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By C. A. Rhoades

A major contributor to the problem of short life expectancy for blade-type conveyor belt cleaners is uneven wear along the blade edge. Uneven wear results in the formation of channels in the blade edge, which allow material to be carried back between the blade and the belt. In an effort to reduce the uneven wear problem, the U.S. Bureau of Mines has studied the mechanisms responsible for effective belt cleaning. From this study emerged a design for a cleaner blade that would greatly reduce uneven edge wear. The design consists of a standard cleaner blade incorporating air passages that allow for the expulsion of air along that part of the blade edge in contact with the conveyor belt surface. The results of 18-h tests indicated that the expulsion of air on the blade edge prevents scratches from developing into deep grooves. These tests showed that effective blade cleaning life can be extended 25 times using the pneumatic cleaning blade, compared with solid metal cleaning blades.

Jan 1, 1989

By J. M. Stuve

Provisional values for the heat of formation of europium trichloride and europium sesquioxide were determined by solution calorimetry utilizing europium metal of more than 99-percent purity. The resulting values for the heats of formation of Eu203 (cubic) and EuCls (hexagonal) were -386,970 ±l,200 cal/mole and -218,740 ±650 cal/mole, respectively, measured at 298.15° K.

Jan 1, 1965

By E. M. SEELEY, F. S. LOTT

Expansion in total capacity of the natural-gasoline industry.to produce light products continued in 1944 and 1945. The average rate of gain, however, was reduced to about 6 percent annually from over 9 percent in the preceding 4-year period. New facilities at cycle plants again accounted for most of the increase in productive capacity. Between January 1, 1944, and January 1, 1946, the number of cycle plants increased from 32 to 37 and their total capacity from 3,278 thousand gallons daily to 4,848 thousand (48 percent). Capacity of all other plants in the industry increased in the same period from 12,735 thousand gallons daily to 13,080 thousand, or only 3 percent. The capacity of the average plant increased to 28,600 gallons a day from 24,400 gallons on January 1, 1944, continuing the established trend. The average capacity of cycle plants increased to 131,000 gallons a day from 102,400 gallons, and the average capacity of all other natural-gasoline plants increased to 22,200 gallons a day from 20,400 gallons. Although the number of plants increased in only three States in the 2-year period (Texas, Okla- homa, and Arkansas), the total capacity of plants increased in eight States. A further decline of 29 reduced the total number of plants to 626 on January 1, 1946. Compared with 10 years earlier, gasoline plants were more numerous in only 4 States: Texas (48 more), New Mexico (7 more), Arkansas (2 more), and Louisiana (1 more). The largest declines, in order, were in Oklahoma, Illinois, Pennsylvania, West Virginia, and California. The number of plants with fractionating equipment for separating the liquefied gases from heavier fractions was 202 on January 1, 1946 and 182 2 years earlier. The principal changes in number and capacity of shut-down plants were an increase in Texas and a decrease in California. Shut-down natural-gaso- line plants are usually among the smallest units in their vicinity.

Apr 1, 1947

By D. A. Baker

This report describes the elemental characterization of chromite and related materials at the Bureau of Mines, Albany Research Center. Analytical methods for determining the major constituents, representing extensive experience, refinement, and development, are described and fully annotated. This presentation should allow other laboratories to use these methods and obtain comparable results with a minimum of time needed for familiarization with individual methods.

Jan 1, 1990

By R. L. Hopkins

The work described was performed to determine whether sulfur compounds of the thienothiophene class occur in crude oil. The presence or absence of various classes of sulfur compounds in crude oils is of interest and value to petroleum science. The Bureau of Mines, for the first time, identified hydro-carbon products of desulfurization that point directly to the identity of two individual thienothiophenes, namely 3-methylthieno[2,3-b]thiophene and 2-meth-ylthieno[3,2-b]thiophene, in Wasson, Texas, crude oil. These identifications, described in detail, were accomplished using microdesulfurization, mass spectrometry, and gas-liquid chromatography.

Jan 1, 1966

By L. H. Johnson

"INTRODUCTION The Pennsylvania anthracite industry produced 53 million net tons of anthracite during 1945. Fifty-one million tons was prepared for the commercial market (3), 3/ and 2 million tons (consisting of fine sizes) was used for colliery power consumption. Of the number of tons prepared for market, 17 million tons (33 1/3 percent) was prepared by the use of acid mine water treated with lime.Mine water from underground workings is pumped, drained, and stored in huge quantities. The mine-drainage systems in the anthracite region handle over 200 billion gallons of water annually, of which 150 billion gallons is pumped to the surface. More than 69 billion gallons of water is impounded in underground pools (1). Much of this water is employed for breaker use, dust-control installations; hydraulic backfilling, combatting mine fires; and aiding in the transportation of anthracite in gently dipping places where sheet iron is used Roos(4) estimates that 1,100 gallons of mine water is utilized in the preparation of anthracite mined."

Nov 1, 1946

The Technology Transfer Seminar on Mine Communications held on March 21-22, 1973, at the Pittsburgh Mining and Safety Research Center, Bruceton, Pa., presented information about recently developed equipment, instruments, and techniques for use in mine communications systems. All of the basic ideas presented in the fine seminar are operational in the Bureau of Mines Safety Research Mine in Bruceton.

Jan 1, 1974

Tax for Toxic Waste Cleanup. - The Superfund Act of 1980 became effective April 1, and provides that producers of certain metals and chemical substances are to be taxed in order to fund toxic waste cleanup. Industry will provide 88% of the 5-year, $1.6 billion fund. The Environmental Protection Agency will administer the Act, but the Internal Revenue Service will be responsible for collection of the industry tax. Under the Act, nickel companies, for example, will be required to pay a tax of 0.225 cents per pound on pure nickel products produced or imported into the United States. Standard for Exposure to Lead. - The Occupational Safety and Health Administration (OSPA) has announced a stricter standard on the test of a worker's exposure to lead. Effective May 15, in all lead intensive occupations with the exception of those at primary and secondary lead smelters, a worker would have to be removed from his work station if the level of lead in his blood tests out at 60 micrograms of lead per 100 grams of blood, instead of the previous standard of 70 micrograms. In the case of primary and secondary lead smelters, the ruling has been stayed until June 1, 1981, to allow time for further study.

Jan 1, 1981

By George H. Schnakenberg

Automation of coal mining activities at the face offers improvements in worker safety, health, and productivity. Introduction of integrated computer-sensor systems to current mining machines will enable these machines to perform some of the most hazardous tasks through supervised teleoperation. The U.S. Bureau of Mines is pursuing the development of the enabling technology necessary to achieve this goal. The research program consists of both basic and applied research, each focused on the fundamental issues of computer and sensor technologies. Short-term research is directed to providing computer-assisted, remote supervisory operation of present underground equipment; the long-term goal is the development of progressively more intelligent mining systems. The research program includes a review of robotic machine and autonomous vehicle technologies and of current mining technology, which provides a base for developing innovative mining methods; research in navigation and guidance technology, emphasizing control of a continuous mining machine; research on coal-rock interface sensing technology for horizon control, and rib thickness control in highwall mining; the development of computer systems and hierarchical architectures for real-time control; and development of expert systems for machine system fault diagnostics and predictive maintenance. This report presents a brief background and the current status for each of these research areas.

Jan 1, 1989

By K. R. Becker

The addition of a force gage and a reaction detector to the Bureau of Mines drop-weight impact apparatus made it possible to examine the details of the force exerted on the specimen and make estimates of the time to reaction. With the current setup the force was found to be oscillatory and not reproducble. However, single well-defined pressure pulses can be delivered to the explosive sample by modifying the drop-weight tools. With a modified test arrangement, the time to reaction and the peak force and energy at the time of reaction were determined as a function of drop-weight height for several different explosives. All these parameters were found to decrease as the rate of force application was increased. The same parameters were also found to vary with the thickness of the test sample. The implications of these results are discussed in terms of practical drop-weight testing.

Jan 1, 1972

By H. H. Schrenk

There are several well-recognized procedures for controlling exposure to hazardous atmospheres in industry. They include (a) substitution of less toxic material, (b) enclosure of processes, (c) wet methods, (d) local exhaust, (e) general ventilation, and (f) use of respiratory protective devices. In addition to their employment as a control measure in occupational exposures, respiratory protective devices also are essential in emergencies that may arise from failure or improper use of other control equipment. Respiratory protective devices usually are employed to supplement other methods of control, as temporary expedients, or when other methods are not readily applicable or practicable. It seems reasonable to assume, however, that where respirators are used consideration has been given to the factors involved and that the devices can provide satisfactory protection if used properly. Their use should not be arrived at simply by a process of elimination of other methods that are more difficult to apply.

Jan 1, 1943

By J. A. Organiscak

Enclosed cabs are a primary means of reducing the silica dust exposure of equipment operators at surface mines. The National Institute for Occupational Safety and Health (NIOSH) has investigated various factor effects on enclosed cab air filtration system performance. Factors experimen­tally investigated were intake filter efficiency, intake air leakage, intake filter loading (filter flow resistance), recirculation filter use and wind velocity effects on cab penetra­tion (inside to outside cab concentration ratio). Adding an intake pressurizer fan to the filtration system was also investigated. Results indicate that the intake filter efficiency and recirculation filter were the two most influential factors on cab penetration. Use of a recirculation filter significantly reduced cab penetration over the intake air filter by itself due to the multiplicable filtration of the cab interior air. Cab penetration was also affected to a lesser extent by intake filter loading and air leakage. Adding an intake pressurizer fan notably increased intake airflow and cab pressure while providing only minor changes to cab penetration.

Jan 1, 2008

By Boyd Guthrie

The current use of Mid - Continent crude oil for the manufacture of war products , such as aviation gasoline and lubricating cil , has caused an acute shortage of available supply from established sources . Therefore , refiners who heretofore have had no reason to use West Texas crude oils now are considering them as charging stock and need more information concerning their characteristics . The Bureau of Mines has published several reports3/ giving analyses of the most important of these crude oils . However, to make the applicable data in these publications readily available to refiners , the present compilation of analyses of West Texas crude oils has been prepared . Data showing the effect of catalytic desulfurization of naphthas from West Texas crude oils have been presented in a restricted Bureau of Mines Report of Investigations . These analyses were made under the general supervision of R. A. Cattell , chief, Petroleum and Natural Gas Division, Bureau of Mines , Washington, D. C. , and N. A. C. Smith, supervising engineer , Fetroleum Experiment Station, Bureau of Mines , Bartlesville, Okla . , and under the direct supervision of Harold M. Smith, senior petroleum chemist, Bartlesville , Okla .

Jan 1, 1944

By Ernest E. Fairbanks

[Microscopic methods have proved to be valuable assets in the study of low-grade ores. While the chemical assay u a ally discloses tine total content of valuable metals in such an ore, a thorough knowledge of the nature of the ore should form the from which to prepare an efficient means of recovery. In the treatment of low-grade ores, inefficient recovery, as indicated bay the amount of valuable mineral permitted to go to waste in the tailings, is too frequently the rule rather than the exception, As methods of recovery become more efficient, many low-grade 10 mineral A posits suddenly assume o commercial significance, In much of this material the minerals are so finely disseminated and intermixed that identification even by microscopic methods is a difficult matter. The application of microchemical qualitative analysis with the aid of new device described in this paper, will solve many of the problems of identification encountered in the study of low-grade potential ores. In these ores, especially, the limitations of ordinary microscopic methods are liable to become very great. The microchemical tests obtained by applying a standard set of reagents to a polished knoting whether or not a tarnishing action develops, have considerable value but arc far from being infallible. It is well-known that electrolytic effects are apt to affect seriously the diagnostic value of the tests, end this effect is encountered much more frequently in dealing with finely desseminated minerals. resort to microchemical qualitative analysis, therefore, becomes indispensable.]

Jan 1, 1924

By A. B. Hooker, L. C. IlsLey

"Field inspections and data relative to the use of rubber-sheathed trailing cables in mines show that much cable is ruined or its probable life shortened by being overheated in service.The length of cable required to make connection from a source of supply to a machine at the face workings may be 100 to 500 feet. As a rule, the cable is carried on a reel and unreeled as required; and thus in most cases soma of the cable is not removed from the reel. The overheating generally occurs in that part of the cable which is left on the reel.Factors that determine the heating of trailing cables are:1. The size of the conductors in the cable.2. The maximum energy to be supplied through the cable, based upon the horsepower of the motor and the degree to which the motor is loaded.3. The voltage of the supply and the variation of the voltage at the receiving end.4. The time length of current flow and whether continuous or intermittent.5. The kind of current (direct or alternating).6. The amount of ca· le left or the reel.7. The type of cable used.8. The kind of reel used.In connecti0n with an investigation of the general performance of rubber-sheathed trailing callas, the Bureau of Mines has made a limited study of some of these factors, including the following points:"

Jul 1, 1931

By By Staff

"These proceedings consist of papers presented at a Bureau of Mines Technology Transfer Seminar on postdisaster survival and rescue research. Several seminars are held each year to bring the latest results of Bureau research to the attention of the mining industry as quickly as possible.INTRODUCTIONThe postdisaster research program is directed toward research and development of technology and equipment that increases the chances of a miner surviving or being rescued after an underground mine disaster. A disaster is an accident of major proportions, and it may result in the entrapment of miners whose normal egress from the mine is cut off. This often necessitates a rescue operation and a means of keeping the trapped miners alive while they await rescue. The Bureau is currently pursuing research to develop the technology that will enhance the ability of miners to survive such an occurrence. The research is divided into two basic problem areas, survival and rescue. Both areas are concerned with the inability of miners and rescue teams to cope with the postaisaster environment, such as toxic gases, unstable roof conditions, water flooding, and lack of oxygen. In addition, research is also conducted to find ways of locating and quickly reaching trapped miners. Most of the research conducted by the Bureau has been directed toward the postdisaster problems associated with coal mines. However, most of the research results are also applicable to noncoal mines as well.The papers presented in these proceedings address some of the recent research conducted by the Bureau of Mines that has been directed toward the postdisaster problems outlined above. The topics covered range from an overview of the technology developed for oxygen selfrescuers to training programs for mine rescue. Any questions or comments pertaining to this research are encouraged and appreciated. Open file report (OFR) references in the proceedings listed as available from NTIS may be obtained from the National Technical Information Service, Springfield, Va. 22161, and are also available for reference at Bureau of Mines facilities in Denver, Colo., Twin Cities, Minn., l3ruceton and Pittsburgh, Pa., and Spokane, Wash.; the Department of Energy facility in Morgantown, W. Va.; the National Mine Health and Safety Academy, Beckley, W. Va., and the National Library of Natural Resources, U.S. Department of the Interior, Washington, D.C."

Jan 1, 1982

By D. Harrington

During the 5-year period 1906-10 inclusive, 84 major disasters (a major disaster being one in which 5 or more lives are lost) occurred in the coal mines of the United States, or an average of 17 per year, and the total number of fatalities from coal-mine gas and dust explosions (major plus minor) for the 5 years aggregated 2,338 or 477.6 per year. The monotonous continuance of coal-mine disasters month by month aroused the people of the United States to such an extent that it was felt necessary for the Federal Government to try to do something looking to the avoidance of the admittedly excessive loss of life in our coal mines, and this was one of the deciding factors in the establishment of the United States Bureau of Mires in 1910. That results have been obtained in this particular cause of coal-mine accidents may be seen from the fact that for the year 1933 but one major explosion disaster occurred in the coal mines of then united States and the total number killed in that disaster was 7. Unquestionably the coal-mining industry through use of oaf or mining practices and aided by the various kinds of work of the Bureau of Mines looking to the prevention of mine fires and explosions is in large part responsible for this very creditable change. If the gas and dust explosion fatality rate of 1.059 per million tons of coal produced during the period 1906-10 inclusive had continued to the first of January 1934, instead of the 6,373 deaths which actually occurred due to gas and dust explosions, there would have been 13,480. Hence, during the 23 years existence of the Bureau of Mines there has apparently been a saving of about 7,102 probable deaths, or an average of more than 300 per year, from gas and dust explosions as against the number which would have occurred had the 1.059 gas and dust explosion fatality rate for the period 1906-10 continued. Thirty-nine persons were killed in all kinds of explosions (both major and minor) in the coal mines of the United States in 1933; if the 1.059 gas and dust fatality rate of the 1900-10 period had been in effect in 1933, about 400 persons world have been killed. Unquestionably, the various teachings of the U.S. Bureau of Mines looking to the avoidance of explosions and fires in mines have had a vital influence in reducing the number of explosions and fires and also in decreasing their destruction in case they occur.

Jan 1, 1934

By Fei Chen, Lesley J. Gaydos, Laurence M. Demers, Douglas C. Kuhn

The fibrogenic effects of silica in experimental animals and humans has been extensively studied (I 7, 20). However, the pathogenesis and molecular mechanisms underlying lung injury and fibrosis resulting from silica exposure remain to be elucidated. It is well-documented that silica can stimulate monocyte-macrophage lineage cells to produce cytokines and growth factors, including interleukin-I (IL- I) (20), tumor necrosis factor-ex (TNF-cx) (I 7), insulin-like growth factor-I (IGF-1) (4), and transforming growth factor-P (TGF-P) (24). Consequently, it has been suggested that the fibrogenic effect of silica may be mediated by cytokines in the fater stages of silicosis. During the early phase of interaction between silica and the pulmonary alveolar macrophage, several direct and indirect lines of evidence suggest that reactive oxygen intermediates (ROI) may play a pivotal role in silica- induced tissue damage (2I, 22). One of the most important components of and contributors to ROI is nitric oxide (NO) produced from L-arginine and molecular oxygen under the catalytic influence of NO synthase (NOS) (I 9). At present, at least three NOS genes have been cloned: a constitutive neuron NOS, a constitutive endothelial cell NOS and an inducible NOS (iNOS) (16). A number of factors have been shown to differentially induce iNOS gene expression in different cell lines including bacterial cell products and foreign antigens. During inflammation, NO is a double-edged sword in terms of the host immune defense mechanisms and the physiologic response to an inflammatory insult. The macrophage is one of the major cellular sources of NO. During the early phase of acute inflammation, NO produced from the macrophage appears to facilitate the clearance of pathogens and promotes a local relaxation effect on the microcirculation of vascular smooth muscle. When the production of NO is left unattenuated, especially under oxidative stress, direct cytotoxic effects of NO can emerge through the formation of peroxynitrite as a result of a reaction between NO and superoxide (2).

Jan 1, 1998

By J. C. LaScola

Development of methanometers and anemometers for underground use in coal mines is reviewed. The first semicontinuous recording methanometer was developed in 1961 in West Germany. The Bureau of Mines developed an instrument using; pellesters that was a continuous recording methanometer. Expansion of freon gas created a vacuum which pulled the methane-air mixture through a tube to an electrically heated, catalyst-impregnated pellester where the mixture was burned. The National Coal Board of England developed a continuous recording methanometer based on the principle of the Davy flame safety lamp. A thermo-pile was used to sense the hurt output of the flame. Finally the Bureau of Mines improved its methanometer by eliminating the freon gas and using a diffuser head to a monitor methane-air mixtures. Development of recording anemometers proceeded from the use of a photo¬cell and light source to sense rotation of the Biram-type anemometer blades to the use of a Hall detector to sense, rotation by measurement of electromagnetic pulses.

Jan 1, 1969

By THEO L. JOHNSTON

In preparing for war , Japan built an iron and steel industry that ranked high with other industrial nations . Deficient in raw materials for making iron and steel , it had to acquire the bulk of its iron ore and much of its coal and scrap iron from foreign sources . Steel manufacture, and fabrication , however , were reserved mostly for the Home Islands , where modern integrated plants produced the implements of war . The vulnerability of relying on imports during the war was recognized early, and steps were taken to exploit iron-ore deposits and develop treatment processes on the Home Islands in order to be as self - sufficient as possible . Although the industry had expanded considerably, the capacity of the large plants still was insufficient for military requirements, so other meth- ods of producing iron and steel were adopted, which in some ways illustrate the desperate effort made to supply the war machine. In developing the iron and steel industry, modern practices of other countries were studied and followed with modifications to suit Japanese con- Aitions. German and American technical ability and equipment played a large part in the program; however, the Japanese had competent furnace technologists capable of obtaining proper equipment performance. For the most part, the standard practice consisted of smelting iron ores in blast furnaces and then refining the pig iron to make steel in open-hearth furnaces. Electric furnaces played an important part, especially in the manu- facture of alloy steels. Various other methods yielded minor but significant production. Among the various other treatment processes used, the production of sponge iron in rotary kilns 'probably was the most important in producing melt- ing stock for steel making. Of special importance was the fact that sponge iron made from low-grade ores contained critical metals, such as nickel and chromium, so that the results were more significant than was generally believed.'

Mar 1, 1948