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By Anthony Iannacchione, Christopher Mark

Residents of Maxwell Hill, a suburb of Beckley, West Virginia, reported from January until March of 1988 a series of earth tremors. The tremors rattled dishes, and the noises associated with tremors were sometimes loud enough to wake people at night. These events were puzzling because Beckley is in an area of low seismic activity. Maxwell Hill is located above abandoned coal mines, though no direct subsidence damage to surface structures has been documented. A research program was initiated to determine whether subsurface ground movements associated with the abandoned mines could be responsible for the seismic activity experienced at the surface. A hypothesis is proposed which states that seismic disturbances can be caused by abandoned mine failure when two conditions are met. First, some instability must exist at the mine level. The most likely cause of instability is the failure of pillars of coal that were left for support at the time of mining. Second, subsurface movements can result in significant seismic activity only when the rock above the mine contains at least one very strong and brittle layer that is prone to fail violently through rupture or fault slip movement. Analysis of the data indicates that both hypothesized conditions for mine-related seismicity appear to have been satisfied in the case of Maxwell Hill. It has therefore been concluded that the earth tremors experienced by Maxwell Hill residents probably are related to the abandoned mines. Analysis of the potential magnitude of these events indicates that they are unlikely to cause significant surface danlage. The probability that future events will disturb the residence of Maxwell Hill should be quite low based on the identified mechanism.

By D. E. Wolfson

As a part of its overall program of coal carbonization, the Bureau of Mines is studying the coking properties of coals that may be used for metallurgical purposes. The objectives of this study were given in detail in a previous report.2/ The inherent suitability of coal for metallurgical use depends primarily on (1) chemical composition, (2) preparation characteristics, and (3) carbonization behavior. The first two factors, as well as the available reserves, are considered in selecting coals for carbonization tests. According to the estimate of reserves by Dowd,3/ the recoverable coal in Floyd County in beds 28 inches or more thick, in thousand tons, is as follows: [ ]

Jan 1, 1958

By Roy F. Abernethy

All samples tested showed some loss of heating value for the 5-month period under all 4 storage conditions. The losses increased as the time of storage increased, with the pan-storage samples showing somewhat greater losses than those in cans. The individual daily analyses for the first 2 weeks and the analyses every other day for the third and fourth weeks of storage vary within the approximate tolerance of the test for heating value. During the first 2 months of storage the changes in heating values were not Significant for the samples from Pennsylvania, Indiana, and Colorado. The Ohio coal indicated some loss by the end of I month, which increased to a value measurable with certainty by the end of 2 months. These data show that (1) small changes may occur even to samples in closed cans and (2) the laboratory sample should be handled as expeditiously as is practical until the analysis is completed. The statement by the ASTM that "If the B.t.u. determination is an important consideration in the sale of coal, the time elapsed between sampling and analysis shall not exceed 30 days,"3/ is quite adequate for 3 of the 4 coals tested. The change in the Ohio coal stored for 30 days is merely indicated and could not be determined with certainty by the techniques normally employed. The data on free-swelling indexes determined on can samples, after 30° C. air drying, show that only the Indiana coal lost more than one unit in free-swelling index number in 120 days. No significant changes were observed with the samples from Pennsylvania, Ohio, and Colorado in the 5-month period.

Jan 1, 1958

By F. Matanzo

[Nine wire rope terminations were pull tested and fatigue tested to destruction to measure the termination efficiency and relative fatigue life. The terminations were selected on the basis off mine site visits and the specimen were assembled in a manner similar to industrial slings. To measure a termination's sensitivity to poor workmanship, both standard and modified assembly specimen were tested. Lang and Regular construction of the 6x19 and 6x37 class wire ropes were used in diameters of 13 mm (1/2 in.), 19 mm (3/4 in.), 25 mm (1 in.), 38 mm (1 1/2 in.), and 51 mm (2 in.). In static pull tests rope class, construction, and diameter interacted with the termination to influence the efficiency of the termination. In axial fatigue tests using only the 6x19 class rope, the effect of rope construction was negligible since failure was primarily dependent on the termination type. The Swaged Socket, a termination requiring a high capacity hydraulic press, gave the best overall performance in terms of efficiency and fatigue life. The short body length of the Zinc Poured Socket (RR-S-550) was attributed with the short fatigue life of this termination. The use of thermosetting resins as a replacement for zinc was demonstrated successfully for some socket designs. The fatigue life of the termination, expressed as a percentage of the fatigue life of the wire rope, was shown to be a guide for the retirement of the wire in these applications where the wiry' rope is primarily in axial loading.]

Jan 1, 1978

By J. C. Edwards

A series of four coal combustion experiments (I)' was conducted at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory in the Safety Research Coal Mine to evaluate the response of optical and ionization smoke and CO sensors to a small 0.61 m square smoldering coal fire which transitions to flaming combustion in the presence of diesel emissions. With the increased utilization of diesel engines in underground coal mines, it is important to be able to discriminate fire products-of-combustion (POC) from diesel emissions. One proposed method to accomplish this is the deployment and interpretation of multiple sensors.

Jan 1, 2010

By R. E. Heithecker

In Kansas, almost every oil well drilled into a limestone formation is treated with hydrochloric (muriatic) acid upon completion. This is done to increase the potential capacity of the well and thereby increase its "daily allowable" production (see p. 9), to shorten the time required to produce the recoverable oil, and to increase the quantity of oil recovered ultimately from the reservoir. The porosity and. permeability of limestone formations seldom are uniform throughout the proved area, consequently the production capacities of completed wells vary considerably. Acid treatment of wells tends to increase production capacity and to equalize potential capacity. If offset wells already have been treated with acid, new wells usually are treated to protect the property on which they are drilled against drainage. Even though competitive conditions do not exist in a field, it

Jan 1, 1939

By George S. Rice

"The emission of hydrocarbon gases from coal beds and contiguous strata causes many accidents in coal—mine workings, the number of fatalities so caused being second only to those due to falls of roof. Gases tend to increase in amount with depth of coal mining, hence the danger of explosion is increased with depth. The pressure of the gas in virgin—coal areas at a distance from mine workings likewise tends to increase with depth from the surface, probably due to corresponding increase in hydraulic head and possibly, when the gas is held in nonporous formations, to greater ground pressure. The rise in gas pressure with depth under usual conditions is shown in wells drilled from the surface and in some coal fields in drill holes into the face of workings; however, under normal conditions of coal formation gas does not issue into workings under high pressure because the coal and adjacent strata have many bedding and joint planes which allow the gas to escape freely at the face of the workings. The rare occurrence of instantaneous outbursts of gas, with violent effects referred to later, constitute the exception.Variations of volume and pressure of fire-damp or methane found in different coal beds by wells at a distance from mine workings, are analogous to variations in volume and pressure of natural gas found in different gas and oil sands, although in general the pressure tends to increase with the depth. Sometimes, however, in tight sands higher in the formation the pressure of gas therein is abnormally high, and on drilling the well deeper gas in the lower strata may be found at lower pressure."

Jun 1, 1934

By H. M. Cooper

Many analysts have had difficulty in obtaining accurate and consistent determinations of the volatile matter in low-temperature coke when the usual standard method for coal was followed. The tendency is toward too-high results, due to mechanical losses which are extremely difficult to avoid or control. With cokes there also may be an error due to excessive oxidation of the fixed carbon. Much of the earlier experimental work on the volatile-matter determination in coal, such as that of Parr,5 Fieldner and Davis,6 and others, 7 has been on the effect of time, temperatures, shape and size of crucibles, method of applying heat, and type of furnace, all of which data has evolved the present A.S. T. M.8 standard method for volatile matter in coal and coke. It is not the purpose of this investigation to deal directly with the above phases of the procedure, but rather to study some of the factors affecting she results in those types of fuel which give erroneous results due to mechanical losses.

Jan 1, 1932

By Laird Crocker

A goal of the Federal Bureau of Mines is to minimize the undersirable environmental conflicts and impacts associated with mineral processing operations. To help reach this goal the Bureau operated a citrate-process pilot plant for the removal of sulfur dioxide from lead smelter sintering machine waste gases to test the process. The process uses a carboxylate solution such as citric acid to absorb sulfur dioxide from waste gases. The absorbed sulfur dioxide is subsequently reacted with hydrogen sulfide to precipitate sulfur and regenerate the solution for recycle. Nominal capacity of the pilot plant was 1,000 scfm of 0.5 vol-pct sulfur dioxide gas. The pilot plant was operated for over 5,400 hr and produced about 55 net tons of sulfur. The operation demonstrated that (1) 99 pct of the sulfur dioxide could be removed from lead smelter sintering machining waste gases containing from 0.1 to 0.6 vol-pct sulfur dioxide, (2) sulfur precipitation and solution regeneration with hydrogen sulfide in conventional stirred vessels was readily controlled, (3) precipitated sulfur could be continuously recovered as a 99.S-pct-pure product by flotation and melting, and (4) 78 dry-vol-pct hydrogen sulfide gas could be produced from pilot-plant product sulfur, natural gas, and steam.

Jan 1, 1979

By M. M. Gilkey

Pegmatites in Colorado occur for 150 miles along the Front Range (eastern-most range of the Rocky Mountains) from Larimer County on the north to Canon City on the south, and west into the Gunnison area. Many of the deposits have been classified. Minerals found in the various dikes include beryl, scrap and possibly punch mica, lithium-bearing minerals, columbite-tantalite, feldspar, and several rare minerals. Pegmatites are abundant in the Crystal Mountain district in Larimer County. About 5 miles south of the Crystal Mountain district and often identified with that district is the Hyatt pegmatite area. The Hyatt Ranch deposit has attracted particular attention because of the comparatively high beryl con-tent of the upper part exposed in opencut workings.

Jan 1, 1960

By John A. Johnson

For the purpose of comparing the amounts of dust produced by various mining operations, samples of atmospheric dust were collected during a complete cycle of drilling, blasting and mucking at or near the face of the Bureau's Mount Weather testing adit while the efficiency of several types of stemming in metal-mine blasting was being investigated. ACKNOWLEDGMENTS All gas samples were analyzed in the laboratory of the Bureau of Mines Gas Section at Pittsburgh, Pa.

Jan 1, 1939

By James C. Barker

A uniquely mineralized area extends from northwestern Canada through Alaska into eastern Siberia. Some of the metals found there are relatively rare in the conterminous United Stales. Among these are cobalt, the platinum-group metals, and chromite. Geologic evidence suggests that cobalt and the platinum-group metals may be present in deposits that could constitute nationally important reserves. Chromite in potentially minable deposits is known, but it may be relatively less abundant. Limited reserves of these metals have been delineated, but most of the favorable terranes and reported occurrences throughout the vast expanse of Alaska remain unexplored. As part of the mineral studies mandated under the Alaska National Interest Lands Conservation Act, the Bureau of Mines' Alaska Field Operations Center and the Bureau's research centers at Albany, Oreg., and Reno, Nev., are cooperating in a long- range program to investigate occurrences and delineate reserves of cobalt, the platinum-group metals, and chromite in Alaska. Studies of other critical and strategic minerals will be phased in during succeeding years, as ongoing projects are completed. This first in a series of annual reports summarizes available information about deposits and past production of cobalt, the platinum-group metals, and chromite, and describes current and planned Bureau investigations of these minerals.

Jan 1, 1981

By Vance G. Leak

A technique for recovering copper and steel from metallic scrap has been developed by the Bureau of Mines based on preferential melting in molten salt baths at 1,150° to 1,250° C, The molten salt, preferably barium chloride or calcium chloride, both minimizes oxidation of the metals and promotes heat transfer. Cleanest separations (0.01 percent copper remaining in iron) have been achieved by pretreatment (dipping or spraying) with sodium sulphate or sodium silicate, which alters and coats the surface of the iron to inhibit the alloying or brazing with copper. An economic evaluation of the process was carried out on six combinations of sweating media and inhibiting reagents. On the basis of the postulated model, a cost of about $0.20 per pound of copper recovered has been determined for the sweating treatment operation.

Jan 1, 1973

By D. Harrington

This circular presents part I of a review of the literature on effects of breathing dusts, with special reference to silicosis, largely in the minim; and allied industries. The literature on this subject is so extensive that no attempt has been made to include all published material but only to assemble some of the more outstanding data on several aspects of the subject. Parts II and III will deal with prevention and treatment of dust diseases and some of the economic and legal aspects of dust diseases in industry, with special reference to mining. Dust diseases arc much before the public at present, and there is good reason to believe that the information on the subject available to the layman is extremely meager; even those rated as experts usually have a more or less theoretical conception of the diseases, their causation, remedies, and prevention, rather than actual experience with them. Until recently little attention has been given to prevention, and the usual attitude of the engineer, upon whom the main reliance for prevention ultimately must devolve, has been to let "sleeping dogs lie" or, more definitely, to "let well enough alone." However, the "laissez faire" attitude no longer is tenable, and in the past few years numerous conditions have caused those engaged in industry, including mining, to bring the subject before the public with a view to ascertaining the facts upon which to formulate remedial measures, primarily preventive.

Jan 1, 1935

By A. J. Williams, R. B. Corbett

"INTRODUCTION This investigation was undertaken to obtain information concerning the effects of boron in steel and its method of addition, so that boron, which is readily obtainable domestically, may be used to relieve the great demand for those scarce, strategic, alloying elements that hitherto have been considered necessary for the successful manufacture of quality steel.Previous Work Guillet 4/ seems to have been the first to predict that boron-bearing steel might have a possible industrial use when, in 1907, he published results of an investigation into the properties of steel containing 0.21 to 1.51 percent boron.Possibly Walter 2/ was the first to appreciate the fact that extremely small percentages of boron are effective in improving the properties of a steel. His patent, issued in 1924 claimed steels containing boron within the limits of 0.001 to 0.100 percent; furthermore, the specifications disclosed that boron increased the hardenability of steel and refined its grain structure. In 1937, Naton and Piwowarsky 6/ otherwise observed that boron increased the hardenablity of steel."

Jun 1, 1945

By R. S. Dean

In addition to the normal work and that pertaining to strategic minerals, the Metallurgical Division has been made responsible for carrying on major investigations in the development of processes' for the treatment of low-grade domestic manganese ores that heretofore have failed to yield products suitable for the preparation of ferromanganese, an alloy essential to every ton of steel produced. These investigations are particularly important at this time because of their part in tucking this country self-sufficient with regard to manganese when the stock-piled ore becomes e exhausted and as foreign shipments of ferro-grade ore are cut off. The results indicate that there is a good probability of accomplishing this objective, while at the same time conservation may be promoted through the use of normally useless material from the large, low-grade ore deposits.

Jan 1, 1941

By Maurice J. Peterson

The applications of optical spectrochemical methods of analysis for determining trace impurities in metals are described, and the need for developing analytical procedures capable of accurately determining fractional parts per million of impurity elements in metals is stressed. Factors which determine sensitivity of detection and means to extend sensitivity levels in spectrochemical methods are discussed. Examples from the current literature illustrate the diversity of spectrochemical techniques that have been applied to the analyses of varied sample types, Many of the methods use preconcentration procedures to increase sensitivity limits. A bibliography containing abstracts of recent methods in included. Optical spectrochemical analysis is based upon the measurement of radiant energy emitted by atoms of the elements to be determined when a sample is subjected to a suitable source of excitation. The behavior of the valence electrons during excitation, usually by an arc, spark, or flame, produces radiant energy of specific wavelengths. This is recorded as spectral line images on a photographic film or plate by the spectrograph; for direct-reading instruments, the spectral lines are detected with photomultiplier tubes. The spectral lines result from the excitation of atoms in the sample. Each variety of atom produces its own characteristic set of lines, thus serving to identify the elements in the sample. Increased concentrations of elements in the excited sample results in increased blackening of the spectral line images.

Jan 1, 1961

By H. S. Kennedy

THE HELIUM ACT (50 Stat. 885; 50 U. S. C. 161,163-166), as amended, places the responsibility for conserving, producing, and selling helium upon the Secretary of the Interior, acting through the Bureau of Mines-the only producer of helium in quantity in the world. It operates 4 plants-I each at Amarillo and Exell, Tex.; Otis, Kans.; and Navajo (Shiprock), N. Mex. The demand for helium has increased steadily since the decline immediately after World War II and is expected to exceed the capacity of the present plants in the near future. The Congress has appropriated $6,000,000 far constructing a new plant. In addition to providing additional capacity to meet increased demands for helium, the new plant will enable the Bureau of Mines to better conserve the helium in, the Government-owned reserves at Amarillo and Navajo.

Jan 1, 1958

By Noel N. Moebs

Bureau of Mines studies of mine roof fall problem in the Pocahontas No. 3 Coalbed of southern West Virgania and southwestern Virginia have established that type and sequence of rock are significant factors in roof competence. The poorest conditions occur where the immediate roof consists of slump structures and slickensided rock. The best conditions occur where the roof consists of a sequence that coarsens upward from shale to massive sandy shale. A small manual of color photographs of rock types was devised to aid in identifying drill cores. Proper identifications should enhance the prediction of areas of potential roof problems in advance of mining.

Jan 1, 1981

By Martin A. Elliott

Recommendations for safe practices in the operation of Diesel engines underground must take into consideration the hazards that might be created if the composition of the underground atmosphere differs from that of normal air. One aspect of this problem was discussed in the second report6/ of this series, which presented the results of tests in which a Diesel engine was operated with mixtures of normal air and exhaust gas supplied to the intake of the engine. Atmosphere .of this type were studied first because they will be present whenever the exhaust was is discharged into the atmosphere of underground workings in which an engine operates. Diesel engines in underground service may operate in another type of atmosphere, namely, one

Jan 1, 1941