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By Walter J. Huff

"INTRODUCTION The technical studies conducted by the Explosives Division of the Bureau of Mines have been summarized in a series of publications issued annually for the past 10 years. 3/ The following account covers studies undertaken from July 1, 1944 to June 30, 1945. The work is set forth under a number of main headings to correspond to the organizational structure of the division, the various activities being under the immediate direction of unit chiefs, who report to the author. Specific credit it due to the unit leader and his assistants.Determination of Ignition TemperaturesThe ignition temperature of mixtures of isobutane and air were determined by the static method using a 131-cc. quartz bull. 5/ The results obtained follow: Prevention of Benzene-Air Explosions by Addition of Nitrogen and Carbon Dioxide The elimination or mitigation of the explosion hazards of combustible gases is a part of the work undertaken by the Bureau of Mines in promoting safety. Explosions can be prevented by the maintenance of concentrations that lie outside the inflammable limits. A procedure has been developed whereby the inflammable limits of many complex gaseous mixtures may be calculated in a rather simple manner without requiring toilsome laboratory experiments. This procedure has been outlined in a number of previous publications. 6./ During the fiscal year under review, essential data required for the calculations of complex combustible gas mixtures containing varying percentages of benzene were obtained. Benzene vapor is a normal constituent of many manufactured gases and is widely used in the solvent industry and in the manufacture of high explosives."

Oct 1, 1946

By W. G. Freeman

This study provides recommendations for improved safety in underground blasting procedures based on in-mine observations of blasting practices in 30 underground metal, non-metal, and coal mines, and the analysis of blasting accidents since 1970 and existing state and federal regulations pertaining to the storage and use of explosives. Results of these analyses and observations indicate that 1) blasting accidents have declined but are an important contributor to the hazards of underground mining; 2) existing regulations are essentially adequate; 3) greater emphases should be placed on human errors and unsafe practices and the enforcement of existing regulations; and 4) future revisions of these regulations and standards should be organized, and their intent coordinated to eliminate ambiguities.

Jan 1, 1980

By D. E. Van Dillen

Three-dimensional structural analyses of three instrumented areas of a deep, longwall coal mine have been performed using the finite element code BMINES. The three Instrumented areas include two single-entry portions and one double-entry portion of the Sunnyside No. 1 Mine, Sunnyside, Utah. The finite element models simulated the sequence of excavation in each test area: the advance of the entry, installation of structural supports, retreat of the longwall, caving behind the longwall, and accumulation and loading of the gob. The structural supports considered in these finite element models include rock bolts, wood cribs, concrete cribs, steel arch sets, and chocks. Mechanical simulation of the geologic environment is achieved through elastic/ perfectly plastic material models employing anisotropy to represent finely layered regions of the medium. The results of these calculations are com-pared with the instrumentation readings from the mine. These measurements include closures, crib loads, rock-bolt forces, and stress growth.

Jan 1, 1978

By Peter G. Groer

The commonly used exact methods (1-2) to determine the WL measure the total a activity or the total number of a counts during three preselected time periods. Due to the half-lives involved (TRaB = 26.8 min, TRaC = 19.7) I these methods take 3S minutes to complete the a activity Ra measurements. Methods using the total a counts, obtained at times less than about one RaB half-life after the end of sampling run into statistical 214 problems. These methods are almost blind to RaB (Pb214) as a consequence of its relatively long half period (see above) and the fact that RaB is a ß emitter. The way out of this dilema is to measure RaB directly through its ß activity. Since RaB's daughter Rae (Bi214) is also a ß emitter, the two f3 spectra have to be separated to obtain RaB alone. How this is accomplished 1s described in subsequent sections describing the theory of the IWLM and its calibration. 2.0 THEORY The IWLM samples air for two minutes and counts this airs ample for two minutes starting 3 sec after the end of the sampling period. The instrument has three channels. The lower a channel, the upper a channel, and one ß channel. The total RaA counts observed are accumulated in the lower a channel, the total RaC? counts are stored in the upper a channel. The total ß counts from RaB and RaC are recorded in the ß channel. These three quantities are functions of NA, NB, and NC, the unknown concentrations

Jan 1, 1975

By T. A. Sullivan

Refining in a molten salt electrolyte was investigated as a means of recovering nickel containing less than 1 percent and preferably less than 0.2 percent cobalt from nickel products containing up to 5 percent cobalt. Electrolytic separation of nick and cobalt was accomplished in a molten KCl-LiCl-NiCl2 electrolyte. Nickel containing less than 0.10 percent cobalt was routinely prepared. Factors that influenced the transfer of cobalt to the refined product were the nickel concentration of the electrolyte, the cobalt concentration of the electrolyte, the ratio of nickel to cobalt in the electrolyte, and cathode current densities. A method of recovering the cobalt from the electrolyte was developed. The possibility of preparing high-purity nickel by this process was shown, as well as the preparation of various cobalt-nickel-tungsten alloys.

Jan 1, 1968

By Andrew M. Leszcykowski

In 1985 at the request of the Bureau of Land Management, personnel from the U.S. Bureau of Mines examined a 27,680-acre portion of the 30,420-acre King Hill Creek Wilderness Study Area (10-19-2) in order to evaluate the mineral resources. The study area, in southwestern Idaho, is underlain by Tertiary tuffs and basalt. There are no known mining claims or prospects in the study area, and no mineral resources were identified. The Volcano mining district is immediately north, but mines there are in granitic rock which does not crop out in the study area. Oil and gas leases were offered for land in the southern part of the area, but no applications were filed, and the lease offering was withdrawn (1985). INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the King Hill Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

By Charles L. Kusik

A study was conducted for the Bureau of Mines, U.S. Department of the Interior, to provide information which will lead to an increase in the recycling of mineral materials, in order to help conserve the Nation's mineral resources. Data were collected on energy requirements to recycle prompt industrial and obsolete scrap for nine metal commodities: Iron and steel, aluminum, copper, zinc, lead, stainless steel, titanium, tin, and nickel and nickel alloys. Major process routes for recycling were considered, starting from the first collection point through scrap preparation, transportation, smelting and/or refining to the molten metal, ingot, or other semi- finished form approximately equivalent to a primary metal of a similar composition. Available data for 1976 were collected on the amounts of each metal commodity recycled by major scrap categories. In addition, energy requirements were estimated for separating municipal solid wastes into four major categories: Refuse-derived fuel, and magnetic, aluminum, and glass cullet fractions. Finally, areas of research were identified to enhance recycling and/or increase the efficiency of energy use.

Jan 1, 1978

By J. Mitchell Linne

In 1986 at the request of Bureau of Land Management, the U.S. Bureau of Mines studied 23,225 acres of the 27,980-acre Jordan Craters Wilderness Study Area (OR-003-128) in order to evaluate its identified mineral resources. The study area is located in Malheur County, OR, about 20 miles northwest from Jordan Valley. No mining activity has been recorded within the study area, and no metallic or industrial mineral resources were identified. Small isolated occurrences of decorative quality stone were identified. However, none of these occurrences constitute a resource. Although the study area is underlain by relatively young volcanic rocks, the area has no known geothermal energy resource.

Jan 1, 1987

By Eugene L. Grumer

High-expansion foam was applied to the flames of six fuels burning in a 1-foot-diameter tray. The flames of three hydrocarbon fuels were more readily extinguished than the flames of methanol, acetone, or unsymmetrical dimethyl hydrazine. The result is rationalized on the basis that heat transfer from flame to fuel surface is primarily radiative with the hydrocarbons and more largely convective with the nonhydrocarbons. INTRODUCTION Equipment for producing high-expansion foams has been developed by the Bureau of Mines to control coal mine fires.5 Recently such equipment has been redesigned for portability and has now been produced commercially for other fire-fighting applications. In May 1961, a 50-by 50-foot gasoline fire was extinguished within 2 minutes by a trailer-mounted foam unit that produced 12,000 cu.ft./min. of high-expansion (1,000:1) foam.6

Jan 1, 1962

By W. A. Calhoun

The purpose of this investigation was to develop economical mineral dressing processes for removing objectionable quantities of impurities, such as quartz and pyrite, from refractory clay deposits in east central Missouri. The presence of excessive quartz in these clays causes crazing. Pyrite causes bloating and unsightly dark blobs on the surface of fired refractory brick. The iron concentration in the proper state of oxidation may also act as nucleation centers for carbon crystal growth which can result in bursting of the refractory. Numerous deposits, representing a very large tonnage, have been examined and prospected by various refractories companies and found to contain impurities in objectionable quantities. Upgrading these clays would greatly extend our reserves of high-quality refractory clays. Wet-tabling and wet-cyclone concentration were found to be effective for removal of impurities from clays. Of the two methods, wet-cyclone concentra¬tion would be cheaper and more effective. Although wet-tabling improved the refractory properties of each clay, beneficiation by wet-cyclone produced clays of superior quality. Clay recoveries by wet-cycloning ranged from 56.1 to 81.8 percent of the weight of the crude samples, and the beneficiated clays contained from 71.9 to 94.4 percent of the total alumina. The pyrometric cone equivalent (PCE) was increased from 1 to 3 cones by wet-cycloning. The beneficiated clays also met the reheat shrinkage requirements on refiring to 1,400° C. Missouri is one of the major domestic sources of fare clay. In addition to deposits of high-grade refractory clays, there arc many deposits that contain small percentages of impurities, which render the clays unfit for the production of high-heat-duty firebrick. Development of methods to beneficiate these submarginal clays to usable materials would greatly increase commercial fire clay resources.

Jan 1, 1961

By James Gibbs

In order to provide an initial approach to the deposits of oil shale, nahcolite, and dawsonite in the central area or the Piceance Creek Basin in northwestern Colorado, the U.S.B.M. and associated contractor personnel drilled and cased a 96-inch ID shaft to a depth of 2,371 feet. The shaft was constructed using ?big hole? drilling techniques and succeeded in giving access to previously inaccessible deposits of the above minerals. This report documents the construction from its beginning in January 1977 to its completion in January 1978. Procedures used and problems encountered are discussed in detail.

Jan 1, 1978

By William H. Schiffbauer

This report details a microcomputer-based control and monitoring network that was developed in-house by the U.S. Bureau of Mines and installed on a continuous mining machine. The network consists of microcomputers that are connected together via a single twisted-pair cable. Each microcomputer was developed to provide a particular function in the control process. Machine-mounted microcomputers, in conjunction with the appropriate sensors, provide closed-loop control of the machine, navigation, and environmental monitoring. Off-the-machine microcomputers provide remote control of the machine, sensor status, and a connection to the network so that external computers can access network data and control the continuous mining machine. Because of the network's generic structure, it can be installed on most mining machines.

Jan 1, 1993

By S. Raghavan

An investigation of the possibility of improving the grinding characteristics of a gabbro ore containing copper and nickel sulfides via a thermal shock treatment technique has been carried out. The results obtained indicate that the breakage characteristics of the gabbro are particles can be significantly improved by preheating the are particles to a temperature around 400°C followed by rapid water quenching. For a given power input and feed size, the thermally treated material produces a product of much finer distribution than the untreated material. An assessment of the improvement in grindability has been made by calculating feed size selection functions for untreated and heat-treated materials.

Jan 1, 1981

By Bruce F. Grant

"INTRODUCTION The future of oil production in the part of the Appalachian region included in southwestern Pennsylvania; West Virginia, and southeastern Ohio is directly dependent on the maintenance of existing wells. This report presents an analytical study of the methods used in oil-well reconditioning in this area. The study is part of a research program designed to evaluate those means of stimulating oil production that can effectively and economically maintain present oil-production rates and make it possible to keep existing wells in operation. Well-reconditioning work was curtailed during the war; therefore, an abnormally large number of wells in the Appalachian Region is now in need of repair. Because the lubricant content of Appalachian crude: oils is high and the refined lubricating oils an; particularly suited to use in high speed, high-temperature engines, the demand for these crude oils during the war exceeds, the maximum rate of production obtainable under wartime operating conditions. Increases in operating, expenses, inability to meet war-time reconditioning costs, and inflexible price structures caused the abandonment of an alarming number of wells during the past 4 or 5 years.As a means of increasing regional oil-production rates, new drilling in the older fields for primary production generally is uneconomical because reservoir pressures in most of the fields have virtually been depleted and the production rates of newly drilled wells are small."

Feb 1, 1948

By P. R. Jones

The Bureau of Mines has written a computer program for the design and cost of a shell and tube type heat exchanger, in which a change in phase occurs on the shell side. The total cost, which was minimized, includes the annual fixed charges and annual operating costs. The program was written to meet the following requirements: (1) Triangular pitch, (2) single or multiple pass, and (3) heating or cooling. Price optimum design was obtained for four standard tube diameters and pitch. Standard heat exchangers whose area equaled or exceeded the required area are also listed. The program was made adaptable to various fluids and to various tube dimensions by including many of the required data such as physical properties of the fluids, tube data, and standard shell data as input data.

Jan 1, 1969

By Robert H. Peters

The objective of the project descibed in this report was to design and field test a model health and safety program at a coal mining company and a gold mining company. The model program was implemented primarily by providing training on loss control, accident investigation, and the operation of mobile equipment; and by providing technical assistance to help solve health and safety problems. Data were obtained from company records on occupational injuries, illnesses, accidents, and "near misses"; and through direct observation of employees performing a large number of randomly selected jobs. At the coal mine, employees were observed five times over a 15-month period. At the gold mine, employees were observed six times over a 16-month period. During the study, the percentage of sampled jobs containing one or more safety deficiencies decreased from 74.3 pct to 36.6 pct at the coal mine and from 86.4 pct to 19.1 pct at the gold mine. Work on this project was performed by Woodward Associates, Inc., under a Bureau of Mines contract.

Jan 1, 1986

By C. W. Morris

The continuous miner training system provides classroom materials training aids, and a continuous miner simulator to provide a short, intensive instruction and skills development program for training or retraining continuous miner operators. This project included refinement of training objectives, revision of training aids, improvements to the simulator, and evaluation of the entire system. This report describes the revised classroom materials and the validation of the training system.

Jan 1, 1982

In 1987 Wyoming became the largest coal producing state in the country. The state is known for its extensive coal resources and extremely thick coal seams. Wyoming's coal reserves total about 69.3 billion tons, or 14.2 percent of the U.S. coal reserve. Coal seams range generally from 10 to 80 feet in thickness, although one seam is 220 feet thick. The coal-bearing areas of Wyoming underlie approximately 41 percent of the state's total land area. Wyoming's coal ranges from lignite to high volatile bituminous. Most of the coal produced is subbituminous from the Powder River coal region near Gillette. The presence of coal in Wyoming was discovered before 1834 on the Belle Fourche River. The state's first mine opened in Carbon County in 1865, and with the completion of the trans- continental railroad, the demand for coal increased. Currently approximately 80 percent of Wyoming's coal production is shipped out-of-state to meet the growing demand for low- sulfur coal to fuel electric generating plants. Wyoming received conditional regulatory approval November 26, 1980. Its Abandoned Mine Land Program was approved February 14, 1983.

Jan 1, 1992

To alleviate the hazard to personnel and danger to equipment caused by fires on large, mobile vehicles. The Approach: A system which automatically senses a fire at its early stage of development, warns the driver of the danger, and activates fire extinguishers in the zone of combustion, How It Works: The automatic fire protection system utilizes both thermal and optical sensors to detect the heat or light given off by a fire in the area of concern (Fig. 1). The system warns the driver of the hazard and then automatically extinguishes the fire with pressurized S-C class powder. The system can also be activated manually from the operator's cab or from ground level. Further, the automatic sequencing of the system can be manually overridden by the driver if he determines that the fire sensors have malfunctioned to cause a false alarm.

Jan 1, 1974

By Albert Ketler

[Early Bureau of Mines research had produced a fluorescent mine illumination system which was approved by MESA under Schedule 29A for use as portable equipment Intense industry preference for machine-mounted hardware required a MESA 2G approved system. The modifications required to upgrade the portable system arc herein described.]

Jan 1, 1976