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By Stephen C. Tadolini

The U.S. Bureau of Mines has developed ultrasonic measurement instrumentation capable of measuring strains and elongations on tensioned and untensioned mine roof bolting systems. This report evaluates the pulsed-phase-lock-loop and pulse-echo systems. The pulse-echo systems measure time of flight of a signal through the bolt. The ultrasonic instrument converts the measurement into elongations or stress. The most recent Bureau instrument development converts travel-time measurements directly into elongation, load, stress, and torque by simple data manipulation from the keyboard. Bolt preparation and instrument calibration are described in detail.

Jan 1, 1990

By Zabetakis M. G.

This Bureau of Mines report presents a brief summary of the explosion trends in United States coal mines for the past 160 years. These trends show that in spite of the overall improvements in mine safety, the number of fatalities from ignitions of methane has actually increased in recent years. Suggestions are made of procedures that can be utilized to reverse this trend.

Jan 1, 1973

By K. L. Paciorek

The primary objective of this final phase of Contract No. H0133004 was to provide a description of all experimental assemblies and procedures used throughout this project in such a detail as to permit duplication of the tests in any other laboratory. A further objective was to summarize and evaluate all results generated throughout the duration of this program and to tabulate all the materials and data in such a manner as to allow this report to be used as a reference index for specific compositions or groups of compositions regarding potential hazards arising from their use .in underground coal mining operations. The report also contains an updated survey of the literature on thermal oxidative degradation of compositions investigated under this contract.

Jan 1, 1978

By M. A. Schellhardt, E. J. Dewees, R. Vincent Smith

"INTRODUCTION Abnormal material requirements of the nation at war impose an intensive demand upon many irreplaceable natural resources. Natural-3as reserves) for example, are being subjected at the present time to extensive depletion by large-scale withdrawals of gas to supply unprecedented demands for fuel and raw materials for the synthesis of strategic products. Fluids produced from many so-called gas-condensate type reservoirs have become an important source of hydrocarbons vital to the war effort.Development of gas-condensate type reservoirs in Arkansas, Louisiana, and Texas in recent years created many problems not common to ordinary gas-producing operations. Early in the development of condensate-type gas fields, general practices were evolved and applied to insure efficient re¬covery of the hydrocarbons existing in the gas phase under initial reservoir pressures and temperatures, put often the practices were predicted mainlyregardingupon generalized theory regarding the behavior of the fluids and were not always the most efficient, because field and laboratory procedure for testing these hydrocarbons had not progressed as rapidly or as far as field development. Specific information regarding the composition and properties of fluids ultimately recoverable from many gas-condensate reservoirs, especially, is lacking."

Oct 1, 1944

By J. S. Kennedy, M. M. Fine

"INTRODUCTION Barite is one of the major industrial minerals whose production has increased considerably in the last 10 years. In 1935 domestic production of barite was 218,075 tons and. had increased by 1944 to 515,136 tons. 3/ Most of the primary uses for barite and barite products were developed before 1935, so the increase in barite production reflects the growth of industry in general rather than any recent developments in barite technology.The principal uses for ground and crushed barrite are as a weighting agent in heavy drilling fluids, as a filler in rubber and other materials, as a pigment and extender in paints, and as a flux in glass melt. In addition, a considerable' quantity of barite serves as the raw material for the manufacture of lithopone and barium chemicals.Specifications for barrite vary widely and depend primarily on the use to which the material is put. The primary requisites for barite used in heavy drilling muds -are that it have a minimum specific gravity of 4.2 and be very,low in soluble salts. A minimun barium sulfate content of 92 percent may be specified; but this is less important than the gravity. 4/ In addition before consumption the material must be ground to '92 percent minus 325-mesh. 5/ Lithopone and chemical manufacturers require a minimum of 94 Percent barium sulfate, a maximum of 1.0 percent iron oxide, and not more than a trace of fluorine. 6/ Barite used as fillers in light-colored products should be of fairly high grade, but the filler used in dark products may be considerably lower grade.Glass barite should contain a minimum of 96 percent barium sulfate, not more than 3 percent moisture, a maxium of 0.2 to 0.4 percent iron oxide, and not more than a trace of titanium oxide. Particle size is a matter of some importance in glass barite, also. 7/"

May 1, 1948

By R. G. Travis

1. Reserve estimates have been made for eight coal beds in Monongalia County, W. Va., but only the Pittsburgh, Sewickley, and Upper Freeport beds are important at this time. The Pittsburgh, Sewickley, Waynesburg, and Upper Freeport beds contain the largest recoverable reserves. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 3,526 million tons as of January 1, 1954. Of this total, 3,294 mil-lion tons is in beds 28 inches and more thick. Areas in each bed except the Pittsburgh were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

By R. E. Siemens

A process is being developed by the Bureau of Mines to selectively recover nickel and cobalt from low-grade domestic laterites. In laboratory evaluation of the process, the oxides in the laterite were selectively reduced with carbon monoxide at temperatures from 350° to 600° C. For material containing more than about 5 percent magnesia, pyrite additions or post-reduction heat treatments were necessary to achieve satisfactory nickel and cobalt extraction for this range of reduction temperatures. Multistage leaching of the reduced material at ambient temperature and pressure in the presence of oxygen, ammonium sulfate, and ammonium hydroxide extracted up to about 90 and 85 percent of the contained nickel and cobalt, respectively. The nickel was selectively recovered from the leach solution by solvent extraction and was then stripped from the loaded organic with dilute sulfuric acid to provide a nickel-rich electrolyte. Treatment of the raffinate with hydrogen sulfide resulted in the recovery of cobalt as a sulfide. The only contaminant in solution was magnesium which was removed by ion exchange or precipitation. In this process the energy requirements are relatively low and except for minor operation losses, only coke and oxygen are consumed.

Jan 1, 1975

By H. E. Dresch

This report summarizes the work accomplished under Bureau of Mines contract H0188068. The contract required design and construction of a high voltage (7.5 KV) explosion proof cable connector for use on underground coal mine drag cables. A connector was constructed with elastomeric phase insulators that provide insulation shielding throughout the connector length. Connector housing was made of flame resist-ant cast poly urethane with no exposed metal components. Electrical and mechanical testing of the completed coupler resulted in satisfactorily meeting most of the design testing requirements.

Jan 1, 1981

By Raymond B. Ladoo

"Domestic Situation:The greatly increased use of lithopone as a base for paints, particularly for interior use, has timulated the demand for barytes to such a degree that the supply cannot keep pace with the demand. Lithopone is an artificially prepared compound composed of about 70 per cent barium sulphate and 30 per cent zinc sulphide, precipitated together. Its most important use is in paint, but it is also used in oilcloth, linoleum, rubber goods, shade cloth, etc.Prior to the war large quantities of barytes were imported from Germany, but during the war imports were negligible, domestic production increased very greatly and is still increasing. Ground barytes as used in paints/ formerly regarded as an adulterant, but now it is generally recognized as a valuable paint constituent. Mile domestic sources have expanded rapidly they have not overtaken the demand and there is need for still greater expansion. Stocks are low, little is being sold on the open market, and prices are high. Since barytes is a gangue mineral associated with metallic ores now being mined in the west, it is suggested that more attention be given to its recovery as a by-product.The following tables compiled from reports of the U.S. Geological Survey and the Bureau of Foreign and Domestic Commerce, indicate the growth of domestic consumption."

Jan 1, 1920

By James F. Devine

The radial, vertical, and transverse components of particle velocity were recorded by Bureau of Mines investigators along gage arrays extending in one or two directions for 145 to 3,170 feet at five quarries. Of the 39 quarry blasts, 12 were instantaneous blasts, 5 were of the one hole per delay type, using millisecond delayed caps, and 22 were multiple hole per delay type employing millisecond delay detonating fuse connectors. Charge weight per hole ranged from 8 to 1,500 pounds, and the charge weight per delay interval, including the instantaneous blasts, ranged from 25 to 4,620 pounds.

Jan 1, 1966

By B. H. Caudle, A. D. PUCKETT

This paper summarizes precent knowledge of the ignition qualities of pure hydrocarbons likely to be present in modern Diesel engine fuels, as shown by an extensive search of the technical literature. The report also discusses the possible significance of cetane number and hydrocarbon struc- ture. Cetane or cetene numbers, and other physical properties, are tabu- lated for about 100 hydrocarbons, and a bibliography is appended. In recent years the Diesel engine has enjoyed increasing popularity due to its dependability, inherent characteristics of fuel economy, and the fact that it operates on a fuel that hitherto has been available in comparatively large quantities at a low price. These qualities have en- abled the compression-ignition engine to compete very favorably with other types of prime movers in many fields and have led to predictions of fur- ther rapid expansion in the application of Diesel power. In a survey of the field of all petroleum fuels for combustion engines, Holaday et al (9) have predicted that by 1948 railroads will be using 10 times as much Diesel fuel as was used in 1939 and that over-all consumption will have doubled that of 1939. Other estimates of the yearly demand for Diesel fuels five years hence vary from 2,6 to 5 times the amount used in 1944. Into this picture has come the question of whether the greatly in- creased production to meet this estimated demand is compatible with the maintenance and possible improvement in quality of fuels necessary to satisfy future engines. Unfortunately perhaps for the Diesel engine, factors other than those of simple arithmetical multiplication must be considered. For example, the consumption of oil in central heating plants doubled from 1935 to 1943, and a further increase of 57 percent of the 1943 demand is expected by 1950. Jet propulsion has been developed to the stage where it is entirely practical for military aircraft. Catalytic cracking plants, many of which were constructed to meet the war- time accelerated demand for high-octane gasoline, are taking their place in the refining industry. All these developments, as well as the Diesel engine, require material of approximately the same boiling range. Virgin gas oils make excellent burner fuels, perform most satisfactorily in the gas-turbine units for aircraft according to present information, and are at a premium as catalytic cracking stock.

Jul 1, 1948

By M. Paczkowski

The use of inert gas systems to extinguish mine fires has been the subject of research for some time in the United States. In some European countries, it is an established practice. Tests were conducted with the CMI Inert Gas System (CMI), which is being used by the Polish mining industry. This system utilizes a modified jet aircraft engine and afterburner as a compact source of combustion products with a very low (less than one percent) oxygen content. Water injected into the combustion products stream provides evaporative cooling and forms a mist with a high cooling capacity. The CMI system was used under controlled conditions to extinguish coal pile fires at the U. S. Bureau of Mines Experimental Mine in Bruceton, Pennsylvania. The test results show that the CMI system can be used conveniently to extinguish fires quickly and to maintain an inert atmosphere in the fire zone to prevent re-ignition.

Jan 1, 1982

By Margaret E. Harris

The formation of nitrogen oxides, the decay of carbon monoxide, and the concentrations of residual hydrocarbons in the secondary combustion zones of propane-air and methane-air flames were studied in three enclosed burners designed to simulate gas appliances such as space and water heaters. The effect of thermally or chemically perturbing the combustion gases above these flames was determined theoretically and by means of factorial experiments. The concentrations of air pollutants and the flame temperatures were measured, and the effects of ingress of secondary air into the primary and secondary combustion zones, flame stability, burner port surface, and simulated recycling of combustion gases were noted. Based on this study, four principles were derived that, applied to gas appliance design, will insure minimal emissions of these air pollutants: 1. Oxides of nitrogen can best be kept low by depressing peak temperatures to about 3,050° F. 2. If this is not possible, then the secondary combustion zone should be cooled rapidly to this temperature. 3. Carbon monoxide concentrations can be limited by rapid induction of secondary air. 4. Hydrocarbon concentrations can be controlled by designing for well-seated, stable flames. In addition, empirical reaction rates were derived that predict the concentrations of nitrogen oxides and carbon monoxide in the primary and secondary combustion zones.

Jan 1, 1970

By Willard J. Tesch

The borehole surveying system described is used to measure ground movement over and near operating mines. The magnitude of any movement is con-trolled by the ground conditions, the mining method, and the mine progress. By correlating these factors with the measured movement, equations can be determined for predicting the effect of mine progress on the surrounding ground. These equations can also be used to predict the effect of mining a similar deposit with similar ground conditions. The borehole surveying system is used in cased boreholes to measure the inclination of the hole in two perpendicular planes. Grooved casing with an inside diameter of 3 inches is grouted in the hole. Two probes are used to obtain the data necessary to calculate the hole position versus depth. One of the probes contains a gyroscope, and the other contains a biaxial force-balance [s]ervoaccelerometer. Readings from the transducers in the probe are punched on paper tape by an automatic data acquisition system as the probe is pulled up the hole at 30 feet per minute by an electric winch. Readings from the inclinometer probe containing the accelerometer are used as input data to an on-line programmable calculator as they are punched on tape. The calculator computes preliminary results of the survey being made. The paper tapes obtained during the survey runs are later used as input to a computer that computes the offsets of the drill hole versus depth in true north-south and east-west planes. These offsets are printed for each foot of depth. Changes in these offsets between the first survey and subsequent surveys are a measure of the horizontal ground movement between the surveys.

Jan 1, 1976

By Terry R. Neumann

During 1984, at the request of the U. S. Bureau of Land Management, U.S. Bureau of Mines personnel conducted a mineral survey of the 28,600-acre South Pahroc Range Wilderness Study Area (NV-050-0132). The Wit derness Study Area is located in Lincoln County, NV, about 900 miles north of Las Vegas. Five mineral properties and two mineralized zones were examined during this study; of these, one mineralized zone, two small prospect pits, and part of two claims are within Wilderness Study Area boundaries. Perlite resources were identified in the study area; however, no significant metallic mineral values were noted at any of the sites. The Wilderness Study Area is dominated by a Tertiary volcanic sequence consisting of an interlayered series of tuffs containing thin beds of volcanic pebble gravel, sandstone, and perlite. At the base of the exposed volcanic section, perlite occurs along a 2.4-mile-long zone that parallel s the study area's northeastern boundary. The perlite is suitable for filtration, insulation, and soil conditioning purposes, Because of prohibitive operation and transportation costs, the estimated 6 million tons of perlite occurring inside the South Pahroc Range Wilderness Study Area are classified as an indicated subeconomic resource.

Jan 1, 1986

By P. A. Bloom

Bureau of Mines research was conducted to develop effective separation methods that might be used in exploiting substantial tonnages of complex barite-fluorspar ores in Arizona. The exploitable reserves now may be increased as recent batch and continuous flotation tests demonstrated that a complex barite?-fluorspar ore from the Red Chief deposit, Yuma County, Ariz., could be selectively treated to concurrently produce (1) fluorspar and (2) a barite byproduct of marketable grade. The sample contained 24.8 percent CaF2 and 24.3 percent BaS04. Processing comprised production of a fluorspar product containing 97 percent CaF2 with an 82 percent recovery, using a sodium fluoride-lignin sulfonate-fatty acid reagent combination. Concurrent retreatment of the fluorspar tailing, using sodium cetyl sulfate as a collector, yielded a barite product of 94 percent BaS04 grade with a 71-percent recovery. The products met specifications for acid-grade fluorspar and drilling mud-type barite.

Jan 1, 1963

By D. Randolph Berry

This manual was prepared to provide essential information to be used when critical decisions pertaining to mine fire recovery or other disaster situations become necessary. It is a state of the art report based upon technology and instruments developed, under a Bureau of Mines Research Contract. A detailed description of the development work and results of full-scale field testing is contained in the Technical Report, Vol. II, of USBM Contract Report H0122045, "Extinguishing Coal Mine Fires by Remote Scaling." Further research and development work has been programmed; consequently, a more complete manual providing detailed instructions and describing available instruments and equipment will be published. Those instruments and special equipment described in this manual must be considered prototype; methodology and applied technology will require special expertise. Consequently, any prospective application of this remote sealing technique will require assistance by the United States Bureau of Mines Research organization and experts from the contractor who developed the basic technology and instruments.

Jan 1, 1973

By Arnold B. Hubbard

This report presents a hydrogenolysis study undertaken to obtain information on the constitution of the kerogen or organic material in Colorado oil shale and to determine some of the properties of the hydrogenolysis products. The high yield of hydrogenolysis products was separated, so far as possible, into type compounds; a number were identified. The results thus obtained were used as a basis for proposing the possible existence of certain structures in kerogen. To the authors' knowledge, few or no hydrogenolysis studies have been made of Colorado oil-shale kerogen by others. However, this method has been used in studying the constitution of coal. In general, the coal studies involved treating pulverized coal at different temperatures and hydrogen pressures with different catalysts. In some instances different solvents were used during the treatments.

Jan 1, 1959

By B. W. Gandrud

The upper part of the Alabama deposits of crystalline graphite consists of an oxidized ore derived from, the underlying unoxidized ore through prolonged weathering. The degree of oxidation in different sections and at different depths within the bed is nut. uniform. The original ore is hard and blue-gray; the weathered product is soft and brown and is the only part that has been mined to any extent. Samples of both oxidized and unoxidized ores were obtained from two of the large graphite deposits of Clay County. Three additional samples of oxidized ore were obtained from different portions of a third property in the same region. In this report, ores 1 to 5 are of oxidized material and ores 6 and 7 of unoxidized.

Jan 1, 1934

By J. L. Holman

The Bureau of Mines is conducting research to improve technology for the recovery of strategic and critical metals, such as cobalt, nickel, and chromium, that are lost in bulk and particulate superalloy-type scrap because it has not been possible to process mixed contaminated scrap efficiently. The research approach involves melting and casting mixed superalloy scrap into soluble anodes for electrodeposition of Ni-Co alloys by controlled-potential electrolysis. The initial experimental results described in this report are from electrolytic tests us-ing alloy anodes cast from elemental nickel, cobalt, and chromium, the main constituent metals of superalloys. Baseline data and operating parameters are necessary for Ni-Co and Ni-Co-Cr alloys before detailed experiments can be conducted on the more complex superalloy scrap. This basic research assessed the effects of cathode potential, S04:CI electrolyte ratio, electrolyte pH, stirring rate, deposition time, cathode current density, and chromium concentration on cathode current efficiency, alloy deposit composition, and deposition potential at a cell temperature of 55° C.

Jan 1, 1985