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

"INTRODUCTIONThe mechanistic details of the biological events leading to coal workers pneumoconiosis (CWP) are not yet fully understood, despite several decades of extensive epidemiologic1.2 and laboratory studies.2-6 Epidemiologic studies1.2 have shown, for example, that the incidence and severity of CWP differ markedly in the different regions and mines at comparable exposures, but laboratory investigations2-6 have demonstrated only partial correlation of the epidemiologic data with the differences in the mineral composition and the rank of coal mined. In particular, while epidemiologic data indicate1.2 direct correlation of the· prevalence and severity of CWP with the rank (i.e., % carbon content) of coal, this correlation has not been established by laboratory4'6 and animal exposure3 studies. In order to explain these results, in 1980 Artemov and Reznik' suggested that perhaps they arise from the fundamental differences in the surface properties of the coal. dusts inhaled by the coal miners and those used in the laboratory studies: while the miners inhale freshly fractured coal particles, henceforth called the 'fresh' coal dust, the laboratory studies generally utilize 'aged' coal dusts (i.e., dusts that have been stored for many days or even longer). Reznik and Artemov' used electron spin resonance (ESR) spectroscopy to show that the mechanical crushing of some Soviet Union coals generated organic free radicals and that the concentration and the decay times (hence the reactivity) of these radicals were higher for the coals of higher ranks. Since some of the radicals decayed within a few minutes in air, the authors surmised that while these radical species could lead to certain specific pathogenic reactions at the sites of mining operations, this might not be the case in the laboratory studies, due to the conventional use of 'stored' dusts which would be expected to contain significantly smaller free radical concentrations. This is consistent with the recent findings that, standardized, aged coal dusts exhibit minimal cytotoxicity. 8While the above mentioned work of Artemov and Reznik7 did suggest a possible new clue to the pathogenesis of CWP (i.e., the role of the coal based free radical species), no direct biological/cytotoxicity data were provided to show that 'fresh' coal dusts were, indeed, more pathogenic than the 'stale' ones. Because of the rather significant implications of the Artcmov-Reznik hypothesis to the understanding of 1hc biochemical mechanism and, hence, the strategies for the eventual containment of CWP, we have initiated a comparative study of the free radical formation and cytotoxicity properties of freshly crushed coal ·particles. As done by Artemov and Reznik, 7 we have used the ESR technique as the direct method of measuring the concentration and decay kinetics of the coal based free radicals. Our preliminary ESR studies on two Pennsylvania coals, a bituminous (carbon content 72 % ) and an anthracite (95 % carbon) coal, have confirmed the Artemov-Reznik finding that the crushing-induced free radical sites are higher on the coals with higher carbon content (i.e., higher rank).9-11 In the present work we describe our more recent results of a parallel study of the time dependence of the decrease in the free radical content of a freshly made anthracite dust (as measured via ESR) and that of the dust's cytotoxicity potential as measured by the extent of hemolysis of (sheep) erythrocytes. We have also investigated the effects of free radical scavengers on the cytotoxicity potential of the dust and deduce that indeed the free radicals could play a significant role in the initial events in the mechanism of the cytotoxic effects due to the inhalation of coal dust inhalation."

Jan 1, 1990

By F. X. Tartaron

This report describes work done by the Bureau of Mines to simplify the design and operation of the vortex cone, a new device for prerefining blast furnace iron. Three new apparatus arrangements were tested. Results with one of these arrangements average 74.2 pct silicon removal and 61 pet oxygen efficiency (disregarding removal of carbon and manganese).

Jan 1, 1965

By O. C. Blade

This report on the properties of burner-fuel oils produced during 1956 was issued under a cooperative agreement between the American Petroleum Institute and the Bureau of Mines, United States Department of the Interior, at the request of the Oil-Heat Institute of America and the petroleum industry. This survey is the second for this type of fuel, the first being made in 1955. 2/ The surveys are conducted to provide information on the characteristics of burner-fuel oils now manufactured for sale. They are similar in pattern to the diesel-fuel surveys, conducted since 1950, 3/ and are not intended to conflict with but rather to supplement them. The importance of fuel oil has resulted in the need for more information by the petroleum industry, manufacturers of heating appliances, and consumers regarding the types and qualities of the fuels currently being marketed. Samples of burner-fuel oil typical of their manufacture during the early part of 1956 were analyzed by the refiners in accordance with instructions from the subcommittee on fuel surveys of the Automotive Research Committee of the American Petroleum Institute, Results of the analyses were transmitted to the Bureau of Mines where the data were studied and compiled as shown in the tables of this report.

Jan 1, 1956

"INTRODUCTION These safety standards for anthracite mines have been prepared for use as a guide for Federal inspectors. They are a revision of ""Tentative Inspection Standards for Anthracite Mines,"" published as Bureau of Mines Information Circular 7282 issued in May 1944 and used as a guide in Federal inspections. No provision made in these safety standards should be construed or operate to nullify any existing State statutes; they are intended to supplement the State statutes in the interest of increased mine safety. Mines are inspected in accordance with the Federal Coal-Mine Inspection and Investigation Act of 1941, Public Law 49, 77th Congress, H. R. 2082. Any unusual hazard noted by an inspector and not covered by these standards will be discussed in the inspection report, and suitable remedial procedure will be recommended.ARTICLE I. - SURFACE STRUCTURESSection 1. Breaker and cleaning plant.Electric switches and controls in breakers and cleaning plants should be enclosed.Where coal is dumped at or near air-intake openings, reasonable provisions should be made to prevent the dust from entering the mine.Section 2. Lamp houseNaphtha or other flammable liquids in lamp houses should be kept in approved containers or other suitable dispensers.Flame safety lamps should be permissible and maintained in permissible condition.Flame safety lamps should be properly cleaned, examined, and assembled by a qualified lamp attendant or other competent person before each period of use. Lamp assembly should again be checked by the person using it immediately before he enters the mine.When not in service, methane indicators, flame safety lamps, and electric cap lamps should be in the custody of competent persons responsible for maintenance and testing."

Feb 1, 1948

By Paul Hatmaker

Diatomite is the name now generally given to a mineral substance composed of the tiny , skeletal remains of diatoms , which are microscopic , flowerless , water plants related to the algae ... This residuum is essentially hydrous amorphous silica. Common names for diatomite are : Diatomaceous earth , tripolite , kieselguhr , and infusorial earth . Strictly speaking , however , the latter material is not diatomite , as it is composed of the fossil remains of infusoria , which usually do not occur with the diatomaceae . Other synonyms for diatomite are : Diatomaceous silica , kieselmehl , bergmehl , diatomeenpeelite , polirschiefer , moler , molera , molererde , de smid earth , fossil flour , mountain flour , farine fossil , white peat , radiolarian earth , chalk rock, ceyssatite , randanite , and tellurine ; also various diatomite products of individual companies are known by their own trade names . Diatomite should not be confused with fuller's earth , for the two are separate and distinct substances . Bentonite , pumice , and tripoli , have also been used erroneously to designate diatomite . Tripolite , however , is a true diatomite formerly mined near Tripoli ..

Feb 1, 1931

By L. A. Neumeier

A refinement of the tungsten-cobalt phase diagram is presented for compositions to 85 at. pct cobalt and for temperatures to the solidus. Preparation of alloys by powder metallurgy methods is described, and the results of studies made by a combination of techniques involving microscopy, X-ray diffraction, thermal analysis, and dilatometry are discussed. The existence of u-W6Co7 is confirmed (rhombohedral D85 structure). The W6Co7 phase forms periectically at 1,685'115° C by reaction of liquid with primary W; the peritectic melt is at 71 at. pct cobalt. The homogeneity range of u-W6Co7 extends to both sides of the ideal stoichiometric ratio, through a compositional range of about 5 at. pct. The compositional limits for u-W6Co7 vary slightly below 1,471°±5° C, the temperature of the eutectic reaction forming u-W6Co7 plus a. The eutectic composition is at 79 at, pct cobalt. The existence of WCo3 is confirmed (hexagonal D019 structure). WCo3 forms peritectoidally at 1,093°±5° C by reaction between a and u-W6Co7 and exists over a narrow homogeneity range of 0.5 to 0.6 at. pct. The solid solubility of cobalt in tungsten is low (maximum 0,9 at, pct cobalt) and results in contraction of the tungsten lattice. Tungsten is extensively soluble in a-Co at higher temperatures; the a-Co lattice is expanded by the presence of tungsten in solid solution. There was no indication of the formation of a o-phase nor of any intermediate phases other than WeCo7 and WCo3. The WeCo7 and WCo3 phases are compared with similar phases in other systems.

Jan 1, 1967

By T. M. Barczak

This U.S. Bureau of Mines report investigates shield mechanics and component stress development in a two-legged longwall shield for unsymmetric canopy and base contact configurations. Previous studies analyzed shield behavior for symmetric contact configurations. The goals of these efforts are to improve longwall support selection and design. This study provides vital information that will help develop improved procedures for performance testing of longwall supports and will benefit future research to improve support design through stress optimization and evaluation of failure mechanisms. Combinations of six canopy (three symmetric and three unsymmetric) and six base (four symmetric and two unsymmetric) contacts provided a total of 36 configurations for evaluation. Of these 36 configurations, 10 were eliminated because of fixture limitations or shield instability. Controlled vertical and horizontal displacements were applied by the Bureau's mine roof simulator to the remaining 26 configurations. Component responses were determined from pressure transducer and strain gage instrumentation in order to identify contact configurations and boundary displacements that produced maximum loading in each of the support components. This report describes these test results and provides conclusions relevant to critical contact configurations for performance testing of longwall supports.

Jan 1, 1990

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized- bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could be incorporated in design, installation, and operation to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized- bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on heated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or "bumps" had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By Staff

This U.S. Bureau of Mines publication presents the results of investigations into the fire and explosion hazards of oil shale rocks and dust. Three areas have been examined: the explosibility and ignitability of oil shale dust clouds, the fire hazards of oil shale dust layers on hot surfaces, and the ignitability and extinguishment of oil shale rubble piles.

Jan 1, 1989

By H. M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since in most fields gas under pressure is the main source of the energy causing the oil to move through the sands into the wells and thence to the surface, coincident production of natural gas will continue as long as present-day producing methods are used. Generally the use of this gas is restricted, since markets are not readily available. Consequently, a large portion of the gas produced is often wasted by being blown into the air. The magnitude of gas waste is well brought out in the following statement by Miller:5 Only a few outstanding examples need be cited to show the enormous production of gas that accompanies the discovery of new sources. In April, 1927, the Ventura field produced approximately 210,000,000 cubic feet of gas a day; and during the summer of 1927 Alamitos Heights reached a peak gas production of 102,000,000 cubic feet a day; on December 1, 1928, as a result of the summer's deeper drilling in the Long Beach field, surplus gas production amounted to 125,000,000 cubic feet a day. It is estimated that in January, 1929, the Santa Fe Springs field will have a daily gas production of 387,000,000 cubic feet from the recently discovered Buckbee oil zone. Of this amount 274,000,000 cubic feet a day will be the surplus above the amount required for field and plant fuel, taken out by utility corporations, and that used in repressuring the Meyer sand which lies above the Buckbee zone.

Jan 1, 1931

By H. F. Yancey

One of the important duties of the Bureau of Mines is to sample and analyze coals and to publish the results of such analyses for the information of producers, consumers, and the general public. Numerous publications containing such analyses have been Issued from time to time. Although the chemical properties of a coal as revealed by its proximate and/or ultimate analysis and heating value aid one considerably in visualizing its probable behavior and in determining its usefulness and value for a specific purpose, they do not furnish complete information. The physical properties of a coal, such as its ability to retain its original form without undue breakage or degradation in size under the various conditions of storage and usage, are also of importance in determining its suitability, technically or economically, for a given purpose.

Jan 1, 1932

By F. D. Everett

The Burgin shaft of Bear Creek Mining Co. near Eureka, Utah, was sunk during 1956 and 1957 as part of an exploratory program, searching for lead, zinc, copper, silver, and gold ore bodies hidden from the surface by several hundred feet of volcanic rocks. This paper describes the sinking methods and operating practices of Centennial Development Co., contracting firm for Bear Creek Mining Co., in sinking a 3-compartment vertical shaft 1,100 feet. The operation featured the Cryderman positive-action, clam-type shaft mucker. The shaft was completed in 142 days by a shaft crew of 10 men and a top force of 10 men, including supervision.

Jan 1, 1959

By A. A. Bakewell

This information circular, which describes mining methods and practices at the Baguio Gold Mining Co., Philippine Islands, is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs. Since January 1952, Baguio Gold Mining Co. has operated its rehabilitated mine and mill in the Baguio district. Postwar labor and supply costs are three or four times prewar costs, whereas ore tenor and tonnage are about the same. Ore reserves remain approximately the same, but deeper and more spreadout operations add to increasing costs. Recently the company has acquired an adjoining property, which may lengthen its life substantially. Costs and general operations are more or less typical of the district, which includes three other active gold mines. Gold ore mined in the district totals approximately 4,300 tons per day.

Jan 1, 1959

By J. P. Powell

The application of secondary producing methods for recovering additional oil from known fields has been recognized for many years as important to the economy of the nation. One of the most successful secondary methods is waterflooding, which conserves our natural resources by preventing premature abandoment of stripper leases and revitalizing previously abandoned areas. Waterflooding as a secondary-recovery method was introduced into the Midcontinent region in 1931, and its use as such has become widespread. As with most new methods, the most favorable fields and leases received primary attention, whereas those with viscous oil or less favorable sand characteristics were bypassed. Numerous reports3 4 5 6/ have been published giving the results of individual waterflooding projects, In this report, attention is directed to the effect of a single factor, the viscosity of the oil produced,

Jan 1, 1959

By Sam Friedman

The Bureau of Mines conducted experiments using bench-scale apparatus to explore the effect of large changes in process variables on the yield and composition of the gases produced by passing 800° C steam through a fixed bed of Pittsburgh seam (hvab) coal. The total yield of combustible gases increased throughout the given range for the following variables: Superficial steam velocity increasing from 0.02 to 0.12 fps, pressure increasing from 1,000 to 6,000 psig, residence time increasing from 0 to 60 minutes, and temperature increasing from 800° to 900° C; however, a greater increase in the yield of hydrogen in comparison with the increase in yield of methane reduced the gross heating value of the gas to around 470 Btu per scf at conditions giving the maximum yield. Pressures of 1,000, 3,000, and 6,000 psig at 0.09 fps steam velocity, 800° C, and 60 minutes residence time, respectively, produced methane yields of 20, 24, and 22 percent, based on maf coal, with the gross heating value of the CO2-free gas decreasing from 552 to 520 and to 470 Btu per scf. Methane concentrations in the CO2-free gas were 26, 22, and 14 percent, respectively. Based on the gross heating value of the coal, the percentage of the heating value recovered in the gas was 60, 71, and 87 percent, respectively. The use of tungsten sulfide as a catalyst for converting carbon oxides and hydrogen into methane was explored briefly using both a sulfur-free gas rich in methane and a sulfur-bearing synthesis gas (3H2:1CO).

Jan 1, 1968

By B. J. Moore

This publication contains routine analyses and related source data for 278 natural gas samples from 14 States. All of the samples were collected during calendar year 1973 as part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 Fifteen previous publications have presented the results of 10,201 gas analyses prior to 1973. The first three, Bulletins 486,4 576,6 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960. The other 12 publications,7 which were issued as information circulars, supplement the three bulletins and contain 4,983 analyses of samples collected since 1960. This publication is the 13th publication supplementing the three bulletins.

Jan 1, 1974

By J. Douglas Causey

No mines are active in the Hunter Mountain Wilderness Study Area (WSA), and no mineral resources have been identified in the WSA. However, the Monarch Mine has low potential for silver, copper, tungsten, and gold resources in quartz veins; the Shirley Ann Group and Sal Group have moderate and low potential, respectively, for silver, lead, and copper resources in skarn; claims overlying the Eureka Quartzite have low potential for silica resources; and the Tourmaline N1-4 Prospect has low potential for tourmaline resources in quartz monzonite. Copper, lead, silver, tungsten, molybdenum, wollastonite and garnet occur in skarn zones between monzonitic and carbonate units. Silver, tungsten, and copper also occur in quartz veins within monzonite. Known metallic mineral deposits are small, erratic and discontinuous. The J. 0. Mine, adjacent to the northeast corner of the WSA, may contain as much as 26 million tons of subeconomic wollastonite resources. The crest of an open pit to produce that resource would extend into the WSA. No information exists on geothermal potential because no exploration has been done in the area. No occurrences of energy minerals are known within the WSA.

Jan 1, 1983

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized-bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could b incorporated in design, installation, and op ration to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized-bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on hated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or ?bumps? had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By Frederick W. Horton

With large deposits of low-grade molybdenum ore and a latent market for molybdenum, which with development might perhaps equal that for tungsten, the United States has for years made no pro- duction of molybdenum ore worthy of mention. In fact, during the decade previous to 1914, there was no output of molybdenum ore in this country except in 1905, 1906, and 1907, when a few small lots of molybdenite and wulfenite were marketed." To ascertain why this possible source of economic wealth should remain undeveloped, the United States Bureau of Mines undertook an investigation in 1914, with a view of assisting the establishment of a molybdenum industry in this country. A preliminary review of the situation showed the following conditions: Briefly there was a lack of any considerable demand for molyb- denum for the one known use that might consume any large tonnage of it, that is, for the manufacture to certain alloy steels to which molybdenum imparts properties roughly similar to those produced by tungsten. It was at once evident that the market for molybdenum in alloy steels must be developed, or that extensive new uses for the metal must be created, before the demand would be sufficient to war- rant any extensive mining of molybdenum ore. Investigation showed that one of the chief factors in retarding the development of any demand for molybdenum by the alloy-steel trade was that manufacturers who might use, or might investigate the possibilities of using, the metal were kept out of the market by the fear of not being able to obtain steady supplies. On the other hand, those who might be interested in the development of some of the extensive low-grade molybdenite or wulfenite deposits in this country were prevented from doing so by the small visible demand and the fear that any large production would glut the market. Owing to these conditions the mining of molybdenum has in the past been confined almost entirely to small-scale operations on high-grade streaks of molybdenite ore, and the methods of recovery have been limited largely to cobbing and hand picking.

Jan 1, 1916

By Forrest T. Moyer

THE injury data and experience in this bulletin are presented in three general sections. The first section contains general and detailed data relating to 1948 injury experience in bituminous-coal and Pennsylvania anthracite mines, separately and combined into totals for all coal mines. The related employment, worktime, production, and productivity data are given in each breakdown of the statistical data. Tables 1 through 22 constitute a subsection and present statistics on number of injuries, frequency and severity rates, average severity, detailed and major causes of injuries, injury records of the coal-producing States, distribution of injuries by part of body, and distribution of injuries by days of disability. Tables 23 through 45, the second subsection, present injury experience in bituminous-coal mines by various selected factors of physical or operating conditions that ma contribute to the occurrence of injuries. The degree of mechanical loading, productivity, size of mine by number of men working and by tonnage mined, thickness of bed, length of shift, number of shifts, type of cap lamps, rating of mine as gassy or nongassy, type of ventilation, and combinations of these factors influencing mine safety are presented in this group of tables. Similar data on Pennsylvania anthracite mines are listed in tables 46 through 63, which comprise the third subsection. The second section of the report contains the generalized annual injury records of bituminous-coal, Pennsylvania anthracite, and all coal mines from the earliest available data through 1948. Tables 64 through 97 list the number of fatal and nonfatal injuries, injury rates, and causes of injuries on an industry basis, the long-term injury records of each coal-producing State, and the related employment, worktime, and production data.

Jan 1, 1952