos;ests ~ ere made aJ,so to aScer ain the effici ency of the recently developed midget i;npi gerS..! for collac ing lead dust. For comparative pur-poses, samples collected by tte large impinger wore included.]

Jan 1, 1938

By David Schlain, C. B. Kenahan, F. X. McCawley

The electrodeposition of protective coatings of tungsten from a sodium and lithium borate - tungstate - tungstic oxide fused salt electrolyte was investigated . Soluble tungsten anodes were employed . Deposits were made on molybdenum , Carpenter 20 stainless steel , Inconel , and nickel . An atmosphere of argon was maintained around the electrolytic cell , and the electrolyte was stirred by rotating the cathode . Thick deposits of tungsten (up to 26 mils ) were made at a temperature of 900 ° C and cathode current densities of 0.3 to 0.4 ampere per square inch with high current efficiencies . The effects of variations in temperature , current density , electrolyte agitation , and tungstic oxide content of the electrolyte and of the presence of impurities such as moisture , air , iron , and nickel were investigated .

Jan 1, 1964

By A. R. Rule

A flotation process was developed by the Bureau of Mines for separation of carbonate and phosphate minerals occurring in unaltered phosphate ores of the Phosphoria formation. The process involves depression of phosphate minerals with fluosilicic acid and flotation of carbonate minerals with fatty acid emulsions. In individual laboratory tests, selective removal of carbonates was achieved with phosphate recoveries ranging from 60 to 80 pct P205. In continuous-circuit testing, sizing and separate treatment of coarse and fine fractions was necessary to achieve 65-pct P205 recovery. Concentrate grade ranged from 26 to 33 pct P205. The flotation tailings containing primarily carbonate and phosphate minerals is a potential fertilizer material. When reacted with H3P04, concentrated superphosphate containing approximately 40 pct available P205 was obtained.

Jan 1, 1974