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By G. W. Jones

[One of the mJor c~ctivities of the Bureau ~f l;ine;: is the j.a-onotion of sdetp in mining a.nJ other inclus tries. 13 cor'ncc tlcn td t~l tiiene activities the 3~.sccu r:e termine? t'le cwl.os:lon ha~arls 95 n,o;r.?xs tibla Tases, vzpor s, aid scli3s aqi iavestig~ ter rnrI.?ns of controlling s-~fi. prevpri ting eqlosians.]

Jan 1, 1941

By Daryl R. Tweeton

The Bureau of Mines conducted experiments to measure the influence of environment on the friction and wear of a steel-quartz system at several speeds and loads. In each test a quartz block was pressed against a rotating ring of low-carbon steel. Environments used were moist air, dry air, dry nitrogen, water, aqueous oleylarnmonium acetate (ClsH35NH3+-OCOCH3), and aqueous aluminum chloride (A1C13). The sliding speeds were 2.2, 13, and 33, cm/sec, and the loads were 6.8 and 13.6 kg. The coefficient of friction, the wear, and the roughness of the surfaces were measured, and the wear debris was examined. The coefficient of friction was significantly lower in moist air at 2.2 cm/sec than for any other combination of environment and speed employed, and was generally an inverse function of the oxidizing ability of the environment. The coefficient of friction increased somewhat with increasing load. The wear of the steel rings was greatest in dry air at all speeds and loads. The wear of the quartz blocks at 180 rpm was greatest in dry air, but at 12 rpm it was greatest in nitrogen. Friction and wear in aqueous oleylarnmonium acetate and in aqueous aluminum chloride were similar to effect in water alone.

Jan 1, 1976

By L. Mallett

The changing demographics of the mining industry make successful passing of knowledge and skills to the next generation critical. Training methods and technologies are being developed to meet this need. Twenty years ago classroom training was largely a one-way transfer of knowledge through instructor lectures. In contrast, instructors today can use virtual reality technologies to guide trainees as they fully participate in learning experiences. Trainees can interact with the virtual work environment, co-workers, and equipment without being exposed to workplace hazards. The speed of advancement in mine safety, health, and production training shows no sign of slowing in the next 20 years. Researchers at the National Institute for Occupational Safety and Health have studied and participated in the evolution of miner training. A look at training materials they have created in the past and those they are currently developing reveals changes in methods and technologies over time and also key characteristics which have remained constant. Possibilities for the future can he discussed in the framework of an implementation of virtual reality in new miner training sessions. The example computer-based training package teaches new miners to read mine maps and provides opportunity to practice navigation skills in a virtual mine. With this 'serious game', trainees experience the look and feel of moving through an underground coal mine while in the safety of their classroom. During field-testing in 2007, trainees and instructors responded very favourably to this new way of learning. The software was usable by mine trainers with even limited computer expertise and could be installed on the affordable computers they were using for their more traditional slide presentations. The Underground Coal Mine Map Reading Training's foundation on past successful development strategies and its acceptance by today's instructors and trainees provide valuable lessons for developing training materials, strategies, and technologies for mining's future.

Jan 1, 2009

By S. J. Broderick

[The term "nonmetallic minerals,? as commonly used in the mining industry, refers to those minerals of industrial importance that are mined essentially for uses other than for the metals contained. The field comprises several hundred minerals of industrial importance, of which 70 have been adequately described in the textbook Industrial Minerals and Rocks.3/ A few of the more important nonmetallic products are sand and gravel, salt, phosphates, clays, refractories, linestone, and cement materials. Some of tic minerals, such as bauxite and pyrolusite, have both metallic and nonmetal is applications, but in this report only the nonmetallic mineral phases are considered. In the organic field of nonraetallics only coal is considered, as, the, others - petroleum, natural gas, natural bitumens, and hydrocarbons - are of no importance in water softening.]

Jan 1, 1941

By Oliver C. Ralston

Nonmetallic technologic investigations of the U. S. Bureau of Mines are headquartered at experiment stations in three widely separated localities of the United States. During 1936, the Nonmetals Division of the Technologic Branch was formally set up by combining the direction off the work of these three experiment stations under one administration. The New Brunswick (N.J.) station which in the past has been known as the Nonmetallic Minerals Experiment Station, is henceforth to be at College Park, Md., as part of the Eastern Experiment Station, and its principal activities will be related to the nonmetallic resources of the Eastern and New England States.

Jan 1, 1937

By H. R. O'Brien

"During the past year, the Pittsburgh experiment station of the Bureau of Mines has been investigating methods for the quantitative estimation of carbon monoxide in blood. This work was necessary because reliable methods of analysis are of the greatest importance in the bureau's research work on prevention and treatment of carbon monoxide poisoning among workers in mines and metallurgical plants. Two of the methods considered involve color comparisons. In one of these methods, differences in tint can be noted fairly readily, while in the other, they are much more difficult to detect. The latter, however, is otherwise considerably simpler. It was decided, therefore, in studying the possibilities of this second method, to use the most sensitive eyes in the laboratory force.Preliminary trials.The method under investigation was the Haldane carmine determination of carbon monoxide in blood. The plain oxyhamoglobin of the blood in dilute solution is a pale straw color, when exposed to carbon monoxide it becomes a cherry pink. In the analysis dilute indigo carmine is added to oxyhsmoglobin until the solution matches in tint the carbon monoxide hemoglobin. The eye wanted, then, was the one most sensitive to faint pinks. But just how to select the analyst was not clear At first the Williams test scale, used in the Navy, was considered, but on con¬sultation with Dr. L. L. Thurston, bead of the Department of Psychology at Carnegie Institute of Technology, the following procedure was adopted.Instead of standard tests made up of all colors, only those occurring in the analysis were used. Solutions were prepared of the two hemoglobins, from which twenty-four different pairs were made up and placed in test tubes like those expected to be used in the analysis. One of each pair differed from the other in percentage of carbon monoxide hemoglobin by amounts varying from 2-1/2 per cent to 20 per cent. Each pair was compared in a box built in our own shop. This was 20 inches long and 5 inches square in cross section. One end was covered with ground glass. Just inside this glass cover were provided two slots, each the width of the test tubes used. The tubes to be compared were dropped into these slots through two holes in the top of the box. The device was placed before a window away from the sun, and so arranged that the light conditions were the same on each slit or opening. The person to be tested was seated before the box, and as the two tubes were placed before him side by side, he marked whether A (left) or B (right) contained the more cherry pink. This procedure was continued till he had compared all the pairs."

Jul 1, 1921

By A. E. Isaacson

The U.S. Bureau of Mines determined the effect of common sulfide minerals on the corrosion rates of various types of ferrous alloy grinding media. Data obtained from this study will aid in determining the contribution of any electrochemical reactions between sulfide minerals and grinding media to the total grinding media consumption. Common sulfide minerals used in this study were chalcopyrite, galena, and sphalerite. In the presence of oxygen, chalcopyrite was found to increase the corrosion rate, galena was found to decrease the corrosion rate, and the effect of sphalerite was dependent upon the type of grinding media. Possible electrochemical reactions of these minerals in the presence of grinding media are suggested.

Jan 1, 1989

By George H. Schnakenberg

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

Jan 1, 1989

By D. E. Traut

The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated by the Bureau of Mines in support of its objective to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium.

Jan 1, 1979

By J. K. Whyatt

Researchers at the U.S. Bureau of Mines have been exploring recent advances in the use of strain-softening constitutive laws that approximate shear fracturing. The purpose of these tests is to investigate shear-fracture-related rock bursts in hard-rock mines. The capabilities and remaining problems in the use of strain-softening laws in finite-element, distinct-element, and finite-difference methods are reviewed. Performance of the finite-difference implementation of strain softening is compared to classic experimental results and observations of rock mass behavior in the Coeur d'Alene Mining District of northern Idaho. The results show promise for developing methods to identify the general location and orientation of shear fractures and their sequence of occurrence, but such methods cannot be relied upon to quantify post-fracture loads or displacements accurately. Uncertainty over the amount of energy consumed by failing rock and the dependency of energy consumption on model mesh definition prevent direct application of the results to analyses of rock bursts.

Jan 1, 2010

By J. J. Burns

Disasters such as occurred at Oppau, Germany, in 1921, at Tessenderloo, Belgium, in 1942, and in this country at Texas City, Tex., in 1947 clearly indicate the explosive hazard associated with the manufacture, storage, and transport at ion of ammonium nit rate The importance and extent of the hazard may be Judged from the large amount of ammonium nitrate produced and transported annually in this country. Between July 1, 1947, and June 30, 1948, it was estimated that the United States produced 461,528 tons of ammonium nitrate commercially for agricultural purposes alone .5/ In addition, U. S. Army Ordnance plants have manufactured and shipped 779,730 tons of ammonium nitrate fertilizer to Germany, Japan, and Korea.6/

Jan 1, 1953

By Maurice J. Peterson

THE VISUAL-ARC spectroscopic method of rapid qualitative analysis of complex inorganic compounds has been popularized in the past few years and is being employed by an increasing number of laboratories. The mineralogy and chemistry departments of several universities recently have added visual spectroscopy to their laboratory curricula. This revival of interest in a somewhat dormant analytical method has been stimulated through the publication of three papers 4 by members of the College Park staff of the Bureau of Mines. These virtually are the only recent sources of information on visual-arc spectroscopic analysis. They include data on the spectroscopic assembly, the analytical procedure, and the practical application of the method to determinative mineralogy and related fields. Requests for reprints of these papers continue to be received; at present only a limited number of copies are available for distribution. In order that these requests may be adequately answered, material from the three papers has been combined and, with some additional data, is presented in this bulletin. Numerous specific inquiries have been received regarding types of equipment available, problems in instrumentation, and information on the approximate sensitivity limits of the elements that can be detected by this method. Some of this material was not included in the original papers. Accordingly, the table of wavelengths has been revised to include the approximate visual-arc spectroscopic sensitivities, and a section on commercially available equipment has been added.

Jan 1, 1953

By Noel N. Moebs

Five LANDSAT lineaments in the coal mining region of southwestern Pennsylvania were investigated by the Bureau of Mines to determine their geologic character, relation to subsurface conditions, and the means of discriminating one from another. The investigation included earth resistivity and very low frequency (VLF) electromagnetic traverses, soil moisture sampling, and a correlation with coal mine roof conditions. The lineaments could not be detected by the methods used, suggesting that they might be a surface phenomenon unrelated to subsurface geologic structures or roof stability in coal mine workings beneath.

Jan 1, 1987

By S. J. Broderick

[The term "nonmetallic minerals? as commonly used is the mining industry, refers to those minerals of industrial importance that are mined essentially for uses other than for the metals contained. The field comprises several hundred rod minerals of industrial importance, of which 70 have can adequately described in the textbook Industrial Minerals and Rocks. A few o f the more important nonmetallic products are sand and gravel, salt, phosphates, clays, refractories, limestone, and cement materials. Some of the minerals, such as bauxite and pyrolusive, have both metallic and nonmetallic applications, but in this report only the nonmetallic mineral phases are considered. In the organic field of nonmetallics only coal is considered, as, the others - petroleum, natural gas, natural bitumens, and hydrocarbons - are of no importance in water softening.]

Jan 1, 1941

By M. S. Seehra, R. S. Pandurangi

"Investigations of the infrared spectra of crystalline and amorphous silica particles of different sizes (0.05, 5, 10, 15, 30, 45, and 260 um) in the range of 400-4000 cm-1 using Fourier transform infrared/photoacoustic spectroscopy we reported. The change in the intensity I of the signal with porosity e of powders follows the e/(1 - e) dependence for strong bands and e dependence for weaker bands as pre¬dicted by the theory of McGovern of al. For strong bands, I also follows the empirical relation I ~ D-n, where D Is the particle diameter in cm and n = 0.34-0.42. The anomalous positive frequency dependence of I on the modulation fre¬quency f observed for the stronger bands in the 45-pm and 260-pm particles Is believed to result from saturation. Some observations on the effect of changing the background from (carbon black) powder to pellet are also made.INTRODUCTIONSince the publication of the Rosencwaig—Gersho (RG) theory on the photoacoustic effect in solids (1, 2), Fourier transform infrared/photoacoustic spectroscopy (FTIR/PAS) has become an important technique for obtaining the IR spectra of surfaces and materials in their natural state (1-12). In the one-dimensional RG theory, the incident radiation, modulated at frequency f, is absorbed by the material to a depth pp = 1/B (B = absorption coefficient), thus setting up temperature variations in the material. These variations heat the adjacent gas/solid interface leading to the pressure fluctuations of the gas above the sample, which in turn is detected by microphone as a PA signal. The thermal wave originating from no deeper than the thermal diffusion length(2k/npcf) 1/2 in the material contributes to the PA signal (here k, p, and c are respectively the thermal conductivity, density, and specific heat of the material). Since u2, can be varied by varying the experimental parameter f, depth pro¬filing by PAS is possible and a number of papers on this subject have appeared in recent years (2-10). Another im¬portant phenomenon is saturation which occurs when the material thickness 1> u> us (1-12).The original promise of PAS for use with powder samples, without the need to ""prepare"" samples as in FTIR spectros-copy, has not yet been fully realized because of several com¬plications. Theoretical works by Monchalin et al. (13) and McGovern et al (14) showed that the interstial gas in the voids of the powders can act as amplifier and that, for the same mass, a finer powder is expected to yield higher PA signal than a coarser powder. Although in a number of earlier studies (15-21) an increase of PA signal with decreasing particle size has been observed, a quantitative check on the equations developed by McGovern et al. (14) has not yet been made. It is necessary to understand the particle size effects in PAS if the promise of PAS for IR spectroscopy of powders is to be realized. In this paper, we report results of a detailed study on the PAS of silica powders for the particle size range of 0.05-260 um and compare the results with theory (14). We have also investigated the frequency dependence of the variousIR modes in these powders and show that the saturation phenomenon affects at least some of the observations. Some observations on the effects of pellet vs powder background are also reported (22-24). Details of these findings are presented and discussed in this paper."

Jan 1, 1990

By Jon C. Volkwein

The Bureau of Mines and many member companies of the Industrial Sand Association have been working in several areas to reduce personal exposure to respirable dust. Areas investigated include ventilation, modification of hardware, moisture addition to the product, and improved housekeeping practices. Ventilation systems have been devised and shown to contain 100 pct of a tracer gas released within the hood. An industrial clean air island has been developed and shown to reduce dust levels 90 pct at the opera- tor's position, Modification of hardware on a bag filling machine has been demonstrated to reduce dust 83 pct at the machine operator's lapel. This particular development has been termed a significant advancement in the state-of-the-art of bag filling by industry representatives. Addition of moisture to dried product materials has been tested with results showing dust reductions of 90 pct are possible!, Control of the moisture addition method still needs refinement and costs may be prohibitive. Dust sampling results clearly show the benefits of housekeeping practices such as building cleaning and vacuum sweeping. Rotation of work schedules is also effective for reducing personal exposure.

Jan 1, 1985

By Henry P. Wheeler

Natural gas was first stored underground in Welland, County, Ontario Province, Canada, in 1915.3/ The following year natural gas in the United States was first stored underground successfully in the Zoar field near Buffalo, N, Y. Only three additional storage fields were in use in the United States in 1930, but by 1940 the number had increased to over 30, and since that time growth has been more rapid. At least 80 fields, with a combined storage capacity of 440,828 MM c. f ., were being utilized by 1949.4 / In May 1952, 142 storage projects having a capacity of 915,000 MM c.f. were in operation .5/ These fields are distributed from New York to California--from Michigan to Texas. In the Appalachian region alone, there are 101 storage fields with a combined capacity exceeding 526,000 MM cu. ft. Why Natural Gas is Stored Natural gas is stored in order to be readily available to meet the needs of consumers.

Jan 1, 1952

By Alan G. Mayton

The Bureau of Mines conducted a study to (1) determine from laboratory tests the feasibility of a photographic method for determining reflec-tances that may be applied to measuring in-mine mineral reflectances and (2) formulate a procedure for collecting and analyzing the data. The method uses a 35-mm camera with automatic flash and a gray-scale re-flectance standard to collect on film the reflectivity data in under-ground mineral mines. After the film is processed, the data on the photographic prints are analyzed in the laboratory with a photometer. Test results show the photographic method can provide values of reflec-tance to within ±5 pet of full scale (full scale = 100 pet). The method's usefulness for determining reflectivity values, within similar limits of absolute percent error at the lower end of the scale, however, has not been completely resolved by the study and consequently warrants further investigation. The method offers an acceptable means for collecting and analyzing reflectivity data for reflectivities at the higher end of the scale, i.e., 50 pet or above; it should be used with caution when reflectivity values are below 50 pet. Four films were evaluated; all gave relatively satisfactory results.

Jan 1, 1987

By F. H. Nehl

Ion elutriation was used to extract silver cyanide complexes and free cyanide from aqueous streams containing up to 10 ppm silver and 5 ppm free cyanide. Screening tests selected nine of 350 different surfactants for further, larger scale experiments. The screening procedure used 0.1 g of each of the surfactants in 300 mL of synthetic wastewater. Air was sparged into the test cell at 50 cc/min. The foam was refluxed during the tests and was not sampled. Samples of the solution were taken at specified intervals and analyzed by wet chemical methods for free cyanide and by atomic absorption for silver content. The most effective surfactants lowered the silver and free cyanide concentrations to less than 0.5 ppm in 1 h or less. These surfactants were quaternary amine salts with one long chain (C12-C18) organic group and three methyl groups. Experiments using 3 L batches of wastewater or an ion elutriation cell continuously fed with solution draining from an inactive heap leach operation confirmed the results from the screening tests.

Jan 1, 2010

By Roger L. King

The Bureau of Mines has developed probes to be used in emergency mine rescue operations by being lowered through a borehole drilled into an underground mine. Various probes can provide two-way voice communication with trapped miners, continuous mine atmosphere monitoring, temperature indication, and television searching capability. At present, an infrared imaging probe is being developed for "seeing" through coal smoke.

Jan 1, 1976