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By W. W. Adams

Coal mining in the United States, had a somewhat higher death rate per million man-hours of exposure among the employees in 1937 than in 1933 to 1936. However, the rate in 1937 was lower and therefore more favorable than that in any year since 1921 but previous to 1933. The nonfatal injury record, which began in 1930, was lower and therefore better in 1937 than in any other year since 1930. Separate figures covering bituminous-coal mines in all States showed a lower fatality rate in 1937 than in any year since 1920 but before 1933, and a lower nonfatal injury rate than that of any year since 1930 except 1933 and 1936. Reports for anthracite mines in Pennsylvania revealed a better safety record for fatal accidents in 1937 than in any year since 1930 except 1933, 1934, and 1936 and a better record for nonfatal injuries than in any year since 1930 except 1933.

Jan 1, 1940

By JOHN BUZARD

In the following pages the writer has endeavored to give an account of the many methods, advantages, and disadvantages of preparing and burning powdered coal. For much of the information jmparted the writer is indebted to various firms in the United States and Canada whose plants he visited, also to the technical press. Manufacturers and operators of coal-fired furnaces can not afford to disregard the possible advantages of pulverizing their coal before burning it. Hence the purpose of this bulletin will be fulfilled if it leads them, after making careful estimates, either to abandon their present method of burning cGal on grates or stokers, and install the pulverizers, conveying system, powdered-coal feeder, and burner best suited for burning powdered coal in their plant, or to reject, as uneconomical, the replacement of their present system of burning coal by a system for pulverizing and burning it. No research work on the combustion of powdered Canadian fuels has been carried out by the Mines Branch, Department of Mines; but if this research work were carried out scientifically by competent engineers, chemists, and physicists, it would show how powderedcoal furnaces and burners should be designed to gi ve an efficiency higher than they give at present.

Jan 1, 1923

By Albert L. Toenges

This paper is the fourth of a series5/ that describes some methods and practices of mining coal mechanically where operations are conducted on more than one shift. Many inquiries have been received regarding methods of extracting pillars with mechanized equipment, and this paper deals primarily with this phase of mechanical mining. Some of the questions that have been asked are:

Jan 1, 1942

By Chas. F. Jackson

The annual reports of the supervising engineers of the nine sections comprising the Mining Division are assembled here and constitute the annual report of the division. In planning activities the aim is to adapt them to changes in conditions, in the needs of the mining industries, and in the public interest; those that contribute most to solving the present problems are emphasized, investigations of less immediate importance being recessed if necessary. The strategic minerals investigations of the bureau afford an example of this change in emphasis to problems of immediate and urgent interest, and during 1941 they comprised, upon the basis of appropriations and expenditures, more than 90 percent of the work of the division.

Jan 1, 1941

By Edward C. Peterson

Recent studies indicate that the United States halt substantial reserves of ilmenite, one of the major titanium minerals. However, the studies showed that sources of rutile, another important source of titanium are limited. This paper summarizes and evaluates results and conclusions reached by the various investigations initiated by the Bureau of Mines and others pertaining to the titanium mineral resources of the Nation. Domestic occurrences of ilmenite that are economically exploitable by present-day beneficiation methods are found in Florida, New Jersey, New York, South Carolina, and Virginia. These deposits are estimated to contain 50.3 million tons of titanium dioxide (TiO2). Occurrences of ilmenite that cannot be processed economically under present technological conditions are found in California, Colorado, Minnesota, Montana, Oklahoma, Oregon, Rhode Island, and Wyoming. These reserves amount to 51.1 million tons of TiO2. Reserves of rutile found in the United States are estimated to be 1.8 to 2.1 million tons of TiO2. Other than occurrences in Florida and South Carolina, rutile is found either in small scattered bodies or in deposits where the mineral cannot be recovered economically by present beneficiation methods.

Jan 1, 1966

By R. E. Morgan

This publication presents abstracts of articles and investigations pertaining to the utilization of fly ash. The terms "fly ash" and "flue. ash," as' used in most of the papers, refer to the ash from pulverized-coal firing collected by electrostatic precipitators or mechanical collectors. Several investigators do not define the material on which they report beyond calling it fly ash, but they probably refer to the fine material resulting from burning pulverized coal. A few of the papers report on investigations involving not only the use of fly ash but boiler slag as well. These can be identified by the title of the articles. Bibliographical information and the abstracts are arranged according to the date the papers were published, with the most recent listed first. With the continually increasing use of pulverized-coal firing, profitable disposal of the fly ash is becoming a problem of greater importance to many utility and industrial companies. Also, in recent years, the public demand for cleaner air, and the more highly efficient fly-ash collectors available have resulted in the collection of a greater percentage of the fly ash produced. The solution to better utilization of fly ash has, therefore, been the object of research for some years.

Jan 1, 1952

By V. Castranova, K. Van Dyke

"I. INTRODUCTIONA mechanism which is present in leukocytes and capable of releasing histamine from rabbit platelets was first described by Barbaro and Zvaitler in I966. A soluble mediator between rabbit leukocytes and platelets was also detected by Siraganian and Osier in 1971. This factor was isolated and characterized in 1971 by Benveniste et al. and named platelet activating factor i PAF). It was shown to be released from rabbit basophils through an antigen - IgE-dependent mechanism. The presence of PAF in human leukocytes' and its aggregation and releasing effects on human platelets were also demonstrated. Chemical analysis has shown that PAF is a glycerophospholipid with a choline polar head group. an ester-linked acyl chain at the second carbon and a nonester link at the first carbon.' The structure of the mediator was found to be 1-O-alky1-2-acetyl-sn-glyceryl-3-phosphoryl choline and it has been chemically synthesized.""' A variable portion exists in the alkyl group attached to the first carbon which can have a variety of molecular sizes such as C and C (where Cu is more abundant). Recent work by Pinckard et al."" has shown that there are at least five variations of the alkyl group.PAF has been shown to have a broad range of biological effects. Release of PAF from alveolar macrophages may be important in asthma, allergy, and shock states. In a rabbit model of antigen IgE anaphylaxsis. PAF can induce all of the effects of antigen challenge and. therefore is presumed to be a key mediator in production of anaphylaxsis. In addition to aggregating and degranulating platelets it is a potent chemoattractant."" and causes contraction of guinea pig ileum contraction of lung tissue and enhanced capillary permeability PAF has important effects in the kidney and is also known as the renal hypotensive factor proposed by Blank et al. who found the structure of PAF independently of Benveniste et al.' In producing these responses. PAF acts by a receptor-like mechanism. In platelets. PAF selectively desensitizes itself but not thrombin or collagen. In smooth muscle tissues a similar phenomenon occurs with anaphylatoxin or other stimuli.In vivo. PAF probably acts in concert with other agents in producing its various biological effects. It causes platelets to release histamine serotonin and RCS (rabbit-contractile substance formed from prostaglandins PPG2, PGH2 and TXA2) which contracts rabbit aorta. PAF can cause cells to release SRS-A and leukotriene B."

Jan 1, 1989

By William O. Vanderburg

This report3/ gives the results of a reconnaissance of mining districts in Eureka County, Nevada, made from September 25 to October 20 and from October 27 to November 5, 1577. During this time, virtually all the districts were visited and many data obtained on active and inactive properties. This report covers the locations of the various districts, geological background, ownership and brief descriptions of mines and prospects, information on past and current operations, and, other data likely to be useful to those interested in the development of our mineral resources. From the viewpoint of past production in the county, the silver-lead-gold deposits at Eureka have been tie most important, followed by the silver deposits at Cortez and Mineral Hill. The period of greatest activity in the foregoing districts was from 1870 to 1990, when Eureka was one of the principal mining areas in Nevada; the production of lead was sufficient to affect its price in all the commercial centers of the world. Eureka also merits the distinction of being the birthplace of the silver-lead smelting industry in the United States.

Jan 1, 1938

The annual reports of the supervising engineers of the nine sections comprising the Mining Division are assembled here and constitute the annual report of the division. In planning activities the aim is to adapt them to changes in conditions, in the needs of the mining industries, and in the public interest: those that contribute most to solving the present problems are emphasized, investigations of less immediate importance being recessed if necessary.

Jan 1, 1941

By J. B. Zadra

Tungsten, a comparatively new metal, is one of the important strategic war materials. In peacetime, tungsten is widely used as a filament in elec¬tric lamps and electronic tubes and is a vital constituent of some of the most important industrial alloys. High-speed tool steel containing tungsten and stellite alloys containing cobalt, chromium, and tungsten are extremely hard and resistant to corrosion. These alloys and the tungsten carbides are unequaled as cutting tools and in other wear-resistant applications. They play a prominent role in the present era of mass production. Alloys containing tungsten resist oxidation at high temperatures and have been key alloys in the development of modern aircraft. The adaptability of tungsten to new uses is expanding, particularly in the high-temperature range. Domestic production of tungsten has come from a large number of deposits in 17 of the 49 States; but, of the total domestic output from 1900 to 1956, more than 80 percent was produced from mines in North Carolina, California, Colorado, and Nevada. The average tenor of the mined ore was less than 1 percent tungsten trioxide (W03).

Jan 1, 1959

The mine surveillance and communication system hereafter described provides continuous local and remote monitoring of several parameters critical to normal mine operation at each of ten underground sites in the Bruceton Research Mine. The techniques employed are well proven and have been care-fully chosen to provide the best solution to the technical problems involved while giving special attention to economic considerations.

Jan 1, 1973

By N. E. Hanna

Originally developed for use in coal mines where on-shift blasting with explosives was prohibited, compressed-air blasting has been used for the past 15 years as a substitute for fixed explosives. With the current commercially available compressed-air systems -Airdox and Armstrong -coal is dislodged by a high-pressure discharge of air from a pressurized shell placed in the coal borehole. In the original systems stationary compressors were mounted on the surface or in the underground ventilated areas. These proved so successful that a mobile compressor unit was developed for use at the working face. Because of the possibility that such a unit might operate in a gassy atmosphere, the Bureau of Mines has investigated the hazards associated with operation under conditions where firedamp could accumulate in explosive concentrations. ACKNOWLEDGMENTS Grateful acknowledgment is made of cooperation of C. E. Carter, H. R. Hiller, R. E. Kennedy, H. Kohn, H. D. Metzinger, J. Mahoney, J. Nickovich, G. So Scott and I. Spolan in the experimental work.

Jan 1, 1956

By B. J. Moore

This publication contains analyses and related source data for 256 natural gas samples from wells and pipelines in 17 States. All of the samples were obtained and analyzed during calendar year 1977 as a part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. 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 The results of the investigation of the occurrences of helium are published annually to make the information available as soon as possible to the gas industry and the public in general. Nineteen previous publications have presented the results of 11,317 gas analyses prior to 1977. The first three, Bulletins 486,4 576,5 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960. The other 16

Jan 1, 1978

By Roger J. Morrell

Disk-cutter experiments were performed on five rock types ranging in compressive strength from 9,000 psi to 27,000 psi. A specially constructed testing machine called a linear-cutter apparatus (LCA) was designed to load and traverse a free-rolling disk cutter across a sawed rock surface. The LCA was instrumented to measure the vertical and horizontal forces acting on the cutter during the run.. The ability of disk cutters to fragment rock was determined for both 60--degree and 90-degree cutting-edge angles, and relationships and regression equations were developed to predict cutter performance based on rock physical properties and applied forces,

Jan 1, 1970

By W. B. Berwald

The United States Bureau of lanes, in cooperation with the Natural Gas Department of the American Gas Association, has been studying actively for the past several years the problem of the flow of natural gas through high-pressure transmission lines. Numerous data on gas flow through pipe lines under many conditions of operation have been obtained by carefully conducted tests, and these data, together with all other available information, have been analyzed Carefully to secure practical facts for the use of operators in designing pipe lines and determining the effects of different operating conditions on pipe-line capacities. The first procedure in initiating this problem was to review, compile, and analyze all of the existing data on the flow of natural gas through pipe lines. Actual data applicable to pipe and operating conditions normally used in the transmission of natural gas were meager, and the several pipe line flow formulas developed by different investigators gave widely varying results when applied to problems of pipe-line design. Therefore, further experimental work under conditions comparable to those found in transmitting natural gas was essential before any definite recommendations could be made. The problem, as originally planned, included flow tests on pipe lines in operation, and in each test the measured delivery vas to be compared with the delivery calculated from several common pipe line flow formulas.

Jan 1, 1931

By W. B. Berwald

The United States Bureau of Mines, in cooperation with the Natural Gas Department of the American Gras association, has been studying actively for the past several years the problem of the flow of natural gas through high-pressure transmission lines. Numerous data on gas flow through pipe lines under many conditions of operation have been obtained by carefully conducted tests, and these data, together with all other available information, have been analyzed carefully to secure practical facts for the use of operators in designing pipe lines and determining the effects of different operating conditions on pipe-line capacities. The first procedure in initiating; this problem was to review, compile, and analyze all of the existing data on the flow of natural gas through pipe lines. Actual data applicable to pipe and operating conditions normally used in the transmission of natural gas were meager, and the several pipe line flow formulas developed by different investigators gave widely varying; results when applied to problems of pipe-line design. Therefore, further experimental work under conditions comparable to those found in transmitting natural gas was essential before any definite recommendations could be made.

Jan 1, 1931

By Mackenzie Burnett

A high efficiency ejector has been developed which solves the abrasion problem associated with remote pneumatic stowing. The system can also produce cemented fills. The ejector is capable of moving the fill material over 70 ft from the injection point and filling the mine opening to the roof level for a distance of about 30 ft in all directions from the borehole. This system operates by the transfer of momentum from a supersonic air stream to the fill material. The momentum transfer results in a horizontal stream of fill material and air at a velocity of about 100 fps. The ejector fits on the bottom end of a 3 in diameter vertical pipe. Fill material is fed into the ejector at a controlled rate through a hopper mounted over the borehole. High pressure air used to operate the ejector is fed through a second 3 in diameter pipe. This system has the additional feature of mixing water in the air stream which increases the potential momentum of the air stream. Where necessary, cement can be added to the gravel to create a cemented fill. The design parameters and test results for four versions of the ejector are presented in this report.

Jan 1, 1991

By V. F. Parry, W. S. Landers, John B. Goodman

"INTRODUCTION The object of this investigation was to demonstrate a satisfactory method of storing slack subbituminous coal in open pits in a manner,that would minimize the cause of the physical deterioration and would have a practical application.The storage of coal by industrial plants is to their advantage, since an adequate operating supplying of fuel is available at all times as insurance against transportation delays, shortages, and strikes. Furthermore, it is possible to participate in low seasonal freight rates and mine costs by permitting the railroads to utilize idle equipment and by taking advantage of the off-peak production at the mines. For a number of years, one of the larger beet-sugar companies operating in the Rocky Mountain region has taken advantage of the lower prices and seasonal production of subbituminous slack coal during the summer months and purchased a large proportion of its requirements for the annual winter campaign. This company, operating sugar-refining plants in the 1943 campaign, used 256,613 tons of subbituminous coal. Of this quantity, 166,636 tons was purchased during the off-peak season and stored for use during the winter. It is the practice of this concern to place coal purchased through the months of January to October in underwater storage for use in the beet-sugar campaign, which lasts from October to as late as, January. The beet-sugar refining ""campaign"" period starts immediately after the beginning of the beet harvest and lasts 60 to 70 days."

Aug 1, 1946

By Noel N. Moebs

The Bureau of Mines studied the feasibility of water diversion and overburden dewatering for underground coal mines in the Appalachian region. All relevant published literature pertaining to the occurrence and control of surface and ground water in underground coal mines was reviewed, and the impacts of mine water with respect to health and safety, production, environment, and costs were assessed and are described in this report. The report also identifies the sources of water inflow into underground coal mines, and gives a summary description and evaluation of techniques that can be used to reduce the amount of water entering these mines. Engineering practices currently used by operating coal mines in the Appalachian region to prevent the movement of ground and surface water into active coal workings were reviewed and are summarized. Major emphasis has been placed on the identification of geologic and hydrologic conditions of the site, the water control methods used, and an evaluation of their technical and cost effectiveness.

Jan 1, 1985

By S. H. Ash

THE information obtained by examining and analyzing the core drillings from 15 diamond-drill holes shows that with the proper equipment little difficulty should be experienced while sinking the shafts at the 15 selected sites. Although a number of holes penetrated formations containing a high percentage of silica,, the health hazard from dust can be removed by using proper dust-control equipment. Methane was detected in small amounts in only one (hole 5) of the boreholes. The methane hazard should present no difficulty if adequate ventilation is employed while sinking the shafts.

Jan 1, 1952