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By Irving Kabik

Chlorates and perchlorates, when mixed with certain reducing materials, may give a detonating explosive of considerable power. Concerning explosive chlorate mixtures, Guttman3/ states that they "have at all times fascinated inventors on account of the large amount of oxygen stored up in potassium chlorate, which can be given off so readily. When Lavoiser and Berthollet tried to make a chlorate powder in a stamp mill in 1788, they made a great show of it, and even two ladies were present. Unfortunately, after a certain amount of pounding the powder exploded and killed an official and the daughter of the Government commissary, who assisted at the experiments.***. It is interesting to observe how the same old mixtures are proposed over and over again with slight alterations only, in order to qualify for a patent. Potassium chlorate with some carbonaceous matter like charcoal, sugar, starch, glycerin, flour, or sometimes a vegetable or mineral oil and the like occurs again and again." Sprengel explosives, in which some of the undesirable sensitivity of the chlorate was minimized by coating the crystals with a liquid reducing agent, received some attention after a patent was issued to Dr. Herman Sprengel in England in 1871.4/ A somewhat similar explosive, known as Rack-a-

Jan 1, 1945

By R. F. Waters

Laboratory-scale selective volatilization methods developed by the Bureau of Mines to recover germanium and gallium concentrates from coal fly ash and phosphorus furnace flue dust are summarized. In the better experiments between 85 and 98 percent of the germanium was recovered as the lower oxide and as sulfides, and between 75 and 97 percent of the gallium was recovered as the lower oxide and as the trichloride. Grades of the condensates were inconsistent and varied between a few tenths of a percent and 8 percent, depending on the method used. In the primary extractions of germanium alone the degree of enrichment surpassed 100 to 1, and for gallium the best ratio was 30 to 1. Upgrading of condensates by vaporization retreatment and by leaching and precipitation is discussed. An appreciable degree of mechanical preconcentration by attrition scrubbing and elutriation was possible on two fly ash samples.

Jan 1, 1967

By N. S. Dalal, B. Jafari, F. H. Y. Green, M. Petersen, V. Vallyathan

"Stable coal radicals (SCRs) were detected by electron spin resonance (ESR) spectroscopy in the lung tissue of autopsied coal miners. The SCR concentrations were measured in the lung tissues from 98 coal miners with and without (a) coal workers' pneumoconiosis (CWP), (b) cancer, and (c) a history of cigarette smoking. Concentrations of SCRs were also determined in the lungs of nonminer controls. The SCR concentration was related to longer mining tenure, CWP disease severity, lung cancer, and cigarette smoking. The mean concentration of SCRs in the lung tissues of miners with 30 ± 1.4 y of coal mining exposure was 5.3 ± 1.3 x 10"" spins/g versus controls who had a nondetec¬table level (< 10 15 spins/g). An increase in disease severity was accompanied by a progressive increase in SCR concentration. A SCR concentration of 4.8 ± 0.7 x 10"" spins/g was found for simple CWP (with moderate coal macules) versus 7.8 ± 4.6 spins/g lung tissue for complicated CWP (with progressive massive fibrosis). Significantly higher (i.e., 10 x 10"") concentrations of SCR in the coal miners' lung tissues were associated with an exposure history in the anthracite regions of northeastern Pennsylvania. These results in¬dicate a possible role for SCRs in the disease process. Furthermore, ESR appears to be an adequate methodology for the quantitation of coal dust retained in the lung and for distinguishing exposures to anthracite and/or bituminous coal.THE PREVALENCE AND SEVERITY of coal workers' pneumoconiosis (CWP) differ markedly between geographic locations, mines, and coal fields irrespective of comparable levels of exposure to coal mine dust These differences cannot be fully explained by the presence of silica and other minerals in the coal mine dust.' Rank of coal is also an important factor in the pathogenesis of CWP. Equally important is that the prevalence of CWP decreases from east to west in the United States,' and South Wales miners develop more severe CWP than miners in Scotland.' However, there are conflicting reports that cast uncertainty on the influence of rank of coal in the development of CWP."" These problems are complicated but will be solved as new technology emerges and as more is learned about the disease process."

Mar 1, 1992

By R. J. Matetic

The objective of this U.S. Bureau of Mines hydrologic-subsidence investigation was to evaluate the effects of longwall mining on the local ground water regime through field monitoring and numerical modeling. Field data were obtained from multiple-position borehole extensometers (MPBX&apos;s) that were used to measure subsurface displacements. Survey monuments were installed to measure mining-induced surface deformations. Numerous drawdown and recovery tests were performed to characterize hydrologic properties of the overburden strata. Coreholes were drilled above the study area to determine lithologic and strength characteristics of the overburden strata using the rock samples collected. Electronic recorders were installed on all monitoring wells to continuously monitor ground water levels in coordination with mining of the longwall panels. A combined finite element model of the deformation of overlying strata, and it&apos;s influence on ground water flow was used to define the change in local and regional water budgets. The predicted effects of the postmining ground water system determined by the model correlated well with field data collected from the fieldsite. Without an infiltration rate added to the model, a static decrease of 3.0 m (10 ft) in water level would occur due to mining of both longwall panels and if an infiltration rate was inputted in the model, no predicted long-term effects would occur to the ground water system.

Jan 1, 2010

This report describes the results of a program to design, procure, install, and evaluate a multi-channel underground telephone system of modern design in the Sunshine Silver Mine near Wallace, Idaho. Although the evaluation portion of the program was deleted, this report contains a cost benefit analysis for such a system using estimates of operational data for the Sunshine Mine. The results show a centrally switched telephone system of conventional design with ruggedized phone enclosures and special environmentally sealed dial pads to be the most economical.

Jan 1, 1982

By K. J. Miller

A two-stage froth flotation technique was developed in the laboratory to separate fine-size pyrite from coal. The process consists of the initial flotation of a 15-percent solids coal slurry with a minimum of frother; the coarse, free pyrite and other refuse are removed in the tailings. The froth product from this first stage is then repulped and treated with a coal depressant, a pyrite promoter, and a frother to float the remaining fine-size pyrite or pyrite attached to coal particles. With the two-stage process, the pyritic sulfur content of a Lower Freeport bed coal sample was reduced from 1.78 percent to 0.75 percent in the first stage, and from 0.75 percent to 0.27 percent in the second stage with good clean coal recovery.

Jan 1, 1972

By E. P. Carman

In this report, the Federal Bureau of Mines presents a summary of the occurrence, properties, and uses of some natural bitumens, using the layman&apos;s or dictionary definition of bitumens - that is, naturally occurring hydro-carbons. Emphasis is on the less common solid and semisolid bitumens, particularly those occurring or used to some extent in the United States. This comprises data from many sources and references to these sources for more detail than is given in this summary. This paper was prepared primarily to answer questions about some of the less known bituminous materials. The word hydrocarbons could just as well have been substituted in the title for bitumens, but bitumens was used, since an abstract of the paper was presented at a meeting where the major emphasis was on bituminous materials. The reader will realize that coals, of which only the more unusual such as the cannel coals and torbanites are discussed in this paper, are primarily mixtures of bituminous materials and carbon. The amount of bituminous material, or volatile matter, in coals is greatest in the lower rank coals and the unusual types described in this paper, and decreases as coal rank increases. However, since no method other than destruction of the original coal substance by heat is known that will separate the volatile matter from the carbon, it appears reasonable to classify the coals with other bituminous materials, particularly since bituminous coal - the most widely used coal - by its name indicates the combination of bituminous materials and carbon.

Jan 1, 1961

The STATE MINERAL SUMMARIES publication provides estimated data and summaries of mineral activities at the State level for 1990. Most of the estimates are based on nine months data. These summaries have been prepared in cooperation with State geological surveys or related agencies. Individual State summaries are published separately as State Mineral Industry Surveys and copies can be obtained from the appropriate State Activities field office.

Jan 1, 1991

By C. M. McKinney

This report contains Bureau of Mines analyses of 291 samples of crude petroleum from the Gulf Coast Area of Louisiana and Texas. Included are 65 analyses from 51 Louisiana fields and 226 analyses from 216 Texas fields. Analyses from the Texas fields include 90 from 58 Upper Gulf Coast fields, 47 from 28 Middle Gulf Coast fields, and 89 from 40 Lower Gulf Coast fields. The analyses represent fields that produced 1,000 barrels or more per day during at least one of the years 19.57 through 1961, with the exception of 23 analyses from the Texas fields. The fields considered are listed by state and geographical groupings, with field names arranged alphabetically within each grouping. The tabulation also includes information concerning the geological sources of the samples. General characteristics of the crude oils and analytical and computed data determined from the analyses are summarized. Crude oil production data are given for the fields for 1960 and 1961 and are cumulative through 1961.

Jan 1, 1963

An accelerated and coordinated program of coal research is believed by many to be a necessary step in assuring coal&apos;s proper position in the expanding energy market. The President&apos;s Advisory Committee on Energy Supplies and Resources Policy, for example, made the following recommendation: We recognize that coal is a great national asset and endorse a cooperative study to determine what research and development could be undertaken. The coal industry and both Federal and State Governments should participate in this study and its costs. Representatives of the coal industry have agreed that such a study should be initiated. Accordingly, Felix E. Wormser, Assistant Secretary - Mineral Resources, United States Department of the Interior, requested the Bureau of Mines and Bituminous Coal Research, Inc., to conduct a survey of current research on bituminous coal. In addition to this survey, studies were made to determine research projects that would be of value to the coal industry.

Jan 1, 1956

By Vernon C. Davis

"INTRODUCTION This report describes the work done and presents the data obtained from limited diamond drilling at the lead-zinc deposits cf the Belle Eldridge Gold Mines, Inc., in Lawrence County, S. Dak. during the summer and fall of 1943. The work was undertaken in an effort to increase reserves and step-up production of zinc and lead so vitally important to the war program.The geology, topography and existing mine workings were mapped and studied. Subsequently, six vertical core-drill holes were put down from surface sites.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our natural resources to the end that they make the greatest possible contribution to national security and economy. The Mining Division, Lowell B. Moon, chief, conducts preliminary examinations, does the actual investigative work, and prepares the final report. The Metallurgical Division, Oliver C. Ralston, chief, analyzes samples and makes beneficiation tests, if such are necessary.Special acknowledgment is made to John Paul Gries, geologist, South Dakota School of Mines, for mapping and interpretation of geology and topography, logging of cores obtained, and his assistance in guiding the drilling."

Mar 1, 1948

By J. G. Kirby

According to the annual Bureau of Mines survey of refinery capacity, there were 343 petroleum refineries in the United States as of January 1, 1953, with a total daily crude-oil throughput capacity of 7,638,661 barrels. Compared with the previous year, this represents a decline of 7 in the total number of refineries, but a gain of 305,776 barrels in daily crude-oil throughput capacity. The capacity of the average refinery to process crude oil increased to 22,270 barrels, a gain of 1,319 barrels during 1952. All refining districts reported increases in installed capacity for the year, with Texas Gulf Coast accounting for 28 percent of the increase; California, 21 percent; and the Indiana-Illinois-Kentucky district, 18 percent. Additional crude-oil capacity under construction January 1, 1953, was 60 percent greater than at the beginning of 1952. The total reported, 509,721 barrels daily, is a record high for refinery expansion. In addition to the new facilities under way, facilities for 127,755 barrels daily are being installed to replace those that are obsolete. Four new refineries were under construction at the beginning of the year, and three of these are now in operation. Plans for five&apos; new refineries have been announced, but actual construction has not been started.

Jan 1, 1953

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigations beginning with No. 4251, of which this is the fifteenth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by halt townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township. The 14 halt-township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project except the deep holes drilled to test the geophysical anomalies. The locations of those holes show on figure 13 in volume 1. The Descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each halt township is given with the discussion covering that area.

Jan 1, 1948

High resolution seismic refraction tomography has proved to be a useful tool to effectively estimate depth of blast induced damage in a mine face. Excavation blast damage can be as shallow as 1 to 2m and requires resolution at a fraction of a meter for effective imaging. We used an accelerometer with flat frequency response to 1000Hz to record data at spacings of approximately 0.25 to 0.5m along mine walls. First arrival times from the seismic data were used to produce P-wave velocity tomograms. The tomograms show transition from low velocity zones to velocity associated with competent rock. We interpret the low velocity zones to indicate residual fracturing from blasting. Experiments on a concrete test block and at two underground mine locations give results that are consistent with fractured rock transitioning to competent rock. Our method can be applied efficiently in an underground environment to provide continuous velocity information with depth into a mine wall over a span of approximately 10m.

Jan 1, 2009

By Louis H. Berkelhamer

"INTRODUCTION The method of differential thermal analysis suggested by Le Chatelier (1)1 in 1887 has recently emerged as an outstanding means of studying the constitution of various substances, particularly clays, soils, and miscellaneous hydrous materials (2). The literature ably discusses the applications and results obtained but has paid too little attention to specific details of construction of the apparatus. Knowledge of the apparatus is of importance to the experienced research man as is extremely useful to the novice v ho ventures into this field of analysis. Further, it is generally acknowledged that the variations in design and conditions of operation are one of the essential causes for differences in characteristic temperatures as reported by various investigators. A step forward in the elimination of such differences is the publication of the details of construction and operation of a simple and inexpensive apparatus that has proved useful at the southern Experiment station of the Bureau of Mines, where it was used in cooperation with the University of Alabama, Tuscaloosa, Ala."

Jul 1, 1944

By Ed Mchugh

NIOSH researchers collected basic data from two blast rounds at the SSX-Steer Mine as a component of a larger study on controlled blasting, the goal of which is to reduce injuries from falling rocks in underground mines. Drilling and blasting procedures at the mine were observed. Rock mass property data were collected, a program of seismic monitoring and analysis was conducted, and 3-D laser survey scans of the workings before and after each blast were performed. The geologic data showed that the rock mass quality was characterized as poor to very poor. It was essentially uniform within the panels examined. The recorded seismic data indicated that fill material acted as an effective damper to seismic energy. The pre- and post-blast laser scans showed both over-break and under-break conditions, highlighting the problems associated with blasting a weak rock mass. By comparing the achieved results to the intended design, potential improvements in the drilling and blasting practices can be identified. Comparison of these data with similar data from other mines will help define how various combinations of rock and fill behave during blasting. Through studies such as these, data collection procedures and analysis techniques can be refined. An ultimate goal is to develop blast procedures tied to rock mass characteristics that can minimize damage to rock in the perimeter of the opening, limiting the amount of loose rock and improving the safety of miners.

Jan 1, 2007

By L. A. Readdy

Pilot Hole "X" was drilled to test the formations through which the ventilation shaft for the proposed U.S.B.M. demonstration oil shale mine will be drilled. The history of the drilling of Pilot Hole "XI&apos; is presented. This historical summary provides the details of method used during the drilling of this hole. Problems encountered during drilling are discussed. The quantities of drilling mud and other materials used to drill the hole are documented.

Jan 1, 1977

By R. Carson Dalzell

The use of nuclear fission for chemical process heat offers the special advantage of high temperature, limited only by materials of construction. The process heat may be supplied economically at elevated pressures, since no compression of combustion air is required. For the initial effort in developing a high-temperature reactor, the indirect cycle, using helium as the heat-transfer medium, was chosen. The major problems are the design of high-temperature fuel elements, construction of an exchanger to transfer heat to process streams in the range of 2,500° F., and development of compressors capable of recycling helium at 1,000° F. and above. A conceptual design of a nuclear reactor to furnish process heat for coal gasification has been made. Spherical fuel elements utilizing a graphite structure, impregnated with uranium carbide fuel, were chosen, as spheres offer the possibility of easier loading and unloading of the reactor. Calculations of pressure drop and gas-pumping power for the system are included.

Jan 1, 1959

By J. C. Duchon

The use of extended workdays or compressed workweeks (regular shift lengths exceeding 8 h) is attracting growing interest in many industries using continuous operations. While extended workdays promise increased worker satisfaction due to more days off, including weekends and holidays, there are legitimate concerns about the potential effects on the health and safety of such a schedule. The U.S. Bureau of Mines (USBM) conducted a study at a Canadian underground copper, lead, and zinc mining operation that was designed to study the safety and performance implications of extended workdays. Measures were taken before and after a change from the old 8-h continuous schedule to the new 12-h continuous schedule, including behavioral performance measures to analyze perceptual-motor changes, continuous heart-rate monitoring and aerobic capacity to measure physical fatigue, a variety of self-report questionnaires to measure perceived adaption and satisfaction with the new schedule, and pulmonary-respiratory measures to examine air contaminant exposure. Based upon the overall acceptance of the new schedule by the workers and lack of change in fatigue-sensitive behavioral and physiological performance measures, this study recommends that the mine retain the 12-h schedule. However, certain precautionary measures are suggested to insure the safety of the workers.

Jan 1, 2010

By Roy E. Peterson

The Bureau of Mines conducted an investigation to produce metallized pellets from domestic iron ore superconcentrates using lignite and subbituminous coal as reductants. Feed materials for the metallizing process consisted of commercially indurated iron oxide pellets and green pellets prepared from upgraded domestic concentrates with graphite or limestone as internal additives. Durability of the green pellets during metallization was investigated in tests conducted in a 7-inch-ID rotating drum furnace. Test results indicated that the major cause of pellet disintegration with the concentrates used was the tumbling action during reduction rather than forces generated within the pellets. In larger scale tests made in a 34-inch-ID by 35-foot-long kiln, the previously indurated pellets were metallized with lignite at 1,030° C with little disintegration. A 96-percent level of metallization was obtained in pellets having an average compressive strength of 420 lb. In subsequent, similar tests using green pellets containing graphite or limestone, pellet disintegration was more severe, with 10 to 40 percent of the feed being lost as dust. The surviving pellets had metallizations ranging from 88.3 to 94.4 percent and compressive strengths ranging from 60 to 68 lb.

Jan 1, 1976