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By John C. Cook

A 1-year program of exploratory research, to determine the feasibility of radar exploration in advance of coal mining, has been completed. Advance detection of obstructions including faults, clay veins, abandoned wells, and pyritic concretions would improve the safety and efficiency of mining. Initial calculations based on laboratory tests of the RF electrical properties of bituminous coals indicated feasibility; radar waves at frequencies below 100 MHz should be detectable through tens to hundreds of meters of coal and be well-reflected by clay, pyrite and metal obstructions. Using a proprietary, experimental, VHF short-pulse "mining radar" system, two cycles of field testing and equipment improvement were completed. Measurements were made in three bituminous coal mines, a quarry, and a salt mine. Comparisons were made with ground-penetrating radar equipment developed by others for salt dome exploration and for military tunnel detection. The proprietary mining radar equipment and techniques used were found to be the most effective known for coal exploration, but further improvements are needed; one major problem in all systems is interfering clutter signals arising in the equipment and from mine room reverberations through leakage coupling of the antennas to the air. Nevertheless, several practical goals have been achieved: excellent radar reflections were received and identified through up to 30 feet of coal; reflections from a wet, abandoned drill hole were identified by their polarization property and detected at distances up to 272 feet, and mine-wall reflections were detected at distances up to 735 feet (both through salt); propagation through and reflections from large vertical clay veins in coal were demonstrated; experimental results agree reasonably well with theory. The results and experience gained during the project affirm the feasibility of the method. They also provide a firm basis for the development of a practical radar technology for exploration in advance of mining. No Subject Inventions, as defined in the contract, were made in the course of this work.

Jan 1, 1971

By R. Havens, B. K. Shilber

"INTRODUCTION In the course of the investigation of the occurrence of manganese deposits in the western United States, ore-dressing tests were made on three samples procured by Bureau of Mines engineers from two properties in southeastern Juah County, Utah, each of which is known by the name Black Jack. To avoid confusion, the tests will be described under the names of the owners Kendall-Duvall and the Empire Mines.None of the samples were amenable to ore dressing for the production of high-grade manganese sinter.Ores from the Kendall-Duvall deposit represent an interesting metallurgical phase of low-grade manganese occurrence, as the occurrence of manganese as silicate (braunite) automatically governs the extent to which they can be beneficiated by mechanical methods of treatment. As less than 50 percent of the total manganese was recoverable by complex methods of treatment in a 40- percent-manganese sinter, attempts were made to recover most of the manganese in a low-calcite, intermediate-grade product that might be acceptable for subsequent metallurgical treatment. By selective flotation of calcite and manganese, up to 68 percent recoveries were obtained in plus 20-percent manganese products..No encouragement can be given for successful ore-dressing of Empire ores as represented by samples received for testing, as no products were obtained that would meet minimum marketing specifications. Empire ore contained only 1 percent lime and might be high enough in grade (19 percent manganese) for direct hydrometallurgical treatment."

Nov 1, 1947

By D. J. Bauer

A primary amine extraction system was investigated for fractionating a cerium-group, lanthanide sulfate mixture. Addition of diethylenetriaminepenta-acetic acid (DTPA) to the amine extraction system resulted in separation factors as high as 5.4 for lanthanum-cerium, 8.0 for cerium-praseodymium, 3.7 for praseodymium-neodymium, and 7.0 for neodymium-samarium. In multistage studies on a cerium-free lanthanide mixture, 96 percent of the lanthanum was recovered with a purity of 95 percent.

Jan 1, 1968

By E. V. Cilento, K. A. DiGregorio, R. C. Lantz

"An electro-optical method was used to quantify superoxide (SO) release from single rat pulmonary alveolar macrophages (PAM) exposed in vitro to respirable quartz and kaolin dusts and in vivo to quartz. Release was determined by measuring the reduction of nitroblue tdrazolium (NBT) to a diformazan precipitate at 550 nm from video-recorded images of individual cells. In vitro exposure to 0.025 or 0.05 mg/ml kaolin for 40 minutes resulted in no significant differences in either the total diformazan produced (max) or the maximum rate of diformazan production (R)./n vitro exposure to 0.025 mg/ml c1uartz decreased max 38 percent while no significant change was found using 0.05 mg/ml. However, R was decreased 31 percent and 24 percent for the low and high dose, respectively. In contrast, PAM obtained from animals exposed in vivo to quartz dust for two or four weeks in inhalation chambers exhibited increased production of diformazan. However, only PAM analyzed three days post-exposure showed significant increases, while PAM from animals sacrificed ten or 31 days post-exposure were not significantly different from control. The combined in vitro and in vivo quartz results might suggest that there is an initital acute response to exposure that decreases the ability of PAM to produce SO, followed by recruitment of production of PAM with increased SO producing capability. It appears that removal of animals from the source of exposure permits PAM to return to control levels of SO production by31 days. Whether this would be true for chronic exposure remains to be elucidated.IntroductionPulmonary alveolar macrophages (PAM) protect the lungs by phagocytizing foreign debris and bacteria.(1) This process involves ingestion as well as destruction of foreign matter. Phagocytosis usually is accompanied by a respiratory burst which increases cellular oxygen consumption leading to the release of highly reactive oxygen metabolites.(2) These agents have been implicated in the killing of bacteria by phagocytes, but they have also been shown to be toxic and,have been linked to cancer, emphysema, arthritis, diabetes, and other diseases.(3) Toxic effects may be a result of 1) an abnormally low production of metabolites, resulting in damage to lung tissue by the respired bacteria and/or dusts; or 2) an abnormally high production resulting in direct damage to lung tissue by metabolites themselves."

Mar 1, 1989

By W. D. Mcmillan

Soapstone is the term applied to an impure, massive, soft rock with a greasy feel. It is of variable composition, consisting chiefly, however, of talc, tremolite, and chlorite. Although limited quantities of soapstone are used as building material, in fireplaces, and in the manufacture of laundry tubs, sinks, laboratory-table tops, and-oven and furnace blocks, the principal part of the production is ground for use in roofing paper, insecticides, and as a filler in asphaltic paints.

Jan 1, 1949

By D. Harrington

While apparently the hysteria with regard to silicosis and other occupational diseases has largely subsided and this subject is being more carefully considered and soberly judged, it would be poor policy for any employer to maintain that the storm has ended and that he can relax and revert to conditions as they were 5, 10, or more years ago. The fact is that the plan of paying occupational-disease compensation is now in its infancy and can be expected to grow rapidly. At present, while all of the States of the Union, including the District of Columbia and excepting only Arkansas and Mississippi, have compensation acts, only the following make provision for occupational diseases to some extent or in one way or another: California, Delaware, Connecticut, District of Columbia? Illinois, Indiana, Kentucky, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Jersey, New York, North Carolina, North Dakota, Ohio, Pennsylvania, Rhode Island, Washington, West Virginia, and Wisconsin. Silicosis is compensable in one way or another in California, Connecticut, District of Columbia, Illinois, Kentucky, Massachusetts, Missouri, New York, North Carolina, North Dakota, Ohio, Pennsylvania, West Virginia, and Wisconsin, and possibly in other States. During the past few months, occupational-disease legislation (largely silicosis) has been considered in some form in Arkansas, California, Delaware, Idaho, Maryland, Kansas, Massachusetts, Michigan, Minnesota, Montana, Nebraska, New Jersey, Ohio, Pennsylvania, Tennessee, Utah and Washington. It will be surprising if comparatively comprehensive occupational-disease legislation is not on the statute books of nearly every State in the Union within the next 5 years. With this situation confronting him, the farsighted industrialist who has the interest of his organization at heart, if he has not already done so will immediately start to "put his house in order" by studying possible occupational disease hazards to his employees and promptly applying known remedial measures or attempting to devise such measures if none exist. Unquestionably, one of the most important of the surveys to be made relates to dust occurrence, as State laws on occupational disease are almost certain to contain provisions, on silicosis and, with almost equal certainty, the provisions of any State law are not likely to be particularly similar to those of other States.

Jan 1, 1938

By Thomas Fraser, William L. Crentz

"INTRODUCTION Sulfur is a most damaging impurity in many of our American coals. From the older coal industry of Europe and Britain we can apparently learn but little about the problem of preparing and using high-sulfur coal. Although washing has long been established there for controlling ash content, sulfur is referred to rarely, as the important deposits are singularly low in sulfur.On the other hand, widely distributed coal deposits of America differ tremendously in sulfur content. Many of the more extensive beds contain too much sulfur for metallurgical use, and almost everywhere except in the Rocky Mountain and Pacific coast regions sulfur control is at least a potential problem. American coal-preparation engineers are confronted not only with great variations in the total quantity of sulfur in coal but with an intricately varying pattern of the physical and chemical forms in which the sulfur occurs. It must be conceded that the baffling problem of sulfur reduction in coal is as yet substantially unsolved, for there are but few isolated instances in which we have been able to prepare a satisfactory metallurgical fuel from coals containing as much as 2.0 percent sulfur in the raw state.It has been assumed generally that organic sulfur, being chemically combined with carbonaceous matter, is distributed throughout the coal matter and that it remains unchanged in the clean-coal part of the product during washing.Sulfur that may be washed out of the coal is that part that is combined with the iron in pyrite lenticles associated with the coal. In most of our coals it has been found that, besides the visible bands, lenses, and flakes of pyrite, extremely small and even microscopic particles of pyrite 4/ are distributed through the coal matter. Only the free, relatively coarse pyrite particles .are removed by conventional coal-washing devices, and usually most of the sulfur is still left in the product."

Dec 1, 1947

By W. W. Agey

The Calico silver-barite deposits near Barstow, Calif., are a potentially important resource. Exploration performed by two major mining companies out-lined large tonnages of ore that assayed at 2 to 3 ounces of silver per ton and 7 to 15 percent barite. Laboratory beneficiation work was done by the Bureau of Mines on four samples to develop methods for recovering the silver and/or barite. Cyanidation recovered from 47 to 60 percent of the silver from ore ground to approximately 100 percent minus 325 mesh. Salt roasting minus 10-mesh material, followed by regrinding and cyanidation, recovered 75 to 85 percent of the silver. From 75 to 90 percent of the barite was recovered in a plus 92-percent barite product from either the natural ore or from cyanidation residues. Salt roasting before cyanidation precluded recovery of the high-grade barite concentrate from the leach tails.

Jan 1, 1973

By Eugene Frey

The Romur is one of several properties in the Copper Mountain mining district, Fremont County, Wyo., that contain scheelite deposits. The district lies on the southern slope of the Bridger Mountains, 18 miles northeast of Shoshoni and 15 miles from the rail point at Bonneville on the Chicago, Burlington & Quincy Railroad (figs. 1 and 2). The tungsten deposits occur in a zone of pre-Cambrian schists and gneisses that have been cut by numerous basic dikes and granite pegmatite dikes. Scheelite occurs in lenses and pods that lie parallel to the foliation and bedding in the metamorphic rocks. The more important deposits are found in a lime-silicate rock consisting primarily of zoisite but with small quantities of quartz and carbonate. Scheelite was found in December 1941, and the area was mapped by the U. S. Geological Survey early in 1942. In November 1942 the Bureau of Mines commenced work on the Stardust-Comet group for the purpose of developing reserves for war requirements. The initial work consisted of driving an alit in the ore zone a distance of 109 feet. This zone was sampled during the progress of the work, and subsequently surface and underground exposures on adjoining properties also were sampled (figs: 5, 6, 7, and 8). One hundred twenty-four samples were obtained. Sample and assay data are shown in tables 2, 3, and 4.

Jan 1, 1950

By Gary W. Krantz

Fibered, portland-cement-based gunite products were applied in the Bureau of Mines Lake Lynn Laboratory Experimental Mine using a variety of pneumatic guns and gunning crews, The demonstrated wet-mix (with silica fume), dry-mix, and surface bonding products were sampled by the Bureau and subjected to a suite of engineering analyses. Gunite flexural and compressive strength, rebound, permeability, porosity, dust loading, shooting rate, crew requirements, and cost factors were evaluated. Steel, fiberglass, or polypropylene fibers were contained in all but two of the gunires tested. Both Bureau and private testing laboratory analyses are provided for some products. Electron probe micro-analysis and X-ray diffraction analysis were performed on the silica fume fraction of the wet-mix gunite to characterize the dust. Aggregate size fraction distribution analyses were performed to provide strength relationships. Results indicate that all of the commercially available fibered-gunite materials tested can provide beneficial sealant, spall prevention, or roof stability control attributes for underground mining environments when applied by an experienced crew using a well-maintained gun, in accordance with product manufacturers' recommendations and when used for the designated purpose.

Jan 1, 1984

By J. Whyatt

A package of bench design programs is being publicly released by the National Institute for Occupational Safety and Health (NIOSH). These programs are designed to provide a probabilistic estimate of the likelihood that various widths of catch bench will be retained. Program modules address the mechanisms of plane, plane step path, and wedge failure. Results are drawn from statistical and geostatistical descriptions of fracture characteristics and other input parameters, and reported as the statistical chance that a given width of catch bench will survive, that is, that a catch bench will remain wide enough to catch rolling and sliding material and prevent such material from posing hazards to miners operating below. The capabilities and application of this software are demonstrated through a case example. Comparing bench width estimates obtained using geologic data with actual widths is a key step in verifying that a program is appropriate for particular site conditions and that proper statistical descriptions of fracture parameters for that site have been developed. Such verification efforts improve confidence, and hence usefulness, of this method for designing future slope benches. Development and release of these programs appears particularly timely given recent progress in photoanalysis methods, which promise to greatly reduce the cost of collecting fracture data.

Jan 1, 2004

By Jeffrey M. Listak

The Bureau of Mines has conducted a rock mechanics study to monitor deformation of near-seam strata above a longwall panel in the Pittsburgh Coalbed. The primary goal was to determine the height of caving immediately behind advancing longwall face supports. This study, although site specific, provides information on the caving mechanism associated with longwall extractions so that strata behavior and its interaction with longwall face supports can be better understood. Two holes were drilled, approximately 550 ft apart along the center line of a longwall panel, from the surface to the coalbed approximately 650 ft below. Various downhole geotechnical instruments were used to monitor strata deformation. In addition, surface elevation surveys were conducted to differentiate between surface and subsurface activity. This report discusses the caving characteristics of the strata as the longwall panel approached and passed beneath the boreholes. Physical property data are also presented to demonstrate the relationship between caving behavior and local geology. Data show that immediate caving of strata above the longwall face occurred at a height less than 23.5 ft and that strata behavior above longwall extractions is highly dependent upon lithology, with major disturbances occurring at weak lithologic zones.

Jan 1, 1986

By G. W. Jones, I. Spolan

"INTRODUCTION The operation of internal-combustion engines at high altitudes and the general aspects of combustion processes in rarefied atmospheres have created considerable interest in the problem of ignition and flame propagation at low pressures. Nuckolls, Matson, and Dufour 4/ have published results on the effect of low pressures on the propagation of flame in gasoline vapor-air mixtures in vessels of large capacity. The volumes of their test equipment varied in capacity from 0.425 to 125 cubic feet. Various sources of ignition were employed. These authors found that the explosive range of gasoline vapor in air decreases with decreasing pressure at pressures considerably below atmospheric, until a limiting absolute pressure of about 33 mm. mercury at ordinary temperature is reached, at which point no appreciable flame is propagated.Experiments carried out at the Bureau with natural gas-air mixtures at reduced pressures have shown 5/ that the limits of inflammability are but little affected at reduced pressures down to 175 mm. mercury. As the pressures of natural gas-air mixtures are reduced below atmospheric, the mixtures become more difficult to ignite; however, if a suitable source of ignition is employed, the limits of inflammability are as wide at 175 mm. mercury absolute pressure as they are at atmospheric pressure. In view of these observations with natural gas-air mixtures, it appears important to investigate gasoline vapor-air mixtures for possible similar behavior. For this reason the tests herein described were carried-out."

Oct 1, 1946

By Ralph H. Espach

The value of careful fractionation in the manufacture of petroleum products is recognized more and more by petroleum refiners. Recent studies have shown that the quality of the products depends largely on the type of fractionating equipment and on the care used in operating the equipment. For example Rue3 has shown that careful fractionation of pressure distillate will greatly reduce the amount of chemical treatment necessary to produce finished gasoline. The advantages of the combination of pipe still and bubble tower in obtaining good fractionation are well recognized in the petroleum industry. However, the equipment designed in the past has in general been much too large for convenient laboratory use. The present paper describes a continuous-distillation apparatus for the laboratory study of fractionation. This apparatus has given very satisfactory results in the study of different crude oils and petroleum products. A discussion of the theory and action of bubble towers has not been given, as this subject has been discussed previously by Cooke and Rue4. It is believed that the distillation curves of the products obtained from this apparatus show clearly its capabilities.

Jan 1, 1928

By W. H. Tomlinson

During the 9 years ended December 31, 1938, 188 fatalities resulted from preventable accidents in and around the coal mines of Indiana; 173 of these occurred at underground mines and 15 at stripping or open-cut operations. In addition, there may have been other unrecorded fatalities during this period. The two organizations receiving notice of accidental deaths at coal mines in this State are the Division of Mines and Mining and the Indiana Industrial Commission. Only deaths occurring at underground mines employing 10 or more men are reported to the former, as neither strip mines nor underground mines employing fewer than 10 men cone within the purview of the Indiana mining law. The mine inspectors have no Jurisdiction over this latter group of mines and do not inspect them. Fatalities at small "wagon" mines and open-cut operations are supposed to be reported to the Industrial Commission; however, in many instances deaths at small mines are not reported, the only record being a death certificate filed with the county or corporation health officer. Thus, many deaths in small mines escape attention, especially when the victim succumbs some time after the injury was received. The data presented here on fatalities in Indiana, during the past 5 years include several instances in which the only record available is a death certificate; possibly others have been overlooked. From 1934 to 1937 the fatality record was progressively worse, that of the larger underground mines in 1937 being more than twice the average for these mines for the previous 4 years and only slightly less than twice the average for all mines, including open-cut operations. The increase in deaths during 1937 was due to two explosions, with 20 fatalities in one and 2 in the other. The number of deaths in the larger underground mines was considerably less in 1938 than in the previous 4 years, but there was no improvement in the number of fatalities at the small mines, or at open-cut mines.

Jan 1, 1940

New Continuous Personal Dust Monitors (CPDM) submitted to NIOSH for approval to sample coal mine dust must accurately measure respirable coal mine dust in mine environments. There are two steps in the process which may be done in any order. The manufacturer is required to submit the results of a comparative underground coal mine dust sampling study, where the candidate CPDM is compared to an approved coal mine dust sampling device (currently the Coal Mine Dust Personal Sampling Unit (CMDPSU)). This testing shall follow the guidelines outlined below and shall demonstrate through weighted regression analysis that the mean coefficient of variation with bias correction is equal to or less than 12.8%. The other step involves laboratory testing to determine the electronic and environmental stability. This testing must be conducted by a private, commercial, academic or other laboratory approved by NIOSH.

Jan 1, 2009

By Thomas L. McVay

Laboratory batch and pilot plant flotation tests were made to determine the feasibility of recovering commercial grade kyanite from a quartzite- kyanite rock from the Graves Mountain, Ga., deposit. Best results in laboratory and continuous tests were obtained using sodium carbonate for pH control, citric acid for quartz depression, and oleic acid as the kyanite collector. Over 80 percent of the kyanite was recovered in a concentrate analyzing 56.8 percent Al203 and 3.8 percent hydrochloric acid soluble Fe203. Subsequent treatment of the flotation concentrate by magnetic separation reduced the acid soluble Fe2O3 to 0.6 percent and increased the alumina content to 59.2 percent. Acid leaching of the concentrate gave a product analyzing 59.7 percent Al203 and about 0.1 percent Fe203. As a result of the beneficiation research, a commercial kyanite flotation plant was completed in September 1962 by private industry.

Jan 1, 1963

By A. E. Harak

To determine the retorting characteristics of a column of mine-run, ungraded oil shale ranging in size from fines to pieces weighing as much as 5 tons, a 150-ton batch retort was designed and constructed at the Laramie Energy Research Center, Laramie, Wyo. The retort vessel is 45 feet high by 11-1/2 feel in inside diameter and is supported in a 92-Foot-high steel superstructure. Mine-run shale from the Bureau of Mines facility near Rifle, Colo., assaying about 25 gallons of oil per ton, is currently being used as the test shale. To date, three runs have been completed. Results of the second and third runs are reported in this paper. The two runs considered in this report are the first of a series of nine to determine operating conditions that will yield maximum oil recovery from a column of mine-run shale. Variables studied :ire the oxygen content of the retorting gas and the space velocity of the retorting gas expressed as ft3 gas/ft3 bed/min. Oil recoveries for the two runs reported are 62.2 volume percent of Fischer assay for the run using higher oxygen and space velocity, compared with 39.3 volume-percent when less oxygen and a Lower space velocity were used.

Jan 1, 1971

By Thomas R. Bur

This method of performing general transformations by use of Eulerian angles greatly reduces the time required for the determination of values for the elastic compliance constants (sij), elastic stiffness constants (cij ), Young's modulus, shear modulus, or Poisson's ratio for any orientation the cartesian coordinate system in an anisotropic material.

Jan 1, 1969

By G. St. J. Perrott

Through the development of manufacturing processes whereby ethylene glycol can be made on a large scale; ethylene glycol dinitrate is now being used in high explosives (dynamites and permissible explosives) by some manufacturers as a low-freezing ingredient of the "explosive oil" instead of such compounds as nitropolyglycerin and nitrosubstitution compounds. The amount of ethylene glycol dinitrate being used constitutes 25 to 50 per cent of the oil. The purpose of this report is to give the results of toots, to determine the effect on the safety and physical properties of permissible explosives of subsituating 25 peg cent of ethylene glycol dinitrate for an equal amount of nitroglycerin or a mixture of nitroglycerin and nitropolglycerin.

Jan 1, 1929