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By A. O. Ipsen

As part of the Bureau's intensive investigation of domestic manganese deposits, lots of ore for testing were collected by Bureau engineers during examinations of several properties in Juab County, Utah. One low-grade and two intermediate-grade samples (13.5, 25.3 and 27.5 percent manganese) were procured by engineers of the Bureau of Mines from the 900--and 1,100-foot levels of' the Tintic Standard mine, situated 2 miles southeast of Eureka, Utah. The ore bodies were described as blocks of ore approximately 60 feet long, 40 feet wide, and 20 to 100 feet deep. The manganese-iron association in the Tintic Standard ores was intimate, and no significant concentration of the low-grade sample was made by ore dressing, However, both of' the higher-grade samples were readily beneficiated to marketable manganese products. Ore from the Oxen No. 5974 claim, 2 miles northeast of Eureka, Utah was low in grade (19.4 percent manganese) and was not amenable to the production of high-grade concentrates owing to the intimacy of association of the manganese minerals with silica. However, a fair manganese recovery was obtained in a product that, when sintered, assayed plus 40 percent manganese. The ore body is reported to be a replacement in limestone and is composed of manganese oxides intermixed with silica, decomposed rhyolite, and limestone. The Fields property consists of five mineral claims situated 3 miles north of Eureka, Utah. The deposit is a replacement in a contact between limestone and a quartz dike. Tests were made on representative samples of a 50-ton lot stored on the property. Although the mineral association in the ore (22.2 percent manganese) is not particularly complex, the physical properties of the manganese minerals render the ore refractory to ore-dressing beneficiation. As the ores varied widely in physical and chemical characteristics, samples from each property were considered as separate ore-dressing problems.

Jan 1, 1949

By C. C. Hwang

The Bureau of Mines formulated a method for calculating the concentration of entrained dust from a dust deposit by a turbulent gas stream. In particular, a diffusion equation is used to calculate dust concentrations in a channel following an explosion. Dust leaving the channel walls was treated as originating from stationary or moving, and single or multiple material sources. Formulas and sample computations for various types of dust sources in circular and rectangular channels are given, based on experimental entrainment rates. The analysis predicts the dust concentration as a function of time and channel space. The results appear to agree with the physical characteristics of explosion-driven dust dispersion in a O.6-m-diameter, 50-m-long explosion tunnel. The analysis is also applied to simultaneous and consecutive dispersion of coal and rock dust from simulated coal mine surfaces (walls, floor, roof, and ribs).

Jan 1, 1974

By F. S. LOTT

Publication of the Bureau of Mines annual surveys of the capacity of petroleum refineries in the United States was suspended after the entry of the United States into World War II . The last published survey was that of January 1 , 1941 , released in April 1941 as Information Circular 7161 . The purpose of this publication is to provide comparable information with respect to crude - oil and cracking capacity on January 1 , 1947. No attempt is made at this time to bridge the gap in annual statistical series from the date of the last published survey to the present one . However , complete summary tables will be included in the succeeding survey for January 1 , 1948 .

Mar 1, 1948

By Ludwig Schmidt

"IntroductionThe evaporation losses of gasoline in the refinery, can be reduced by proper methods of refinery construction and operation. When gasoline evaporates slowly, as when stored in tanks that are not vapor tight, the most volatile part evaporates first, so that the remaining liquid in not only less in volume, but is also lower in quality. In some,evaporation changes the characteristics of the product so much that it must be reblended to meet trade specifications.Refiners are, therefore, greatly interested in the various appliances and methods used to reduce these losses. In the past this interest has been directed largely to storage tanks, probably because evaporation from tanks is more readily observed than losses during other refinery operations. As tests by the Bureau of Mines on evaporation of gasoline from small storage tanks had indicated that the losses during the various stages of refining might be equal to or greater than those of standing storage, a survey was during the spring and early summer months of 1924 in a large number of refineries in the Mid-Continent field. In order to enable the refiner to select the results of those tests that conform most nearly to the conditions that he has to meet, tests were conducted at various stages of refining, as follows: (1) Randown tanks, (2) (agitators), (3) filling tank cars, (4) storage of refined products, and (3) miscellaneous handling. The results are presented in this paper."

Nov 1, 1925

By F. E. Diebold

The methodology for describing the geochemistry of elements in a coal seam have been developed. This has been applied to the Rosebud Coal Seam, which is an economically important member of the subbituminous coals of the Fort Union Formation in Eastern Montana. The method development has involved a detailed study of two popular techniques for determining the metal geochemistry of coal, namely, whole coal analyses and coal physical fractionation. The mathematically contrived element associations (whole coal analyses technique) and the element concentration trends in the float and sink fractions (physical fractionation technique) are considered to lead to only qualitative conclusions concerning the chemical associations of the elements in coals. Additionally, the processes taking place with the coal during low temperature ashing in an oxygen plasma are experimentally investigated and shown to be of sufficeint extent that the use of such low temperature ash for deciphering element geochemistry is questionable. The method developed in this study is a chemical fractionation that involves the sequential leaching of coal with water, 0.5 N HC1, 3 N HC1, 2 N HNO3, and 48% HF. These leach solutions are shown to selectively dissolve the predominate inorganic phases, sulfates, Ca and Mg carbonates, Fe sulfides and K alumino-silicates and quartz, respectively. These phases were identified with the use of XRD, SEM, EM and leaches (water and 0.3 N HC1) of whole coal and low temperature ash. The incorporation of the anion-exchange step in the leaching scheme was investigated and was observed to warrant further study of such intensity to be, at the time, unuseable. The use of this sequential leaching technique on several coal samples from the same seam generates element concentration trends that can be quantitatively interpreted with respect to the chemical associations of the minor and trace metals in the coal seam. The properties of the various seams of economic importance in the Fort Union Formation in Eastern Montana are compiled and presented. The subsequent conclusion is that there is not a large variation in the properties of these coal seams and that the variations within the Rosebud are within one order of magnitude. The chemical fractionation technique, investigated in this study, was applied to composite tipple samples of the Rosebud seam. Each composite sample represented 76,800 tons of coal. A minimum of 32% of the Ca and Mg are present as separate water soluble sulfates. An excess of the sulfate ion in the water extracts shows the predominating influence of the ion exchange capacity of the organic compounds in the coal. Based upon the CO content of the coal and the HC1 leachate data, 25 to 30% of the alkaline earth elements exist as separate carbonates and the remainder are associated with the organic compounds. The small fraction of the illite that dissolves in the HC1 and HNO3 leachates accounts for the K and Al. Slight dissolution of the pyrite in the HCl solvent occurs, the small amounts of Li and As do not relate to any known phase and Mn is present as a separate carbonate phase. Fe and a significant amount of the As exist in the pyrite that is dissolved in the HNO. Se is equally partitioned between the pyrite and the organic compound~. Most of the trace elements are found in the HF solutions. Li, V, and Cr were interpreted to be associated with the clay minerals (kaolinite and illite). Ni and Pb appear to be present as separate phases and 50% of the Hg is HF soluble but is not chemically related to any known inorganic phase.

Jan 1, 1983

By J. B. Gayle

Many investigators have reported studies of size distributions for particulate solids ; usually , these have involved the fitting of size distribution data to a particular mathematical function . Such studies are of unquestioned value and have contributed much worthwhile information regarding the breakage mechanisms for a variety of brittle materials . In connection with a Bureau of Mines study of the size distribution of coke , which has been subjected to the standard American Society for Testing Materials (ASTM) tumbler test , attention was focused on the relation between the 1 -inch tumbler index (usually considered to be indicative of the ability of coke to resist degradation by impact ) and the 1 /4 - inch tumbler index ( indicative of the ability to resist degradation by abrasion ) . Specifically , it was noted that for certain sets of data the correlation coefficients denoting the relation between these indexes were positive ; for other sets of data , these coefficients were negative . Preliminary consideration of this problem indicated that the usual interpretation placed on correlation coefficients was erroneous in this particular instance because the variables being correlated were necessarily related . The work described in this report was undertaken to clarify the interpretation of results of correlation studies for variables of this type .

Jul 1, 1960

By H. B. Humphrey, F. E. Cash

The Southern Appalachian coal field extends southward across Tennessee in a belt about 50 miles wide between the eastern and middle sections of the State. The earliest record of the production of coal in Tennessee is for 1840, and the first inspection laws were passed in 1881. In 1887, a second act of the legislature created the office of Chief Inspector, but little was done until 1891 when a new act was passed giving to the Department of Mines added duties and powers. Since that time, except for the years 1915 to 1918, com¬ prehensive annual reports have been published. Data for the tables given in this paper are taken from these annual reports, from those of the Southern Appalachian Coal Operators' Association, and from the publications of the United States Bureau of Mines, which has main¬ tained a station at Jellico, Tenn., since 1911. Complete figures for 1930 are not available yet and they are not included in the averages. The State Department of Mines, the operating companies, and the United States Bureau of Mines cooperate in accident-prevention work. It is the purpose of this report to present in uniform tables the available statistics in regard to fatal accidents in Tennessee and in the coal mines of the United States, in order that the progress in mine safety in Tennessee may be compared with that of the country as a whole, and the present period may be compared with various periods of the past, to indicate the main points of attack in the reduction of accidents.

Sep 1, 1931

By George S. Rice

"It is well known that the lost coal left in the ground in mining, under such conditions that recovery is practically impossible, constitutes a large proportion of the coal in the beds worked. A recent estimate, in a paper on ""The World's Fuel Supply"" presented by Prof. L. P. Breckinridge, of Yale University, before the Annual Meeting of the. American Society of Mechanical Engineers, places the average loss in bituminous coal mining as one-third left in the ground.The bald statement that there is a loss of one ton of coal for every two recovered may seem to those not familiar with coal mining to imply inexcusable and wanton waste. Perhaps a better way of expression is in terms of total recovery rather than in terms of losses. Many mine superintendents and mine owners will readily concede that their total recovery may be only 60 to 75 per cent, but to state that they are wasting 25 to 40 per cent arouses antagonism. The suggestion is of willful waste, whereas the majority of the operators try to the best of their ability to get a high recovery under the adverse and complex conditions that confront them. These involve natural, commercial, and labor conditions, and the requirement in many cases of boundary pillars under railroads and buildings, which may be called for in the deed or lease, or in the absence of specific exemption in the deed or lease, the common law requirement that a surface owner is entitled to the support of the surface."

Apr 1, 1921

By D. J. Parker

This report is based on data collected in and about the Liberty mine of the Liberty Fuel Co. by D. J. Parker and W. W. Kessler on December 13 and 14, 1933. An important phase of an examination to determine the general condition of a mine with respect to safety is the collection of dust samples from rock- dusted areas. Definite conclusions, based on intelligent interpretation of the analyses of such samples, can be reached only when the general condition of the mine is known. A similar examination and report were made on this property in January 1930 by D. J. Parker and R. I. C. Manning. Since that time much has been done by the management to improve safety conditions in this mine. The changes made will be noted in the course of this report. The mine is in Spring Canyon at Latuda, Carbon County, Utah, and is served by a branch line of the Denver & Rio Grande Western Railroad about 7 miles long and connecting to the main line near Helper, Utah. The writer desires to express his sincere appreciation for the many courtesies and helpful cooperation extended by Superintendent George Schultz and Mine Foreman F. W. Koelling.

Nov 1, 1934

In the interest of safety in mining, the Bureau of Mines recommends: 1. That cages or skips used for hoisting or lowering men in vertical and steeply inclined shafts shall be provided with safety catches designed to prevent falling of the cage or skip if the hoisting rope or other connections break; and 2. That cars used. for hoisting or lowering men with ropes in slopes shall be provided with arresting devices, other than ordinary brakes, that come into action if the hoisting rope or other connections break. In presenting this decision, it is recognized that the principal requirements for safety in hoisting operations are the use of hoisting ropes of ample size and strength to provide a factor of safety recognized as adequate by the best en engineering practice; their proper care, protection against undue wear and corrosion, and frequent inspection; and immediate removal of ropes from service when inspection or tests cast doubt upon their further safe serviceability.

Jan 1, 1938

By Terry S. Cory

This report covers magnetic field strength measurements vs range and frequency in low-medium coal mines. Both quasi-conductor-free and conductor-proximity areas were investigated. The program covered 5 mines, 4 seams, 6 measurement sets, and 3 geographic areas. The results have been summarized in terms of maximum communication range expected per seam and noise condition. Scatter gain is further explored as a simple measure of energy coupled to conductors.

Jan 6, 1978

By Annie G. Smelley

As part of its program to develop technology that will encourage maximum utilization of the Nation's mineral resources, the Bureau of Mines conducted research on debrining potash-clay waste slurries by means of flocculation with a high-molecular-weight polymer and subsequent solid-liquid separation on a rotating trommel screen. In laboratory batch tests, potash-clay waste slurries were consolidated from initial clay contents of 8 pct to final contents of 30 pct with a polymer dosage of 1.2 Ib/ton of dry clay waste. Small-scale continuous tests yielded debrined products containing 20 pct solids using a polymer dosage of 1 Ib/ton of dry clay solids.

Jan 1, 1983

By Phillip N. Yasnowsky

This Bureau of Mines report summarizes State severance taxes imposed on minerals and mineral fuels, provides a hypothetical example of how a State severance tax affects selected components of a firm's income statement, and uses the Bureau's Minerals Availability System (MAS) to estimate the effect of assumed changes in State severance tax rates on copper recovery cost at given levels of potential copper availability. A reduction of the rates to zero or a doubling of them results in changes in costs that are of the same order of magnitude as the cost of transporting copper to the United States from major foreign producing countries.

Jan 1, 1982

To develop a simple device for rapidly determining the shearing strength and angle of Internal friction of coal and rock in situ. Approach Use a portable, permissible, hydraulically operated device in boreholes as deep as 100 feet into the rib, floor, or roof of the mine. How it Works The device, called a Borehole Shear Strength Tester (BST), is inserted Into a 3-inch-diameter borehole to the desired depth, locked Into position, and activated to shear the rock or coal in the borehole walls. The normal and shear pressures exerted by the BST, which are recorded during the test, are used to calculate the shearing strength and the angle of internal friction. The BST consists of 3 main components and several minor components. Main components are: ? A shear head with 2 shear plates that bite into the rock when normal pressure is applied. ? A hollow hydraulic jack with RW drill rods that pull the shear head when shear pressure is applied. ? A console with a hand pump and two hydraulic gages to activate the device and to indicate the pressures that apply the normal and shear faces to the shearing plates.

Jan 1, 1981

By Charles L. Kimbell

This study is intended to serve three roles. First, it represents a global overview and summary to supplement and complement the five regional companion volumes of the 1991 edition of the Minerals Yearbook International Review. In this regard, it also extends previous time series under this title that appeared as the introductory chapter to the international volume of the Minerals Yearbook from the inception of that volume in 1963 until it was subdivided into separate regional volumes in 1989. The basic statistical presentations herein generally contain data through and including that for 1991, although in a few instances the most recent statistics are those for earlier years because more recent, comprehensive global statistics simply are not yet available owing to delays in data collection and processing in some countries and continued governmental suppression of data in others. The second role of this study is to provide an update to the coverage of events impacting the world's mineral industry that have occurred between the end of 1991 and the preparation of this study. Inclusion of this update is almost essential because of the potential effect of some of these events on global mineral industry activities.

Jan 1, 1993

By J. B. Newson

This is one of a series of circulars dealing with mining methods, practices, and costs. It describes the method of sinking a shaft 60 inches in diameter with a shot drill, as employed at the Idaho Maryland mine, Grass Valley, Calif. The operation involved a great deal of experimentation in applying the shot-drill method to large bore drilling, overcoming mechanical and other difficulties which developed during sinking, and developing operating technique. Under such circumstances, costs are obviously higher than they would be after the pioneer work has been done, but even so, these actually obtained compare favorably with costs of sinking by more conventional methods. ACKNOWLEDGMENTS The authors are indebted to Mr. Errol McBoyle, president of the Idaho Maryland Mining Co., not only for his cooperation and advice during the sinking of this experimental shaft, but for permission to prepare this article for publication with the inclusion of cost data.

Jan 1, 1936

By Mark S. Redfern, Kim M. Corneliusa, Christopher A. Hamrick, Sean Gallaghera

Coal miners often handle heavy electrical power cables, weighing up to 10 kg per meter. These cables are manually lifted and attached to the mine roof to prevent damage from mobile underground equipment. Data suggest that workers who commonly perform cable handling tasks experience a high rate of lost time back injuries. In this study, six male underground miners performed a total of 12 cable-hanging tasks in standing, stooping, and kneeling postures, during which kinematic and ground reaction force data were collected. Reductions in vertical work space were found to result in a linear increase in the peak moment experienced by the lumbarspine (p<0.05). In restricted postures, peak moments were not significantly different in stooping vs. kneeling postures (p>0.05). Average lumbopelvic flexion during the tasks was highest in stooping conditions, followed by standing and kneeling exertions (p<0.05). Implications of this data with respect to design of cable handling tasks are presented and discussed. Keywords: Biomechanics, posture, low back pain, restricted workspace, mining

By M. J. Ankeny

Coal-mine haulage ranks second as a cause of coal-mine fatalities, and the prevention of such accidents will materially improve progress in safety in the coal-mining industry. Beginning March 1950, Federal coal-mine inspectors were made responsible for completely investigating all fatal accidents in and around coal mines. During these 10 months, Federal coal-mine inspectors investigated 447 fatal accidents. This is a study of 121 of the fatal haulage accidents investigated, which constituted 27 percent of fatalities from all causes. Haulage employees represent only 12 to 15 percent of mine personnel, but, on the basis of accident frequency, their work is the most hazardous in coal mines. Fatal haulage accidents occurred in 53 bituminous coal-producing counties representing 14 States and Alaska. The physical conditions represent a cross section of&apos; producing coal beds. Mining and transportation methods vary, from those of small hand-loading mines to those of modern mechanized mines.

Jan 1, 1951

By T. Bertke

This document assesses the environmental aspects of a preliminary design for processing kaolin clay as the domestic resource for recovery of alumina by a hydrochloric acid leach-HCl gas induced crystallization process. The report covers waste sources, control measures, and potential environmental and health effects applicable to the process technology.

Jan 1, 1980

By C. P. Fang, V. A. Marple, K. L. Rubow

"Studies of the flow fields and particle impaction characteristics are more complicated in multi-nozzle impactors than in single-nozzle impactors, since the jets of air must penetrate cross-flowing air to impinge on the impaction plate. Results of heat and mass transfer analysis are employed to describe the cross-flow pattern in multi-nozzle impactors. A cross-flow parameter has been derived to predict the deflection of the air jet by the cross-flow. This parameter is expressed as a function of the geometric parameters for the multi-nozzle impactor. DnN 4D,, where N is the number of nozzles, Dn the nozzle diameter and D, the nozzle cluster diameter. Empirical particle collection data show that multi-nozzle impactors operate satisfactorily, if the cross-flow parameter is less than a critical value of 1.2. Impactors operating with a cross-flow parameter larger than this critical value are shown to possess poor particle collection characteristics.Inertial impactors of many designs have been used for sampling aerosol particles. Impactors can be single stage, consisting of a nozzle and an impaction plate, or a cascade impactor with several stages in series. The simplest design for a stage is a single nozzle with a flat impaction plate. However, many designs use stages with multiple nozzles of identical size, which allows for compact impactors to be designed at rather substantial flow rates and moderate pressure drops.Nearly all of the theoretical work, and much of the experimental work, has been performed on single-nozzle impactors. The results of single-nozzle impactor analysis are often applied to multiple-nozzle impactors, which are assumed to be a group of individual nozzles, each operating as though they were single nozzles. However, an important fact is often ignored: the interaction of flow from adjacent nozzles can change not only the fluid mechanics in the impaction region, but also the locations of the jet stagnation points, and the impaction characteristics of each nozzle.The effect of multiple nozzles on the particle collection characteristics of impactors has been studied by a few investigators. May (1964), Fletch et al. (1967), Friedrichs (1968), and Vaughan (1986) reported that the quantity of particles in deposits of nozzles in the first two stages of the Andersen multi-nozzle cascade impactor were not equal. The inner deposits appeared to contain fewer particles than the outer ones. However, Vaughan (1986) in addition showed that many of the deposits in the outer three rows were missing on the first stage, even though the outer deposits that were present were larger than the inner deposits.May (1964) conducted experiments and explained the phenomenon of smaller deposits near the center than near the edge. He noted that in Andersen cascade impactors the air issuing from the nozzles moves radially outward along the narrow channel between the nozzle plate and the impaction plate. This flow at 28.31min -1 created a pressure difference of about 1 mm water between the inner and outer sections of the channel. The effect was most pronounced in the first two stages, where the pressure drop across the nozzles was also about 1 mm water. Here, the flow velocities in the nozzles, and hence the deposits, were smallest at the center and increased toward the periphery of the impaction plate. since the pressure drop across the nozzles was the smallest at the center and a maximum at the periphery. This effect was negligible in the lower stages because of a larger pressure drop across the nozzles. According to May (1964), this effect could be eliminated by increasing the nozzle-to-impaction-plate distance to three nozzle diameters and improving the nozzle arrangement to allow air flow to escape to the periphery more easily."

Mar 1, 1992