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? A roof bolter reaches for a lever while guiding the drill with his other hand. Since he's watching the drill and many of the controls look and feel alike, he hits the wrong control and crushes his hand. ? Six hours into the night shift, an ore truck driver dozes off. The truck plows over the berm and down into the pit. ? Fleeing a afire, a face crew sees smoke in the intake entry. Assuming the fire is ahead, they cross over to another entry, but soon encounter even worse smoke. These very different accidents have at least one factor in common: the human factor. The actions, decisions, thoughts, or perceptions of one or more humans contributed to the accident. These are just a few examples of safety problems researched by the Human Factors Group of the Pittsburgh Research Center, U.S. Department of Energy.

Jan 1, 1998

To provide accurate navigation and control of continuous mining systems.

Jan 1, 1996

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

Several ignitions or mine pa, which might have led to explosions, and at least ona mine fire attributed to heated leg wires of electric detonators, have occm.rred. at rn1::.es in which outside shot firing is practiced. Photographs taken at one mine ind.la.ted. that the wires became red hot during firing. These results having been --i·-led. to the .Lttention of the electrical section of the Bureau of the Mines, ignitions the tests and to reportd aid in herein preventing were made future to trouble determine of if this possible kind, the cause of The investigation, which 1• considered preliminary, included tests to determine the conditions tha.t cause gas ignitions from heated. leg wires of electric and. of detonators, copper leg possible wires, remedies The tor samples such of heating, wire used. and in the the relative test were behavior the of reg\llar ironDa. Pont iron and copper leg wires (No, 22 A,W,G.) C\1t from Du. Pont electric detonators.

Aug 1, 1922

By John W. Frey

This paper presents one of a series of digests of foreign mining legislation and court decisions that is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Persia has been prepared from the best available information in Washington but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers , to whom it is being referred through the courtesy of the Department of State .

Nov 1, 1929

By L. C. IlsLey

A preliminary investigation has recently been made by the U. S. Bureau of Mines to determine whether or not the ordinary mine- type telephone is entirely safe in gaseous atmospheres . Two well known makes of mine- type phones were purchased for this investigation . It is not conceivable that the current necessary for talking over telephones could ignite gas . However , such phones are provided with efficient magnetos , and it was believed that danger might result from the ringing of the magneto . Again , while this type of phone has been designed to have a certain measure of dust and moisture tightness , evidently it has not been designed as an explosion- proof device . either with regard to cover joints and fastenings or strength of castings . Therefore , the problem was simplified . First it was assumed that owing to the construction of the telephones the gas would penetrate into their interior , and the question was to ascertain whether or not the gas would be ignited from the operation of the magneto .

Jan 1, 1922

The objective is to provide effective training on refuge chambers for underground coal miners. This training will increase knowledge about how to teach miners to operate, transport, and inspect a refuge chamber; what to expect psychologically and physiologically inside a refuge chamber; and how to decide when to use a refuge chamber. Background During 2006?2007, several disasters occurred at U.S. underground coal mines, resulting in 28 fatalities. These disasters led to new approaches to mine safety and health, as well as new federal regulations. One new technology mandated by federal legislation is the refuge chamber. Refuge chambers are movable shelters that are either made of steel or inflate from a steel skid as a tent. They can potentially save the lives of miners during an underground mine emergency by providing breathable air, food, water, and a safe environment for up to 96 hours. Because the refuge chamber is a new technology, recommendations, information, and training products are greatly needed.

Nov 1, 2009

By Wesley A. Grosh

The Sutherland copper prospect is situated in Floyd County, Va. The immediate area was prospected around 1850, and one of the adits possibly dates from that time. Little or no ore has been mined from the deposit. The deposit is a mineralized sulfide zone occurring in mica schist and consisting mostly of pyrrhotite with minor amount of copper. A magnetometer survey of the deposit by the American Metal Co. in 1939 showed an anomaly that was thought to indicate a zone: of secondary enrichment. The Bureau of Mines diamond-drilled 14 holes, totaling 913 feet, and opened an adit during February and March 1943. No appreciable copper values or indications of secondary enrichment were found.

Jan 1, 1948

The dust exposure of the longwall shearer operator is usually determined by his position relative to the cutting drums. The dust generated during cutting may travel up-wind, against the primary airflow, and be carried out into the walkway where it can contaminate the intake air for as much as 10 feet outby the shearer operator's controls. Thus, both head and tail drum operators are exposed to un-acceptably high levels of air-borne respirable dust. One Solution The latest generation of long-wall shearers has features that make the use of radio remote or umbilical (hard wire) remote control relatively easy to implement. Remote control can enable shearer operators to control machines from positions that are less dusty than normal control stations. With either type, the head-drum operator can now control the shearer from a position up to 20 feet on the intake-air side of the shearer, while the tail-drum operator's station is now located across from the head drum.

Jan 1, 1984

By N. S. Dalal, W. Irr, X. Shi, V. Vallyathan

"Inhalation of crystalline silica is associated with a biphasic biologic response of acute cell injury and chronic pulmonary fibrosis. Dust induced cell membrane injury leading to the release of lysosomal enzymes and cell death has been implicated as the initial important biologic event triggering the fibrosis. However, it ls also possible other biologic reactions could alternatively, or in addition to these enzyme related cytotoxicity reactions, alter the normal functioning of cells. It is well known that phagocytic activation results in the production of oxygen radicals which are highly cytotoxic to cells. In healthy - lung, protection against the toxic effects of the normal balanced ·biologic reactions are provided by a number of defen1e systems including antioxidants. In disease or condition of overproduction of oxygen radicals, biochemical protection may be overwhelmed with resultant cellular injury.Our recent observations have shown that reactive oxygen radicals (ROR) are generated during grinding of crystalline silica. We hypothesized that these newly generated RORs may cause cell injury, lipid peroxidation, or even damage to macromolecules such as DHA. Biochemical aberrations caused by the inhalation of crystalline silica with ROR at occupational settings might overwhelm cellular and antioxidant defense systems of the lung leading to injury and subsequent fibrosis.To test this hypothesis, we have investigated the generation and decay of ROR produced by crystalline silica using electron spin resonance (ESR) and investigated its toxicity with conventional biologic tests at various time intervals after grinding. We also studied the decay of these newly generated RORs in buffer and the effect of antioxidants and scavengers in the abolition of cellular damages."

Jan 1, 1989

By N. S. Dalal, B. Jafarl, M. M. Suryan, V. Vallyathan

"The biologic events leading to coal workers' pneumoconiosis (C'WP) are not yet fully understood. There is no good correlation between toxicity studies or animal models with human epidemiologic and pathologic data. Several studies have shown that the severity and prevalence of the CWP in miners correlate strongly with the rank and type of the coal mined. However this has not been found to be the case with laboratory animal models or in vitro studies. In 1980 Russian scientists Artemov and Resnik suggested that the discrepancy may be related to the excessive amount of short-lived free radicals present in freshly generated coal mine dust. Because of their short life, such free radicals would be absent in the ""stale"" coal dust used in most animal experiments. To test this hypothesis we have undertaken a systematic study of the generation, reactivity with oxygen and biological significance of free radicals in coal dust.Electron spin resonance (ESR) was used as a technique for the direct detection of radical production and kinetics of decay. ESR signals from the newly generated radicals decreased with time on exposure to oxygen or when stored in biological buffers at a rapid rate. In vitro biological tests were carried out which suggest that the reaction between the newly generated radicals and oxygen plays a significant role in the sample's cytotoxicity.Materials and MethodsESR measurements were made at X-band (~9.7 GHz) using a computer-controlled Bruker ER200D ESR spectrometer. 11te two coals studied in detail were obtained from the Pennsylvania State University Coal Depository. These were, a bituminous sample, PSOC-1172 (72% carbon) and an anthracite sample, PSOC 867 (95% carbon). Coal particles of several millimeter (mm) dimensions were evacuated to a pressure of ~10-3 mm Hg typically overnight. Without exposure to air, these particles were ground in an agate mortar with an agate pestle for about 30 minutes and then sieved through a 20 \1111 mesh filter before ESR measurements or cytotoxicity studies. As an index of cytotoxicity, hemolysis was measured according to the method of Harrington, with minor modifications. Sheep erythrocytes (2%) were incubated with test samples at 37°C for one hour, and the hemoglobin released was quantitatively estimated photometrically. Additionally, release of alveolar macrophage enzyme lactate dehydrogenase (LOH) was estimated after incubation of the macrophages with the coal particles at different time intervals after the grinding. Enzyme activity was assayed according to the method of Wrobleski and LaDue and expressed as percent of enzyme released in 2 hours per million cells with 1 mg of coal."

Jan 1, 1989

By W. C. Phalen

"The term ""manjak"" is applied to a variety of bitumen or solid hydrocarbon occuring on the Island of Barbados, West Indies, and in Utah, Cuba, and Trinidad. The deposits on the latter island are found within a distance of three miles of San Fernando, the second largest town on the Island, and within three miles of the famous asphalt lake.In chemical composition, manjak is like asphalt. It is almost pure bitumen. Its melting point is, however, more than 4000F. whereas asphalt melts at 1000F. In composition, it consists of 80 to 90 per cent carbon, the balance being chief¬ly hydrogen, with a small quantity of sulfur. It resembles coal in appearance, is odorless, hard, and brittle. It is found in thin beds between layers of clay.The island of Trinidad is rich in this mineral resource. Its development has as yet hardly begun, and the exportations already made have been with the view of testing out the ma-terial. During 1918, exports to the United States were valued at about $3100, and in 1919, up to October 1, they totaled 41 tons, valued at $1900. Prior to 1900, manjak was mined on a small scale in Trinidad, but for various reasons, very little was done between 1900 and 1913. In the latter year, mining operations were resumed by the Trinidad-Tarouba Oil Development Company, of San Fernando. At the present time, there are five shafts, one of which has reached a 37 foot bed of manjak at a depth of 400 feet. Operations could be greatly extended if there were a greater demand for the material.It has not been found profitable to export manjak from Trinidad in the crude state as the price received, namely $35 per ton, hardly covers mining expenses. These are increased by the necessity for careful and thoro timbering on account of the clay formation.Compounds, made by combining manjak with mineral oil command fair local prices which have enabled mine operations to proceed at a profit. Experimentation is still in progress with different mixtures of manjak and oil for various purposes. The manjak, recently sent to the United States was for the purpose of ascertaining whether American oils would be more economical and useful for mixing with the manjak than the Trini¬dad oils. It is the plan to erect a plant very soon for the manufacture of a variety of manjak paints and compounds.Manjak is rapidly increasing in use, particularly in connection with the oil industry. It is produced in close proximity to the oil wells in Trinidad. It is boiled with oils at high temperatures and converted into compounds and paints for nearly every purpose where a preservative is needed, for example, on pipe lines, boilers, chimneys, and miscellaneous iron ware, machinery, etc. It is usually applied in the liquid state, hardening into a tough, rubberlike coating. It has low viscosity, and is not affected by ordinary heat. It makes an excellent insulating material and is impervious to both air and water. In hot and damp climates, like that of Trinidad where pipe lines quickly deteriorate, their life has been pro-longed for extended periods when painted with this material."

Nov 1, 1919

By S. H. Katz

Artisans and laborers in mineral industries where the air is dusty with particles of reel: are subject to a peculiar pulmonary disease known as miners' phthisis or stone cutters' consumption. In granite cutters the disease is specifically designated as granite pneumoconiosis. Very fine particles of the harder rocks are especially injurious when inhaled into the lungs. It is estimated particles about one micron (1/23000 part of an inch in diameter) are most injurious, because larger particles are more readily removed by the cilia and,wet surfaces of the respiratory passages before reaching the lungs, while smaller particles either do not readily lodge or are more easily eliminated. Silica, of which quartz and flint are composed, and which forms a large part of granite, is one of the hardest of the common rock-forming materials. It is also very insoluble when silica lodges in the lungs elimination is difficult. Rock constituents of granite other than silica are probably injurious but in a lesser degree, and this is also probably true of limestone and the softer rocks. Ultimately a worker who daily inhales much granite dust has considerable deposited in his lungs. If he continues at his trade the lung tissue becomes harder and less elastic, he finds himself short winded, and in extreme cases death may come either directly or indirectly as a result of lung failure.

Feb 1, 1921

By T. R. Taubert, D. H. Carlson, J. H. Johnson

"ObjectiveDevelop a portable emissions measurement apparatus to sample and measure tailpipe concentrations of diesel particulate matter (DPM), carbon monoxide (CO), carbon dioxide (COJ, nitric oxide (NO), and nitrogen dioxide (NOJ under steady-state engine load and speed conditions during a 1-minute test.BackgroundThe U.S. Bureau of Mines (USBM) has a comprehensive research program to develop ways to reduce exposure of miners to diesel exhaust pollutants. Engine maintenance has been shown to have important effects on such exposure.Accurate measurements of tailpipe emissions are becoming an essential part of a good maintenance program for underground mines that use diesel-powered vehicles. Past studies of particulates in U.S. underground coal mines have shown that DPM alone may be present at concentrations greater than 1 milligram per cubic meter (mg/m3), half the 2-mg/m3 limit for respirable coal mine dust. A poorly tuned (smoking) diesel engine may be the sole cause for respirable dust concentrations exceeding the limit. Although there is currently no standard specifically for DPM in U.S. mines, regulatory steps are underway, and significant reductions of DPM levels in both coal and metal mines will most likely be required.Tailpipe emission measurements can provide diagnostic information to identify engine malfunctions such as clogged air cleaners, faulty injectors, or incorrect injection timing. In some cases, mine vehicle tailpipe DPM concentrations have been reduced up to 50 percent by engine maintenance and adjustments.An accurate measuring instrument would also be useful for determining the effects of exhaust control devices on tailpipe emissions. Little information is currently available about the overall effectiveness of exhaust controls after long-term use. Raw exhaust concentrations with and without the control device can be measured in underground mines, and from these data a control efficiency can be calculated. Knowledge of the effectiveness of exhaust control devices over time is needed to make intelligent decisions on bow to use and maintain these devices, and when to replace them."

Dec 1, 1995

By F. E. Wormser

"Arsenic has been recently quoted at 10 1/2 - 11 cents per pound, an increase over the prevailing price of last fall, when arsenic was cents, as against pre-war prices around 4 cents is evidently a sustained demand for this material. The following statements are intended to summarize briefly some particulars regarding arsenic.Commercial arsenic is the white arsenious oxide (As203). This is the form in which it is generally marketed, as the uses of arsenic demand its industrial application in this form. Arsenic as an element finds rather restricted use in the hardening of lead shot, ere it is to some extent replacing the use of antimony, while white arsenic is employed in a variety of manufacturing processes, chief of which is the manufacture of insecticides and sprays. The poisonous nature of most arsenic compounds, the commonly known ones being paris green and lead arsenate, and its relative cheapness, make arsenic a material suitable for this purpose. The stimulation of agriculture during the war greatly increased the demand for arsenical insecticide. Glass making consumes a large amount of arsenic as it has been impart increased brilliancy to the glass. Crude commercial arsenic is often used to kill weeds along railroad tracks. Arsenious oxide is used also for preserving hides, while the disulphide, AS2S2), finds an application in dehairing hides for the finest grade leather, as it least affects the product. Orpiment (As233), is used in textile dyeing. Wall paints and wall paper formerly consumed considerable arsenic in the form of paris green, but this use has been largely,given up due to the poisonous nature of the dust from the product. Sodium arsenate for a similar reason, is now little used in printing where it had found application. The great objection to arsenical yes and paints is the risk of poisoning from use of the manufactured article. Sodium arsenite is the principal poisonous in¬gredient of many cattle and sheep dips. Arsenic compounds are also used medicinally."

Jan 1, 1920

By F. J. Bailey

"In the fall of 1919, the U.S. Bureau of Mines began an inquiry as to the possibility of utilizing airplanes in conjunction with its rescue work, for quickly transporting engineers and oxygen rescue-apparatus to mine disasters.It was realised that this proposed use of airplanes has serious limitations, and if it were feasible, that the Bureau would have to rely on the cooperation of the established aviation fields of the U. S. Air Service for furnishing airplane service. Therefore Van. H. Manning, Director of the Bureau of Mines, under date of October 28, 1919, wrote the Director of Air Service outlining the rescue and first aid organization of the Bureau, the location of headquarters of district engineers, the distribution of safety cars and stations, and other essential details, and asking whether the Air Service could cooperate with the Bureau in the event of serious mine disasters. Major-General Charles T. Menoher, Director of Air Service, responded that the Air Service would be glad to cooperate insofar as possible, and designated those Air Service stations nearest the district engineers' headquarters, which might be best able to assist.The Bureau of Mines has ten mine rescue cars and eight mine safety stations distributed throughout the mining regions of the United States. The cars are each equipped with sets of oxygen mine-rescue breathing-apparatus and first-aid supplies. The car personnel consists of a mining engineer, surgeon, foreman, first-aid miner, clerk and cook. A foreman miner is in charge of each station and at five of the eight stations are mine safety trucks. The work of the cars and stations is two-fold; (1) Assisting in rescue and recovery work at mine disasters, and (2) training miners in mine rescue and first-aid methods, and in investigations looking to prevention of mine accidents. The country is divided into nine safety districts, with nine district engineers in charge."

Apr 1, 1920

By Richard H. Oitto

The Bureau of Mines and Kaiser Steel Corp. are cooperatively demonstrating the shield-type roof support in the longwall mining of a 10-1/2-foot-thick coalbed at the York Canyon mine near Raton, N. Mex. As part of the demonstration, the shield supports have been successfully and safely moved from a completed longwall face to a new longwall face. When these shield supports were moved in 1976 they were the largest and heaviest longwall support system in use in U.S. coal mines. The shield supports, preparations for moving them, the actual move, and installation at the new face are discussed.

Jan 1, 1977

By A. R. Elliott

In the early part of the your 1919 the Bureau of Mines undertook a study of methods of handling oil after it had buon produced, with the view of pointing out the losses due to evaporation and other causes. Observations on present methods show that the oil is subject to largo losses in both quantity and quality from the time it loaves tho well until it is recoivod by the pipe-lina company. During this time it is splashed into four or more tanks of various sizes and with little or no protection over the tops. From the settling tank, where the flow of oil is tamporarily stopped in order to permit sparation of ter and sediments, through the gago tanks and leaso gathering tanks to the largo tank storage where it is hold for many days, rich gasoline vapors roadily escape, especially from tho ghor gravity oil. As no effort is made to measure the oil before it reached the storage tanks, where it is delivered to the pipe-line company, the lossos of the light products of the oil can only be approximated, and, as final results will show, are no doubt usually very much underestimated. In conducting this investigation, the Bureau has endeavored to make tests that would show quantities and values lost, in order to impress better upon those concerned what might be saved through a little more diligence. Eperiments were conducted on both California and Mid-Continent oils. The field operimental work done in California, on which a report is to be published in the near future, is cutlined briefly below: The field work consisted in collecting from operating companies data on storage of oils in large tankage and in performing experiments in the field on storing and piping oil to small lease tanks under practical conditions. Acourate Easurements were takon on the volume, gravity and gasoline content of the oil as it passed through the various stages in its removal from the lease. The work extended over the four seasons of the year in order to obtain better the effect of varying winds and high and low atmospheric temperatures during those periods. Thanks are due to the many oil operators who have taken a personal interest in the work and gave valuable information and assistance. One company furnished the oil and tanks and much of the apparatus and labor. This company also per- mitted the work to be done on its properties in the Coalinga field. This was of material aid, as the results were to be comparative and therefore it was necessary that the same gravity oil be used throughout the experiments.

Oct 1, 1920

By Thomas Varley

"Concentration, ore-dressing, or the dressing of minerals are common terms used in metallurgy and indicate processes of separating valuable minerals from worthless gangue. It is understood, of course, that the products from such processes, being separated from the various minerals and gangue, are ready for commercial sale or for further treatment by smelters and refineries.Gravity concentration takes advantage of the difference in specific gravity of the various constituent minerals and gangue of waste material in the ore. The two most common forms of concentration by this means are jigging and table concentration. Jigs usually are used in the separation of relatively coarse material and the tables for the finer material, the line of division in general being about 20 mesh.There are mar factors to be considered .before a decision can be made as to what method would be best adapted to the successful treatment of an ore and only by careful experiments can this be determined. Among the important factors to be considered are. The nature of the minerals present, their physical and chemical relations to the gangue material, and the gangue material itself. Perhaps the most important is the number of minerals present and their relation to each other.Metals exist in ores in three principal forms -- sulphides, oxides or carbonates, and native. Concentration by gravity methods is in general best suited to sulphide ores, although in some places considerable success has, been obtained in the concentration of oxide ores by gravity methods."

Apr 1, 1920

By E. D. Gardner

An explosion occurred in a high-pressure compressed-air line in October, 1930, at an Arizona copper mine. The explosion was unusual, and nothing had teor. noted by the plant operators to indicate the possibility of such an occurrence. It is necessar The air is The mining company uses compressed-air locomotives to haul about 4,500 tons of ore per day from the stopos to the pockets at two hoisting shafts. The ore cars hold five tons each, and are pulled in trains of 30 cars. to charge the locomotive with compressed air at both ends of the trip. conveyed from the compressors at the surface to the distributing points unier roun in special high-pressure four inch steel pipe that was tested to withstand 2500 pounds per square inch before being installed. The air is delivered to the loco- motives at a pressure of 1000 pounds per square inch. There are no receivers in the system. The air for running the locomotives is compressed by one three-stage and two four-stage compressors which have capacities of 600 and 300 cubic feet per minute, respectively. These machines are operated by electric power, and are in an end of the main compressor building in which air is compressed to supply the air drills in the mine. Whenever the demand decreases, as at the noon hour, one or more of the Compressors are shut down. On this particular occasion, at the end of the noon hour, one of the operators was approaching the high-pressure compressors to start the two smaller machines that were not running, when the explosion took place under the floor a few fost ahead of him. The man was mocked down and received some superficial cuts and bruises, but was not seriously injured. The floor was torn , the side of the building blown out, and holes imo cited in the roof some twenty feet above. The explosion was immediately followed by a fire which was quickly put out by the plant operators with hand fire extinguishers. At the time of the explosion the 600 cubic foot compressor was running alone, and the pressure in the system at the machine registered 1040 pounds por square inch. On examination it was found that two 6-fout sections of pipe, about tan feet apart, were completely ruptured into twisted fragments; the rest of the pipe line, apparently, was not injured. The destroyed sections were in that part of the pipe near the large compressor and above the connection from the two smaller machines. It is not definitely mom what caused the explosion. Explosions in other compressed-air systems have taken place, and, although of rare occurrence, have caused loss of life. Such explosions are not confined to high-pressure installations and several have occurred at plants compressing air te one hundred pounds per square inch, or less. plosions of this nature are not to be confused with the rupturing of compressor cylinders from excessive air pressure caused by the discharge valve being closed.

Feb 1, 1921

By Scott Turner

To be successful , human exertion employed for the creation of value requires power and heat ; the ability to produce concentrated power in great quantities has resulted in the relatively recent industrial development that is so profoundly affecting the world . In our commercial history , we have advanced through several stages in the selection of the most suitable fuels , continuously striving to increase the flexibility and range of energy- transmission . The easy distribution of light , power and heat is the leading factor in the decentralization of industry which promises to correct some of the serious evils that have followed in the footsteps of our commercial development . The distribution of fuel in quantity in so convenient a form and with such an attractive reliability- factor as can be had with gas , meets the modern conception of efficient service . Natural gas has been used in this country for more than a century, but recently it has attained a prominence far in excess of anything known in its earlier history. We may consider that we are now getting into our real stride in the utilization of our natural- gas resources . : In a country like the United States , wherein we are accustomed to mammoth achievements , we may be inclined to accept casually the noteworthy technical and economic advances which have resulted in the expansion of natural- gas distribution . About three years ago , the transmission of natural gas a distance of more than 250 miles from its source was first accomplished , and this was really a noteworthy engineering feat . Today , this useful commodity is being transported twice that distance , and lines are being laid which will carry gas more than 900 miles from the points of occurrence . Let us not take such outstanding improvements too much as a matter of course ; the industry should be congratulated on its long steps forward .

Oct 1, 1930