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By John C. Machisak

INJURY DATA and experience at coal mines in the United States for 1957 are presented in this bulletin under the following general sections: (A) General injury experience: Tables 1-6: Current data on number of fatal and nonfatal injuries, frequency and severity rates, and average severity. (B) Selected injury experience: Tables 7-36: Current data on causes of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employ¬ment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines. (C) Injury experience, by States: Tables 37-41: Data on injuries, injury rates, employment, causes of injuries, and severity rates. (D) Major disasters: Table 42: Data on major disasters from 1948 to 1957. A major disaster is defined as a single accident in which, or as a result of which, five persons or more are killed instantly or die at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 43-47: Data on fatalities and their causes at bituminous-coal, lignite, and anthracite mines from the earliest records through 1957.

Jan 1, 1960

By Geo. H. Williamson

This paper describing the dredging operation of J. K. Davison & Bro. on the Allegheny River near Pittsburgh, Pa., is one of a series being prepared for and published by the United States Bureau of Mines on methods and costs of dredging sand and gravel in the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of H. R. Hissrich, chief engineer of the Goodman Engine and Machine Co., in compiling details of the dredge construction; of H. H. Stewart, auditor of J. K. Davison & Bro., in preparing cost and performance tables; and of J. R. Thoenen, mining engineer of the United States Bureau of Mines.

Jan 1, 1932

By F. E. Griffith, C. H. SEELING

Cardox blasting is used widely in coal mines in the United States . A model of a Cardox blasting device was approved by the Bureau of Mines subject to certain conditions and limitations , and the approval was extended to other models from time to time . Certain special hazards are entailed in the use of Cardox as with explosives . One of these is flying shells . In some blasts , the Cardox shell is violently ejected from the borehole and flies like a projectile , frequently ricocheting off solid objects and striking points considerably off the line of its initial flight . Flying shells have been known to pierce the webs of structural - steel beams , to pass through both sides of allsteel mine cars , to be driven through stout hardwood timbers , to knock out timber sets , to damage loading equipment , and to break or short - circuit power lines . A considerable number of shot - firers and other workers have been struck by flying shells and killed or injured . Accidents from this cause , although not as frequent as other types of mine accidents , are usually serious , closely approximating accidents caused by blasting with ordinary explosives . The increasing number of such accidents prompted a Bureau of Mines field investigation of possible methods of preventing dangerously violent ejections of Cardox devices . This report contains pertinent data collected during the investigation and describes methods tested and discarded as well as the development and proof of an apparently satisfactory method .

Jun 1, 1943

By T. E. Swigart

In the production of oil end gas, engineering methods have been applied less than in any other branch of the oil industry. While refineries, gasoline plants, pipe-line and other transportation systems, and even drilling wells to a great extent, take advantage of engineering skill, the tendency has been to assume that the handling of producing wells is merely a mechanical and routine matter. At present few companies employ engineers to study oil and gas production methods with a view of increasing the general efficiency of recovery, but in vie, of the advancement in other lines of the petroleum industry by the application of engineering principles, does it not seem likely that the production branch may benefit also by engineering studies? Engineering applied to the handling of producing wells falls under two general headings, - first, the efficient handling of wells from the time of their inception in order to obtain the greatest possible ultimate production, and, second, the rehabilitation of old properties that have been handled carelessly in their early lives. To date, the engineering work that has been done on oil production problems falls mostly in the second class. For example, the use of vacuum and the application of compressed air have proved successful in some instances in stimulating wells of low gas pressure. These methods are costly to apply and are adapted to small wells in which the gas is almost exhausted, or in which the original gas pressure is negligible. The experiments described in this paper fall under the first heading, as they were made with an idea of learning toe probable extent to which the gas production of an oil well can be curtailed while gas in the sand is still plentiful, and thus saved for doing work during the later period of a well's life. Because of the scope of the experiments, this paper does not include a discussion of back pressure on flowing wells or for purposes other than cutting down the gas produced with each barrel of oil.

Jan 1, 1922

By J. B. Gayle

The removal of coal particles from a slurry by flotation is made possible by the formation of stable aggregates with air bubbles of suitable sizes. The formation of such aggregates is theoretically possible only for certain favorable combinations of the solid-liquid-gas interfacial tensions. Because interfacial tensions involving solid phases are not conveniently measurable, a related variable, the contact angle, frequently is used as a measure of the floatability of various materials. Zero angles indicate nonfloatable substances, and large angles indicate substances having a high degree of floatability. During a study of contact angles for coal and substances related to coal in their similarity of response to various physical and chemical treatments, particularly flotation, carbonization, and oxidation, the reproducibility of replicate determinations taken within a 4-hour period was found to be much better than that for comparable results taken over a longer period of time. Consideration of possible causes for these differences led to an investigation of the effects of temperature variations on contact angles. References to literature revealed only a small amount of information, some of it apparently conflicting. Specifically, Sutherland and Wark4/ found that temperature variations "within limits" did not appreciably influence the angles measured for galena conditioned with potassium ethyl xanthate. On the other hand, McGlashan and McLeod5/ presented preliminary data showing that for sphalerite conditioned with potassium ethyl xanthate the angle is maximum at 25° to 35° C., depending on the pH of the system.

Jan 1, 1960

By George A. Savanick

The U.S. Bureau of Mines has patented and transferred to industry an abrasive-enhanced water-jet rock drill. This drill incorporates three novel components: a collimator, jet deflectors for cutting clearance, and an unpressurized swivel, which rotates at 1,000 rpm while passing 20 gpm of an abrasive slurry flowing at 1,000 ft/s. Drilling occurs through the action of a 10,000-psi, 2O-gpm water jet into which is entrained 72 lb/min of abrasives. The pumps, hoses, and fittings are those commonly used in the water-jet-cleaning industry. Only inexpensive, common sandblasting abrasives are used. This drill can cut through hard rocks with moderate-pressure jets; e.g., rocks with a compressive strength of 73,000 psi can be drilled with a 1O,OOO-psi abrasive jet. In addition to drilling holes, the drill can cut deep, narrow kerfs; collar a hole at any angle; drill through rubble; and chamber holes. The development of the abrasive jet drill is a significant advance in the state of the art of hard-rock drilling. The Government of the United States has licensed the abrasive jet drill patent to Weatherford Water Jetting Systems.

Jan 1, 1989

By R. D. Ladoo

"At the beginning of 1920 a general feeling of optimism was noted in many talc-producing districts. The industry seems to have recovered from the temporary depression of the first half of 1919 and many mills are running at capacity production with their entire output for 1920 contracted for. The imports of talc for 1919 were only slightly larger than in 1918 by weight and probably no more by value. Thus foreign competition has not begun to be seriously felt. Several new companies in this country have been organized, some to operate new deposits and others to continue the work done by others.An interesting phase of the present situation is the possibility of increased use of talc in paint. There is a shortage of barium sulfate used as,paint filler. Since, for some uses, talc is considered second only to BaSo4 as a filler for paint, it is possible that part of the shortage could be relieved by an increased use of talc.A series of physical tests upon all pigment materials used in the manufacture of paints is being conducted for the Paint Manufacturers Association of the United States. It is important that all types of talc be represented in these tests. Producers of finely ground talc, 200 mesh and finer, are urged to submit samples of at least two pounds each of these grades that are available to paint makers with trade name and quality data, to the Institute of Industrial Research, 19th & B Streets, Washington, D. C., where the tests are being conducted.The Talc Products Company, Inc., Washington Building, Los Angeles, California, has recently been organized to develop a large body of talc one mile north of Riggs, San Bernardino County, California, This deposit contains a compact, white talc which can be sawed into crayons. The company's mill, at Los Angeles) is equipped with a unit of the Raymond system of grinding and air separation, and pencil sawing machines. It is reported that the pencils are being successfully used in Pacific Coast ship yards.The mining of talc where no mill is owned by the operator and the consequent sale of talc in its crude massive state has not proved profitable in a number of cases recently noted. Under exceptional circumstances, where mining costs are low and the product can be sold to a mill near the mine, the operation maybe profitable, but this condition is not common. One mine of this type has recently closed down, at least temporarily; but a second, more fortunately situated, in another district, is continuing operations, although plans are being made to erect a mill in the early spring. Most satisfactory results are ordi¬narily obtained where the mine and mill are owned by the same company.The sale of the Balmat mine of the International Pulp Company, near Gouverneur, N. Y., to J. H. McLear, Gouverneur, and H. G. McLear of New York, has been reported. It is stated that a large part of the property has been already leased to the Sylvia Lake Company, who will operate it. ""Cement, Hill, and Quarry""* states that ""the first mining done on this property was for silver and lead, but it developed into a good zinc producing property and later it was worked for its talc deposits. It has passed through several hands, the American Pulp Co., the Union Talc Co., and the International Pulp Co., all having had it in successive periods since 1891."""

Jan 1, 1920

By Richard F. Hewlett

Use of digital computers makes possible a more efficient and complete analysis of data from a mineral deposit . This computer program was written and used during an investigation into the efficiency of methods of computing grade and tonnage of ore , wherein it was necessary to make repeated computations involving different combinations of data . This investigation was part of a continuing program of sampling methods research at the Bureau's Denver Mining Research Center.2-4 This program is designed to compute tonnage and average grade for 40 cutoff grades using either the statistical or polygonal methods . tational rate is from 200 ( input bound ) to 1,400 assays per minute , depending on the use of either individual ( one assay per card ) assay- interval length or

Jan 1, 1963

By Perry G. Cotter

The objective of this investigation was to synthesize and investigate the properties of a high-temperature refractory material based on a combination of boron, silica, and magnesium. A magnesium-thermic reaction was used for the synthesis. X-ray examination of the product indicates that the crystalline portion of the composition is a combination of magnesium borides, magnesium silicate, and magnesium orthoborate. Chemical analysis of a representative sample shows, in weight-percent, boron 17.6, silicon 23.9, magnesium 17.8, and chromium 0.5. The balance is largely oxygen. The composition is resistant to high temperatures under oxidizing conditions and is stable in water, hydrochloric acid, and hydrogen. It has a low density (less than 3 grams per cubic centimeter) and a hardness value in the range of quartz. It has a melting point above 1,700° C. and can be hot-pressed to shape in the temperature range between 1,200° and 1,350° C. The properties described in this paper indicate that the material may have some uses as a high-temperature refractory, and because of its boron content it may have some value as a thermal-neutron-absorption material.

Jan 1, 1961

By Richard D. Graves

Pitch from low-temperature carbonization of bituminous coal was hydrogenated at cracking conditions in a continuous bench-scale unit to produce low-molecular-weight oils and tar acids. The pitch contained 15.6 pct benzene-insoluble material, 4.0 pct hexane-soluble oil, and 80.4 pct asphaltene by weight. At 475° C, 7,500 psig, and 1.5 hours residence time, hydrogenation products, based on the weight of pitch, were about 36 pct oil boiling below 325° C, 24 pct hexane-soluble heavy oil, 17 pct asphaltene, 1 pct benzene insolubles, and 12 pct hydrocarbon gases. The yield of tar acids boiling below 250° C was 4.3 pct, and the yields of C6 to C8 paraffins, naphthenes, and aromatics were each less than 1.0 pct. The yield of tar acids was within the range of yields obtained by hydrogenation or high-temperature carbonization of bituminous coal (2 to 5 wt pct). Yields of oil boiling below 325° C increased with increased residence time or temperature. There was little or no effect of residence time on yields of alkali- soluble material which contained tar acids. Yields of hydro-carbon gases increased markedly with an increase in temperature from 475° to 500° C. Lowering the hydrogen pressure to 4,500 psig resulted in yields similar to those obtained at 7,500 psig.

Jan 1, 1962

By J. C. Edwards

To have the capability to predict the development of localized spontaneous heating within a porous coalbed that is subjected to forced air ventilation or in an otherwise quiescent environment in which buoyancy develops, the Bureau of Mines developed three time-dependent mathematical models, which were used to calculate the temperature increase associated with chemisorption of oxygen by the coal. In each model, spontaneous heating is driven by an Arrhenius first-order reaction between the oxygen and coal. Two models are two-dimensional, and one is one-dimensional. In the first two-dimensional model, a constant-velocity forced convection airflow is specified; and in the other, buoyant flow is allowed to develop in the absence of forced convection. The third model evaluates the airflow from Darcy's law and a specification of the pressure at the surface of a one-dimensional porous coalbed. Numerical computations demonstrated how each model could be used to predict the onset of spontaneous heating when the porous coalbed was subjected to constraints of an imposed internal heat source or a high temperature airflow. The effects of particle size and coalbed compaction upon spontaneous heating were examined with the third model.

Jan 1, 1990

By P. W. Jerant

The methane emissions from an advancing coal mine section were continuously monitored for 120 days. During this time, the section advanced 2,000 feet into virgin Pittsburgh coalbed producing 54,565 tons of coal with a total methane emission of 91 million ft3. Analysis of the data gathered showed that daily methane emissions did not correlate with overburden thickness and daily coal production. A good correlation was found between the daily methane emission and the average length of rib exposed to virgin coal.

Jan 1, 1976

By Harold E. Heide

The United States is the world's largest consumer of tin and depends entirely upon foreign imports for its major source of supply. Only a small quantity of tin is produced on the North America continent. The advent of the war in Europe in 1939?brought a threat to our foreign sources of supply, and the Congress took steps to forestall shortages of tin and other metals. By authority of the Strategic Minerals Act, passed by Congress in 1939, and subsequent legislation, the Bureau of' Mines ?and Geological Survey conducted investigations of domestic tin deposits. Most of the tin that has been produced in North America came from the Seward Peninsula, Alaska.

Jan 1, 1948

By Walter K. Utt

The U.S. Bureau of Mines conducted research to develop an accurate, real-time, position monitoring and warning system for the vehicles used in surface mining. The product of this research will be technology to reduce accidents and injuries associated with the operation of surface mining haulage equipment. The position monitoring system should reduce accidents related to vehicle position and also increase the efficiency of haulage operations. This research was conducted in preparation for development of an accurate, real-time position monitoring and warning system, which notifies equipment operators when they deviate from a known safe course and are approaching a fixed hazard. A radar positioning system designed for marine applications was evaluated and a series of tests was run to determine the accuracy of the radar positioning system when used in a land vehicle. The radar position determination was compared to surveyed values. Both static and dynamic (moving vehicle) tests were conducted. The static test results were marginal and the dynamic test results were not accurate enough for the position monitoring and warning system. Although a promising technology, the system tested needs to be modified to meet the accuracy requirements of mobile mine equipment.

Jan 1, 2010

By Michael S. Miller

In 1987, 1988 and 1989, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the Sperry Creek Wilderness Study Area (OR-003-035; 5,600 acres) and the Gold Creek Wilderness Study Area (OR-003-033; 13,600 acres), plus an additional area (OR-003-033; 2,180 acres) adjacent to the Gold Creek Wilderness Study Area. The wilderness study areas and the addition are south of the Malheur River and are about 20 miles east of Juntura, Oregon. The wilderness study areas and the addition are underlain by volcanic rocks, predominantly basalt and rhyolite flows, breccias, and welded ash-flow tuffs. Lacustrine deposits containing diatomites occur mainly at the east side of the Gold Creek Wilderness Study Area and addition. Alluvium lies along the Malheur River, in terraces and fans south of the Malheur River, and along the floors of some creeks. Shear zones and faults have offset the rocks and provided channels for eruption of volcanic rocks and epithermal mineralization by hot springs.

Jan 1, 1989

By L. W. Kelly

The primary purpose of this paper is to show the appreciable savings that were made by roof-bolting the main west entry of the Kings mine, which was to be the permanent, main haulage road, as compared to the cost of supporting the same roof with peg timbering as first planned. Additional items that might prove valuable to other mine operators are contained in this paper and detailed below. 1. A detailed cost of the system of roof support known locally as the peg-timbering method is given. It consists fundamentally of supporting steel cross bars on pegs inserted into holes drilled in the ribs close to the roof. 2. A method of supporting the roof in caved entries is shown, where such support must endure for an extended period in haulageways and air courses.

Jan 1, 1952

By Kathleen M. PH. D. Kowalski

This paper discusses human judgment and decision-making under stress. The authors review selected recent literature across various disciplines and suggest a definition of stress within the context of decision-making during the management of emergencies. They also discuss fieldwork by the Pittsburgh Research Laboratory, NIOSH, which explores traumatic incident stress, the relationship between previous training and performance under stressful conditions, and human behavior in underground mine fires. The authors assert that stress is one of the factors that decision-makers must contend with in most life-or-death situations. They suggest that a better understanding of individual's judgment and decision-making activities while under stress would yield a better understanding of how people reach the choices they make in emergencies. This enhanced understanding would be of enormous value to emergency managers, researchers, and policymakers.

Jan 1, 2008

By Frank Ruskey

This report describes a computer program devised by the Bureau of Mines to model coal-mining situations where one or more panels encounter oil or gas wells. The program seeks in several hundred trials to evade the wells if possible or to minimize their influence by shifting or skewing the mine plan and/or adjusting the centerline dimensions of the entryways. Upon completion of computations, the program sorts the hundreds of models which have been tested, and lists the 10 best with their associated parameters. It also draws a mine plan of the best configuration, showing the entryways and crosscuts along with the "lost" coal remaining in the barrier pillars surrounding the various wells.

Jan 1, 1972

By W. E. Wallace

Volume-rate-of-flow measurements were made of the flow of mercury through porous samples under conditions of no field, magnetic field transverse to the direction of flow, and transverse magnetic field and electric current to determine if a magnetic method might be potentially useful in the study of pore-size distribution. No change was observed in the flow rate from the application of a magnetic field alone. The application of both field and current produced an electromagnetic pumping action with or against the direction of flow, depending upon the direction of the electric current. This pumping effect was observed to be greater in a rectangular porcelain sample than the calculated value for an equal-Sized open channel.

Jan 1, 1969

Objective The Roof Monitoring Safety System (RMSS) introduced in late 1997 has been modified to improve durability and simplify the measurement of roof or rib movement. Greater knowledge about the stability of roof and rib rock is expected to result in safer conditions for the mine worker. Developing safety tools and methods is part of NIOSH’s mission to prevent work-related injuries and deaths. A mining operation with a proactive approach to control ground conditions is in a better position to make essential decisions related to mine development and take remedial actions in the event of roof or rib falls. Background Falls of roof and rib rock are responsible for a high number of mining injuries and fatalities. Visual inspections and the sound of breaking or cracking rock are often relied upon to indicate unstable roof conditions. In some mines, roof bolt holes are checked for separations or gaps with a scratch tool; this provides further information about the stability of the roof. Monitors such as the RMSS can confirm roof movement that was surmised only by eye or ear, or potentially detect movement that was missed by these means. An added safety feature of the RMSS is the capability of locating the measurement station at a distance from where the monitor is placed in the roof. Stone and other industrial minerals are the basic raw materials used in construction. Continuing economic growth and highway building in particular have resulted in record demand for stone. This high demand, coupled with increasing constraints on surface mining, have caused many new .stone mines to be developed underground. These new mines in many cases will be employing new and inexperienced miners who may not have the ability to recognize unstable ground conditions using just sight and sound. From the initial introduction of the RMSS, it was anticipated that improvements and modifications would occur. We correctly assumed that, once miners and operators were exposed to the monitor. suggestions would evolve. In one case, the RMSS was used to determine if an impact hammer used on a mechanical scaler was causing or increasing instability of roof rock. The test showed little or no movement resulted from this method of scaling under the particular conditions at this mine. In another instance, an operator needed to monitor the stability of a haulageway in a benched area that had very high ceilings. The RMSS requires a 2-in-diam hole for installation; however, only roof bolt holes of a smaller diameter were available, and it was impossible to drill new holes at that height. The operator attached a 2-in collar at the roof line and was able to install the RMSS. These examples illustrate the potential for further enhancements of this tool. NIOSH continues to seek additional candidate sites for use of the RMSS. As usage increases, we anticipate further refinements and additional applications. How It Works The new RMSS, cable, and read-out box are shown in figure l. The read-out box has a green light that stays lit until battery replacement is needed. The red light is set to conic on to indicate movement. The red light can he adjusted for increments of movement as low as .010 inches. The RMSS red light should not be considered as a primary or only means of determining the stability of roof or rib. It is intended to serve as a supplement to existing methods or procedures for determining stability. An overview of the RMSS components is shown in figure 2. Movement of rock layers within the mine roof is measured relative to a fixed-point calibration at the monitor housing. The housing contains a potentiometer, roller switch, plastic rack, and spur gear. Movements are detected by the transfer of electromotive forces

Jun 1, 2000