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By R. L. Hopkins, H. T. Rall

A continuous method has been developed for preparing thiolacetic acid . Acetic anhydride and hydrogen sulfide are passed concurrently over an amine ion- exchange resin , under 20 - psi pressure . The thiolacetic acid , a product of the reaction , is flashed continuously from the crude reaction mixture and is purified by fractional distillation . The yield of thiolacetic acid is in excess of 80 percent based on the acetic anhydride charged . INTRODUCTION In the synthesis of reference compounds needed in the identification of sulfur compounds in petroleum , thiolacetic acid has become an important reagent because of its use in the synthesis of thiols by addition to appropriate olefins : R - CH = CH₂ + CH3 - COSH R- CH2 - CH2 - S - COCH R - CH2 - CH₂ - SH + CH3COONa NaOH (1 ) The commonly used procedures for its preparation , as described by Clark and Hartman (1 )4 and by Ellingboe (2 ) , are based on the batchwise reaction of acetic anhydride with hydrogen sulfide :

Jan 1, 1964

By BUREAU OF MINES

A complete list of permissible mining equipment, rescue apparatus and gas masks tested prior to January 1, 1925, was published in Bureau of Mines Technical Paper 3761. The present list includes all equipment tested and approved by the Bureau, up to and including January 1, 1926, and supersedes the list issued as Serial 27202 in November, 1925. It covers electric air compressors, coal drills, mining machines, mine pumps, room hoists, switches, electric cap lamps, flame safety lamps, electric hand and trip lamps, flash lamp, methane indicators and detectors, blasting units, storage battery loco- motives, power trucks, self-contained oxygen breathing apparatus and gas masks. The system under which these devices were tested permits the manu- facturer, after his equipment has passed certain tests prescribed by the bureau, to mark his equipment with a seal showing that it has been "approv- ed" by the Bureau of Mines. The tests are designed to insure that the equipment has the minimum requirements for safety in use. The only object of the bureau in making such tests and publishing lists of permissible equipment is to safeguard the lives of workers and to help lessen the hazards of mining.

Feb 1, 1926

By D. A. Reynolds, L. P. Rockenbach

"The method of analyzing light oil for benzene is fully described by Fieldner and others 4/ and Kester and Kolmes 5/. In this procedure, benzene is determined by shaking 20 cc. of the 79º to 81º C. boiling point cut from the fractionation of the refined light oil with 3 volumes of 98—percent sulfuric acid in an A. S. T. M. separator funnel of the type used for determining water in bitumi¬nous materials. After the mixture has been shaken 5 minutes it is allowed to settle at least half an hour and the acid is drawn off; the residual oil is reported as paraffins and the decrease in volume as benzene. The method has been found satisfactory for light oils from coals carbonized at 5000, 600°, and 7000 C. but does not give accurate, reproducible results for oils from the 800° C. tests.The content of benzene of the 790 to 81° C. cut is high, 90 to 95 percent, for 800° C. light oils, whereas for lower—temperature light oils it is considerably less. Benzene is the most difficult of the aromatics to sulfonate, hence the acid concentration must be maintained above 95 percent to insure complete sulfonation. Sulfuric acid (98 percent) reacts with benzene, but its reaction with paraffins at ordinary temperatures is negligible; however, more concentrated acid will attack paraffins and give erroneous yields of benzene. The reaction between benzene and sulfuric acid forms water that will dilute the acid. The effect of this dilution may be overcome by increasing the acid-to-oil ratio or increasing the strength of the acid. The latter, however, must not be used, because the stronger acid reacts with paraffins."

Mar 1, 1942

By H. S. Chiang, Zhao. Y. F., G. C. Sun, S. S. Peng

"Chiang; H. S. West Virginia UniversityPeng, S. S. West Virginia UniversitySun, G. C. West Virginia UniversityZhao, Y. F.West Virginia UniversityDust sampling was performed in two longwall faces working in two separate seams. Instantaneous dust samples were measured by RAH's. for various locations In the longwall faces. Preliminary analysis of the data shows that in addition to the shearer's haulage speed, there are four major factors that influence the airborne dust distribution in longwall face areas: locations with respect to the position of the shearer's cutting, hardness of the materials, characteristics of water spray, and roof conditions. This paper presents the effects of those four parameters in detail.INTRODUCTIONA research project was initiated in September 1983 to measure and construct .a dust distribution map for the longwall face. During the first year, airborne dust samplings were performed in two longwall panels located in northern and southern West Virginia and working in the Pittsburgh and Eagle Seams, respectively. The physical parameters and equipment employed for both panels are 1 isled in Table 1. Figure 1 shows the detailed characteristics of the coal seams. Notice in both panels floor cutting was involved either to gain sufficient mining height or to reduce the adverse effects associated with a soft floor.The purpose of the research is to define the dust distribution at any instance in the longwall face area so that proper working positions can be determined and/or effective dust control techniques can be developed.This paper presents the partial results obtained during the first year."

Jan 1, 1988

By Dorsey A. Lyon

"The ceramic industry of the United States has a total yearly manufactured product of nearly half a billion dollars, despite large foreign importation.After careful investigation of the industry by the Bureau of Mines, it is the belief of those in charge that the usefulness of the industry can be greatly enlarged and the importations greatly lessened through the development of processes that will lead to a greater and better development of the ceramic resources of the United States. This will result in a greater industry with more men employed than ever before, and perhaps a world's supremacy in ceramic trade matters.Investigations in behalf of the ceramic industry are being made at the Bureau of Mines experiment ceramic station at Columbus, Ohio, under the supervision of R. T. Stall, superintendent, who reports a number of instances of practical, beneficial cooperation between the industry and the station during the last fiscal year.Graphite to Crucibles:Prior to 1914, practically all graphite crucibles manufactured in the United States were made from Ceylon graphite bonded with German Klingenberg clay. It was the general belief among graphite crucible manufacturers and users that good crucibles could not be made from American bond clays and graphites.Graphite crucibles were essential for melting certain alloys and special steels urgently needed for the manufacture of war materials. The demand for such metals was so great that it created an unprecedented demand for graphite crucibles.After the European war began no Klingenberg clay could be shipped out of Germany. However, it was fortunate for the cyucibly makers that they had large stocks of Klingenberg clay on hand. When the stock of Klingenberg clay became exhausted, it was necessary for the credible makers to turn their attention to American clays. There were no data or other information available to guide the crucible makers in the selection of good bond clays for their crucibles. It was necessary for them to select their clays more or less by ""guess"", which resulted in the period of service or life of graphite crucibles being shortened 15 to as much as 60 per cent."

Feb 1, 1921

By Charles A. Kumbe

"INTRODUCTION The Sullivan Mine was examined by Thomas L. Chapman, an engineer of the Bureau of Mines, in March 1943. Samples taken from the few mineralized exposures justified further investigation of the property. To determine whether extensive exploration of the property would be warranted, the Bureau did a small amount of trenching and underground work during April 1943, 3/ under Bureau project 1462.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its, primary objective the, more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratary project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurigical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests.The investigations of the and Metallurgical Branches of the Bureau, as reported in this paper, were supervised by J. Hedges, district engineer for Arizona, and S. R. Zimmerly, regional engineer for the Western Region, respectively."

Feb 1, 1947

By H. B. Brunot

A complete list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1947, was published as Information Circular 7432.2/ A list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar years 1947, 1948, and 1949 was published as Information Circular 7569. The present list supplements Information Circulars 7432 and 7569 and includes all of 'the equipment approved during the calendar year 1950. Information Circular 7465, which included a list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar year 1947 therefore is superseded.

Jan 1, 1951

By John R. Shattuck

As a part of the general chromite investigation in California designed to aid In the production of chromite during the recent war emergency, the Bureau of Mines explored the Coggins property in Siskiyou County, Work by the Bureau in cooperation with the Federal Geological Survey began in October 1942 and was concluded in March 1943. This report presents a brief history of the mine, outlines the physical features of the district, describes the deposits) and explains the work completed by the Bureau of Mines, Table 1 shows the analysis of diamond drill-hole samples. The logs of drill holes are in the appendix.

Jan 1, 1949

By E. L. Sweeney

The mine and mill of the Davis-Dunkirk Lines, Inc., are about 16 miles by road south of Prescott, Ariz., which is the nearest railroad point for receiving mine and mill supplies and for shipping concentrates to smelters. A good trucking road reaches within 2 miles off the property, but from that point the grade is very steep. Outgoing loads are limited to 2 tons. The topography near the mine is exceedingly rugged, and the area is slightly wooded. The climate is mild excepting in a few winter months, when the snowfall is heavy. Electric power is secured by way of a 4 1/2-mile, high-tension line connecting with the main line of the Arizona Power Co. The concentrator was intended to treat 60 tons or more daily of gold-silver-copper ore and make a single gold-silver-copper concentrate for shipment to a copper smelter.

Jan 1, 1933

By Eugene T. Sheridan

The 23d annual survey of the peat industry by the Bureau of Mines, United States Department of the Interior, revealed that 75 producers in 17 States re-ported commercial production of peat in 1956. Forty-seven producers reported humus production, 19 reported reed-sedge peat, 17 reported moss peat, and 1 reported muck. This total exceeds the number of active operations, but several producers reported recovering more than one type of peat. Fifty-five percent of the total production was reported as peat humus, 30 percent as reed-sedge peat, and 15 percent as moss peat. A negligible amount was reported as other types. More than one-fourth of the total output was raw peat with no preparation, other than having been air-dried. The remainder consisted of processed peat prepared for use by cultivation, shredding, or kiln drying.

Jan 1, 1958

By A. B. Hooker

A list of permissible mine equipment, tested and approved by the Bureau r. Mines previous to January l, i-)4, , was published in Bureau c Moines In ornation Circular 7207.3/ The l ,.t c -. that dote was complete as to equipmentthen available and in current Information Circular 7210,?+/ published as a supplement thereto, listed equipment approved during; the calendar 1942. Information Circular72x'3,_/ published as a second supplement thereto, ! listed equipment approved during the calendar year 1943. The present listis. Another supplement covering approvals issued during the calendar year 1c)44. The items are numbered crud to indicate the consecutive order in which each typo of machine or device was approved _.c?. in its particular classification. Thus Information Circular 7207 gave 1,t drills and drilling much fines on the Bureau'sactive.. d active list Ih: additional anal approval: were given in 1942 the three issued in 19 and one issued :n 1944- bring the total to `3. Item 111, under. Loading Machines and conveying appeared in lnformation Circular 7207. It is repeated ',tore to _how that on j,,l was granted Curia 1the optional of this loader when modified .'or 2 0. alt ciruits .]

Jan 1, 1945

By M. D. Aldridge

This document reports the results of a two-year research effort aimed at improving communication systems used in coal mines. This work was conducted under a program whose original goal not only involved the development of practical and effective electronic systems for operational communications, but also for monitoring, at a central location, remote instruments at key positions in a mine. About half way through the originally proposed three year effort, the program was redirected to phase out the communication effort at the end of two years and to concentrate the program" resources on the investigation of new monitoring system concepts developed by this research. Thus, the work reported here is incomplete relative to the originally pro- posed program. However, the work was carried to the point of providing sufficient evidence to aid in the comparison of certain new communication concepts. For the concepts chosen for this study, the work was stopped short of hardware development and field testing, Several reports in the form of Master's theses and a Doctoral Dissertation have resulted from this research. They each report in considerable detail the results of several individual" contributions to this program. In preparing this report, an attempt has been made to provide a complete description of the significant results but with- out burdening the reader with the minute details. These more detailed reports are referenced heavily for the convenience of those interested. PRESENT COMMUNICATION METHODS Two types of communication systems are presently used In coal mines. They are: 1, Various forms of telephone systems, and 2. Carrier current radio systems using the trolley line as the interconnection circuit. Carrier current radio is used almost exclusively for control of rail trafflc by the dispatcher. Almost all other communication uses the telephone system, Telephone lines generally extend to areas where trolley lines are not present such as the outside offices and warehouse. Therefore the telephone system provides the primary means of voice communication. Telephones - Telephone systems employed in American coal mines fall into three categories. 1. Paging type telephone systems - these systems have individual stations which use battery powered transistor audio amplifiers to boost signal levels for normal communication. When in the page mode,

By Lung Cheng

The Bureau of Mines has installed passive water explosion barriers in two operating mines to determine their usefulness in U.S. coal mines. The primary objective of this field trial was to determine the effect of the explosion barriers on mining operations. Data were also obtained on the ability of the barriers to withstand the mine environment and on the effect of the barriers on belt operation, ventilation, worker travel, and rock dusting. Fifty barriers were installed at three separate beltway locations, and periodic inspections were made. A year after installation, no defects of the barriers or support hardware were detected, nor was any complaint as to the presence of the barriers made by the mine personnel. To date, 2-1/2 years after installation, the barriers have had no detrimental ef-fect on rock dusting, belt operation, or ventilation. Costs of material, fabrication, and installation are reported herein.

Jan 1, 1984

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Uruguay has been prepared from the best available information in Washington, but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Sep 1, 1930

By E. P. Youngman

The mining law of May 16, 1884, is still the basic mining legislation in Smeden. To satisfy a demand for a revision of the entire mining law, special commissions have been at work for a number of years; but present indications are that the work will require several more years for its completion. The changes contemplated would affect mainly the relations between the nine operator and the landemer, as the present law, according to general opinion, tends unduly to jeopardize the landowner's right in favor of the miner. The socialist party desires additional changes, especially in the direction of giving more direct control of the industry to the State, a control that it now seems to exercise through individual agreements with mining companies. Its control of the Lapland iron mines comes through its sharing the ownership with the Luossavaara-iirunavaara Altb. In this instance, the Government should be Considered as a private commercial body, since the agreement with the company

Apr 1, 1933

By R. S. Dean

A general survey of the metallurgical work of the U. S. Bureau of Mines has been given in an article in the Missouri School of Mines Alumnus, and a somewhat more detailed review of the bureau work on lead and zinc will be found in the Mining Congress Journal. C. C. Furnas has contributed one general mathematical article. Dean, R. S. U. S. Bureau of Mines. 4, 1930, pp. 7-8. Program of Metallurgical Investigations of the Missouri School of Mines Alumnus, vol. 4, No. Investigations of the U. S. Bureau of Mines on the Milling and Smelting of Lead and Zinc. Min. Cong. Jour., vol. 16, 1930, p. 799, 808. Furnas, C. c. Evaluation of the Modified Bessel Function of Am. Mathematical Monthly, vol. 37, the First Kind and Zeroth Order. No. 6, 1930, pp. 282-287.

Apr 1, 1931

By H. B. Humphrey

In the 39 years from 1891 to 1929 , gas and dust explosions in the coal mines of Tennessee caused 413 deaths , or one- third of the fatalities in the mines for that period . Inasmuch as explosions caused but about 15 per cent of mine fatalities for the whole United States for this same period it is evident that the Tennessee coal mining record is by no means good , as far as explosion fatalities are concerned . Since 1926 , Tennessee has had a clear record as to fatalities from explosions ; this fact may be credited very largely to the improved conditions and safer practices in Tennessee's coal mines which have been brought about by the work of the State Inspection Department and of the Southern Appalachian Coal Operators Association directed toward adoption of safety precautions and practices most of which are advocated by the United States Bureau of Mines . Chief among these improvements are the replacement of black powder and dynamite by permissible explosives , improved ventilation , and the installation of rigid methods of inspection for gas . With the present tendency for operations to pass into the hands of responsible and informed management , and with unrelaxed care and inspection , the good record of the past several years should be maintained .

Apr 1, 1931

By William L. Crentz

1. SALES PUBLICATIONS

Nov 1, 1949

By John I. Kasteler

The Rambler mine is in the Douglas mining district, Albany County, Wyo. (fig. 1). The property was first operated about 1870 for gold found in the outcrop of a leached ore body. Copper and metals of the platinum group were discovered, in 1900, or soon thereafter, and intermittent mining was done until 1918, when a fire destroyed the surface plant, and the underground workings caved. The mine has since been idle. The Bureau of Mines conducted a development project on the property from October 1942 to October 1943, with a recess period between November 1942 and August 1943. Ten diamond drill holes, totaling 1,859 linear feet, were drilled on the property (fig. 2). The mine dump was sampled after preparation with a bulldozer. Assay determination and spectrographic analyses disclosed small quantities of copper and metals of the platinum group in the samples. Determinations were made on 11 samples from the diamond drill holes and 23 samples from the mine dump. The assay results and spectrographic analyses are given in tables 1 and 2. The logs of the diamond drill holes are given in an appendix to this report.

Jan 1, 1949

By K. K. Kershner

The purpose of this investigation was to develop methods on a laboratory scale for recovering tin from metallurgical slime, Tin chlorides were volatilized using mixtures of hydrogen chloride and reducing gases, such as hydrogen, carbon monoxide, hydrogen sulfide, ethane, propane, and butane. Optimum conditions were found to be n mixture of 3:1 of hydrogen and hydrogen chloride at 475° C. Over 95 percent of the tin was volatilized as chlorides. Low temperatures and relatively rapid rates of reaction are distinct advantages of the chloride volatilization process. Research is being continued with various slimes and will be extended to tin ores, where the method offers interesting economic possibilities in comparison with current tin-smelting practice.

Jan 1, 1957