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In order to reduce waste and improve resource conservation, mine planning, and development, the U.S. Bureau of Mines is investigating the effects of multiple seam interactions associated with longwall coal mining. Field investigations were conducted at a mine located in Boone County, WV, where a longwall panel was operating subjacent to room-and-pillar workings in an overlying seam. To assess the effects of overlying workings on longwall headgate stability, the Bureau gathered various geotechnical information at this minesite. Headgate pillars and entries were instrumented and monitored to study their behavior during side-abutment loading as the longwall panel approached and passed beneath the overlying room-and-pillar developments. The two operations are separated by 800 ft of interburden, and although interactions between operations separated by this distance are uncommon, geomechanical measurements indicate the occurrence of an interaction. These measurements show that convergence on the headgate entries was most adverse subjacent to barrier pillars in the overlying mine. Pillar measurements indicate that side-abutment pressure increases were slightly greater than predicted values. Several factors related to both geology and mine design, believed responsible for this large interactive distance, are discussed.

Jan 1, 1990

"For a good many years the Bureau of Mines and various state mining experi¬ment stations have endeavored to develop some method of utilizing the immense deposits of lignite in the United States. Work in relent year has indicated that the best method of this is to drive off the moisture and most of the volatile water from the lignite in some form of carbonizing apparatus leaving a residue high in fixed carbon and low in moisture and volatile matter, which by briquetting can be made into a high-grade fuel. The earlier forms of carbonizing equipment tried were complicated, costly to build and keep in repair, and could not be operated intermittently without being seriously damaged. During the year 1922, however the Bureau of Mines devised a very simple carbonizing oven which produces a uniformly well carbonized product. This oven is essentially a vertical shaft with means for supplying raw lignite at the top and discharging the carbonized limited at the lower end. Air in regulated amount is admitted to the shaft at two horizons, and a zone of combustion maintained through which the column of lignite passes. The lignite is thus carbonized by construction of its contained matter and a small proportion of its fixed carbon, leaving most of the fixed carbon in the carbonized product or ""char"". The degree of carbonization can be closely controlled by varying the volume of air supplied to the oven and the rate of travel of the charre down the shaft.The ""lignite char"" produced is a soft material resembling charcoal more than coal or coke, but somewhat harder than charcoal. A typical analysis is shown in the table headed ""Fuels,"" further on in this papers."

Feb 1, 1924

By James M. Spear

The U.S. Bureau of Mines conducted a mineral survey of the Domeland Addition (5207) and Woodpecker (5206) RARE II areas during the summer of 1979. These study areas were examined to determine the presence or absence of mineral resources and reserves and where possible, to estimate values. The study areas are 9 air mi northeast of Kernville, California, and encompass 47,400 acres of primarily granitic rocks of the Sierra Nevada batholith with some scattered exposures of older metasedimentary, volcanic, and metavolcanic rocks. These other rock units partially surround the exposed batholith in the Domeland Wilderness and consist mostly of late Paleozoic quartzites, mica schists, marbles, and meta-volcanics, Mesozoic quartz diorite and gabbro intrusives, and local Tertiary basalt and andesite flows.

Jan 1, 1981

By Jr. Reistle

The tests reported in this paper were made in the East Texas field in the summer and fall of 1932 as a part of the Bureau of Mines study of the operation of flowing wells and reservoir performance; and to determine, if possible, the minimum reservoir pressure necessary to produce the wells in this field by natural flow through different sizes of flow strings. The minimum reservoir pressure that would be required to Maintain natural flow through 2 1/2-inch tubing was determined experimentally for the existing energy conditions in the East Texas field. With the present available data, however, it is impossible to predict accurately or to determine by calculation the necessary energy requirements for maintaining the vertical flow of oil and gas mixtures under all conditions. Although some valuable data were obtained which seem to have application to the solution of problems involving vertical flow, this important research of the petroleum industry is so involved that more study of the complicating factors influencing the flow of oil-gas mixtures through vertical pipes is required.

Jan 1, 1933

By L. A. Morley

This report summarizes the work performed on Bureau of Mines Contract J0199106, "Portable Trailing Cables, Splices, and Couplers - Design and Installation Considerations," from May 1, 1979 until December 31, 1981. Splice installations and considerations for the possible use of conductive-rubber shielding in low-voltage trailing cables as well as coupler installations in high-voltage cables were the principal tasks. Flammability measurements on cable components and general testing facilities for mine electrical equipment were secondary tasks. Theoretical and empirical data indicate that conductive rubber with high resistivity values is an unsatisfactory shield design for current-sensing fault detection. Elimination of partial discharge in coupler installations requires meticulous care.

Jan 1, 1982

By Harold L. Rhodes

The Bureau of Mines has developed a method for determining the H2S content in natural gas samples. A gas chromatograph with a flame photometric detector was used to analyze samples with H2S concentrations ranging from 5,000 ppm to a minimum detectable limit of 0.01 ppm. A mass spectrometer was used to analyze samples containing H2S in amounts greater than 5,000 ppm. Methods are presented for preparing containers for H2S samples and for preparing standards using partial pressure and weighed standard methods, Sample collection techniques are discussed, as are analytical results which illustrate the loss of H2S while in the sample container and provide a basis for evaluating containers used for sampling and standard preparation.

Jan 1, 1979

By Merle L. Bowser

The Bureau of Mines has developed a portable recording methanometer that utilizes the Bureau's methane sensor. The methanometer can operate continuously for at least 30 hours on small, sealed, rechargeable lead-acid batteries.

Jan 1, 1969

By David M. Gullikson

As part of its program of petroleum production research the Federal Bureau of Mines has long been engaged in the study and development of systems of analysis of oilfield waters (8, 12, 20, 21, 22, 27, 30).21 However, many of the early chemical procedures developed by the Bureau and widely adopted by the petroleum industry are time consuming, and some are unreliable for determining certain constituents found in California oilfield waters. Because of the need for more rapid and more accurate methods having greater sensitivity with low concentrations of some constituents, a study has been made by the Bureau's Petroleum Research Laboratory at San Francisco, in developing new techniques and modifying previously published techniques for analyzing oilfield waters by flame spectrophotometric, potentiometric, and colorimetric methods. Test solutions were synthesized for testing the suitability and accuracy of the procedures, and the effect of interfering ions. These solutions contained known quantities of characteristic constituents of oilfield waters including sodium, magnesium, potassium, calcium, lithium, strontium, barium, sulfate, chloride, bromide, iodide, carbonate, bicarbonate and borates in a wide range of concentrations. The compositions of these synthetic brines are listed in table 22. Many California oilfield waters contain salts of petroleum-derived organic acids and several synthetic oilfield waters also were prepared to which large quantities of naphthenates or salts of petroleum acids were added.

Jan 1, 1961

By Gerald T. Homce

A system capable of monitoring a mine electrical power system to detect incipient electrical component failure could significantly improve power system safety and availability. The U.S. Bureau of Mines funded a contract with The Pennsylvania State University (Penn State) to establish the theoretical and technical framework for such a system. This report briefly outlines the contract, reviewing related Bureau and Penn State work prior to its award, and describes support work carried out by the Bureau. The main focus of the report is on research efforts by Penn State and subsequent results. An existing algorithm for incipient-failure detection and classification was studied, and recommendations are made to improve its performance. In addition, mathematical models of cable-connected motor systems and deteriorating motors were developed and implemented on computers. These models and laboratory tests were used to study and document relationships between component deterioration and electrical terminal effects. The project was supported by the U.S. Navy and the nature of its interest in the application of failure prediction techniques is also included.

Jan 1, 1989

By Joan C. Biordi

A molecular beam-mass spectrometer-low pressure flat flame apparatus has been constructed for the purpose of examining the chemical microstructure of normal methane-oxygen-argon flames and those inhibited with Halon extinguishants. Details of construction and performance of this apparatus and of related flame temperature measurements are given. Particular attention is paid to the empirical characterization of the perturbation to the flame caused by the sampling probes. The composition profiles obtained for normal flames are compared to those of flames inhibited by CF3Br. In addition to the usual stable species (CH4, O2, CO, CO2, H2O, H2, and H2CO), the inhibitor, its products and intermediates associated with its reactions could be followed. In particular, hydrogen bromide, bromine atoms, hydrogen fluoride, and carbonyl fluoride were observed. The relatively rapid disappearance of inhibitor and early appearance of fluorinated reaction products suggest a short lifetime for the CF3 radical in this system. Observation of COF2 suggests that CF3Br is effective as an inhibitor, at least in part, by virtue of its interference with the oxygen containing species of the normal chain reaction. Profiles of the 17+ peak at low electron energy suggests that the hydroxyl radical may also be sampled, but the profiles obtained are not yet sufficiently accurate to determine the effect of inhibitor on this important flame radical.

Jan 1, 1973

By J. R. Long

The investigations described herein are concerned with a portion of a systematic research, by the Federal Bureau of Mines on ductile titanium. The Bureau's work on the metal has resulted in development of a semi commercial process for the preparation of titanium and has also made available significant information on the fabrication and physical properties of this new strong, light, corrosion-resistant metal. Considerable interest has been aroused by this work, and a number of other laboratories have begun similar investigations. However, the necessity for Consolidating titanium by normal powder metallurgy methods presents difficulties in producing commercial forms and shapes on a large scale. This investigation was therefore undertaken for the purpose of improving the technique for consolidation of titanium powder into solid nonporous metal.

Jan 1, 1949

This manual provides instructions for installling, operating, and maintaining protective canopies on the Joy Mfg. Co. cutter. These instructions are based upon two actual installations: one made in a mine and one in the factory. The parts list and engineering drawings for the protective canopies are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other cutters with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other cutters and can determine any necessary modifications if they are not.

Jan 1, 1973

By Loren R. Anderson

This Volume documents the use of the Cone Penetrometer data analysis computer programs VERT and HORZ. The programs are interactive in that they prompt the user for input data and allow correction and modification to be made. The programs read data from the results of cone penetrometer soundings and convert the data to values of tan ø. Mean, standard deviation, skew, kurtosis, linear trends and autocorralation are computed by the programs.

Jan 1, 1982

By D. H. Hileman

Economic investigations indicate that bituminous coal can be mined underground in the Uinta region and marketed at a cost competitive with that of other energy sources in the West. A selling price of $3.90 per ton of coal was calculated from a cost analysis of a projected coal mine in the Emery coal- field of Utah. Although mines in some of the coalfields have extremely difficult mining conditions and cannot compete in the energy market at this price level, at least two other coalfields in the Uinta region contain coal reserves that could be mined and sold at a price of approximately $3.90 per ton. Projections by power companies and other coal-consuming industries indicate a strong future market for the large coal reserves in the Uinta region.

Jan 1, 1970

By J. P. McGee

The Bureau of Mines is doing research and development work on a coal-fired gas turbine plant initially developed by the Locomotive Development Committee, (LDC) of Bituminous Coal Research, Inc. The Bureau is redesigning the turbine blading and some of the auxiliary equipment, and is reerecting, the plant at the Morgantown (W. Va.) Coal Research Center. The present goal is a 1,500-hour run at virtually the same operating conditions used by the LDC in their final 1,100-hour test with the turbine. This will allow the Bureau to properly evaluate the new blade design. Erosion of the turbine blades (particularly the roots) by ash in the hot gases from the combustion of coal was the most serious problem in extended operation in earlier experimental work. New blades made of Stellite6 are being fabricated for the stator and rotor, and armored wear strips of titanium carbide will be inserted in the blades at the areas of probable maximum ash velocity and concentration. The trailing edges of the rotor and stator blades are being thickened and thinned, respectively, to induce the ash to travel to the casing and prevent it from returning to the base of the rotor blades. The first stage rotor and second stage stator blades are being removed to provide an annular space for maximum quantities of coal ash to centrifuge to the casing. Additional blades will be added to most of the rows in the stator to stop secondary flow of dust-laden gas toward the rotor. A contract has been awarded for fabrication of the new blades. The 1,500-hour run will be started as soon as the new blades are installed.

Jan 1, 1962

By H. Tomlinson

Fatalities from falls of roof and coal are responsible for the death of more than 1,000 miners annually in the bituminous coal mines of the United States, or practically one-half of the total fatalities in and about these mines. The men are killed by falls singly or in small groups and little or no publicity is given these accidents as they lack the spectacular features of gas and dust explosions. As a result, the public and even the miners have the impression that accidents from falls of roof and coal are just one of the unavoidable hazards of the coal-mining industry. This belief is not true. Accidents caused by falls can be avoided largely by the application of sound engineering principles, by education, and by proper leadership in the industry, just as gas and dust explosions and accidents caused by explosives have been reduced in recent years.

Jan 1, 1933

By H. Tomlinson

Fatalities from falls of roof and coal are responsible for the death Of more than 1,000 miners annually in the bituminous coal mines of the United States, or practically one-half of the total fatalities In and about these mines. The men are killed by falls singly or in small groups and little or no publicity is given these accidents as they lack the spectacular features of gas and dust explosions. As a result, the public and even the miners have the impression that accidents from falls of roof and coal are just one of the unavoidable hazards of the coal-mining industry. This belief is not true. Accidents caused by falls can be avoided largely by the application of sound engineering principles, by education, and by proper leadership in the industry, just as gas and dust explosions and accidents caused by explosives have been reduced in recent years. The necessity for studying falls of roof and coal becomes apparent by referring to the following data from a table by Adams and Chenoweth:3

Jan 1, 1933

By S. A. Matthes

This Bureau of Mines report describes analysis of a copper slag for 13 elements from a single sample solution by flame atomic absorption spectroscopy. Samples are dissolved with 7 ml of an HC1-HF-HN03 (3:1.5:2) mixture in heated plastic pressure vessels. A 1.5-pct boric acid solution is added to dissolve precipitated fluorides and to reduce matrix effects that interfere with atomic absorption analysis. Preparation time is less than 1 hour per batch of 10 samples. Total analysis time is less than 6 person-hours for 130 determinations with an average relative standard deviation of 1.83 pct for the 13 elements. Simple acid standards were used for all determinations. Values obtained by this method are in excellent agreement with values obtained by slower, more costly procedures.

Jan 1, 1980

By C. W. Davis

There are four parts to this circular and, respectively, they list firms in the Eastern (pp. 5-8), Southern (pp. 9-10), Central (pp. 11-15) and Western (pp. 16-22) United States and Provinces of Canada. Before listing the laboratories and the work performed there, it is proper to make clear what is done and what is not done by Federal bureaus, States, and Territories, as well as by Canada and Mexico. FEDERAL Bureau of Mines. - The Bureau of Mines does not make assays, analyses, or tests for individuals or firms unless they be incidental to investiga¬tions that are of possible benefit to the entire mineral industry. All significant results obtained in this way are made public through published reports. Any mineral sample sent to this Bureau for simple identification will be subjected to a cursory examination.

Jan 1, 1938

By R. H. Sprute

The Bureau of Mines conducted a feasibility study and designed an operational system for consolidating waste coal sludge in a 110-acre pond by applying direct current between buried and floating electrodes. Consolidation would reduce the sludge to half its present volume, there-by extending the working life of the pond as well as creating a safe, stable impoundment. The project was conducted by the Bureau under an agreement with the Washington Irrigation and Development Co. (WIDCO), located near Centralia, WA. Part 1 of this report, published as Report of Investigation 8666 in 1982, covers the results of laboratory tests at the Bureau's Spokane Research Center and of a small-scale field test at WIDeO's coal preparation plant. Test results show the process is efficient and cost-effective when power is applied at low current density. Part 2 (this paper) describes a detailed design for an electrokinetic system to dewater WIDCO's 110-acre pond with a 27.4-acre electrode array. Densification of the inactive sludge pond will require 3.6 yr of treatment for a total cost of $1,450,000. The study and design are site specific, but design procedures and analyses are sufficiently detailed to serve as a guide for applying the process to any sludge pond.

Jan 1, 1988