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By H. P. Greenwald

"INTRODUCTION In the course of its studies of the explosibility of various coal dusts in the Experimental coal mine, the Bureau of Mines has tested coals representing the entire range of volatile content found in the United States. In connection with their work the Bureau's field engineers some¬times meet operating officials who are not impressed by the fact that there is an explosion hazard in mines working low—volatile coals. Actually the difference in explosion hazard between high—volatile and low—volatile coals is one of degree and not of kind. The purpose of this paper is to set forth briefly the experimental evidence that has been accumulated on the explosibility of coal dusts containing 8 to 31 percent volatile matter on a dry, mineral—matter—free basis.There have been numerous dust explosions in mines in which coals were worked that have compositions within this range. Those explosions are listed in an appendix, together with a bibliography of Bureau of Mines papers describing explosion tests in the Experimental coal mine."

Jan 1, 1940

By E. M. Tignor

A research program to aid development of improved methods for increased production of petroleum from partly depleted reservoirs is a vital part of the Bureau of Mines effort to effect true conservation of that mineral resource. This report presents results of an investigation to identify the clay minerals within some Appalachian petroleum-reservoir sands, the effect of clay content on the fluid-flow behavior of those sands, and the use of brines in water-flooding operations. Permeability measurements using kerosine, calcium chloride brine, simulated oilfield brine, potassium chloride brine, sodium chloride brine, and distilled water were made on reservoir-rock cores. Clay fractions were separated from sand grains of disaggregated portions of each core sample, and the clay minerals were identified by the differential thermal analysis method. Relations of the permeability to various fluids were developed.

Jan 1, 1957

By [F. P. ] Stambaugh

Results of research on the hydrothermal precipitation of zirconium oxide from the Bureau of Mines' zirconyl chloride-sulfate strip liquors indicate that nuclear grade material can be prepared by this process. Greater than 99% of the zirconium value can be precipitated at 250-260°C in short (5-10 minutes) reaction time without consumption of acid value of the liquor. Thus, precipitation of zirconium dioxide on a continuous basis, i.e., the zirconium dioxide is precipitated in a continuous mode of operation by pumping the strip liquor through a heated pressurized reactor and recycle of the acidic (spent) liquor to the process stage are favored. The results of accompanying studies of liquod/solid separation, product washing and dewatering, product purity, and chlorination of the product are presented and discussed.

Jan 1, 1980

By N. A. C. Smith

This report on the physical and chemical properties of typical crude oils of southern Louisiana and southern Texas is the seventh in a series of preliminary chapters of a bulletin covering the producing districts of the United States. Preceding reports* may be obtained from the Bureau of Mines on request. The details of the methods used in this survey in collecting samples and making laboratory tests have been discussed in the first three papers. A method of summarizing and interpreting the laboratory data has also been given, but most of the crudes included in the present report differ so radically from those previously reported, that it has been found advantageous to adopt a somewhat different method in making summaries. This method is described in detail later. If any errors or omissions are noted by readers, it is hoped that these will be brought to the attention of the Bureau of Mines, for correction before the appearance of the final bulletin.

Jan 1, 1922

By Robert H. Ridgway

This paper presents the results of the second in the series of annual canvasses on the consumption of ferrous scrap and pig iron in the United States, inaugurated in 1935 by the Bureau of Mines and published in Report of Investigations 3329. The study was undertaken in response to requests from trade organizations and others for detailed statistics on this phase

Jan 1, 1937

By J. Owens

Advanced materials development ranks as one of the most important high-tech industries of the future in the United States. Recent breakthroughs can be attributed to advanced computer technology, powerful mathematical models, and more precise analytical tools that enable scientists to examine and control properties of materials as never before. Discoveries now being made are providing many industries with opportunities to improve product lines, fabrication techniques, product reliability, and so forth. More¬over, industries, such as space, medicine, and defense, which require stringent: design and perfomance specifications in highly competitive world markets, increasingly demand these new materials. The definition of advanced materials used here is one that has been adopted by the U. S. Bureau of Mines: Those materials which have been developed over the past 30 years or so, and which are being developed at present, that exhibit greater strength, higher strength-density ratios, greater hardness, and/or one or more superior thermal, electrical, optical, or chemical properties, when compared with traditional materials.

Jan 1, 1991

By M. J. Ankeny

This is a study of 58 fatal haulage accidents investigated by Federal coal-mine inspectors during the period January - June 1951. The information presented in this circular was obtained by analyzing fatal haulage accidents in 33 bituminous-coal producing counties representing 11 States. The physical conditions represent a cross section off producing coal beds. Mining and transportation methods vary, from those of small hand-loading mines to those of large modern mechanized operations. These data are thought to be representative of haulage conditions within the bituminous-coal mining industry and are submitted to follow up the Information Circular 7604 ?Analysis of Haulage Fatalities in Bituminous-Coal Mines - 1950.? Coal-mine haulage ranks second as a cause of coal-mine fatalities, and the problem of haulage safety is complex. It is subject to constant change and is comprised of numerous influencing variables, which are not always obvious. The solution to this problem will not come through the application of any standard formula or mechanical approach since the inherent factors are strongly influenced by the human equation, and the chain of circumstances is further affected by expediency.

Jan 1, 1951

By R. L. Solmer

During 1959-61, the Bureau of Mines investigated the strain and deformation induced in rock and concrete linings around mine openings by retreat panel caving at the Climax Molybdenum mine. Two concrete-lined slusher drifts on the Phillipson level of the mine were instrumented with both electrical strain gages and extensometers. Changes in strain and deformation were recorded over an 18-month period during the undercutting and caving of the mining panel. General agreement was found between the strain and deformation measurements and the hypothesis that the vertical component of the stress field on the openings is almost completely removed by undercutting. This phenomenon is a possible explanation for the structural failures that occur in the slusher drifts during the undercutting cycle.

Jan 1, 1965

By I. L. Nichols, K. C. Dean, P. H. Johnson

Hydrochloric acid , sulfuric acid , and chloridizing roast- water leaching methods for dissolution of cesium and rubidium from Maine , Canada , and Southern Rhodesia pollucite ores and their flotation products were investigated by small- scale tests . Optimum conditions were determined to be ( 1 ) for hydrochloric acid leaching , use 12.7 equivalents of 8.8 normal acid per equivalent of cesium in the sample and leach for 6 hours at 100 ° C ; ( 2 ) for sulfuric acid leaching , use 12.7 equivalents of 14.4 normal acid and leach for 2 hours at 120° C ; and (3 ) for chloridizing roast - water leaching , roast minus 200 - mesh ore, limestone , and calcium chloride in a ratio of 2 : 4 : 1 , respectively , for 1 hour at 900 ° C , and leach the calcine for 1 hour at 80 ° C with enough water to give 35 pct solids . Extractions of cesium from ores and flotation products containing over 20 pct cesium were in excess of 97 , 93 , and 96 pct for the hydrochloric acid , sulfuric acid , and chloridizing roast - water leach processes , respectively .

Jan 1, 1964

By Arthur L. Murray

"While serving as surgeon with rescue car No 11 of the U. S. Bureau of Mines, the writer visited the principal metal-mining camps of Utah during the latter part of 1919. In visiting the mines, meeting and conversing with miners, and talking over the medical situation with physicians in the various camps, the number of cases of lead poisoning encountered was great enough to attract attention.With a view to procuring more definite information as to the number and distribution of cases of lead poisoning throughout the State, a study of the records of the State Board of Health was undertaken. Utah had no ordinance re¬quiring the reporting of occupational diseases, so it was not possible to secure data an cases A study of the mortality records by years gave the following results.:Year Deaths from lead poisoning.1910,11911,01912,21913,11914,61915,41916,11917,31918,11919,2These few deaths would seem to indicate a fairly low case rate, but when it is realized that lead poisoning is rarely an immediate cause of death and that the train of sequelae in this disease frequently leads to chronic involvemeets of the digestive, nervous, circulatory or genito-urinary systems, it is apparent that the number of deaths showing lead poisoning as the cause can not be taken as an index of the cases prevalent. The time elapsing between the presence of the active signs of lead poisoning and the terminal illness from pathologic conditions excited by lead absorption may be years, and the initial cause, lead poisoning, is frequently lost sight if entirely, hence the death certificate shows no evidence of the primary cause."

Aug 1, 1921

By R. H. Sprute

The Federal Bureau of Mines conducted full-scale field tests in electro-kinetic dewatering and consolidation of slimes in cooperation with the Hecla Mining Co. at two of the firm's underground mines in north Idaho. To test the technique on new deposits, 4,000 ft3 of slimes from a collection sump, pumped into a watertight stope equipped with electrodes, were treated in two steps. Immediately after placement, direct current was applied using a floating electrode to hasten settlement of suspended fine particles. After removal of clarified water, the residue was further dewatered and hardened with electrokinetic treatment. In 25 hours, the material had become firm and dense with a surface capable of supporting workmen. In testing old deposits, 10,000 ft3 of slimes, placed in an unused tail drift 10 to 12 months previously, were treated. This material was sufficiently consolidated by electrokinetics to allow its removal from the mine with standard ore-handling equipment. In both tests, electrokinetic treatment densified slimes in a relatively short time with moderate power consumption.

Jan 1, 1976

By D. R. Hanson

This Bureau of Mines study examines the acoustic vibrational spectra of rock slabs in the range of 0 to 5,000 Hz. The power spectra of so-called drummy rocks were found to be diagnostically enhanced in the range of 200 to 1,000 Hz. Comparison of the power in this band with that in a band from 3,000 to 3,500 Hz provides a quantitative measure of rock stability. A prototype field instrument was designed, constructed, and field-tested. This battery-powered instrument computes the power contained in the two frequency bands mentioned, compares the magnitude of these two quantities, and displays a number that is related to the detachment of the block tested. Field tests show that this instrument is capable of giving reliable measurements of block stability under conditions of noise and dust that would seriously degrade the accuracy of normal sounding techniques.

Jan 1, 1985

By A. L. Engel

Production of chromite in California has been from many small, high-grade mines. The opening of the Purchase Depot at Grants Pass, Oreg., in 1951 has stimulated chromite mining in California, and a large number of properties are being reexamined as there is a possibility that some low-grade ores from many of these properties can be beneficiated to meet the purchasing schedule. The Bureau of Mines in its program of conservation is continuing ore-dressing tests on chromite ores to better evaluate their potential. This report is a compilation of preliminary concentration tests on samples from five different properties in California. The concentration tests were made on ores from the David mine, Butte County, the Seiad Creek mine, Siskiyou County, the High Plateau mine, Del Norte County, Bud's mine, Tuolumne County, and tailings from the Miller concentration plant in San Luis Obispo County, Calif., to determine the possibility of beneficiating these ores so that they will meet the specifications for the Government stockpile.

Jan 1, 1956

By P. R. Bremmer

As part of a program to devise alternative technologies for producing alumina from domestic resources, the Bureau of Mines investigated the leaching of calcined kaolinitic clay to form basic aluminum chloride solutions. Bench-scale experiments were conducted for single-stage batch leaching with AICl3 solution and three-stage countercurrent leaching with substoichiometric HCI. Variable conditions of clay calcination and leaching were studied to determine their effects on aluminum extraction and pregnant liquor composition,

Jan 1, 1984

By Susan M. Moore

Many challenges are faced by workers in lower-seam (42 inches or less) mines. The lower-seam heights confine mine workers to their knees as they perform their daily tasks such as installing roof bolts, delivering supplies, repairing belt, or cutting coal. Miners working in these lower seams often consider kneepads to be their only line of defense against knee injuries. However, healthy knees do not start and stop with kneepads. Other interventions such as changing postures, proper hygiene, and work station design may also be used to reduce mine workers? risks for developing knee injuries. Incorporating these and many other interventions into a mine worker?s ?way of life? is an important step to ensuring a long, healthy career and retirement. Keeping knees healthy is also a key aspect to reducing costs in low-seam mines as the industry battles rising health care costs, and training/recruitment of replacement workers is time-consuming and costly. Educating the workforce about the possible interventions to reduce knee injury risk is a primary objective for the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). Therefore, NIOSH researchers, along with industry and academia, developed a training package to educate the mining com­munity about some possible interventions beyond kneepads that may be used to help decrease knee injury rates. Increased awareness and simple changes are the first steps to reducing knee injuries.

Jan 1, 2008

By Eugene H. Skinner

The U.S. Bureau of Mines conducted experiments on the use of lightweight concrete in the density range of 100 Ib/ft3 for liners in underground mines. Three test sections were completed: a monolithic, portal-type structure with integral walls and arch constructed aboveground; an underground test section constructed in a mine drift using plywood forms; and a second section constructed in a drift using an air-supported formwork. The lightweight concrete in the two underground test sections was placed using piston pumps and a slickline. Fiber reinforcement was added to the concrete in the mine sections without any apparent problems with either pumping or placement of the concrete. In another experiment, the Bureau and Hecla Mining Co., Mullan, rD, used lightweight concrete in the density range of 25 Iblfe to replace timber blocking in a raise preparation structure. Other experiments are described in which low-density, lightweight concrete blocks were produced for mine ventilation doors, stoppings, and barricades. Other mine uses reviewed include pillars and collapsing beams. An advantage of low-density concrete is that it will display up to 50% deformation at a constant yield stress. These hlllovative concepts in deformable concrete lining systems will aid mine operators by decreasing capital and maintenance costs, increasing the available space in underground haulageways, and providing productivity gains and improved resource recovery in the soft, caving, squeezing, or bursting grollnu conditions often found in deep mines.

Jan 1, 1989

By D. S. Kingery

Efficient transportation is necessary to complement modern mechanized mining methods. The increasing trend toward high-capacity face loading equipment has demanded equally efficient haulage methods; this has been met by increasing mine-car sizes, using larger locomotives, and increasing haulage speeds, all requiring properly installed and maintained haulage roads specifically designed for this type of traffic. The recommendations and specifications included in this circular were made to point out salient factors important to the proper construction and maintenance of track haulage roads and to serve as recommended standards for track installation and maintenance. GLOSSARY OF TERMS USED Haulageway. - The track, walkway, trolley wire, feeder lines signal end telephone lines, signals, telephones, support, and drainage of the entry referred to. Subgrede. - The base upon which the ballast is laid.

Jan 1, 1954

By Ernest W. Johnson

In most underground iron mines in the Lake Superior district the active workings are at considerable depth. When additional openings into such. nines are needed, operating officials are eager to discover more efficient methods of constructing them. In recent years, openings into two mines in the district were made by the borehole method,-which employs chilled-iron shot as the cutting medium. Others were made by the churn-drill method, in which pilot hole is churn-drilled and subsequently reamed to a desired but relatively small diameter. Both methods are comparatively new and unique, at least in some phases and in their application.

Jan 1, 1946

By W. E. Anable

The Bureau of Mines researched methods for recovering copper from cyclone and electrostatic-precipitator dusts of primary copper smelters as part of its program to maximize minerals and metals recovery from primary and secondary domestic resources. Small-scale studies showed that use of 110 pct stoichiometric sulfur and 123 pct stoichiometric carbon, based on producing a 40-pct copper-iron matte, resulted in the recovery of 95 pct of the copper contained in the dust. Typical mattes contained less than 10 pct of the arsenic, 30 pct of the bismuth, and 45 pct of the antimony and tin contained in the dust. Matte was converted to blister copper by injecting up to 200 pct of the stoichiometric oxygen requirement over a period of 2 to 3 hours. Up to 76 pct of the copper contained in the dust was recovered as a crude blister copper containing about 2 pct arsenic, 0.5 pct antimony, and less than 0.1 pet bismuth and tin. A matte-white metal product resulted from carbothermically reducing dust with coal, lime, and silica. Up to 95 pct of the copper was recovered in the combined product.

Jan 1, 1981

By Wilber Duvall, Leonard Obert

"INTRODUCTION This report is the first of four to be presented on the microseismic method 4/ of predicting rock failure in underground mining. The application of the microseismic method to one specific case, namely, that of predicting rock bursts in deep mining, has been described in two previous reports. 5/ 6/ Since the publication of these reports 5/ 6/ the method has been extended to other fields of mining, end it is the purpose of this report (Part I) to describe the general microseismic method, giving the empirical facts upon it is based, the different testing procedures, the method of recording and analzing the data, and the interpretations that can be obtained there-from. Part II will describe a series of laboratory experiments that were performed to give information on the origin of microceismims and the microseismic properties of various rocks. Part III will cover application of the method to specific mining problems together with a brief description of a number of investigations performed during, the last three years. Part IV will describe in detail the microseicmic equipment used in the various phases of these investigations."

Feb 1, 1945