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By William P. Diamond

In this U.S. Bureau of Mines study, production trends have been analyzed for 82 gob gas ventholes on 7 longwall panels in the Lower Kittanning Coalbed, Pennsylvania. Cumulative production from individual holes was found to vary considerably, ranging from 0.03 x 106 to 10.1 x 106 m3. Peak production rates were generally about 0.03 x 106 to 0.06 x 106 m3/d, but rates over 0.10 x 106 m3/d were observed. The variability of gas production from individual holes can be attributed to' several factors, including completion practices and problems, the extent of fracture development in the strata above the extracted panel, water production, and location on the panel. Of particular significance is hole location. Holes on the ends of the panels, where overburden strata are in tension because of the support of the surrounding pillars, were generally the highest and longest producers. This observation led to the experimental placement of gob gas ventholes in the zone of tension along the margin of a panel, instead of in the traditional centerline location, which is in compression. Analysis of 7 months of gas production data indicates that the experimental near-margin holes produced 77 pct more gas than did centerline holes on the same panel.

Jan 1, 2010

By W. W. Odell

"It has long been recognized that coke is a more desirable fuel than bituminous coal in water-gas apparatus of present design, but still considerable headway has been made in the use of the latter fuel as a substiaute for coke. This is particularly true in the Central States where the supply of high-grade coke has been very limited and uncertain during the past few years, and where coking coals of low sulphur content were available in quan¬tities. In fact, with, the present difference in price of coal and coke, it is possible to realize a marked saving when using a coking bituminous coal as generator fuel.Difficulties have been encountered in the use of such fuel, but they have, to a large extent, been overcome. One of the chief obstacles in the use of the more general utilization of bituminous coal for water-gas manufacture, is the fact that, with normal operation, the capacity per unit of time is reduced. This of course is a serious problem for plants operat¬ing at capacity with coke fuel. However, this difficulty can, to a large extent, be remedied by a changed method of operating, and can be entirely remedied by a combination of the latter with a change in the design (or proportions) of a water-gas set. The preceding statement, the reader will understand, refers more particularly to a carburetted water-gas set.In the manufacture of water gas from coke, present practice requires that for continuous 24-hour service the heat of combustion of all the carbon monoxide (CO) generated during the air blow be utilized in addition to the sensible heat of the gas coming from the generator. This is doubly true when making carburetted water gas from bituminous coking coal. The reasons why this is so are apparent when the following factors are considered."

Nov 1, 1920

This summary of State laws on explosives was compiled primarily to ascertain what subjects relating to their control have been acted upon by each State legislature and, in general, how they have been treated. It does not include any legislation passed after 1942, or any proclamations, regulations, or administrative orders. It does not purport or attempt to be authoritative. If any problem arises involving interpretation of the statutes of any particular State, the original source must be consulted for the exact words used by the legislature. This summary, however, will be useful in determining whether relevant statutes exist, and in locating them quickly with a minimum of effort. It will be of value also in comparing statutes in one State with similar statutes in other States to determine what construction has been placed upon them by the courts of these jurisdictions or to contrast the varying provisions of many States upon a similar subject. To make these comparisons easier, the statutory provisions for each State have been grouped under several major topics in outline form. Although this sometimes has resulted in disruption of the continuity of individual acts, the increased general clarity and availability of comparable sections have more than justified the procedure followed.

Jan 1, 1943

As part of its regular program to provide timely information on domestic mineral commodities, the Bureau of Mines conducted an engineering appraisal of more than 1,300 lode and placer gold deposits in the United States to deter-mine their gold production potential. While these deposits were estimated to contain over 400 million ounces of gold, only 9 million ounces, or slightly more than 2 percent, was found to be producible at $35 per ounce under prevailing mining and metallurgical technologies. The study revealed that any significant increase in available gold in the United States is most likely to come from the discovery of new sources, intensive exploration and development of the more promising known mineralized areas, and development of new or improved mining and metallurgical techniques.

Jan 1, 1967

By B. J. Dalton

The Bureau of Mines Helium Research Center has as a long-range objective the development of an equation of state for helium that will allow all of the thermodynamic properties to be calculated within the accuracy with which they are known. If this objective is to be realized, a method of calculation must be known. This report gives the principles of the method we use in such problems. A computer program was developed for predicting these properties, including those at the critical point, that is perfectly general and applicable to any equation of state. To demonstrate the efficacy of our method, this computer program was used to evaluate thermodynamic properties of a Redlich-Kwong fluid in the two-phase region. Expressions for calculating various thermodynamic functions specific for this particular equation of state are derived. Numerical values are tabulated and graphs are presented for all functions calculated. It is shown that for a Redlich-Kwong fluid there are finite discontinuities in (1) the second temperature derivative of the Gibbs free energy or chemical potential at the critical point, (2) the second derivative of the vapor pressure curve with regard to the temperature on passing through the critical point, and (3) the measured heat capacity at constant volume on passing through the critical temperature when the calorimeter is filled to the critical density. It is also shown that the heat of vaporization is infinite for a Redlich-Kwong fluid at absolute zero.

Jan 1, 1969

By Lex B. Golden

The purpose of this investigation was to evaluate the corrosion properties of certain alloys of titanium and to compare them with those of unalloyed titanium. Such information should make it possible to determine the desirability of substituting these alloys for commercially pure titanium in certain applications. Titanium-manganese, titanium-chromium-iron, and titanium-vanadium-iron alloys, with 2 types of unalloyed titanium, I consolidated by arc melting and the other by powder-metallurgy techniques, were included in the study. Tests were carried out in sulfuric, hydrochloric, phosphoric, nitric, and mixed acids and in chloride solutions. All solutions were saturated with air.

Jan 1, 1957

By James H. Russell

The Bureau of Mines, U.S. Department of the Interior, in cooperation with the Department of Energy, has attempted to increase the activity of nickel catalysts for converting synthesis gas, derived from coal, to a substitute natural gas. This report describes the effects of low-level additions of B, Ca, Ce, Co, Mn, Mo, Pd, Re, Ti, Y, Zn, and Zr on the methanation activity of Raney nickel. The methanation rate at 320° C and the resistance to poisoning by 2 ppm H2S were used to compare catalysts. The effects of the additions were small, and the experimental variances were large, necessitating the use of statistical methods to identify significant effects. Co, Ti, Y, and Zn improved the resistance to H2S poisoning, but only Co improved the methanation rate In some individual catalysts containing Ca, Mo, or Mn, both the methanation rate and resistance to H2S poisoning were improved.

Jan 1, 1980

By Walter W. Kaufman

This report summarizes a study conducted to determine the state of the art of various rock removal systems and their capabilities. The Objective of the study was to determine if currently manufactured equipment can adequately accomplish rock removal in surface mine reclamation applications. Evaluations of state reclamation regulations, with regard to topsoil rock content, were made to determine the rock removal requirements. The major categories of equipment studied are rock pickers and rock rakes. The impact of rock removal implementation on the reclamation operations is discussed in detail.

Jan 1, 1979

By R. K. Koch

The Bureau of Mines developed a zircon sand molding process for static casting of small titanium or zirconium shapes. Castings with unfinished weights up to 3.5 kg (7.7 lb) were produced in an inductoslag furnace and castings up to 7 kg (15.4 lb) were poured in a consumable electrode skull-casting furnace. Molds and cores were made by ram-molding, foundry-grade zircon sand (AFS gfn 93 to 95) bonded by grade D waterglass and tempered with water. Molds and cores were cured either at 250° C (482° F) or 900° C (1,652° F). Castings from the higher temperature molds broke cleanly from the sand while the lower temperature molds produced castings that had to be cleaned by sand-blasting. However, low-temperature cured molds and cores have a number of advantages as follows: (1) A faster, less energy-consuming curing cycle is used; (2) expended cores are water soluble which greatly facilitates core removal; and (3) enough of the binder in crushed expended molds is reactivated by temper water so that the molding mix can be reused five times without any fresh binder additions and up to twenty times without exceeding a total cumulative binder addition of 52 ml/kg dry sand. Crushed used molds that had been cured at 900° C had no detectable binding strength when mixed only with temper water. A large number of oxide and silicate mold washes were studied for improved casting integrity. The most effective wash found for zirconium or titanium casting was monoclinic zirconia (325 mesh).

Jan 1, 1977

By Charles B. Kenahan

The chemical and galvanic corrosion properties of commercially pure titanium, a titanium-manganese alloy, a titanium-aluminum-tin alloy, 2 titanium-copper alloys, and 2 titanium-aluminum alloys were studied. Tests were conducted in synthetic ocean water, tapwater, 1-percent sodium hydroxide, 5-percent ferric chloride, and 5-percent ammonium sulfate solutions, various concentrations of sulfuric and hydro-chloric acids, and 1-percent oxalic acid. All tests were carried out at 35° or 60° C., with a flow of air or helium. Dissimilar metals involved in galvanic-couples experiments were aluminum, magnesium, and stainless steel. Electrode-potential measurements on single (uncoupled) specimens were also measured. Commercially pure titanium and the titanium-base alloys were generally quite similar in their resistance to corrosion, whether alone or in. contact with a dissimilar metal. Contact with the titanium metals caused aluminum and magnesium to corrode by galvanic action. Coupling with stainless steel in sulfuric acid solutions decreased the normal corrosion rate of the titanium metals. Contact with aluminum in air-aerated oxalic acid and 0.1N sulfuric acid solutions resulted in cathodic corrosion of titanium and the titanium-base alloys; however, there were a few exceptions. The copper alloys showed better corrosion characteristics than titanium in certain sulfuric acid solutions but were more susceptible to chemical attack in some hydrochloric acid solutions.

Jan 1, 1958

By McElroy. G. E.

"INTRODUCTION The ventilation of development faces in mines for diluting gas or dust concentrations and, in hot mines for providing air-motion cooling effect, by fan pipe units discharging high-velocity streams of air close to the face, is an important phase of mine ventilation. The effectiveness of such units depends largely on the air-flow distribution between the pipe discharge and the face, a subject on which little definite information is available. A study of the air flow from grills into rooms 3/ has provided some basic data, but under conditions no different from mine fan-pipe installations in development ends that the data are of doubtful application to mine installations, owing to differences in air-flow conditions.The purpose of this report is to present and discuss the results of an initial series of tests of a general investigation designed to yield definite laws and design data for the discharge of fan-pipe lines in mines. This series was planned to yield preliminary data on the effects of velocity of discharge, size and shape of pipe, and adjacent walls on the air-flow distribution. Tents were made on 10-inch pine with seven different end conditions and one change of wall condition. Changes in size and shape of discharge wore made by short transformation pieces directly at the discharge end, with the result that effects due to contraction and expansion of the flow, which proved to be of much greater importance than was expected, totally obscured any normal effects due to size and shape. The results of this series of tests, therefore, relate to 10-inch pipe with various discharge designs and are so reported."

Aug 1, 1940

By Nunna Malakondaiah

Plant samples collected from the mined sites of Beulah, Center and Zap and the test sites of North Beulah 1, North Beulah If, South Beulahh and Center were analyzed for their nutrient concentrations. The vegetation from the mined areas generally showed lower concentrations of Na, P and Cu and failed to meet the nutritional requirements for beef cattle as defined by National Research Council (minimum requirements are: Na, 600; Cu, 4; P, 1800 µg/g dry weight). Plants from Beulah showed generally higher concentrations than from Center or Tap. Tissue concentrations of K varied significantly between sites for 5 species due to the low tissue concentrations at Center. Deficiencies are difficult to isolate as the sampling was done in mid-summer and generally during that season the tissue concentrations tend to decrease in several species. All of the plant species at the unmined sites, with the exception of western wheatgrass at Zap, had lower concentrations of P than the minimum nutritional requirements for beef cattle. Sodium concentration was low but Cu was marginal to adequate in plant species at the unmined sites. Concentrations of K, Mn and Cu in western wheatgrass were greater at Center than at Zap while the opposite was true of the concentrations of Zn, Cu and P in blue grama and Cu in green needlegrass. Amending the spoil with slack at North Beulah I decreased the concentrations of Zn, Cu and P in wheatgrasses grown on spoil from 0-2, 5-10, and 20-25 foot depths, respectively. In general, the mean tissue K+/Na+ ratios were greater in plants on slack amended spoils, primarily due to the reduced Na concentrations in the tissue. At North Beulah II test site, only wheatgrasses grown on spoil amended with slack showed significant increase in K and decrease in Na and Mn concentrations. At South Beulah test site which received 12" topsoil over graded spoil, leonardite amendment decreased P concentrations in all of the grasses as compared to control, whereas fertilizer treatment increased the same. Nutrient concentrations were lower in both fescue and needlegrass with leonardite treatment and higher with fertilizer treatment although not significantly different from control. The concentrations of Ca, Mg, Na, Fe, Cu and N in grasses grown on topsoil at Center test site were significantly higher than on slack amended spoil. Legumes grown on topsoil at Center site contained higher concentrations of P than those grown on spoil; there were no significant effects due to slack on spoil or topsoil. The data presented in this report act only as an indication of between-treatment and between-species differences in tissue composition of plants harvested in mid-summer season. With respect to the nutrients analyzed, since none were found to be toxic, the cattle can safely feed on the vegetation of these mined areas.

Jan 1, 1982

By S. M. Shelton, F. D. DeVaney, M. M. Fine

Ferrograde manganese ore or its equivalent is essential to the manufacture of every ton of steel produced ; although it is well -known that there are large deposits of low - grade ore in the United States , the production of substantial amounts of ferrograde material from domestic sources presents a problem that becomes more and more critical as the stockpiled ore is depleted through inability to obtain adequate supplies from foreign sources . Consequently, a program of laboratory and pilot - plant investigations designed to solve the problem of obtaining a domestic supply of manganese has been undertaken by the Metallurgical Division, Bureau of Mines . This paper is one of a new series that will include reports of results obtained in the various investigations conducted under the manganese program . The scope of the program and the organization that was set up to direct and supervise the work were discussed in the foreword of the first paper of this series , Report of Investigations 3606 , Manganese Investigations 1. Concentration of Manganese Ores from the Drum Mountain District, Utah, by S. R. Zimmerley, J. D. Vincent , and C. H. Schack . Other reports will be published as the work progresses .

Feb 1, 1942

By E. J. Gleim

A list of permissible mine equipment, tested and approved previous to January 1, 1942, was published In Bureau of Mines Information Circular 7207.3/ The present list covers additional equipment approved during the calendar year 1942. The items have been numbered to indicate the order in which each type of machine or device was approved in its particular classification. Thus, Information Circular 7207 gives four air compressors on the Bureau's active list, and the present circular gives the fifth to be approved. Items 90 and 94 under Loading; Machines land Conveyors also appear in Information Circular 7207. These numbers are repeated hero to show that approval was granted during 1942 for additional voltages on machines previously listed one voltage only. Equipment listed in these circulars is approved by the Bureau of Mines only when found upon inspection and test to comply with minimum standards of safety as outlined in schedules prepared on the basis of many years of experience in dealing with safety problems of the coal-mining industry. The use of such equipment in mines known to be gassy, as well as in those which may become so, is earnestly recommended in the interests of safety. This circular is published so that the industry may be kept informed as to the many types of machines, devices, and lamps that arc available for reducing explosion and other hazards incidental to coal mining. The present paper and Information Circular 7207 together give the complete list of all available permissible .Mine equipment.

Jan 1, 1943

By J. P. Capp

The Federal Bureau of Mines and the Alabama Power Company conducted an experiment in underground gasification of coal at Gorgas, Ala. involving the use of hydraulic fracturing to increase the air acceptance of a coalbed for the introduction of combustion air and removal of product gases. Air acceptance is defined as the flow rate of air which can be injected into the coalbed at 65 p.s.i.g. This was the second time the hydraulic-fracturing technique was used at Gorgas. Sand suspended in a heavy oil served as the fracturing fluid in the first experiment; in the second the sand was two to six times larger and was suspended in a water-starch gel. In addition to providing further tests of the underground-gasification process, the purpose of the second experiment was to determine the effects of the larger sand and greater volumes of a water-base fluid on (1) the extent of the fractured area, (2) the air acceptance of the coal, and (3) the rate at which a gasification path could be carbonized (linked) through the coal, and to compare these results with those of the first experiment. The coal was fractured by injecting 11,000 lb. of sand and 33,580 gal. of water and water-gel at 200 to 600 g.p.m. and 900 to 1,000 p.s.i. The fluid fractured the coal and the sand served as a propping agent to hold the cracks and crevices open. Pressures during the fracturing operation at test boreholes indicated that the fracturing fluid extended only about 150 ft. from borehole H, the point of application of the fracture. Injection of air revealed that the air acceptance of the coalbed within this e t was materially increased. On the other hand, increased air acceptance also was noted at boreholes up to 280 ft. from borehole H and at the electrolinking area 300 to 400 ft. away, indicating that the fracture effects extended considerably farther than was evident from observation. Similar effects were noted at approximately the same distances after the first hydraulic fracture.

Jan 1, 1961

By Frank J. Wiebelt

As a result of the examination of many copper-zinc properties in the West Belt area of California, nine were chosen for exploration projects by the Bureau of Mines. This was part of the Bureau's wartime mineral-development program aimed at maintaining production of essential metals and increasing ore reserves. The properties explored were the El Dorado, El Dorado County; Copper Hill, Newton, and Gray House, Amador County; Constellation, North Keystone, and Collier, Calaveras County; and American Eagle and Akoz, Mariposa County. In addition to surface sampling and mapping, 41 holes, aggregating 18,134 linear feet, were diamond-drilled. Detailed results of the work done on all properties except the El Dorado and Akoz are given in this report. The El Dorado and Akoz were discussed in Reports of Investigations 3896 and 4144, respectively. Figure 1 is an index map showing the location of the mines covered in this publication.

Jan 1, 1951

By Ernesto Villaescusa, Andres Brzovic

Rock masses of the primary copper ore at the El Teniente Mine are very competent and massive. The rock mass contains almost no open discontinuities. Nevertheless, there is a high frequency network of small discontinuities coupled with widely spaced faults. A data collection campaign designed to characterize the rock structure was recently implemented. The results show that conventional analysis in terms of discontinuity frequency does not predict differences between two studied sectors. However, when an empirical definition of a weak discontinuity is applied, appreciable differences between the two sectors appear in terms of discontinuity frequency and predicted in situ block size distributions. These differences are in accordance with actual observations at the mine site. Due to the geological features of the primary copper ore, rock mass classification schemes cannot be readily applied to characterize these rock masses.

Jan 5, 2007

By J. P. McGee

As part of a joint U.S. Atomic Energy Commission-Federal Bureau of Mines program for using nuclear energy to supply process heat, a simulated nuclear loop has been constructed to test components. This loop has been operated for more than 1,800 hours at 100 p.s.i.g. Of this period, 23 hours were at 2,500° F. and higher; 540 at 2,000° to 2,500° F.; 840 at 1,500° to 2,000° F.; 200 at 1,000° to 1,500° F.; and 260 below 1,000° F. Leakage at flanges and welds was not a serious problem. A helium-recycle system with gas temperatures of 2,300° to 2,500° F. and a static pressure of 250 p.s.i.g. appears feasible. Difficulties were encountered with the recycle compressor due to thermal distortion of the impeller and shaft. The use of sealed bearings limits compressor operation to the life of the bearings.

Jan 1, 1960

By Robert L. Rough, William E. Eckard

Laboratory data obtained from a Bureau of Mines rotary air core of a well near Sugar Grove , Warren County , Pa . , were instrumental in initiating hydraulic fracturing in the area to stimulate oil recovery from Glade sand oil reservoirs . This report outlines the general geology , lease development , reservoir- rock characteristics , and oil - production history of Glade and Clarendon sand reservoirs in Warren County . The methods of well completion for single- stage and multiple- stage hydraulic fracturing of old and new wells are discussed , and a range of hydraulic fracture treatment data from 29 Glade sand and 10 Clarendon sand wells is presented . A composite decline curve representing oil - production data from six wells shows probable results of hydraulic fracturing . Average cumulative oil production during the first 100 days after hydraulic fracturing with a sand - carrying liquid is compared with production after conventional shooting with liquid nitroglycerin .

Jan 1, 1964

By J. G. Donaldson

The Bureau of Mines investigated the formation of boron and boron-carbide coatings by vapor-phase reactions. Optimum parameters were determined for hydrogen reduction of boron trichloride and for the fonnation of boron-carbide coatings on graphite by reaction with the depositing boron. At 1,300° C, about 85 percent of the boron was deposited. Tungsten substrates did not react with the boron deposit; other substrates reacted to various extents. The hydrogen reduction of boron tribromide was briefly investigated. Boron carbide was deposited at 1,300° C by adding methane to the boron trichloride-hydrogen feed gas. The chemical composition of the vapor-deposited boron carbide approximated B4C. A method of etching B4C was developed to study its microstructure. When boron was deposited on graphite at 1,500° C, very hard, uniform, strongly adherent coatings of B4C were formed that might be useful in rocket nozzle applications.

Jan 1, 1968