Search Documents

By T. F. Anstett

The Bureau of Mines investigated the availability of platinum from known major deposits in market economy countries. Fifteen of these deposits contain demonstrated resources totaling 302 million troy ounces of platinum. Detailed geologic, engineering, and cost evaluations were performed on each deposit to determine its potential for platinum production. There are large amounts of demonstrated platinum potentially available from market economy deposits that were not analyzed owing to lack of adequate data or to technological limitations. These include 297 million troy ounces contained in the UG2 and Platreef of the Bushveld Complex, South Africa. This analysis indicates that about 11 0 million troy ounces (2.3 million ounces annually) of platinum are potentially available at the January 1980 producer price of $420 per troy ounce, nearly all from South Africa. An additional 85 million troy ounces occurring in Zimbabwean deposits would become available only through more than a quadrupling of that price. In order to meet projected world demand of 3.5 million troy ounces in 1990, platinum price may have to increase. Only one domestic deposit, the Salmon River in Alaska, is capable of producing platinum at $420 per troy ounce. Regardless of price, at assumed production capacities, domestic deposits could supply less than 10 percent of annual U.S. requirements.

Jan 1, 1982

By Kevin A. Rider, Bernard J. Martin

Reaching movements are planned and subsequently executed [1] using visual and somatosensory feedbacks [2], where absence of visual feedback is known to increase endpoint variability [3]. Visual occlusion decreases the ability to make rapid online compensatory movements, which results in initial radial deviations that are highly correlated with radial dispersion at the target. Perturbations of rapid, visually-guided reaches are compensated on-line and result in endpoint dispersions poorly correlated with initial deviations, emphasizing the strong effect of visual feedback in temporally-constrained reaching tasks. In control conditions (no vibration), these uncompensated, rapid reaches serve as estimates of the individual’s intended trajectory. When ride motion is present, trajectories of rapid, visually-occluded reaches provide a measure of the natural biodynamic response of the cantilevered spine-arm-hand linkage. These intended movement trajectories and the biodynamic response (vibration feedthrough) are used to predict the effect of ride motion on the performance of rapid reaching tasks. Goals of this study are to investigate the influences of vehicle motion on human reaching and pointing, and to reveal movement strategies used in visually-occluded reaching tasks. Methods A six degree of freedom human-rated Ride Motion Simulator (RMS) was used to generate a dynamic vehicle environment. Participants performed discrete, rapid pointing tasks to targets presented on three touchpanel displays under stationary and random whole-body vibration. Reach instructions included successfully reaching identical circular targets (Ø = 0.25”) with the right index fingertip as fast as possible. Targets were presented on resistive-touch displays mounted approximately 60 cm from the participant’s nasion. The touchpanel displays were located in the forward and lateral directions at eye level, and forward at 45° of elevation. These displays measured the spatial error of the reach destination. A ten-camera VICON motion capture system recorded the upper body kinematics of the participant. Reflective markers were placed on the participant’s torso, head, and arms. Initial kinematics of the fingertip (i.e. time and magnitude peak tangential velocity) and tangential velocity at target were used to estimate the planned endpoint of the reach. Results and Discussion Ride motion resulted in increased endpoint variability compared to reaches performed in the stationary condition. Reaches to the elevated touchpanel consistently resulted in the largest variability across all motion conditions, suggesting that a vehicle occupant would not be capable of accurately activating a control in that location. Principal axes of endpoint ellipses were along and perpendicular to the direction of fingertip movements. Example graphs of endpoint variability with ellipses containing 95% of the data points are shown in Figure 1. These ellipses

Jan 6, 2006

By Harry Dobroski

Communications with moving tracked vehicles in a rail haulage mine pose a difficult problem. These communications take place from dispatcher to vehicles or from vehicle to vehicle via the trolley line, which is a very poor communications line. As a result, deadspots and high-signal areas can occur anywhere along the line, or signal can decrease simply as a function of distance. An analysis is made of the trolley line as a communications line, and methods of improving its characteristics are discussed. Data from inmine experiments are presented, showing actual improvements in communications. Recent Bureau developments in new hardware are also discussed. These include an adaptive speaker control for existing carrier phones and a new generation of improved carrier phones.

By Jerome Apt

This manual has been prepared fur the help and guidance of underground coal mine operators. It details both common and unique engineering methods by which the respirable dust, which is generated in coal mines, can be controlled. This document was compiled by Apt, Bramer, Conrad and Associates, Inc. under contract number H0111464, issued by the U. S. Bureau of Mines and forms Volume II of the final report. This contract was authorized by and executed pursuant to the Federal Coal Mine Health and Safety. Act of 1969 (P. I. 91-173; 83 Stat. 742).

Jan 1, 1972

Three complete connector assemblies and six separate contacts were submitted to a series of tests to establish the connectors permissibility and compliance with U. S. Bureau of Mines research Contract #H 0110423 D.C. portion. Test Procedure TPC-0118 was coordinated, and the test plan approved by the Bureau as fully complying with the intent of the contract for the direct current connectors. The components and connector assemblies have been demonstrated in testing that they meet or exceed all the requirements of the test procedure.

Jan 1, 1974

By Rose L. Ballard

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are tables that show the principal nonfuel mineral commodities exported from and imported into the United States, and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume II of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines. Because of inadequacies in the statistics available, some series deviate from the foregoing definition. For gold, silver, copper, lead, zinc, and tin, the quantities are recorded on a mine basis (as the recoverable content of ore sold or treated). However, the values assigned to these quantities are based on the average selling price of refined metal, not the mine value. Mercury is measured as recovered metal and valued at the average New York price for the metal.

Jan 1, 1981

By Oliver Bowles

The mineral asbestos, because of its unique fibrous character, is allied to cotton and wool but has the advantage of heat and fire resistance; therefore, it supplies many industrial needs for which no substitutes are yet available. This report covers the essential features of the asbestos industry, including occurrence, production, mining, milling, utilization, international trade, and marketing. The United States leads all countries in the manufacture of asbestos products, but domestic sources furnish only a small fraction of the raw material required. As the United States is dependent to so great an extent on foreign supplies of raw materials, the bulletin deals at length with the asbestos industry in foreign lands. Several reports now available deal with the industry in individual countries. Among them are Chrysotile Asbestos in Canada, by J. G. Ross; Asbestos in the Union of South Africa, by A. L. Hall; and a series of articles on the Russian industry, by Walter A. Ru Keyser. These have been drawn upon freely, and full acknowledgment is hereby made for the helpful information thus secured. The file of the magazine Asbestos also has furnished many valuable data touching all phases of the industry. Many other books and articles listed in the bibliography at the end of this bulletin have been utilized and have been supplemented by the author's intimate acquaintance with the industry for about 20 years. The intent is to present a concise, world-wide, historical, technical, and economic treatment of the asbestos industry.

Jan 1, 1937

By Piyush K. Dutta

This report describes the design, development, manufacture and incorporation of noise control features on a jumbo drill and the results of successful tests of this drill in surface and underground mines. The noise-reducing features developed under this program are applicable to future designs of jumbo mounted drills that can be cost effectively manufactured and have the potential to reduce noise levels at the operator's position from 115-120 dBA to 95 dBA or less without a reduction of currently attainable drilling rates.

Jan 1, 1985

By Gerald J. Joy, Paul J. Middendorf

This study examines the patterns and trends in noise exposure documented in data collected by Mine Safety and Health Administration inspectors at U.S. coal mines from 1987 through 2004. During this period, MSHA issued a new regulation on occupational noise exposure that changed the regulatory requirements and enforcement policies. The data were examined to identify potential impacts from these changes. The overall annual median noise dose declined 67% for surface coal mining and 24% for underground coal mining, and the reduction in each group accelerated after promulgation of the new noise rule. However, not all mining occupations experienced a decrease. The exposure reduction was accompanied by an increase of shift length as represented by dosimeter sample duration. For coal miners exposed above the permissible exposure level, use of hearing protection devices increased from 61% to 89% during this period. Participation of miners exposed at or above the action level in hearing conservation programs rapidly reached 86% following the effective date of the noise rule. Based on inspection data, the occupational noise regulation appears to be having a strong positive impact on hearing conservation by reducing exposures and increasing the use of hearing protection devices and medical surveillance. However the increase in shift duration and resulting reduction in recovery time may mitigate the gains somewhat.

By T. J. Ballard

The Rickard mine in York County, S. C., named for the original owner, Alexander Rickard, was operated about 50 years as. No records are available of the quantity of corundum shipped. Pratt states, "Many tons were picked up from the surface and shipped." The mine was visited on August 6, 1943, by the author, accompanied by Gilbert W. Withers of Atlanta, Ga. Investigation of the property was begun by the Bureau of Mines after some initial work by the Mi-Cor Corp., a company organized by Gilbert P. Withers of Atlanta to explore the property. In conducting the Bureau program, 754 linear feet of trenches were dug, 110 feet of old drifts cleaned out and examined, and 38 feet of shaft retimbered.

Jan 1, 1948

By Thomas L. Ochs

The stripping of iron-laden solvent with hydrochloric acid in the iron-removal step of the clay-hydrochloric acid process for the extraction of alumina from calcined kaolinitic clay results in a loaded ferric chloride stripping liquor. Treatment of this stripping liquor at boiling with calcined kaolin to form insoluble Fe203(s) and a dilute A1C13 solution was undertaken by the Bureau of Mines to characterize process problems and to aid in sizing of solids-liquid separation equipment. Variables identified as important in the chemical reaction were calcined kaolin particle size, ratio of calcined kaolin to FeC13, and reaction time. These parameters were tested for significance and their interactions investigated. Fine calcined kaolin (-65 mesh) at a greater than 1:1 mole ratio of contained acid-soluble A1203 to Fe203 equivalent of the FeC13 in the stripping liquor required less reaction time than coarser (-16 mesh) material. Solids-liquid separation of the reacted slurries by both settling and filtration requires flocculation.

Jan 1, 2011

By M. E. Hawkins

This Bureau of Mines report provides information on all of the 329 proved salt domes in the Gulf Coastal States and offshore area of the United States. It includes specific data related to location, depth to the cap rock and to the salt, storage facilities for LPG, and production of salt, sulfur, petroleum, and rock related to or associated with the dome structure in the subject area. Also included is a brief history of the salt, sulfur, and petroleum industries as related to the salt domes. Gulf Coast salt domes were the scene of the first discovery of a large deposit of rock salt in North America, the birthplace of the Frasch sulfur industry, and the location of the first large oil gushers that ushered in the modern liquid fuel age.

Jan 1, 1966

By Gary E. Sherman

To aid the U.S. Army Corps of Engineers in their Resource Development Navigation Study, the U.S. Bureau of Mines (Bureau) examined the potential for mineral development near ten Alaska port sites. This report presents the results for the following four sites: Balboa Bay, Beluga, Lost River, and Point MacKenzie. There are 579 known deposits within the area considered for these ports. The majority of the deposits are located within a highway/railroad corridor examined for the Point MacKenzie port site. Based on the current level of knowledge, coal deposits near the Beluga and Point MacKenzie port sites are most likely to be developed in the near future. This conclusion is based on the fact that coal projects in these areas are actively being pursued for development. The mineral wealth surrounding the four port sites is substantial. Mine models were used to examine the potential for mining tin, gold, silver, copper, and molybdenum. The models were based on published reserve and grade data and therefore do not include proprietary company data which, if available, would likely change the analysis results. Of the models examined, the tin placer mine model developed for the Lost River port site proved to be closest to being economic.

Jan 1, 2011

By Nathan Feldstein

The wetting of coal dust by aqueous solutions of surface active agents (surfactants) has been studied. Selected for study were thirty coals and typical surfactants selected from the typical classes of anionic, non ionic and cationics. Of these three classes the practical use of cationics in aqueous solutions has been eliminated due to the inherent negative Zeta potential charge of the representative coals studied. The wetting of the coals has been examined by column flow, contact angle, and settling rate measurements. Results indicated that both anionic and nonionic surfactants are to be considered viable for use; low critical micelle concentration values are also preferred for the surfactants. Study of native waters showed substantial variation in properties, i.e., pH, calcium ion concentration, and conductance. pH variations were also noted to affect the effectiveness of selected surfactants. Combinations of nonionic and anionic surfactants have, in certain instances, produced synergistic enhancement in the coal wetting superior to the effectiveness of each surfactant alone.

Jan 1, 1981

By D. E. Wolfson

As a part of its overall program of coal carbonization, the Bureau of Mines is studying the coking properties of coals that may be used for metallurgical purposes. The objectives of this study were given in detail in a previous report.2/ The inherent suitability of coal for metallurgical use depends primarily on (1) chemical composition, (2) preparation characteristics, and (3) carbonization behavior. The first two factors, as well as the available reserves, are considered in selecting coals for carbonization tests. According to the estimate of reserves by Dowd,3/ the recoverable coal in Floyd County in beds 28 inches or more thick, in thousand tons, is as follows: [ ]

Jan 1, 1958

By Wils L. Cooley, Herman W. Hill

'The electrical behavior of ground beds is often quite different from what would be expected based on experience with electric circuits. An explanation for this unique behavior is given, through means of an analogy, which should promote intuitive understanding of ground beds. The nonmathematical development of the text is complemented by an extensive appendix which describes the details of ground bed calculations. This work was supported by U.S. Bureau of Mines contract G0144138.

Jan 1, 1979

By M. G. Zabetakis

This publication contains highlights of a 4-hour lecture and demonstration by the Bureau of Mines on the fire and explosion hazards of flammable liquids and solids, oxidizing materials, corrosive liquids, and compressed gases. The authors first presented this material as part of a 2-week course given to officers and enlisted men at the U.S. Coast Guard's Dangerous-Cargo Handling School, established at Fort Eustis, Va., in 1959. The Bureau was asked to present the lecture and demonstration because of the extensive experience of its researchers in handling certain harardous commodities.

Jan 1, 1961

The objective of this handbook is to provide the inspector with guidance for recognizing hazards from inhalation contaminants in above ground work areas of underground and surface coal mining and processing facilities and evaluating these hazards by collecting samples or making field determinations and interpreting the analytical results. There are several portions of the handbook which should prove most useful to the inspectors. The names and locations of these portions are listed below: Survey Check List (Page 2-3) Rules for Determining if Sampling is Required (Page 2-1) List of Most Frequently Encountered Contaminants (Page 2-2) List of Candidate Contaminants and their Sampling Conditions (Table 2, Starting on page 2-5) Interpretation of Results (Page 2-16) Procedure for a, Health and Safety Inspection (Page 2-25) For obtaining information not available from the above mentioned portions of the handbook, the inspector is directed to the Table of Contents, the Glossary of Terms, and the List of Commercial Products Encountered in Surveys.

Jan 1, 1975

By J. R. Thoenen

Profits in the crushed-stone industry, as in any other, represent the difference between selling price and production cost. When consumer demand increases rapidly, as occurred in the crushed-stone industry from 1918 to 1927, selling prices tend to rise. Cost of production usually rises, also, owing to the expense of expanding facilities, searching for and developing new quarries, and purchasing, installing, and operating new equipment. Frequently, also, the inattention of managements to the details of operating costs is responsible for their increase. This is not due to negligence but rather to the necessity of confining attention to the problems involved in producing material to supply orders. When market conditions change and consumer demand becomes stabilized or contracts, the producer r s attention usually is directed to assuring the orders necessary to keep his enlarged facilities busy. Hence, competition increases and soiling prices decline.

Jan 1, 1939

By Joseph C. Zelanko, Anthony T. Iannacchione

One of the most difficult, longstanding engineering problems associated with coal mining is the catastrophic failure of cog mine structures known as bumps. For more than 70 years, researchers and practitioners have assembled a wealth of technical information on coal bumps in an attempt to understand and control them. However, many technical issues raised long ago are still being debated today. This paper examines past experiences and recognizes achievements in the realm of coal bumps. U.S. Bureau of Mines (USBM) researchers collected and analyzed 172 coal bump incident reports and compiled the pertinent statistics into a database. Actual field studied are also discussed. Examination of past experience has shown that there is no one set of defining characteristics that is responsible for coal bumps. In all cases, bumps occur when complex arrangements of geology, stress, and mining conditions interact to interfere with the orderly dissipation of stress. However, it is evident from the database that a tremendous reservoir of knowledge has been established from past experience that has unquestionably limited the severity of coal mine bumps in the United States.