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By Ralph D. Gift

This report describes a program of research to evaluate methanometry in coal mines. The program commenced by conducting an extensive state-of-the-art survey. Details of the survey are presented which includes a rating of various types of instruments that can be used to detect and record methane gas. Laboratory test data, on mine instruments tested are presented together with results from a computerized statistical analysts.

Jan 1, 1972

By William L. Crentz

Late in the nineteenth century en active coal-mining industry was begun in the Lower Freeport bed near Reynoldsville, Pa., where the bed thickened to more than 10 feet in places . The coal was readily accepted as an excellent steam fuel. Much of the thick coal his been depleted, but there are many areas where the deposit averages about 14 feet in thickness. As the more desirable mining sites were worked out in the Lower Freeport bed, other beds were exposed from which will come the county's major cowl production in future. The Lower Freeport bed is still the most important bed in Jefferson County from a production standpoint. The Lower Kittanning bed is second. Sporadic mining is being done in the Upper Freeport, Upper Kittanning, Middle Kittanning, Clarion, and Brookville beds. Strip mining has permitted recovery of much coal that could not be mined profitably by conventional underground methods.

Jan 1, 1953

By P. B. Lorenz

Wettability measurements and laboratory waterflood tests were compared under a wide variety of conditions. Experiments were conducted with synthetic and natural crude oils, treated and untreated outcrop and oilfield sandstone cores, and synthetic brines with and without caustic, detergent, or phosphate additives. Measurements were made on equilibrated and unequilibrated systems at 77° and 150° F. Wettability was evaluated by the Bureau of Mines method from capillary pressure curves determined with a centrifuge. The waterflood data were fitted by empirical curves; the parameters of the curves characterize primary and subordinate production and also give the ultimate oil recovery. Results showed that wettability measurements at 77° F were useful predictors of recovery efficiency in waterflood tests run at both temperatures. Oil recovery in the early stages of waterflooding increased with increasing water wettability; however, the ultimate recovery was highest at a slightly oil-wet condition. The oil displaced at highest speed in the centrifuge was correlated with ultimate recovery in waterflood tests. Chemical additives to the brine sometimes lowered wettability and also sometimes improved waterflood recovery, but wettability and recovery were not correlated with additives present. The effect of additives on recovery in waterflooding was best seen in water-oil ratio curves.

Jan 1, 1974

By Victor R. Spironello

The Bureau of Mines has studied slags associated with ferrous melting, to evaluate substitutes for the auxiliary flux mineral, fluorspar. A waste material recovered from alumina reduction cells, "used potlining," was tested in an 18-in-ID basic-lined cupola and in a 1/4-ton, pilot-scale, basic oxygen furnace (BOF). One potlining fraction, No. 1 cut, is a carbonaceous (graphitic) material and represents the bulk of the entire cell lining. The other fraction, No. 2 cut, is a refractory backup. These materials contain significant quantities of fluorine and other elements fn various compounds. The potlining fractions were blended in ratios believed representative of available materials. Both lump and pelletized forms provided extremely fluid slag. No adverse effects were found on furnace performance, chemistry or strength of the metals produced, or the environment. Fluorine recovery in the slag and fluorine losses to the scrubber water and solids were about the same as when fluorspar was used. There was apparently no lining loss from the cupola, but there was lining attack in the BOF. Since the fluidizing ability of potlining is due in part to sodium and other elements such as aluminum and silicon, less fluorine is needed in the slags when potlining is used.

Jan 1, 1983

Reduce accidents associated with handling of the electrical trailing cable and the water hose on mining equipment. Approach Two reels were mounted on a loading machine to store and release the lines as required during face operations. How It Works A hydraulic motor, which is actuated by a treadle valve in the operator's cab, controls the reel on which 50 feet of electrical power cable is stored. A spring motor resists unwinding of the other reel on which 50 feet of water hose is stored. Both reels are mounted on the right rear of the loading machine. See Figure 1. Following common mining practice, the cable and hose are anchored to fixed points at the first intersection outby the face. Tramming forward causes the cable and hose to be pulled from the reels. Depressing the treadle valve causes the electric cable reel to turn and wind-in any slack in the cable. The spring tension on the water hose reel automatically rewinds the water hose when the loader is trammed in reverse.

Jan 1, 1978

By J. Mitchell Linne

The principal mineral commodity in the Orleans Mountain RARE II area (No. 35019) is gold. Gravel deposits along the Salmon River contain placer gold. Lode gold with associated silver is contained in quartz veins. Many placer mining claims have been located within the study area in the Salmon River district. Four placer patents totalling 230 acres were issued for claims on the Salmon River between Lewis Creek and Forks of Salmon. On this same reach of river, adjoining and overlapping the study area boundary, approximately 3.3 million cu yd (2.5 million cu m) of gold bearing gravel with values ranging from $0.51 to nearly $5 per cu yd (50.66 to $6.50 per cu m) (gold valued at $400 per troy oz), are contained in three placers, the Bloomer, Pot Luck, and Horn (table 1). Within the study area boundary there are approximately 950,000 cu yd (726,000 cu m) of gold bearing gravel in these three placers. These three mines yielded nearly 12,000 oz (373,000 g) of gold and more than 300 oz (25,000 g) of silver between 1872 and 1913.

Jan 1, 1982

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 Francis X. Cannaday

Equipment and techniques were developed with Bureau of Mines facilities for measurement in the laboratory of sonic shear wave velocity in variously shaped rock specimens in a wide range of sizes. A variety of rock types was tested. The shear wave front is produced by electronically excited, piezo-electric ceramic) disk-shaped transducers. Transmitter and receiver are interchangeable. Special equipment components were Bureau produced; other components were commercially available. The equipment permits quick measurement of shear wave velocity on variously shaped specimens with a minimum of specimen preparation. The technique, under favorable conditions, allows for determination of the moment of arrival of the shear wave when it is superimposed on a weak longitudinal wave.

Jan 1, 1968

Provide the U.S. mining industry with technology for designing environmentally sound, low-cost in situ leach mining operations to produce copper from small, deep, and/or low-grade copper oxide deposits. Approach Investigate the feasibility of a new mining method--in situ leach mining-as an alternative to conventional mining for copper. Study fundamental leaching technology that will facilitate future commercial operations. Develop guidelines and procedures that will enable mine operators to design and evaluate in situ leach mining operations for any specific copper oxide deposit.

Jan 1, 1989

By Kent Volkmer, Mark Sanders, Gregory Krohn, Tyler Blake, Daniel Wick, Barry Beith

This report describes a study designed to evaluate a proposed modification in the cap lamp battery cord intented to reduce the incidence of snagging and catching of the cord. A three phase evaluation as performed comparing a prototype with the standard, currently available cord. First, a "pull test" equipment was run. The second evaluation was a body conformity study. The third evaluation involved subjects performing common tasks in a low seam coal mine simulator. The results of these evaluations clearly demonstrated significant safety advantages of incorporating coiled cord into the design of the cap cord. The coil cord presented less of a snagging hazard, allowed the wearer more time to respond to a snag, and transmitted lower levels of force to the helmet when snagged. The research team recommended that cap lamp cords be commercially developed which incorporate coiled cord at the battery and helmet.

Jan 1, 1980

By John Durkin

Information on vertical magnetic noise in the voice frequency band, both within and above coal mines, is needed for the evaluation of through-the-earth baseband electromagnetic communications at mines where horizontal loop antennas are used. This report discusses the theory of the source of electromagnetic noise, the propagation of this noise to an observation point above a mine, and its interaction with the local earth conductivity structure, which gives rise to vertical magnetic noise. The relationship of surface noise to underground noise is also discussed. Bureau of Mines investigators made surface and underground vertical magnetic noise measurements at a number of coal mines located through- out the United States. These data were modeled through regression analysis to characterize expected noise levels. The results are presented, including results in one-third octaves for use in evaluating the expected performance of through-the-earth communication systems by articulation-index studies.

By Albert L. Toenges, Henry E. Dekay, James N. Scudder

Support of the immediate roof in coal mines is essential for their safe operation, and timbers are the most common means of support. Their effectiveness depends upon their resistance to decay. The theory has been advanced by some mine operators that rock dust, which is applied to ccal-mine workings to prevent propagation of explosions, accelerates the decay of mine timbers. As the results of part 1 of this study were inconclusive, the study was continued. Its principal objectives are: 1. To determine the effect of rock dusting upon decay of mine timber. 2. To compare the extent of decay of timbers in two mines in which underground conditions are similar. 3. To determine the loss in strength of the timbers after exposure to mine atmosphere. The studies were carried on in the Crucible mine of the Crucible Fuel Co. where the first part of this study was made, and in the Isabella mine of the Weirton Coal Co. The mines are on the Monongehela River and are adjacent.

May 1, 1943

By Kenneth E. Hjelmstad

In situ leach mining operations often encounter difficulty maintaining adequate leach solution flow into the are formation. Swelling and dis-persion of clay particles in the formation are often responsible for this permeability loss. Permeability and leaching tests were done in the laboratory on clayey ores to evaluate a clay-stabilizing polymer's effectiveness in preventing these problems. Test results indicate that treating the ores with the stabilizer could maintain permeabilities two to five times greater than the long-term permeabilities present in untreated ores. Both alkaline (pH 8.5) and acidic (pH 2.0) leaches were used in the permeability-leaching tests. Since in situ leaching throughput rate is directly related to permeability, these results also indicate a potentially beneficial effect on operating parameters such as capacity and injection pressure. To determine the reasons for the success of the clay stabilizers, an investigation was conducted to cieter-mine the effect of the stabilizer on clay swelling and dispersion. Clay-swelling tests indicated that the clay stabilizer reduced clay swelling. Zeta potential measurements made on fine clay particles treated with the stabilizer were compared to measurements made on untreated particles and indicated that the stabilizer was electropositive and, therefore, could reduce the degree of negative charge on the particles and their tendency to disperse or migrate.

Jan 1, 1984

By Kung-Lee Wang

SUSTAINED growth characterized the U.S. economy in 1964. Many new peaks were achieved in production, sales, employment, employee earnings, and business profits. At the end of 1964, the economy had experienced 4 years of uninterrupted expansion, and the greatest net gains in output for all postwar cyclical advances had been registered. There were no indications of the various weaknesses which have previously characterized advanced stages of business expansion. Both gross national product (GNP) and national income were 6.7 percent higher than in 1963. In 1964 GNP totaled $628.7 billion, a gain of $39.2 billion over the 1963 figure. On an overall basis, prices rose 1.75 percent in 1964. The real volume of output of goods and services (GNP in constant dollars) increased by 5.0 percent ill 1964; this was more than the 3.8-percent gain in 1963 but less than the 6.6 percent gain in 1962. The 1964 output gain also exceeded the average 3.7 percent annual increase for the postwar period. Congress authorized a two-stage tax reduction designed to further stimulate economic growth and employment. The tax cut favorably affected the 1964 economy in the following ways: By helping to boost personal income, corporate profits, and industrial production; by accelerating the pace of consumer spending and business capital expansion; and by increasing employment, thereby reducing unemployment to 5 percent. Three major problems remained unsolved. These were unemployment of 3.7 million persons, poverty conditions among more

Jan 1, 1965

By N. S. Dalal, X. Shi, P. M. Gannett

"Chromates are known to induce tumors (1, 2), mutations (3), and DNA damage (4-6). However, the underlying biochemical mechanism(s) is (are) not fully understood (6). Recent studies have indicated that hydroxyl (·OH) radical may play an important role (7-11). The mechanistic studies of Cr(Vl)-related ·OH radical generation in biochemical systems have shown the reaction of a Cr(V) species with hydrogen peroxide (H20 2 } through a Fenton-like mechanism to be one of the important steps (9-11): Cr(V) + H20 2 - Cr(VI) + ·OH + OH-. (1)In biological systems the Cr(V) species are generated via the reduction of Cr(VI) by a variety of components, such as microsomes (12), mitochondria (13), mitochondrial electron transfer complexes (14), and at least three flavoenzymes (glutathione reductase (GSSG-R),3 lipoyl dehydrogenase, and ferredoxin-NADP+ oxidoreductase) (9, 15, 16). In the case of flavoenzymes, Cr(V) formation is accompanied by the reduction of molecular oxygen ( 0 2 ) to H20 2 • The Cr(V) species then reduces H20 2 to generate •OH radicals and Cr(VI) (16).To understarid the mechanism by which Cr(V}-generated ·OH radicals cause cytotoxicity, Aiyar et al. (8) investigated the reaction of Cr(VI) and H20 2 to generate ·OH radical and its reaction with 2'-deoxyguanine (dG) to form 8-hydroxy-2'-deoxyguanine (8-0HdG}:"

Mar 1, 1992

By L. C. IlsLey

One of the details which the engineers observe closely in conducting tests on explosion-proof type equipment at the Pittsburgh experiment Station of the Bureau of Mines is the construction of covers and their means of fastening. These covers are of particular concern from a safety standpoint, because they are very liable to be frequently disturbed for the purpose of making inspection or repairs to internal parts of motors, controllers, etc. When depended upon to permit frequent inspections it is desirable from a practical operating standpoint that the cover be easily and quickly removed and replaced. The position that been taken by the Bureau of Mines is that the questio of ease with which covers will permit inspection should be determined by the mamu- facturer and the user. If the scheme used requires considerable effort, as in the removal of several bolts, it has been assumed that the one going to all this trouble to get the covers off could be trusted to put the cover back in place properly, especially as the approval plate generally calls specific attention to this point. Where a cover is simply screwed in place, fastened by a single bolt, or secured by a hing in or other similar arrangement, the bureau has not been willing to assume that the, cover would in all cases be properly fastened and has required further security by means of a lock or seal. In the course of its investigations the bureau has had occasion to inspect and test five types of covers as follows: (1) Covers having two plane surfaces bolted together. (2) Covers having two plane surfaces held together by lugs, clamps, or other means besides bolts. (3) Covers which have screw thread and fit a similar thread in the compartment. (4). Covers having plane surfaces with the addition of a tongue-and-groove joint at about the center of the plane surface and in general secured by hinge pins or similar means of fastening. (5) Covers in the form of an annular ring accurately fitted to a motor shell which can be rotated around the shell, and thus make easy access to inspection openings in the shell and rotated back again to effectively seal these openings. Tests. have also been made of large bolted covers having a smaller and more accessible cover within the large one, which could be opened for inspection purposes.

May 1, 1930

By E. C. Perkins

As part of a program for developing methods of using domestic titanium deposits, the Bureau of Mines investigated methods for chlorinating titanium slags prepared from titaniferous minerals by electrosmelting. Titaniferous slags were made from ilmenites in the following deposits: Valley County, Idaho; Trail Ridge, Fla.; Aiken, S. C.; and Maclntyre, N. Y.; titaniferous magnetite from Iron Mountain, Wyo., were also evaluated. The tests were made in two chlorinators, a 4-inch and a 36-inch unit. Preliminary testing was done in a 40-millimeter bench-type unit. Chlorine gas was contacted with a loose mixture of titaniferous slag and carbon at a high temperature to form titanium tetrachloride. The moving-bed system used in this work involved a downward movement of feed countercurrent to the chlorine flow, and residues continuously removed from the bottom of the reactor. The performance characteristics of these slags depended on their composition, which varied widely according to the geographic source of the ore. The results showed that all but two of the slags could be chlorinated as effectively as rutile, converting 70 to 80 percent of the titanium to the tetra-, chloride. The two slags that proved difficult were made from New York ilmenite and Wyoming titaniferous magnetite. These slags contained enough magnesium to cause clinkering, which necessitated that the bed be prematurely withdrawn before more than 70 percent of it could react. The iron content of the slags did not interfere with operating the chlorinators. The data from the 4-inch and the 36-inch units were in agreement on the relative amenability of the slags to chlorination.

Jan 1, 1962

By R. P. Vinson, Abdurrahman Cetinbas, Joseph Cervik, M. G. Zabetakis

The effect of water infusion on the flow of methane and on the production of dust was investigated at an active face in the Pittsburgh coalbed. The average total flow of methane at the face decreased by approximately 79 percent, whereas the flow from the ribs increased about 24 percent after infusion. On the day after infusion, dust concentrations appear to have been reduced; however, the presence of large quantities of rock dust obscured the results on the following days.

Jan 1, 1972

By Linda L. Chasko, Charles P. Lazzara, Gary Braselton, Ronald S. Conti

Preparedness is an important element of any underground mine's strategic plan in dealing with an unexpected event, such as a fire. A fully implemented fire preparedness and response plan is essential in reducing the probability and seriousness of a mine fire. This report describes the development of an underground coal mine fire preparedness and response checklist (MFPRC). The checklist is a data collection instrument for profiling both the fire prevention and response capabilities of a mine site and usually requires 3 to 4 days to complete. The checklist encompasses conditions, procedures, and equipment that have frequently been identified as the primary or contributing causes of underground coal mine fires. At least 1 day is needed underground to evaluate the water system. This entails measurements of water flows and pressures at fire hydrants, and water throw distances of fire hose and nozzles at several locations (mains and branch lines). A few of the other topics that are discussed with mine personnel include detection and suppression systems, combustible materials, mine rescue and fire brigades, and firefighting equipment. The MFPRC was developed by the National Institute for Occupational Safety and Health (NIOSH),Pittsburgh Research Laboratory. Under a Cooperative Research and Development Agreement (CRADA) with Cyprus Amax, Twenty mile Coal Co. (Oak Creek, CO), the checklist was field tested and further refined. Additional field tests were conducted at several other operating coal mines.

Jan 1, 2000

By F. J. Palumbo

Effective recycling or disposal of flue dusts is a continuing problem for copper, brass, and bronze smelters. Over 300,000 short tons (st) of dust is generated annually by U.S. secondary copper, brass, and bronze smelters. The Bureau of Mines has developed an alkaline leach method for recovering metal values from copper converter flue dust containing zinc, tin, lead, and copper. The dust was leached with a hot solution of ammonium chloride and ammonium hydroxide to solubilize ZnO. All of the tin (as Sn02) and the metallic copper, lead, and zinc, as well as possible insoluble compounds of each, report to the residue. Dissolved copper and lead salts are removed from the leachate by cementation with granular zinc. Zinc oxide is precipitated by diluting the leachate with water. The tin-rich (9.8 pct) residue has a ready market. The cement product is recyclable to the smelting operation. The ZnO is at least 97 pct pure and has potential marketability.

Jan 1, 1985