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By C. W. Owings

Recent recommendations of the Bureau of Mines regarding, rock dusting to prevent dust explosions in coal mines have been issued as Mine Safety Board Decision 32 and printed as Information Circular 7109.5/ The last paragraph on page 2 of I. C. 7109 states: After a mine or any part of a mine has been rock-dusted, samples of dust for analysis should be taken from the floor, ribs, roof, and timbers at such intervals of time as will give apple warning of need far redusting in order to maintain the required minimum percentage of incombustible in the mine dust. Details of the methods of sampling and analysis are given in Bureau of Mines Information Circular 7113.

Jan 1, 1940

By John H. Thompson

Recent studies ** at the Pittsburgh Experiment Station of the Bureau of Mines have revealed some interesting facts as to the probable behavior of steamed coke in the blast furnace . The literature on the chemistry of the blast furnace was tho roughly reviewed , and with this information in mind , the probable behavior of the coke sulphur in the blast furnace was deduced . Enough small - scale tests were conducted to furnish a check on most of the important deductions , and the conclusions derived therefrom accord with what is already known in regard to the forms of sulphur in coke , and fit in well with the general opinion concerning blast-furnace reactions .

Aug 1, 1923

By R. D. Leitch

[The accepted theory of acid formation in coal mines with the subsequent appearance of the acid in coal-mine drainage, is oxidation of iron pyrite and subsequent solution and hydrolysis of the iron sulphate formed. It has also been found that 5 gobbed sections and worked-out areas, where there is usually an abundance of iron pyrite-bearing, materials in contact with air, are the sections that make the most important contribution to the quantity of acid drainage. It would thus seem obvious that if oxygen can be kept out of contact with tae acid-forming materials in tie- sections mentioned the amount of acid in coal-mine drainage could be reduced markedly and corrosion problems with mine pumping equipment and general stream pollution mitigated thereby. Although the efficiency of the suggested remedy as been borne out by laboratory experiments6, it has appeared desirable to substantiate the laboratory work by field observations in so far as pertinent data are available. It has been difficult to learn of mines or sections of mines about to be sealed, whereby an actual comparison of the drainage before and after sealing can be made. In view of that difficulty it has been necessary to devote attention to a comparison of the character of the water from areas already sealed with that from open but otherwise comparable sections of the sane mine. Previous cork has shown that the acidity of drainage in different parts of the same mine may vary, but if it can be shown also that the water from sealed areas is with but fen exceptions less acid than the otherwise similar open sections of tae same mine, the laboratory finding will be supported in a practical gray. This report presents some of the evidence that has been obtained.]

Jan 1, 1930

By Alan G. Mayton

A prototype end-cab shuttle car (SC) design has been developed to improve protection and address ergonomic concerns of the SC operator in low coal mines. The new design features an end cab transversely mounted to the SC and equipped with a closed-circuit video system. The end cab was retrofitted to a low-coal SC and evaluated in surface trials at the U.S. Bureau of Mines. During surface trials, test operators evaluated the end-cab SC relative to visibility; cab features-space, seating, controls, and operator position; tramming-inby, outby, and turning corners; and dumping. Trials were conducted using 12 test subjects; 6 were experienced SC operators. Results of the trials were promising. Of the experienced operators, the only operator with low-coal experience gave the new design the highest rating. Four experienced operators rated the end-cab design "better" to "much better" than a standard center-driven, side-cab SC for visibility when tramming, protection from roof and rib hazards, and no change in seat position with direction of travel. This report discusses research to modify a used 21SC JOY SC, retrofit the SC with the Bureau-developed end-cab, and evaluate the retrofitted end-cab SC in surface trials.

Jan 1, 2010

By Arthur L. Murray

"During recent months much criticism as to the efficiency of mine labor has been heard from various, sections of the country. No doubt much of this criticism has been well founded. The present lack of efficiency and of stability is due primarily to a spirit of restlessness and partial irresponsibility engendered during the transition from war conditions to peace time conditions. This spirit or unrest not only among the laboring classes but in every branch of the human family following a period of intense nervous tension in a nation appears to be a natural sequence of war and beyond the control of man. This condition will gradually disappear, and the majority of our people will again assume their natural order of living, but labor will for a considerable period be sensitive to these influences, whether they be exerted for good or for evil. Employers of labor should take cognizance of this fact and bend every effort towards the development of measures that promote efficiency and permanence of the working force.Labor efficiency depends upon many and varied factors. Some of these factors as applied to mine labor are briefly enumerated in the following paragraph:Selection and Placement of Manpower:In the selection of men the two main considerations are physical ability and adaptability. The laws of mechanics should be applied in the selection of men as in the selection of machinery. If a machine is required for a certain class of work, the type of machine known to be mechanically fit for such work is selected. Likewise, men should be selected with regard to their physical and temperamental fitness for the kind of work expected of them."

Apr 1, 1920

By R. L. Crosby, L. W. Higley

Magnesium- rich magnesium- aluminum- zirconium alloys in the cast and in the extruded and heat- treated condition were studied to identify the phases present and to determine phase distribution . In cast alloys , two intermetallic compounds were identified : ZrAla by X- ray diffraction ; and Mg₁ Al₁₂ by microscopical observation . Based on microscopical comparisons between the known phases in the cast structures and the phases in the structures of extruded and heat - treated rods , ZrAl₂ and Mg1 , Al12 were identified in the structure of the latter . The presence of these intermetallic compounds in rod specimens could not be confirmed by X- ray diffraction . ZrAl₂ was observed in the structure of extruded and heat - treated rod specimens containing as little as 0.01 weight - percent zirconium . The presence of aluminum restricts the solubility of zirconium in magnesium because of the strong tendency to form ZrAla . This intermetallic compound segregated in clusters of small particles in the matrix of cast alloys , and only slight improvement in distribution was noted when the alloying techniques were varied .

Jan 1, 1964

By J. C. Meeks, C. L. Klingman

An instrument that is sensitive , portable , safe , and low in cost was developed by the Bureau of Mines for detecting helium leaks by comparing the thermal conductivity and flow rate of the atmosphere around the suspected leak against a reference of helium- free air . A vacuum pump pulls the sample gas through a restriction and over thermistor elements , the combined electrical output of which is affected by thermal conductivity and flow rate of the sample gas . Tests showed that the battery - operated Helium Leak Detector was effective and rugged instrument that could be operated safely in explosive atmospheres . The instrument could also detect , but not identify , other gases such as methane , hydrogen , argon , carbon dioxide , and Freon 12 .

Jan 1, 1964

By Wm. O. Vanderburg

This paper describing the mining practices at the Block P mine of the St. Joseph Lead Co. at Hughesville, Mont., is ore of a series of similar papers being prepared by the Bureau of Mines on mining practices, methods, and costs in the various miner of the United States. ACKNOWLEDGMENTS In the preparation of this paper the writer acknowledges the assistance of R. H. Willcomb, general manager, William Thorson, mine superintendent, and B. P. Bellport, mining engineer, of the Hughesville division of the St. Joseph Lead Co.; and of E. D. Gardner; supervising engineer, U. S. Bureau of Mines, Southwest Experiment Station, Tucson, Ariz.

Jan 1, 1931

By Arnold F. Stalder

The measurement of various gas concentrations in the atmosphere at a particular location has become a problem of considerable importance. Levels that need to be monitored vary from the range of percent for constituents such as oxygen to parts per million levels for gases like nitrogen dioxide. In particular, mine air can become contaminated with noxious or toxic gases from several sources: fires within the mine, diesel-powered equipment, and explosive sources. The contaminants that result are carbon monoxide (CO), carbon dioxide (CO2), and oxides of nitrogen (NO and NO2). Additionally, oxygen (O2) may be depleted. Thus, the workman can be exposed to potentially toxic or asphyxiating atmospheres. A device was needed that will continuously monitor the mine air in working areas and provide warning of hazardous atmospheres. The Mine Air Monitor was conceived as being a portable, rugged instrument capable of measuring the concentration of the various atmospheric constituents in the mine environment. The unit was to provide both warning signals and quantitative measurements when hazardous contaminants existed at too high a level, or when the oxygen was being depleted. The initial concept involved optical sensors for all of the contaminating gases to be measured, namely CO, CO2, CH4, and NO2, and an electrochemical cell to monitor O2. When the explosion proof requirements of Schedule 2-G made the concept appear to be unfeasible from the standpoint of weight and portability, the program was redirected and a three channel monitor employing electrochemical sensors was adopted. In this case the gases to be monitored were O2, CO and NO2. The remainder of the program was oriented towards obtaining good, commercially available lectrochemical sensors for the above gases, testing them, reducing deficiencies noted during these tests, and making the necessary modifications to integrate the three sensors into a Mine Air Monitor suitable for the mine environment.

Jan 1, 1974

By D. W. Frommer, M. M. Fine

"INTRODUCTION Laboratory mineral-dressing investigations covered by this report show that ores from Montgomery County, Ark., and Morgan County, Mo., are potential sources of barite and zinc. Fine grinding and froth flotation yielded drilling-grade barite from the former and chemical-grade barite and zinc concentrates from the latter.Samples from these deposits were subjected to a laboratory investigation to develop an economic and feasible treatment. The Arkansas ore, submitted by the Husky Refining Co., consisted of an intimate mixture of the economic mineral and quartz. Fine grinding and fatty acid flotation were utilized to effect a good recovery of a drilling-grade product. The other was a zinc-barite ore submitted by the Rocky Ford Mining Co., Stover, Mo. There was no problem in the recovery of zinc (most of which occurred as sphalerite), but the recovery of barite by flotation was complicated by the presence of gangue carbonates. Ultimately, an excellent recovery of barite was achieved with a relatively new type of flotation promoter, petroleum sulfonate.In recent years, barite has become one of the major industrial minerals as an essential ingredient in heavy drilling fluids, pigments, and chemicals. New sources of this important commodity are always interesting; thus, it is the purpose of this report to present information that may permit commercial exploitation of two deposits not in production."

May 1, 1952

By F. R. McDonald

This report presents a discussion of the spectra of 39 condensed thiophenes in which the structure includes at least 1 benzene ring. The vibrational bands present in three regions of the infrared spectra of these thiophenes were interpreted by comparing the similarities of the spectra of condensed thiophenes with the spectra of substituted benzenes. In the overtone-combination region 23 of the 39 condensed thiophenes had spectra which contained sufficient detail to be usable for correlating this region of the spectrum with the appropriate benzene spectrum. In the in-plane deformation region it was possible to make correlations for the vibrations of 18 of the 39 condensed thiophenes whose infrared spectra were studied. In the out-of-plane deformation region the C-H out-of-plane vibrations for hydrogen on benzene rings in the condensed thiophenes can be correlated using known data from substituted benzenes.

Jan 1, 1967

By JOEL H. SWARTZ

During a series of resistivity measurements carried out in 1929 and 1930 a number of questions arose concerning the effect of topography on the character of the curves and the depths attained , the ratio of true depth to certain radii interpreted as representing depth , etc. To answer these questions it was decided to undertake a series of experimental investigations on artificial strata . It is the purpose of the present paper to present the results of the studies thus undertaken .

Feb 1, 1931

By D. G. Kesterkel

Low-melting thoriurnrbase binary alloys or metal solutions were prepared by two different techniques involving the electrolysis of ThO2 dissolved in fluoride melts. Experiments were performed at 950° to 1,250° C using electrolytes containing ThF4 and various alkali and alkaline earth fluorides. In the first method, electroreduction of ThO2 and deposition of thorium on a nickel or iron cathode formed a molten alloy that dripped off and collected on the bottom of the cell, or in a tungsten cup. An electrocodeposition technique was used to prepare thorium-base alloys or solutions containing nickel, iron, chromium, or manganese. Electrolytic reduction of the component metal oxides and simultaneous deposition of the two metals on a tungsten cathode yielded a liquid alloy product. Complementary experiments were performed on the fused fluoride electrowinning of dendritic thorium from Th02 at 1,075° to 1,200° C in which thorium crystals were recovered and arc-melted into buttons. Major contaminants were aluminum, carbon, copper, iron, oxygen, and silicon, totaling 0.2 percent.

Jan 1, 1966

A revolutionary development in blasting materials has occurred in recent years. Ammonium nitrate, sensitized by the addition of a small percentage of No. (class) 2 diesel fuel or other suitable petroleum product, has been adopted as a low-cost, efficient blasting agent2 in a wide variety of mining, quarrying, and heavy construction operations. Moreover, the ready availability of the component supplies throughout the Nation, together with the ease of formulating them into effective blasting agents, has made it possible for the blaster himself to prepare the mixes at the site of use. Recently, most established explosives manufacturers have begun supplying premixed AN-FO (ammonium nitrate-fuel oil) or a comparable product to various mining operations. However, many individuals and small business establishments are marketing premixed products prepared in facilities that are often poorly constructed and poorly located. Although these blasting agents have partly or wholly displaced explosives such as dynamites in many applications, there are some blasting operations in which the fuel-sensitized ammonium nitrate agents do not appear to be well adapted. As long as the hazards they present are clearly understood and respected, ammonium nitrate-based blasting agents have important safety characteristics when prepared under competent factory control or field-mixed under equivalent close control. This publication attempts to summarize the knowledge of those hazards and to incorporate practical ways to cope with them.

Jan 1, 1963

By D. S. Kingery

Investigations over several years have disclosed that the principal manners of occurrence of shuttle-car injuries are in order: 1. Victims in contact with roof or crossbars. 2. Victims in contact with ribs or timber legs. 3. Victims falling from, or jerked from, shuttle cars. 4. Victims in contact with overhanging brows or protruding pine for pin timbers, or water lines. 5. Contact with persons or collisions with parked equipment. 6. Victims injured by roof falls or falling timbers caused by knocking out roof supports with shuttle cars. 7. Victims injured by runaway shuttle cars. 8. Victims injured while loading or unloading timbers or other materials from shuttle cars. These recurring types of shuttle-car accidents reflect the physical conditions of the working sections, certain safety deficiencies in shuttle-car maintenance and design, and unsafe practices by operators.

Jan 1, 1952

By L. E. Dalverny

This Bureau of Mines report describes the deployment, 5-month operation, and lessons gained from a continuous gas monitoring system using sampling-tube bundles at an underground mine fire in West Virginia. Research information gained indicates the utility of relating certain gas concentration ratios to events during fire development, mine reventilation, and mine recovery. In addition to monitoring the quality of remote fly ash seals, the system provided timely warning of dangerous gas concentrations which developed during surface and underground recovery activities. An evaluation of system components is supplemented by recommendations for improvements.

Jan 1, 1975

By W. P. Yant, H. C. Fowler

"INTRODUCTIONHydrogen sulphide is probably the most toxic gas associated with crude oil. Hydrocarbon (petroleum) vapors themselves are harmful to the human system, but hydrogen sulphide, when present, is usually more important from the standpoint of health and safety. These conclusions were reached in an investigation of the toxic gases encountered in the transportation end refining of high-sulphur petroleum. The results of that investigation are presented in Bureau of Mines Bulletin 23l. although the writers of Bulletin 231 paid no direct attention to the production of oil in the field, they attributed to hydrogen sulphide reports of accidents caused by gas in the oil fields of Mexico.During the development of oil fields in Texas, a ""poison gas"" was encountered that constituted a decided health and safety hazard. The present report discusses an investigation of this gas made in July, 1926.The major portion of the investigation was conducted in the Panhandle field of Texas, but the study also includes the Big Lake and McCamey fields.Scope of WorkThe work undertaken in each field included:Examination of the gas-coming from representative wells at various locations in the field; also analyses of the gas-air mixtures to which the workmen were or might be exposed.Observation of symptoms of poisoning and severity of these symptoms."

Oct 1, 1926

By F. E. Brantley, D. M. Yergensen, D. A. Martin

Fluidized - bed roasting was investigated as a means of decomposing gypsum and gypsum mixtures to produce a gas rich in sulfur dioxide and a lime or portland cement residue . Ninety- eight percent desulfurization of gypsum in a 10 - inch fluidized- bed reactor took 1.5 hours at an operating temperature between 1,200 ° and 1,225 ° C. A cement- type residue was obtained but had to be refired at 1,450 ° C before mortar prepared from it met the physical specifications for cement .

Jan 1, 1963

By J. R. Long

The investigations described herein are concerned with a portion of a systematic research, by the Federal Bureau of Mines on ductile titanium. The Bureau's work on the metal has resulted in development of a semi commercial process for the preparation of titanium and has also made available significant information on the fabrication and physical properties of this new strong, light, corrosion-resistant metal. Considerable interest has been aroused by this work, and a number of other laboratories have begun similar investigations. However, the necessity for Consolidating titanium by normal powder metallurgy methods presents difficulties in producing commercial forms and shapes on a large scale. This investigation was therefore undertaken for the purpose of improving the technique for consolidation of titanium powder into solid nonporous metal.

Jan 1, 1949

By F. S. Crawford

The average visitor to a large electric-shovel operation may wonder how electric power can be treated as carelessly as apparently it is in open-pit mining, and how the mining company can string it carelessly along the ground in great, black, hoselike cables, whereas the power company, which has learned to respect his deadly agency, keeps power lines far out of reach. This is explained by the fact that this particular kind of application of power to moving machinery requires the use of trailing cable instead of the more permanent type of construction that permits a moving contact, such as a trolley. The cables are designed to insulate fully the enclosed power lines against damage and loss of current; and employees are taught to handle them carefully, although engineers are not satisfied that the trailing cable is foolproof and are seeking constantly to improve methods and equipment to insure greater safety. In some sections they rely mainly on the construction of the cable and perfection of equipment, while in others additional precautions are taken, such as handling the cable with rubber gloves, slings, tongs, or loops. In some sections no temporary repairs are made to cables, while in others such repairs are made and later are vulcanized in the shop. At some operations the cycle of shovel duties is arranged so that cables are very seldom exposed to flying rock fragments while at others this exposure appears to be unavoidable. Methods of fastening the cable to the shovel frame and transporting the loose cable vary. Inspection and care of the cable are important in insuring its safety and durability. A limited amount of information was obtained by field engineers of the United States Bureau of lines from operators in various parts of the United States, as methods of handling electric-shovel operations differ with the districts; practices followed and equipment used in these districts are described in this circular.

Jan 1, 1936