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By Alan H. Goode

As part of the Bureau of Mines program to broaden utilization of abundant low-quality mineral materials, the Tuscaloosa Metallurgy Research Laboratory conducted beneficiation studies on two Alabama clays. The main purpose of these studies was to develop improved plasticity and green strength in both clays and compare these improved properties with those of a typical ball clay. Whiteness of the clays was also considered. The results indicated that by adjusting the pH of the kaolin to approximately 9, a substitute for ball clay could be obtained. The investigation also showed that by a combination of attrition grinding and sodium dithionite leaching to remove iron, the underclay could be upgraded to a ball clay material.

Jan 1, 1975

By F. W. Cox

Exhaust emissions were measured from 25 aircraft turbine engines using Jet A fuel. Analytical apparatus, procedures, and results are described. Carbon monoxide, carbon dioxide, nitric oxide, nitrogen dioxide, and aldehydes were measured at engine operating modes representing power levels used in airline operation. Carbon monoxide, hydrocarbon, and aldehyde emissions were highest at idle and lowest at takeoff; oxides of nitrogen were lowest at idle and highest at takeoff. Of the total oxides of nitrogen emitted, nitrogen dioxide constituted from 10 to 100 pct, depending on the exhaust gas temperature. Engines retrofitted with smoke-reducing burner cans produced less carbon monoxide, hydrocarbon, and aldehyde emissions, and slightly more oxides of nitrogen then engines with standard burner cans.

Jan 1, 1972

By W. Hermanson

This report, which covers the period from January 16 to October 21, 1974, describes the work performed in compliance with the requirements of contract no. H0242028 and modifications 1 and 2 thereto. The purpose of the contract was to further reline and modify three of the canopies (shuttle car, loader, and roof drill) which were developed under contract no. H0220031, and to conduct further testing and demonstration of the relined designs. Modifications I and 2 involved conducting further in-mine evaluations of the face. drill and cutter canopies, also developed under contract no. H0220031. In addition to the canopy modifications, the contract involved an evaluation of an operator's seat concept for a shuttle car which was developed for the USBM by another contractor.

Jan 1, 1974

By Julian Vigil

Mountain bumps have been a problem in the coal-mining industry since the 1920's. The problem became severe in the late 40's and early 50's with the introduction of mechanized mining. Fatalities and serious injuries resulted from mountain bumps during this period. Mountain bumps again caused fatalities in the 80 's. Interviews were conducted mostly with retired coal miners having experience in bump conditions with five different coal companies. These men held positions as president, general manager, roof-control specialist, mining engineer, inspector, superintendent, mine foreman, shift foreman, section foreman, miner operator, electrician, and general laborer. Together, their comments give a good idea of the things tried to mitigate mountain bumps in the Appalachian Coal Fields.

Jan 1, 1991

By Peter F. Strong, Robert L. Lagace, Alfred G. Emslie

This paper is concerned with the theoretical study of UHF radio communication in coal mines, with particular reference to the rate of loss of signal strength along a tunnel, and from one tunnel to another around a comer. Of prime interest are the nature of the propagation mechanism and the prediction of the radio frequency that propagates with the smallest loss. Our theoretical results are compared with measurements made by Collins Radio Co. This work was conducted as part of the Pittsburgh Mining and Safety Research Center's investigation of new ways to reach and extend two-way communications to the key individuals that are highly mobile within the sections and haulage ways of coal mines.

Jan 1, 1973

The generally disappointing results obtained in the present study, together with the high material costs involved, preclude any general recommendation for a continuation of the work. One recommendation arises, however, from some observations on the application of latex to spoil banks. It was found that dilute latex used on a slope of spoil bank material at an application rate of 400 lbs per acre (dry basis) stabilized the soil and made it much more resistant to washout by rainfall. It is recommended that a study be conducted to use latex for temporary stabilization and/or sealing of spoil banks before and during reclamation procedures, on coal slurry ponds and coal refuse piles.

Jan 1, 1972

By Dorsey A. Lyon, Robert M. Keeney

In the inquiries and investigations that the Bureau of Mines is making with a view to increasing safety, efficiency, and economic development in the metallurgical industries, the application of elec- tricity to various processes, and especially to those in the manu- facture of iron and steel, is being given attention. Some results of the work already done are presented in this bulletin, which gives a historical review of the development of electric furnaces for making iron and steel, and discusses the problems that remain to be solved in the use of electric furnaces for the smelting of iron ores and the production of pig iron at a profit on a commercial scale.

Jan 1, 1916

By A. J. Hudson, M. R. Yenchek

Faulty insulators on mine trolley/track haulageways may allow the flow of leakage currents into the mine roof and ultimately result in combustion of the local roof material. The National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL), has devised a passive means to detect overheating insulators on direct current systems. The detector consists of a spring-loaded cartridge that ejects a reflective streamer of white Teflon tape when subjected to elevated temperatures. The cartridge assembly can be easily installed over the outer metallic shell of an existing trolley line insulator. If an insulator overheats due to ground leakage currents, the visible streamer alerts mine personnel traveling on the haulageway.

By J. C. Kerkering

The Bureau of Mines used mathematical reliability theory to define, for use in the mining industry, the concepts of risk, safety, reliability, hazard, and mean time between accidents. In this report, the definitions are explained theoretically and illustrated by application to actual underground mine accident data extending over a 9-1/2-year period. The theoretical development proceeds along two parallel analytical paths. For each line of reasoning, the data are presumed to be independent. If they are not, the analysis stops, although there are interesting implications when dependency is demonstrated. The first method uses the elapsed times between accidents as the basic data. These elapsed times are fitted to a negative exponential distribution function using least squares and yielding the function parameter, P1 The P1 is used to form the Poisson distribution function for the data, which is then used to define the safety-related concepts. The second method uses the maximum likelihood estimator to formulate a Poisson distribution function for the data. The function is tested for adequacy by a goodness-of-fit test; if the fit is acceptable, the Poison function is used to define the concepts. Both methods were applied to the data base, yielding nearly identical results.

Jan 1, 1987

By Martin Berman

The Bureau of Mines has investigated the mineral matter content of 38 American coals using X-ray fluorescence. Measurements of the Ka intensity for magnesium, aluminum, silicon, sulfur, calcium, and iron permit the determination of those elements as well as an indirect determination of the ash con-tent of the coals. The percentage of each of the six elements was corrected for absorption by all six elements as well as by hydrogen, carbon, nitrogen, and oxygen. It made little difference whether the values used for hydrogen, carbon, and nitrogen were obtained from chemical analysis or whether average values for all coals were used. In all cases, oxygen was obtained by difference. The correction for absorption by all these elements involved the inversion of a 6 X 6 matrix and was performed by computer. Assuming that the elements magnesium, aluminum, silicon, calcium, and iron were present in the ash as oxides, the quantity of ash was determined. The results for the mineral elements as well as for ash and oxygen were in good agreement with chemical results. Particle size was found to have a significant effect on fluorescence intensities. A study of size effects was made for pyrite particles, since the sulfur content of coals is of particular interest. Theoretical equations were derived and verified relating the intensity to particle size. It was found that the coal samples must be ground to less than 2 microns. Sulfur appears in several forms in coal, and the effect of sulfur form on intensity was investigated. It was found that the Ka intensity was independent of sulfur form but the Kß intensity varied with the type of sulfur. Thus, the Ka intensity was used for determination of the quantity of sulfur present. Utilization of the sulfur KB intensity did not permit a determination of the proportions of sulfur forms present in coal. However, for synthetic mixtures of cystine and pyrite in carbon black, measurement of sulfur Ka and Kß permit determination of each constituents from measurements of sulfur intensities alone.

Jan 1, 1968

By C. E. Augustine, P. Nicholls

"INTRODUCTION A layer of soot on the heating surface of a boiler decreases efficiency because it increases resistance to the flow of heat, with the result that the heat transfer to the water is lower and the temperature of the flue higher than they would be if the surface remained clean. The percentage of reduction in heat transfer depends on the position and area of the sooted. The percentage of reduction in heat transfer depends on the position and area of the sooted surfaces, the thickness of the most, until the percentage of the total heat absorbed by those surfaces when clean; thus it will vary with the type of boiler and in particular with the ratio of the area of the convection heating surface to the total area. Medium-size and large boilers usually are equipped with soot blowers, and tests have been published giving the increase in efficiency resulting from removal of the soot. Fuel savings up to,8 percent have been reported, but 4 to 5 percent is probably more conservatives. However, these savings may not be due wholly to a reduction the thermal resistance of the surfaces but may be due partly to improvement in the combustion because of better draft or more uniform flow of the gases. In addition, the deposits on the surface of boilers include as a clinker, and as the size of the boiler and the rate of burning increase very little or none will be soot.There are no corresponding test data on small boilers operated at low rates of burning. In stall boilers, deposits are much thicker, and it might be expected that the reduction in efficiency would be greater; in fact, statements have appeared suggesting that the decrease may be as high as 50 percent. This investigation was undertaken because the Bureau frequently receives requests for authoritative information on the effect of soot in small and other heating boilers."

Feb 1, 1935

Reduce longwall shearer operator's dust exposure by selecting the best drum water spray sys-tem for minimizing dust generated durinq cutting. Approach Three of the most commonly-used drum water spray systems were installed on the same set of shearer drums and compared to determine which system best suppresses dust. The spray systems studied were: ? pick-point flushing ? cavity filling ? water-through-the-it Instantaneous and gravimetric sampling instruments were used to measure the respirable dust exposures of the shearer operators and dust concentrations downwind of the shearer. The Three Systems: Longwall shearer drums are routinely equipped with internal drum spray systems since these systems have been shown to be more efficient than external systems in terms of dust suppression per gallon of water applied. All U.S. longwall shearer faces utilize some type of internal water delivery spray system. The two most common systems are bit-or pick-point flushing and cavity filling. Pick-point flushing uses nozzles mounted in the bit blocks or in special blocks immediately in front of the bits. Cavity filling utilizes spray nozzles installed in a pipe manifold mounted on the drum hub between the scrolls or along the edge of the vane scrolls; water is sprayed radially from the manifold towards the adjacent vane scroll.

Jan 1, 1986

By Joseph P. Flick, Kathleen M. Kowalski, Lynn L. Rethi, Roberta A. Calhoun

Many miners are involved in tasks at the mine site that are similar to those sub-tasks performed in general construction, maintenance and repair (CMR) type work activities. As a result, many of the injuries in the mining industry today can be traced to employees performing these CMR type work activities. Indeed, a recent analysis of a major aggregate company revealed that 65% of all injuries documented originated from performing such CMR activities. It is hypothesized that the number of injuries to miners performing construction, maintenance and repair (CMR) work activities on mine property may be reduced through improved training that focuses on better hazard recognition using the numerous visual and other cues that are available for evaluating workplace health and safety hazards. To this end, researchers at NIOSH’s Pittsburgh Research Laboratory have merged two proven methods of training miners to recognize hazards, stereoscopic (3-D) slides and the concept of degraded images, into this training program. Stereoscopic (3-D) slides have been shown in earlier NIOSH and U.S. Bureau of Mines research to be an effective training aid for improving the ability of miners to recognize various geologic and mining-induced irregularities that can cause groundfalls.3 They realistically portray the natural mine environment, and thus are an excellent training aid for teaching miners to recognize such visual cues. The degraded image concept, originally developed by the military and used for target detection training, describes scenes where the target is partially hidden by cloud cover, dust, rain, natural barriers, buildings, or other obstructions that can camouflage or confuse the target. Research had shown that flight observers who were trained with less than ideal (or degraded) pictures were more successful in subsequent identification of targets than those trained using ideal (or highlighted) pictures of targets. In order to investigate this concept for training miners to recognize hazards, NIOSH researchers developed a prototype hazard recognition training program using such mining scenes. A control program based on traditional highlighted mining scenes was also developed. Both programs were applied to subjects in a field experiment. Results indicated that miners trained with the degraded images did significantly better on a follow-up test of hazard recognition.4 This hazard recognition program teaches trainees to look for hazards in a more realistic manner than that of the control program. This specific training program for CMR activities involves using the degraded image concept and 3-D slides. The module is designed to educate workers on hazard identification techniques and safe work practices. It focuses on teaching miners techniques for recognizing visual (sight) cues, and then uses these cues to evaluate mining conditions. It should be stressed that other senses, such as sound can also play an important role in hazard detection.

Jan 1, 1999

By M. O. Renwick, Paul Zinner

"INTRODUCTION In September 1943, the Bureau of Mines conducted a limited program of churn drilling on the Winskell property in the Shullsburg area of Lafayette County, Wis. The work was undertaken as part of a general investigation by the Bureau of the zinc-producing area of southwestern Wisconsin at a time when special effort war being made to increase the production of metals necessary for the war program.Drilling described supplemented a previous drilling program conducted by the Vinegar Hill Zinc Co. The results of both programs encouraged subsequent investigation by the Cuba Mining Co. and eventual development of the Andrews mine.ACKNOWLEDGEMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by such project as soon as praticable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the investigative work, and prepares the final report."

Aug 1, 1947

By Harry W. Campbell

A mineral survey conducted by the U.S. Bureau of Mines in 1984 identified no mineral resources or prospects with mineral development potential in the Pit River Canyon Wilderness Study Area (WSA). Basalt suitable for aggregate and fill is in the WSA but rock of this nature is abundant in the region and closer to potential markets.

Jan 1, 1984

By A. J. Farstad, R. G. Olsen

The Coal Mine Health and Safety Act of 1969, passed by Congress in the wake of the disaster at Farmington, West Virginia, led to an extensive study by the National Academy of Engineering of the problems involved in coal mine safety. One of the results of this report and subsequent research conducted by the U. S. Bureau of Mines has been the investigation of electromagnetic techniques for the location of trapped miners after a mine emergency. The Westinghouse Georesearch Laboratory has been involved in both the 2 theoretical and field studies relating to this problem. A compact personal beacon transmitter has been developed which can be attached to and powered by a miner's lamp battery. A compatible lightweight loop antenna package has also been developed which can be easily carried on a miner's belt. This antenna can be quickly deployed on the mine tunnel floor. For the purpose of calculating its electromagnetic fields on the earth's surface, the loop can be considered to be a magnetic dipole buried in the earth. (The earth is assumed to be homogeneous and to have a conductivity of s mhos/m.) The surface of the earth is assumed to be uniformily sloping and the transmitter dipole oriented as in Figure 1. The fields on the earth's surface can be computed by using a superposition of the fields of a 4 vertical magnetic dipole3 and of a horizontal magnetic dipole in proportions which depend on the slope of the terrain. In the case of level terrain a null in the horizontal magnetic 5 field occurs on the surface directly above the dipole. This null is designated as the apparent source location and is the criterion by which the source is located. The criterion was tested at two hardrock mines and two coal mines in the fall of 1972. The apparent source locations were compared to actual locations determined by conventional surveying techniques. It was found that due to nonlevel terrain the apparent and actual source locations differed by up to 13 meters. This discrepancy can be resolved by an examination of the fields of a source beneath uniformly sloping terrain. Figure 2 shows the experimental and theoretical results for a

Jan 1, 1973

The following additional studies are recommended: 1. Future development of the magnetic sludge process should involve optimization of the process variables; these include stirring rate, sludge heating time, aeration rate, method of preliminary sludge dewatering, and the effects of magnetic separation for final sludge processing. In addition, the matter of amenability of coal mine waters to treatment should be considered more thoroughly by means of a more comprehensive literature review as well as actual tests on mine drainage samples. 2. The technique of sludge freezing should be explored further. Emphasis should be given to conservation of energy in the process, and the filtration characteristics of the resulting sludges should be evaluated. 3. Further studies should be conducted on the feasibility of the CO2-addition approach to mine drainage sludge densification. The filtration characteristics of product sludges should be evaluated, and the possibility of recovering and recycling the residual alkalinity of the sludge, either directly as CaCO3 or as CaO plus CO2 after calcination, should also be explored further. 4. Efforts should be made to develop cost data for the conceptual processes involving magnetic sludge formation, sludge freezing, and C02 pretreatment, with the purpose of selecting at least one of these processes for further testing at a field site. 5. The use of inexpensive waste materials (e.g. fly ash, "red dog," slag) as sludge additives, possibly in conjunction with coagulant aids, should be considered further. Results of the present studies have indicated that such materials, employed in relatively large amounts, increase the density and enhance the filterability of sludges from lime neutralization of coal mine drainage. The use of pulverized blast furnace slag in this regard appears particularly promising, and studies should be made to ascertain its availability, relative cost, residual alkalinity, and behavior as an additive in conventional mine drainage treatment processes involving lime neutralization and aeration.

Jan 1, 1971

By A. W. Ambrose

"Records of individual wells form the basis for the successful operation of any company engaged in the production of petroleum. The expense attached to the compilation of records is negligible in comparison with the benefits resulting from their use. There a company has not a complete system of records, immediate attention should be given to the preparation of forms upon which to collect data, and, to the collection of data for these forms. The records needed vary with each district, but for each field a set should be adopted that will best meet the needs of each property. Practically all operators, and particularly all successful operators, agree on the necessity of good records, shopping what the wells have done, are doing, and may be expected to do in the future. Any operator realizes the value of records of sales of oil and should place almost equal emphasis on the records of well logs and histories showing the east and present performances of wells. Indeed, trustworthy records are absolutely necessary for the proper operation of any oil or gas property.Complete records should be kept on each well from the time the location and elevation are determined until the well is abandoned, and the engineer should review old records often enough to be familiar with the past performance of the various wells and with the conditions that affect production. Some of the forms that may be prepared are:--"

Mar 1, 1920

By Sean Gallagher

Study Design. A split-plot experimental design was used to evaluate the influence of posture, trunk angle, and rotational velocity on peak torque output and myoelectric activity during maximal trunk extension maneuvers. Objectives. To determine whether the kneeling posture alters extension torque capabilities in isometric and isokinetic exercises as compared with standing. Also, to ascertain whether recruitment of trunk muscles is modified by such a postural change. Summary of Background Data. Factors such as workplace geometry may force workers to adopt awkward or unusual postures in the performance of manual tasks. An understanding of the limitations placed on strength in unconventional working postures is crucial to the proper design of jobs. Methods. Twenty-one healthy male subjects (mean age = 36 years 7 SD) performed 12 trunk extension exertions in standing and kneeling postures. Isometric tests were performed at 22.5°. 45°, and 67.5° of trunk flexion. isokinetic tests were done at three velocities: 30°/sec, 60°/sec, and 90°/sec. Electromyographic data were collected from eight trunk muscles to assess muscle recruitment under each condition. A prior; orthogonal contrasts were specified for analysis of both torque and electromyographic data. Results. The kneeling posture was associated with a 15% decrease in peak torque output when contrasted with standing; however, no concomitant change in trunk muscle activity was evident. Trunk hyperflexion (isometric tests) and increasing rotational velocity (isokinetic tests) were associated with reduced torque in both postures. Trunk muscle activity was primarily affected by changes in trunk angle and velocity of contraction. Conclusions. A reduced extensor capability exists in the kneeling posture, despite equivalent trunk muscle activity. The similar activation patterns in both postures suggest that the strength deficit does not result from alterations in trunk muscle function. Rather, it may be the consequence of a reduced capability to rotate the pelvis in the kneeling posture, due to a disruption of the biornechanical linkage of the leg structures. [Key words: electromyography, isokinetic, isometric, low back pain, posture. strength1 Spine 1997;22:1864-1872

By A. R. Elliott

"In addition to the usual interpretation that is placed on the words ""thief"" and ""thieves"", the petroleum industry also uses these words when referring to an instrument that is used for taking samples of oil from a tank or reservoir. It is an abbreviation of the term ""thief-tube"". It is desirable in sampling volumes of oil in tanks or reservoirs to obtain samples at different intervals below the surface of the fluid, because of the variation in the character of the oil at different depths. It is for this purpose that the ""thief"" is used.The subject of oil thieves is probably as old as the oil industry itself. Opinions as to which is the most practical instrument for thieving oil in tanks, to obtain a true average sample, differ wherever oil is produced and is analyzed. Every district, and even many of the companies within the district, will have different appliances for ""grabbing"" oil samples. It is interesting to note in passing that though the thief has an apparently insignificant part in the handling of oil, yet the results depending on it are of paramount importance practically every branch of the transportation, refining, and marketing of petroleum. Determinations, particularly dependent on a representative sample, are made by the centrifuge, laboratory distillation tests, and the hydrometer.The purpose of this article is to discuss conditions found in the California fields. Only a general description of types of thieves and the methods of using them will be given. However, it is believed sufficient data are given to enable the reader to form his own opinion as to which of the devices is most practicable under the prevailing conditions. Thieves of all types have their good points, speaking broadly, and it is possible to get good results with any of them, provided they are operated according to instructions and with due care. In work of this kind the advantages or disadvantages reside in the person operating the instrument rather than in the instrument used."

Apr 1, 1920