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By K. C. Strebig

The effect of some organic additives in diamond drilling of quartzite was investigated in the laboratory with a drill instrumented to measure the rate of penetration, the thrust, and the torque and to record each as a function of the distance drilled. A statistical plan was followed throughout the investigation, and an equation representing the bit performance was derived from the mathematical theory of reliability. The coefficient of friction in drilling increased with the use of additives, although the wear coefficient decreased. The decrease in wear associated with an increase in energy per unit volume consumed and the increase in penetration rate resulted in a net decrease in the cost per foot of drilling. A hypothesis explaining the effects achieved with the additives is given.

Jan 1, 1971

By Thomas W. Martin

This chapter includes tables from 1984 that were not available in time for publication of the 1984 Minerals Yearbook, but does not include corresponding tables for 1985. The value of raw nonfuel minerals produced in the United States during 1985 was estimated at $23.2 billion, an increase of $0.07 billion over the value for 1984. This is the third consecutive year that the value has increased, and except for a decrease in 1982, the value for each year has increased since 1971, or 13 out of 14 years. However. while the value of industrial minerals production continued to grow, reflecting the growth of the domestic economy, the value of metal mine production decreased in 1985 by 6%. This drop was more than offset by a 3% increase in the value of industrial minerals production because the value of industrial minerals produced was more than three times larger than the value of metals. The decrease makes 1986 the third year in the past 5 years in which a drop in the value of metal mining production occurred in the United States where production continued to lag behind growing world production. Domestic production of such major commodities 88 aluminum, copper, iron ore, phosphate rock, and zinc continued to decline owing to a number of international and domestic factors. Gold continued to be the most active commodity in the domestic metal mining industry. Despite lower prices, gold output increased to 2.5 million troy ounces, a 19% increase over that of 1984. The estimated annual production capacity of new gold mines beginning production exceeded 1 million ounces.

Jan 1, 1987

By Robert C. Gabler

Evaluation of incinerated sewage sludge as a secondary resource for aluminum, phosphorus, and minor constituents such as copper and zinc was initiated as part of the Bureau of Mines secondary resource program. The elemental composition of sludge ash for 14 plants in 11 U.S. cities was determined. Comparing industrialized cities with cities where most of the sewage is domestic, significant differences in heavy metal content were noted. Various parameters were investigated affecting the extraction of metals and phosphorus from a typical industrial city sludge ash and from a Palo Alto, Calif., sludge ash with a high precious metal content. Three extraction-recovery procedures for metals and phosphorus using sulfuric acid leaching, ion exchange, and various precipitation techniques were investigated. The last procedure developed was a combination approach using a three-stage countercurrent sulfuric acid leach that recovered most of the economic values from the sludge ash and also removed the leachable fraction of elements of environmental concern.

Jan 1, 1979

By George J. Conroy, Angel G. Jordan, Eugene W. Bartel

Time-domain reflectometry has long been an accepted and used method for locating electrical faults in electrical cables. The process has, however, required the use of equipment that is somewhat complex and difficult to use. The skill level needed to operate such equipment is high. Therefore, the use of the time-domain reflectometry process has been limited to selected locations and controlled environments. The process, however, has great potential for mine system applications. The ability to locate and repair trailing power cable without removing it from the mine would result in great savings in cost and employee-hours. Therefore, an automatic microprocessor-controlled time- domain reflectometry system was developed to reduce process complexity and skill level needed to operate the unit. The theory of operations is discussed along with the computer analogies used in the unit. The present unit capabilities are presented and future areas of application and research are discussed.

Jan 1, 1979

By Hisataka Sakakibara

Although the pathophysiology of vibration-induced white finger (VWF) is still under discussion, evidence has been accumulated to understand the underlying mechanism. VWF is pathophysiologically characterized by an enhanced vasospastic response to cold, which can result from an imbalance between vasoconstriction and vasodilation in the digital arteries in response to cold (i.e., vasoconstriction-dominant). The imbalance is supposed to be due to faults in vascular vessels and sympathetically mediated vascular tone. Enhanced vasospastic response to cold Narrowing of arterial lumen with medial smooth muscle hypertrophy. Possible functional factors for enhanced vasoconstriction • Increased sympathetic nervous activity to cold (e.g., norepinephrine) • Increased release of endothelin-1 (ET-1; an endothelial-dependent vasoconstrictor) from the endothelium • Increased reactivity of alpha2-adrenoreceptors to cold Possible functional factors for decreased vasodilation • Decreased release of nitric oxide (NO; an endothelial-dependent vasodilator) from the endothelium • Decreased release of calcitonin gene-related peptide (CGRP; a vasodilatory neuropeptide) from sensory afferents The question is how their interrelations or imbalances among them are Vibration and arterial damage The next question is, how does hand-arm vibration exposure induce such pathophysiological changes in VWF patients? Recent morphological evidence from animal experiments shows that vibration acceleration stress (including shear stress) and smooth muscle contraction contribute to arterial damage of smooth muscle and endothelial cells. The vibration-induced arterial damage is frequency-amplitude-dependent.

Jan 6, 2006

By Christopher Van Dyke, Edward L. Petsonk, Knox Van Dyke, Vincent Castranova, Ji-Hee Kang, William Pailes

"INTRODUCTIONPlatelet-activating factor (P AF) has been shown to mediate a broad range of biologic activities (1). Chemical analysis has shown that PAF is a glycerophospholipid with a choline polar head group, an ester-linked acyl chain at the second carbon of the glycerol backbone, and an ether linkage at the first carbon. The alkyl group attached to the first carbon can exist in a variety of chain lengths, with the C16 and C18 forms predominant in humans. The structure of P AF has been identified as 1-0-alkyl-2-acetyl-sn-glycerol-3-phosphorylcholine (2,3).PAF can be released from a variety of cell types, such as basophils, neutrophils, and alveolar macrophages ( 4-6). Stimuli for the release of P AF include calcium ionophore, phorbol esters, chemotactic agents, and zymosan. In addition, endotoxin has been shown to be a potent stimulant of P AF release from alveolar macrophages (7).P AF has been shown to have a number of pulmonary effects. It has been associated with asthma since it can cause contraction of pulmonary tissue (8) and leukotriene secretion from leukocytes (9) and induce airway constriction when inhaled by humans (10). In addition, PAF is a potent chemoattractant and can cause migration ofneutrophils into the airspaces of the lungs (11,12). Endotoxin is a lipopolysaccharide-protein complex derived from the cell walls of gram-negative bacteria. I.PS is the lipopolysaccharide portion of endotoxin. LPS contains four covalently joined subunits: lipid A, 3-deoxyoctonate, a core polysaccharide moiety, and an 0-specific antigenic polysaccharide side chain. Rough LPS contains no 0-antigen side chain. The liP.id A portion of LPS has been associated with most of the biolQgic effects of endotoxin (13). This lipid A subunit consists of a D-glucosamine disaccharide backbone substituted with four fatty acid side chains. Endotoxin is found in a wide variety of occupational settings associated with organic dusts derived from plants or animals, such as cotton, cereal grains, silage, rice, and poultry (14-18). In addition, airborne endotoxin has been found in sewage treatment plants, composting plants, offices with contaminated humidifiers, and showers or saunas (19-22)."

Jan 1, 1990

By A. C. Fieldner

"Gas hazards may be divided into two principal classes- namely (1) inflammation and explosions; (2) asphyxiation and poisoning. Inflammation and explosion are prevented first by adequate ventilation so that gas sufficient to propagate flame or explosion can not accumulate, and second, by avoiding sources of ignition such as open lights, flames, sparks, electrical arcs, short circuits, or sparks. Ventilation is also the best preventive measure against asphyxiation and poisoning from toxic gases. When men must enter unventilated or poorly ventilated places containing poisonous or asphyxiating gases, suitable gas masks, hose masks, or oxygen breathing apparatus should be worn. As a rule, loss of life and property from gas hazards is due to ignorance of the properties and hazards of various gases commonly used, and consequently a failure to use proper measures for eliminating and meeting these dangers. It is the purpose of this paper to describe briefly the common gases and vapors with respect to the hazards involved in their use and to discuss the necessary precautions and methods for avoiding these dangersLight, heat, and power are prime essentials of our modern industrial civilization. The combustible gases and vapors used for the production of these necessary elements of our existence comprise the largest and most common group of domestic and industrial gas hazards. Almost every individual in his daily life subject to possible danger from asphyxiation, fire, or explosion due to one or more of these gases. For evidence one need only refer to the daily newspaper where headlines such as the following are frequently seen; ""Family asphyxiated by carbon monoxide from gas heater;"" ""Schoolhouse wrecked by gas explosion in basement;"" ""Man killed by automobile exhaust fumes in his garage;"" ""Fireman overcome by smoke fumes in basement ""Woman"".""Boman severely burned by accidental ignition of gasoline used in cleaning gloves;"" and 'in recent Years we often see ""Building wrecked by explosion of still in residential district.""It will be noted that these accidents are due to inflammation, explosion, or asphyxiation. Any combustible gas or vapor, when mixed, with air or oxygen within certain limiting proportions, will explode on ignition. The violence of the explosion varies with respective proportions of air and gas, and with the degree of confinement of the mixture. For example: Mixtures of natural gas and air containing between 4.5 and 12 per cent natural gas will explode, or propagate flame throughout the mixture without the continual presence of the source of ignition that started the inflammation. The table following gives the explosive limits of the common combustible gases and air:"

Jun 1, 1926

Reduce the dust levels to which jacksetters and helpers on auger mining sections are exposed by identifying viable, effective methods for control-ling respirable dust on these sections. Approach The Bureau of Mines con-ducted laboratory tests and respirable dust surveys to identify the factors that distinguish clean auger mining operations from dusty ones. Study Results Results of the Bureau's study revealed that ventilation is the most important element of auger mining dust control. The four must important venitilation parameters are airflow, curtain configuration, curtain setback, and curtain installation.

Jan 1, 1988

Viable domestic mineral industries are essential to the economic health of the United States and the well-being of its citizens. The charts in this publication reflect developments significant to the Nation's mineral industries during 1975. Last year was a year of reduced activity for the Nation's mineral industries. Although the value of the country's total mineral output rose, for example, the overall production and use of many minerals fell. At the same time, the industry experienced lower profits and higher debt/equity ratios. These and other adverse effects on many segments of the Nation's mineral industries resulted from the overall decline in domestic and international economic activity.

Jan 1, 1976

By E. H. Denny

The coal and metal mines of the United States furnish this country with a large part of the fuel and material necessary to support our industries and thus make possible the welfare and prosperity of our people and even the continuance of our present-day scale of civilization. Mining companies furnish material to industry with one general purpose in mind -- the making of a profit on their work. Efforts are being made successfully and continually to reduce operating costs, to increase production per man, and to perform work as far as possible mechanically and with more efficiency. These efforts are made primarily to reduce costs, to increase production, or to do both - in other words to make more profits or more certain profits. In the endeavor to reduce expense companies are considering more and more the factors which enter into costs of production, among them the factor of accidents and their cost. This paper endeavors to estimate the approximate cost of accidents to the mining industry in order to present the saving possible through accident reduction or elimination.

Jan 1, 1929

By Charles Vaught

The purpose of this study was to determine mine workers' state of fie-fighting preparedness and the technology being used to detect and respond to underground coal mine fires. To investigate this problem, 214 underground coal miners were interviewed by U.S. Bureau of Mines researchers. Frequency distributions of workers' responses are presented in this report, along with segments of narrative accounts, to profile miners' fire-fighting capabilities. The data indicated that much variability exists from mine to mine and that there are several important changes operators may undertake in order to make miners better prepared to deal with fire underground: select appropriate sensors, establish and test a warning and communication protocol, construct a system capable of delivering hundreds of gallons of water per minute for sustained periods, institute formal fire preparedness audits, develop case studies of events that occur at an operation to use as teaching and assessment tools, and provide structured practice that can be incorporated into fire drills.

Jan 1, 2010

By Doris M. Hyde

To a greater or lesser extent, the economies of the smaller Caribbean Island countries continued to have common problems. These included unemployment, inflation, foreign exchange shortages, trade deficits, and unstable world prices for their exports. Declining prices for petroleum provided some relief from scarce foreign exchange. Overall, the mineral sector remained stable. The Amerada Hess Corp. crude oil transshipment terminal on St. Lucia was completed during 1981. However, there were no shipments during the year. No official reason was offered for the delay in opening the terminal, but it may have been related to the world surplus of crude oil that occurred in 1981. There has been no further action on the refinery, which was to complete the island's petroleum complex. During the first half of 1981, an announcement was made that a second oil transshipment terminal would be built on St. Lucia. The report indicated that the terminal was to be financed by Saudi Arabia and include underground storage. After the original announcement, no further information was made available. This terminal, like the Hess petroleum complex, may have been temporarily postponed because of the crude oil surplus.

Jan 1, 1983

By W. A. Calhoun

The purpose of this investigation was to develop a procedure for removing excess iron from representative samples of bauxite ore from the Quapaw deposit of American Cyanamid Co., Saline County, Ark., in order to produce a beneficiated ore suitable for use in the alum industry, At the request of the sponsoring company, the samples were reduction-roasted at 800° C. and then magnetically separated. Although some rejection of iron was effected under these conditions, the general results were not satisfactory, A much more successful procedure, from the standpoints of both rejection of iron and recovery of alumina, consisted of a short (l5-minute), low-temperature (400° C.) oxidizing roast, followed by a 2-minute interval in a hydrogen atmosphere, then cooling to room temperature, and, finally, high-intensity magnetic separation to remove the iron.

Jan 1, 1957

By Thomas R. Bur

The strain and pressure gage methods for evaluating the relative performance of explosives in rock were compared. This comparison was based on a study of the responses of strain and pressure gages to explosion-generated seismic waves. Several explosives) representing a wide range of detonation pressures) were used. In general the relative performance of these explosives) as determined from amplitude) impulse parameter) and energy parameter measurements) is the same if the compressive portion of the strain pulse and the comparable portion of the pressure pulse are considered. Other similarities and differences of the two methods are also discussed.

Jan 1, 1967

By W. H. Tomlinson

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

Jan 1, 1940

By F. C. Trutt, J. Sottile, J. L. Kohler

Presented in this paper is a theoretical review of the relationships that should exist between electrical winding parameters and the mechanical vibration of a-c machine elements under normal and faulted operating conditions. Also included is data from an experimental study that relates stator vibration and bearing vibration to selected winding faults in a synchronous machine. Consideration of these results indicates a significant relationship between electrical deterioration and mechanical vibration and thus provides the motivation for additional study and a basis for future applications.

By R. D. Leitch, J. G. Calverley

"INTRODUCTION Although many investigators have provided information on the strength and other properties of concrete the published literature cites few data on the effect of mixing cement with acid mine waters or on acid resistance of concrete in contact with mine waters. Most of the reported work on the effect of impure waters has dealt with the resistance of cement specimens to ""sulfate waters,"" that is, waters or soils with a relatively high sodium sulfate content. The ""Merriman test"" is used commonly to determine the corrosion resistance of cements for 28 days, but it does not seem certain that a cement having a high sulfate resistance in the Merriman or similar tests necessarily will show correspondingly great resistance to the sulfates of iron and, particularly, to sulfuric acid, which usually are present in acid mine waters. Extensive use of cement mortar for laying up masonry stoppings in coal and other mines and for constructing concrete mine haulageways and shaft linings, coal-storage and other retaining walls, highway bridges, culverts, and many other types of construction where it is difficult to obtain fresh water for mixing or where the structures are later exposed to contact with acid waters makes it important to know the effect of these conditions on cement and whether there is a cement better suited for such work than ordinary portland cement.CONDUCT OF THE INVESTIGATIONFor a short time early in 1935 the opportunity to obtain at least some additional information on the effect of acid mine water on cements was presented by the Relief Works Division, which provided money for irregular and indefinite employment for several months. Purchase of apparatus or material was not permitted under this arrangement, and indefinite duration of the work, intermittent employment, and finally complete cessation of the work prevented planning for extensive investigation of this particular problem."

Jan 1, 1940

By John W. Buch

Upon review of German World War II mining practices and equipment for planning coal, the Federal Bureau of Mines initiated research leading to the development of a pneumatic planer for anthracite. The results of tests are reported in this manuscript. It was demonstrated (1) that hard anthracite can be planed and (2) that the design and operating requirements are within the limits of present-day engineering and technology. For hard anthracite, the depth of cut indicated is 4 to 6 inches; with a chain pull of 20 to 40 tons and the speed of planer travel of 18 to 20 feet per minute, a 40-hp. motor will be required for the planer hoist. Compressed-air requirements for the planer will be 250 to 300 c, f, m, at 60 to 70 p. s, i. It was learned that the length of the 4 individual sections of the planer should not exceed that of the individual troughs of the armored chain conveyor (5 feet in this instance); otherwise, bottom coal will be left in synclines, and the planer will override the conveyor at anticlines. Pneumatic pushers should be operated from a separate compressed-air line fitted with a pressure regulator. Results indicate that additional development work is warranted.

Jan 1, 1957

By F. C. Gregory

"The ""safety bonus"" in metal mining is a sum in addition to the regular wage, paid to foremen or bosses for keeping the accident rate down to a specified minimum. It has been used with success for some time by certain companies as a regular part of their safety work. It is desirable from the employer's point of view in that the desired results in accident reduction must be accomplished before the bonus is earned; and from the standpoint of the recipient, in that he receives a reward for the additional effort which he has put forth in order to earn the bonus.While this paper relates to the safety bonus as applied in the metal mining industry, the bonus system discussed herein will apply equal well to coal mining, oil-field work, and other mineral industries.Various estimates have been made as to the percentage of accidents that can be prevented through physical safeguards, adoption of safe working methods, and other safety measures which can be initiated and carried out wholly through the management or the safety department. This percentage will always be a vari¬able according to the local plant and conditions. But all who have been engaged in accident prevention agree that such work alone cannot bring the accident fre¬quency down to where it should be, and that it is very necessary to work directly with the workmen, in an effort to make each individual do his share in making the work safe. In this latter phase of the work, the boss who has immediate super¬vision of the men is the one who can do the most, since he is in daily and frequent contact with the men while they are at work. In the metal mines, the shift and stope bosses are the key men; in the oil fields, the ""tool-pushers"" or sub-foremen, and the same applies to all industries. So it becomes necessary to keep these sub-foremen constantly interested in accident prevention, both because they are in personal touch with the men and because they are responsible for production and hostile to any plan which they think will interfere with their output. In large organizations it is the shift boss who represents the company and its policies to the man on the job."

Jun 1, 1924

By Guy A. Johnson

Combining contract and in-house research, the Bureau of Mines has developed and inmine-tested a novel device to improve the field-of-view of operators of off-highway mining equipment. This device utilizes a downward-looking, flat fresnel lens. The lens, plus louvers to reduce glare, is housed in a protective steel structure. The complete unit is called a blind area viewer. The viewer, when mounted on the right- front corner of the deck of most large haulage trucks, will increase a driver's direct field-of-view from about 35 pct (of where he/she has to drive) to about 80 pct. The improved visibility allows the driver to see possible collision hazards and roadway obstacles better, thus improving mine safety and increasing productivity. Economic analysis shows that the blind area viewers, which are now commercially available, pay for themselves in about a month on a 170-ton-capacity truck. The viewers are also applicable to other large mining equipment, such as front-end loaders, draglines, and downhole drills, or any place where seeing around a corner would be advantageous, such as along conveyor flights in processing plants during startups.

Jan 1, 1983