Search Documents

By Parry. V. F.

"INTRODUCTION Coal is a compressed mass of heterogeneous, macerated, metamorphosed plant remains that have collected in the earth's crust. Probably no two beds of coal have identical properties, and different parts of the same bed may vary considerably when measured by some of the many empirical tests that have been developed to classify or differentiate the properties of coal. Because of this great variability in properties, the commercial processing of coal to produce coke and byproducts has developed largely as an art based on experience, rather than as a science. Much empirical chemical research, however, has been and is being conducted on coal carbonization, and this work is of practical value in obtaining larger yields of gas and byproducts and in the improvement of the physical properties of the coke.Both ultimate and proximate analyses have been used for correlating purposes. 3/ In the United States the proximate analysis is used for the classification of coal according to rank and grade. The proximate analysis can be employed usefully in the coal—carbonization industry because separation of the combustible matter of coal into volatile matter and fixed carbon is, in fact, a small carbonization test conducted on 1 gram of coal heated in a platinum crucible.Small—Scale Laboratory Coking Tests,Many empirical tests have been devised for determining the coking properties and measuring the yield and quality of gas and byproducts obtainable from various coals. These tests, made on samples ranging from 25 grams (about 1 ounce) to 5 kilograms (11 pounds), furnish information that is roughly proportional in practical value to the size of the sample carbonized. However, the cost of the carbonization test also increases with the amount of the sample, so that for preliminary surveys of a number of coals, samples of 25 to 1,000 grams usually are employed."

Dec 1, 1939

This is the sixth 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 Department of the Interior. The first report gave data on motor gasolines sold during the winter of 1935-36.3/ The present report covers 54 brands of gasoline represented by 1,480 samples plus those from the Pacific Coast, which were averaged by the Pacific Coast Technical Group before being submitted and are published exactly as they were submitted. In some areas reports were received from 8 to 10 companies on the same brands of gasoline, whereas in other areas only one company reported on a brand. Thus, it can be seen that some of the data are more representative than others. The inclusion of data from several cities within some of the districts has improved the report by reducing the number of brands reported by only one company. Several changes have been made in the districts. A new district, Memphis, Tenn., has been formed to include Arkansas and western Tennessee. The Rocky Mountain areas have been divided into three sections. Salt Lake City and Denver form the Middle Rocky Mountain district; Laramie, Wyo., Idaho, Montana, and Spokane, Wash., are included in the North Rocky Mountain district, and Arizona, New Mexico, and El Paso, Tex., have been combined to represent the South Rocky Mountain district. The Cleveland district has been expanded to include Ohio an,"- Indiana. Eastern Pennsylvania, Maryland, and northern Virginia are included in the Washington (D. C.) district. The Atlanta district includes Georgia, South Carolina; Mississippi, and northern Florida.

Jan 1, 1938

This Bureau of Mines report reviews the information presented at the Sixth Mineral Waste Utilization Symposium cosponsored by the Bureau of Mines, U.S. Department of the Interior, and the IIT Research Institute. Environmental scientists and engineers from nine countries participated in the symposium, which was held May 2-3, 1978, at the Chicago campus of IIT Research Institute. The 56 papers presented on the reclamation and recycling of mining and mineral wastes, municipal solid waste, industrial wastes, and scrap metal are summarized herein.

Jan 1, 1980

By D. J. Dollhopf

An overburden handling dragline operation was conducted at a strip mine near Colstrip, Montana. The objective of the demonstration was to determine the degree a dragline could mix overburden inhibitory zones during the spoiling process. In order to quantify the mixing process the overburden was: 1) scatter spoiled; 2) dump spoiled; and 3) spoiled in a normal manner. This demonstration was part of an effort to investigate means of reestablishing non-polluted hydrological systems in areas where surface mining directly impacts shallow ground-water resources. When inhibitory material constituted < 5% of the total overburden volume, such material was essentially not detectable in the resultant spoil pile. When inhibitory material exceeded 15% of the overburden volume it was always found in the resultant spoil pile, generally with a smaller extent, indicating partial dilution. Inhibitory overburden zones often reappeared at the base or top of spoil piles in the potential aquifer and root zones suggesting the need for selective placement procedures. Scatter spoiling did not appear to be significantly more effective than normal spoiling, however clump spoiling seemed to produce less mixing of inimical zones. Mining activity has reduced ground-water levels within 1600 m of the active pit. The aquifer which is developing in spoils appears to have similar confinement characteristics as those that existed in the premined aquifer. To date no definite trends have been observed concerning changes in surface or ground-water chemistry associated with mining.

Jan 1, 1978

By Galen G. Waddell

This report describes a method of measuring and analyzing the initial deformation which occurs in the medium surrounding a mine accessway as the opening is created. Discussed are (1) the hypothesis upon which the research is based; (2) the in situ rock-deformation measuring equipment developed; (3) the field tests, consisting of measuring the deformation of the medium around two 4-foot-diameter raise bores as the boring progressed; and (4) a finite-element technique to correlate theoretical with experimental results, using elastic theory. Described also are the raise-bore operation and performance. The instrumentation developed proved to have the sensitivity and resolution necessary to measure rock deformation around a full-scale raise bore during excavation. Tests show the relationships of rock deformation to progress of the raise boring and to time. The initial deformation of the opening appeared to be elastic. Using the deformation records and an estimated field stress, the modulus of elasticity was determined for the rock mass. In addition, the importance of this type of measurement in assessing support-problem areas is discussed.

Jan 1, 1971

By A. W. Hall

A nuclear method was developed for continuously and automatically deter-mining the moisture content of coal flowing through a bin. Fast neutrons from a 1 curie americium-beryllium source penetrate the coal, are thermalized (slowed down) by hydrogen in the moisture, and are counted by a thermal neutron detector. The difference between the number of these thermal neutrons and those thermalized by dry coal (in a reference drum) is a measure of the moisture content of the coal. A materials handling system was developed and in tests at a commercial coal preparation plant, moisture in coal was monitored continuously within 0.2 percent of values determined by conventional means. The meter responded rapidly to change in moisture content, making it adaptable to automatic process control, and was operated for 1 year without malfunction or recalibration. Shielding of the source by the coal kept the neutron flux level at the bin wall less than 1 milliroentgen per hour, a safe level for personnel.

Jan 1, 1973

By John C. Machisak

INJURY DATA and experience at coal mines in the United States for 1956 and 1956 are presented in this publication with a minimum of interpretation and comment because of the numerous tables required to afford detailed comparisons between the 2 years. Corresponding table., for 1955 and 1956 follow in consecutive order under the following general sections: (A) General injury experience: Tables I to II: contain current data on number of fatal and nonfatal injuries, frequency and severity rates, and average severity. (B) Selected injury data: Tables 12 to 77: Contain current data on causes of injuries, distribution of injuries by part of body injured, clays 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 78 to 87: Contain data on injuries, injury rates, employment, cause of injuries, aid severity rates by States. (D) Major disasters: Table 88: Contains data on major disasters, 1947 -56. A major disaster is defined as a single accident in which, or as the result of which, five or more persons are killed instantly or died at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 89 to 93: Contain data on fatalities and their causes at bituminous-coal and anthracite mines from the earliest records through 1956.

Jan 1, 1960

By Annie G. Smelley

As part of its program to develop technology that will encourage maximum utilization of the Nation&apos;s mineral resources, the Bureau of Mines conducted research on debrining potash-clay waste slurries by means of flocculation with a high-molecular-weight polymer and subsequent solid-liquid separation on a rotating trommel screen. In laboratory batch tests, potash-clay waste slurries were consolidated from initial clay contents of 8 pct to final contents of 30 pct with a polymer dosage of 1.2 Ib/ton of dry clay waste. Small-scale continuous tests yielded debrined products containing 20 pct solids using a polymer dosage of 1 Ib/ton of dry clay solids.

Jan 1, 1983

By Frank C. Townsend

Centrifugal model embankments with varying geometries and materials were constructed of- coal waste material, accelerated From 100 to 120 times earth&apos;s gravity, and subjected to various throughflow rates until failure occurred. Complementary laboratory tests were performed on the waste materials to obtain strength and permeability parameters for analytical calculations to predict observed centrifugal model behavior. Failures in the form of deep.-seated failure, or erosion and sediment transport or a combination of both, occurred in model embankments with 1V:1-1/2H and 1V:2H slopes when the phreatic surface due to seepage exited on the downstream slope: Positive seepage control, i.e., a toe drain successfully prevented sloughing and failures. Slope stability analyses agreed well, albeit conservatively, with observed model performance. Factors of safety ranged from 0.7 to 1.02 at the instant of failure for models with retrogressing slips as compared with 1.05 to 1.7 for stable embankments, These models verified existing criteria of a minimum safety factor of 1 3 and the necessity of positive seepage control.

Jan 1, 1980

By Steven R. Munts

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 39,420 acres of the 60,960-acre Skedaddle Wilderness Study Area in order to evaluate its identified mineral resources. There are no known mines or mining operations in the study area. None of the prospects or claims in or within a 1 mile peripheral zone around the study area have recorded production. At least 276 recorded lode, 6 unrecorded lode, and 29 placer claims have been located in and within about 1 mile of the study area. Approximately 191 of the claims are in the study area. Four of these were current in 1985; all four are wholly or partly inside the study area. None of the study area was being explored by private industry in 1985. Metallic and nonmetallic commodities present in the study area consist of gold, mercury, perlite, basalt, pozzolan, stone, and sand and gravel. Perlite is represented by a single deposit which contains 184,000 tons of subeconomic resources in and adjacent to the study area. No other sites contained identified resources. There are no other identified nonmetallic resources in the study area. Occurrences in and near the study area contain small amounts of gold and mercury in vein-type deposits and show characteristics similar to bulk-tonnage, low-grade gold deposits. No base-metal resources were identified. The gold and mercury mineralization and perlite deposit are spatially related to a volcanic center located in the Skedaddle Mountains. Prospects in the Skedaddle Mountains may contain both precious metals and perlite resources, but additional work is required to adequately delineate these areas.

Jan 1, 1987

By Michael J. Sapko, William D. Monaghan, Michael A. Trevits

Mine seals are used extensively in underground coal mines to segregate mined-out areas and to isolate fire zones or underground areas that are susceptible to spontaneous combustion. Over the years, 30,000 mine seals have been erected in underground coal mines in the United States. Mine seals, along with rock dusting and ventilation, represent the fundamental means of preventing underground coal mine explosions. In this study the National Institute for Occupational Safety and Health (NIOSH) used ground penetrating radar (GPR) technology to determine if each of three test mine seals were uniformly constructed. Three mine seals representing different construction methods and materials (cast-in-place foamed cement; solid block, polyurethane foam and gravel; and wire mesh, rebar and gunite) were erected at the NIOSH Lake Lynn Laboratory’s underground mine as part of an on-going research program. The seals were imaged using GPR with 400-, 500-, 900-, and 1,000-MHz antennas. We found that variations in uniformity existed in the material for the cast-in-place foamed cement seal. Variations in uniformity also existed in the seal made from solid block, polyurethane foam and gravel. The post-processed radar records correlated closely with recovered core samples (areas of gravel and polyurethane foam, and areas containing only polyurethane foam). Finally, the radar records of the seal made of wire mesh, rebar and gunite showed the various components. The results of this work suggest that GPR could be used as a tool to evaluate mine seal characteristics and construction uniformity.

By Charles E. Whieldon

Data on the oilfields in Mahoning, Columbiana, Carroll, Jefferson, and Harrison Counties, Ohio, were collected from scattered sources and compiled to make the information readily available to operators who may be interested in conducting secondary-recovery operations in the area. General geology, oil production, oil-productive acreage, core data, reservoir calculations by townships, and miscellaneous data and reference material are presented.

Jan 1, 1965

By R. L. Rough

Photoelastic, wire resistance, and borehole-deformation gages were used to measure the in situ strains when an outcropping Black Hand Sandstone Formation in Hocking State Forest, Hocking County, Ohio, was overcored to stress-relieve the surrounding sandstone. Strains transmitted to the photo-elastic gage did not produce isochromatic patterns suitable for quantitative analysis. Strain readings from the wire resistance gage indicated tensile-strain loading during overcoring; readings from the strain-gage bridges in the borehole-deformation gage indicated compressive-strain relaxation during overcoring. The magnitude and orientation of the computed stress fields obtained from both gages were comparable when the corresponding tensile and compressive elastic moduli were applied. Stresses computed from deformation and resistance gages at depths to 5 feet showed the maximum stresses to range from 1.042 to 2.121 times greater than the minimum stresses. The bearings of principal stresses calculated from the deformation gage readings varied between N 61° E and N 83° E; the wire resistance strain gage bearing computations varied between N 68° E and N 82° E. Measurements of in situ strain in sandstone were shown to have promise but to require further development in field technique that could likely be achieved through experience.

Jan 1, 1971

By Donna L. Anderson

This U.S. Bureau of Mines report describes a system to determine the position and heading of a continuous mining machine during the maneuvers required at the face area of a mine. The system consists of commercially available angular position sensors and a computer interface developed and tested at the Bureau. The sensors employed are laser-based scanning devices that report the angular location of retroreflective targets within their 90° field-of-view. The targets are mounted on the continuous mining machine; the laser scanners are mounted on an external reference structure. The computer interface consists of a single-board computer-controller programmed to gather and process the angular position information, and to calculate the machine&apos;s position and heading relative to the reference structure. A sensor fusion algorithm will be incorporated into the computer interface programming to increase the accuracy and reliability of the system.

Jan 1, 1989

By Paul L. Campbell

Investigations by the Federal Bureau of Mines of methods of upgrading tar obtained by low-temperature carbonization of lignite showed that ß,ß?-oxydipropionitrile, ß,ß?-iminodipropionitrile, and ß,ß&apos;-thiodipropionitrile were effective solvents for extracting aromatics (aromatic hydrocarbons plus polar compounds) from coal-tar neutral distillate fractions. Batch extraction showed that these solvents extracted approximately the same percentage of aromatics from various neutral oil fractions boiling between approximately 170° and 350° C. In continuous countercurrent extractions using oxydipropionitrile and iminodipropionitrile, approximately 30 to 35 vol.-pct, and 65 to 70 vol.-pct, of the aromatics in 170° to 350° C. neutral distillate oil were extracted at room temperature when solvent-to-oil ratios were 2:1 and 12:1, respectively. As the concentration of aromatics in the neutral distillate oil fraction decreased, the capacities and, to some extent, the selectivities of these solvents for the remaining aromatics decreased. Aromatics were isolated from the extracts and the solvents recovered by washing the extract fractions with a low-boiling paraffinic hydrocarbon such as heptane, using hydrocarbon-to-extract ratios of at least 2:1. The heptane wash removed most of the aromatics but only part of the polar compounds (compounds containing oxygen, sulfur, and nitrogen) from the extracts. The recovered oxydipropionitrile and iminodipropionitrile, containing polar compounds, were effective in extracting aromatics from neutral distillate oils. The contaminated solvents showed essentially the same capacities and selectivities as the pure solvents.

Jan 1, 1961

By F. J. Perzak

The Bureau of Mines conducted a flammability study of plastic ventilation ducts. Six rigid 16-in-diam fiberglass-reinforced plastic ducts from five manufacturers were examined using laboratory-scale, large-scale, and full-scale fire tests. The laboratory-scale tests included the American Society for Testing and Materials E162 radiant panel test, the E2863 oxygen index test, and the standardized small-scale flammability test (S3FT) developed by the Mine Safety and Health Administration (MSHA), U.S. Department of Labor, and replicated by the Bureau of Mines. Ten-foot lengths of the same ducts were also subjected to a large-scale vertical fire test, and 20-to 30-ft lengths were tested in a full-scale in-mine fire test at the Bureau&apos;s Lake Lynn Laboratory mine. The data from the laboratory-scale radiant panel test and oxygen index test indicated that the ducts were fire-resistant, However, five of the six ducts failed the S3FT and vertical fire tests, and four of the ducts failed the full-scale in-mine tests with flame propagation rates that ranged from 3 to 10 ft/min. The results indicate the need for improved fire-resistant plastic ducts. The good agreement between the S3FT re-sults and the vertical and full-scale tests show that the S3FT provides a good indication of the flammability of fiberglass-reinforced plastic ducting under realistic fire conditions.

Jan 1, 1987

By Raja V. Ramani

The potential usefulnuss of reclaimed surface-mined land has received much attention in recent times. This attention is partially due to the establishment of federal environmental reclamation standards but concern for achieving better land uses has also been shown by interested members of the mining industry. In an effort to develop a procedure for evaluating postmining land use potentials, specific mines in various regions of the U. S. were studied to determine the extent of current mined-land planning and to discover characteristics that are regional in nature. As part of this investigation, a 430-acre surface mine in Clear-field County, Pennsylvania has been studied. Established site planning principles have been applied to the case study site including formation of a data base, development of alternate land use plans, and evaluation of the economic, environmental, and social impacts of the land use alternatives. Key factors affecting site realization have been identified along with positive suggestions for applying land use planning processes to mined-land planning.

Jan 1, 1983

The general nature of the special constructional features that are required to provide safety from explosion hazards on machines approved as permissible by the Bureau of Mines is fairly well known to mining men who are at all interested in safety. These requirements are outlined in the schedules, under the provisions of which the investigations of such machines are conducted. Also, the method of conducting inspections and. tests of such machines has been described in Bureau of Mines Bulletin 305, Inspection and Testing of Mine Type Electrical Equipment for Permissibility, published in 1929. A more detailed knowledge of the special safety features of a particular machine is often useful and sometimes essential for inspectors, safety engineers, maintenance men, and engineers in selecting machines for a particular application. Three bulletins that give information of this nature have been published by the bureau, viz., Bulletin 313, Permissible Storage-Battery Locomotives and Power Trucks. Bulletin 343, Permissible Coal-Handling Equipment. Bulletin 382, Permissible Coal-Cutting Equipment.

Jan 1, 1937

A preliminary program dated April 25, 1974 was prepared for Development Engineering, Inc. (D.E.I.) on research and development, laboratory; field and other engineering studies for the disposal of retorted oil shale. This program was revised and published as a final document dated December 17, 1974. The document included a discussion on the peculiarity of retorted shale materials to be investigated and a discussion of the various laboratory and field tests which would need to be conducted to define their physical and chemical properties. The proposed research and development program was divided into eight work phases as follows: I - Program Development II - Exploratory Laboratory tests on old U.S.B.M., retored shale III - Laboratory tests on Pilot Plant retorted shale IV - Laboratory tests on retorted shale from Semi-Works Plant, and field and test plots and ponds. V - Field compaction tests

Jan 1, 1975

By William R. Hardwick

Present information indicates that a copper deposit can be safely fractured with a nuclear explosive and the copper successfully recovered by the in-situ leaching method. The process is not yet at the stage where it can be presented t ) the mining industry as a technique proven in all its aspects, but it is a method with high success potential. Unknown factors must be evaluated by a full-scale test before the economics or the extent of the use of the method by the mining industry can be predicted. Preliminary calculations indicate that the cost of fracturing a copper deposit nuclear explosives may range from l.8 to 55.2 cents per ton or in some case: less than a cent per pound of recoverable copper. Copper may be recovered at less cost than by conventional methods. Deposits with 4 pounds of recoverable copper may be economic and production from a deposit may begin in less than half the time required for conventional methods.

Jan 1, 1967