Search Documents

By T. T. Campbell

This report describes the development of new electroplating baths from which tin-nickel alloy plate was deposited. Although tin-nickel plate can be deposited from an aqueous ammonium bifluoride bath, the corrosive nature of this bath has served as a deterrent to its use. The Bureau of Mines felt that more general acceptance of this new alloy plate would follow if neutral or alkaline baths could be developed. Promising results were obtained from electrolytes containing both tin and nickel chlorides dissolved in triethanolamine-hydrochloric acid or in ethylene glycol hydrochloric acid baths. Current efficiencies close to 100 percent were obtained with these baths. Research revealed that tin-nickel plate could be produced from organic solvents or from mixed aqueous-organic electrolytes. The composition of the alloy deposit - 65 percent tin and 35 percent nickel - was found to exhibit the same single-phase structure that is obtained from the commercially accepted fluoride-type bath.

Jan 1, 1959

By Kenneth H. Johnston

Information and data necessary for research on improving methods of oil recovery from low-permeability reservoirs and for comparison and evaluation of performance of such reservoirs with those producing from more permeable sands were obtained. Core analyses, well logs, production tests, well stimulation techniques, primary and secondary production records, and data on two water-flood projects were examined for wells producing from the Bartlesville sand, West Avant field, Osage County, Okla. Overall recovery from the study area was generally poor with only 9.0 percent of the pore volume recovered to January 1, 1968. Larger fracture treatments (8,000 to 12,000 gal) could have resulted in an increase in primary oil recovery. Secondary recovery by water-flooding accounted for only 1.9 percent of the pore volume because of the inability to control the large volume of injection fluid that escaped from the flood patterns and the excessive volumes of water produced with the oil. Future waterflood development in other low-permeability reservoirs should include the drilling of new input wells, use of injectivity surveys to locate possible natural fracture systems, or zones of high permeability, and control of injection fluids by altering flood patterns and/or plugging of the more permeable zones.

Jan 1, 1968

By D. W. Frommer

Laboratory mineral-dressing investigations were conducted on talc-bearing samples from Arkansas and Texas under the Bureau of Mines program of examinations and surveys, which is concerned, in part, with the improvement of conservation and utilization of domestic mineral resources. Two of the soapstones in question were successfully upgraded by flotation, utilizing stage additions of a frother and an amine to promote their talc content. The process could enable the producers to meet more rigid specifications of higher priced talc commodities. INTRODUCTION Talc is an industrial mineral with distinctive properties, such as softness, smoothness, large surface area in relation to mass, chemical inertness, and good retention as a filler, that make it particularly valuable to a number of industries. Sales to 6 industries -ceramics, paint, insecticide, rubber, roofing, and paper -consumed 84 percent of the domestic production of talc, pyrophyllite, and ground soapstone in 1952. Mine production in that year totaled 600,908 tons. Sales of crude and ground material were 593,147 tons valued at $11,347,317.2/

Jan 1, 1956

By W. A. Cole

The sulfur shortage that existed during the Korean conflict stimulated interest in coal measures as possible sources of sulfur. One of the areas brought to the attention of the Bureau of Mines was in Marion County, Iowa, where comparatively high-sulfur coals and other marcasite-bearing strata were known to occur. A Bureau of Mines engineer inspected the marcasite occurrence on December 4, 1954; this prompted further work on the Iowa coals and associated formations as a source of iron sulfides. An investigation of the Iowa high-sulfur coals was undertaken including core drilling, field reconnaissance, and compilation of data pertinent to consideration of the following: 1. Upgrading Iowa coal by mechanical cleaning and the feasibility of recovering sulfur from coal brasses. 2. Possibility of processing the high-sulfur coals by adaptation of methods employed in processing industrial gases to produce sulfur and sulfur products. 3. Possibility of finding concentrations of iron sulfides in associated rock formations in sufficient quantity for economical recovery.

Jan 1, 1957

By Larry G. Stolarczyk

This report deals with the creation of an efficient method to determine if command, control, communication and monitoring (3cm) equipment in coal, metal and non-metal mines is susceptible to Radio Frequency Interference (RFI) from the Medium Frequency (MF) radio communications system. A qualitative and quantitative RFT test plan was developed for in-mine and laboratory evaluation of the equipment. The laboratory testing was accomplished using the TEM Test Chamber. Detailed information on the Test Plan and the TEM Test Chamber is included. During in-mine testing of the MF System some underground equipment malfunctioned when the transmitter's radiating antenna was in close proximity. Electromagnetic Compatibility (EMC) testing was done on three levels; Component (circuit or box), subsystems and system. Nine tables are included which show the results of testing various equipment for RFI.

Jan 5, 1986

By J. W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and from the data developed to determine: 1. Which coals either as mined or after beneficiation by conventional preparation are chemically suitable under present standards for producing metallurgical coke. 2. Which coals require special and more intensive treatment in preparation than is now practiced. 3. Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation by present-day methods. This report is one in this county series that describes the preparation characteristics of the coals of Lee County, Va.

Jan 1, 1957

By Lewis C. Karrick

In studying the destructive distillation or pyrolysis of oil shales, the primary consideration is to determine the effects of heat on the organic components of the shale. The impracticability of separating these organic components, collectively known as "kerogen", from the mineral matter with which they are associated renders the problem extremely complex. The behavior of the kerogan in the shale while undergoing the heating process is probably different from that of the same kerogen if it could be isolated and treated under similar temperature conditions, and in fact the results of actual distillations have shown that the physical properties of the mineral matter in the shale may be the cause of much variation in the products of retorting. It must be remembered that the inorganic .material of the shale is a heterogeneous mixture of minerals solidified into a very close-grained compact mass. This mineral mass has a thermal conductivity different from that of the kerogen, thus complicating the problem of even distribution of heat. Furthermore, the temperatures of dehydration of gypsum end some; hydrous silicates are included within the temperature range of the shale distillation, These minerals are frequently present in the shales; and the evolution of water vapors from them will affect the partial pressures of the hydrocarbon vapors evolved from the kerogen, probably tending toward, the improvement of the quality of the oil distillates. Carbonates and sulphides which are also frequently present begin to decompose within this range of temperature, and the gases produced from them may alter the chemical constitution of the oils produced from the kerogen.

Jan 1, 1922

By E. J. Gleim

Many people consider the mining of coal to be an extremely hazardous occupation; but it should be remembered that most large industries have to meet special conditions which, if not dealt with properly, might become hazards to life and property. Mining men may not always be fully aware that some practices and certain equipment that is incorrectly designed or maintained can lead to dangerous conditions. In endeavoring to help the coal-mining industry to prevent accidents and disasters, the Bureau of Mines has engaged in a program of education on conditions and practices that must be avoided. An effective way to teach safety is by visual demonstration. For example, it is generally known that certain kinds of electrical flashes have ignited explosive atmospheres in mines, but actually to see and hear explosions caused by electrical sparks of different size and character under laboratory control is likely to teach a much more emphatic and lasting lesson than would be learned by merely reading about them. The interest manifested by those who witness the demonstrations seems to prove that this is true. The purpose of the demonstrations is not to discourage the use of electricity in mines, but rather to indicate what types of equipment (including some generally regarded as harmless) can ignite gas and what safeguards have been developed to prevent such ignitions. It is hoped that this information will improve the ability of mining men to cope with underground hazards.

Jan 1, 1937

By Donald W. Mitchell, John Nagy, Edwin M. Murphy

Information is presented on remote sealing of a mine passageway through a borehole by five methods : PPnneeuummaattiicc injection of mineral wool and sand, ureaformaldehyde foam , balloons , urethane foam, and caving by blasting . An adaptation of the method using pneumatically conveyed mineral wool was tried in an operating mine . Further research is needed to simplify and to improve the techniques involved , as well as to explore the possibilities of other methods and combinations .

Jan 1, 1964

By F. R. Cattoir, D. H. Baker

Fused - salt electrorefining has been successfully applied to the purification of vanadium metal . The electrolyte used in this refining technique was sodium chloride to which had been added 3 to 6 percent vanadium as vanadium dichloride . The average deposition current efficiency was 91 percent . Oxygen and nitrogen , the impurities in commercially produced vanadium metal , were reduced by two - thirds of the amount contained in the feed material . Hardness of the vanadium- metal product was reduced from an initial 97 Rockwell B ( RB ) to a minimum of 35 Rg . The reduction of these impurities markedly improved the plasticity of the final product obtained by melting the crystalline cell metal into small ingots . These ingots could be given a 99 - percent cold reduction by rolling before edge cracking appeared . Growing interest in high - purity vanadium and the industrial need for purer metals and improved alloys for use under high temperatures and high speeds have demanded the elimination and/or control of impurities . Accordingly, research to eliminate or control the undesirable impurities has been expanded .

Jul 1, 1960

By Kenneth C. Stewart

This contract was directed toward a study of the attenuating properties of earmuffs as worn by miners. Two attenuation measurement procedures were utilized. Human subjects were tested in a diffuse sound field according to threshold shift procedures recommended by the American National Standards Institute and a physical measurement procedure was accomplished in the same diffuse field on the same human subjects with microphones placed simultaneously on the inside and outside of the muffs. All measurements were obtained in one third octave of random noise. The results of the study indicated that physical and psychophysical attenuation measurements are in essential agreement at frequencies from 125 Hz to 2 KHz. Above 2 KHz the psychophysical measurement demonstrates larger amounts of attenuation than the physical measurement. The difference in attenuation ranged from approximately 7.0 dB to 9.0 dB at frequencies of 4 KHz and above. A possible explanation for the observed differences in attenuation has been presented.

Jan 1, 1980

The object of this program was to design and build a self-contained system for remote monitoring of the atmosphere in mines. The system developed uses the mine pager phone line as the primary communication channel and also has the capability of using 208 Hz in the ELF band for wireless transmission through the earth. The depth for through-the-earth trans- mission is expected to be about 80 to 90 meters in high conductivity soil and is limited by the noise level in the ELF band-pass filters. The underground components of the TEM System are energized by mine power through a battery charger - storage battery power supply. In the event of mine power failure the battery capacity is more than sufficient for one week's operation with interrogations every four hours.

By Robert P. Vinson

A sequential sampler, based on the Archimedes screw, has been developed by the Bureau of Mines. Its initial purpose was to collect air samples during tracer gas studies in underground mines. However, the basic concept can be applied to other sampling needs, including sampling of liquids. A prototype was built and successfully tested in the Bureau's Experimental Mine at Bruceton, Pa. The simple design makes the sampler inherently durable and low in cost.

Jan 1, 1976

By Isaac A. Zlochower, Kenneth L. Cashdollar

The Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health conducted a study of the explosibility of various metals and other elemental dusts dispersed in air, with a focus on the experimental explosion temperatures. The data are useful for understanding the basics of dust cloud combustion, as well as for evaluating the explosion hazards in the minerals and metals processing industries. The dusts studied included boron, carbon, magnesium, aluminum, silicon, sulfur, titanium, chromium, iron, nickel, copper, zinc, niobium, molybdenum, tin, hafhium, tantalum, tungsten, and lead. The dusts were chosen to cover a wide range of physical properties - from the more volatile materials such as magnesium, aluminum, sulfur, and zinc to the highly "refractory" (very low volatility) elements such as carbon, niobium, molybdenum, tantalum, and tungsten. These flammability studies were conducted in a 20-L chamber, using strong pyrotechc ignitors. The experimental data obtained included the minimum explosible concentrations, maximum explosion pressures, and maximum explosion temperatures. A unique multiwavelength infrared pyrometer was used to measure the temperatures. For the elemental dusts studied, all ignited and burned as air-dispersed dust clouds except for nickel, copper, molybdenum, and lead. The measured maximum explosion temperatures ranged from -1 550 K for tin and tungsten powders to -2800 K for aluminum, magnesium, and titanium powders. The measured temperatures are compared to the calculated, adiabatic flame temperatures. In general, the dusts whose experimental temperatures were closer to the adiabatic values were those with the finer particle sizes, those that were more easily vaporized, and/or those that were intrinsically more reactive.

By M. M. Fine

This report describes a Bureau of Mines technical feasibility study of simultaneous reduction and induration of pelletized iron ore to make a product with superior qualities as blast-furnace feed. Highly reduced, physically competent pellets can be made from magnetite and specularite concentrates that contain small additions of bentonite as binder. In batch tests, pellets were dried, surrounded with solid fuel in crucibles, and heated to the reducing temperature. Total iron content of the best products was higher than 80 percent and crushing strength of 1/2-inch metallized pellets ranged up to 600 pounds or more. Comparative tests of several commercial oxide pellets showed a wide range in crushing strengths, but most values were less than 350 pounds. Continuous tests in a rotary kiln resulted in the same degree of reduction, but the pellets had lower crushing strengths because of the limitations in the maximum operating temperature of the small kiln.

Jan 1, 1962

By Frank D. Lamb

Pyrophyllite, a hydrous aluminum silicate (Al2 Si4O10 (OH)2 ) has been mined in North Carolina and marketed without beneficiation for the past 100 years, but recent demands for higher-grade material indicate that an economical concentration method is needed for at least a part of the pyrophyllite production. Past production has depended upon selective mining and hand sorting, which is often unsatisfactory because of the finely disseminated character of the ores. The major impurity in North Carolina pyrophyllite ores is quartz, which accounts for the abrasiveness of the commercial product. Since pyrophyllite is only slightly heavier than quartz, those ores cannot be beneficiated by simple gravity-concentration methods. Some separation can be attained by differential grinding and air classification because of the difference in hardness of the two minerals) but the separation is not sharp. Froth flotation of pyrophyllite from Quartz has never been attempted commercially, but if the demand for high-grade material is sufficient, it would seem that this process offers the most premise of being economically feasible.

Jan 1, 1950

By T. A. Gray, L. M. Crayne, P. Glogowski, Trevits. M. A.

Of the 19 major mine fire events (including thermal events) that have occurred in the last 6 years (2000-2005), it is estimated that remotely constructed mine seals could have been used at 65% of the events to control or suppress the fire. Underground observations of seals that have been remotely installed during mine fire events show that they often do not fully achieve mine roof-to-floor and rib-to-rib closure. Unfortunately, the inability to reliably close the mine void has limited or precluded the regular use of this technology. The National Institute for Occupational Safety and Health is conducting full-scale underground experiments at the Lake Lynn Experimental Mine to identify and remedy existing remote sealing technology shortcomings, to develop novel technologies, and to transfer the new or improved technologies to the mining industry. This paper will discuss the remote mine seal testing program and will provide the results of the in-mine experiments. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

By C. D. McMaster, John C. Hartley

Three systems that monitor ventilating fans are described . These electronic monitoring systems automatically perform most of the operations required to conform with the provisions of the Federal Mine Safety Code in the event of fan failure or slowdown .

Jan 1, 1964

By Thomas M. Barczak, Ron Smith

Steel liner plates, which are bolted together to form a shell, are commonly used to provide temporary protective linings in the tunneling industry to ensure the stability of the tunnel and safety of the workers until more permanent ground reinforcement can be installed. As the ground deforms to try and close the opening, the liner plate is radially stressed, and by deforming redistributes these loads back to the surrounding insitu earth. Grouting behind the plates is done to fill any voids and ensure uniform contact to the strata around the back of the plates. Another function of the liner plate in some applications is to act as a platform or structure for the mining machine to react against in order to develop the necessary forward thrust to be able to excavate the face. In this case, the liner plates are loaded axially as a horizontal column of bolted liner plate rings, creating a jacking force against the liner plate assembly. In general, the buckling strength of the plate sections determines the jacking force capacity. Historically, the jacking force capacity of tunnel liner plates has been theoretically determined by some simplistic equations developed from tests of single liner plates. Recently, full-scale tests on a complete circular section of bolted liner plate ring segments have been conducted in the NIOSH Safety Structures Testing Laboratory using the unique Mine Roof Simulator to apply controlled loading in a manner that simulates the real world environment. Due to the unique size and capacity of the Mine Roof Simulator, these are believed to be the first full-scale tests conducted on the jacking force capability of tunnel liner plate rings. These tests indicate that the previously used theoretical equations tend to over predict the jacking force capacity of these tunnel liner plates. Unanticipated deformations in the field have been observed at loads below these theoretical design loads, therefore, a more accurate determination of the jacking force capability was needed. This report summarizes the full-scale test results, examines design parameters that impact the jacking force capability, and develops new mathematical models to improve the prediction of design loads.

By R. T. Artz

Disposal of sewage is an important part of mine sanitation. Improper... handling and.disposing of sewagerare conducive to the spread of disease and often add foul and nauseating odors to the mine air. The diseases spread by unsafe methods of disposing of waste in mines are typhoid fever, cholera, amebic dysentery, hookworm, and other intestinal diseases due to parasites. Sanitary toilet facilities, with a good sewage-disposal system, each maintained in good order at all times, should help to prevent the spread of diseases transmitted by intestinal body wastos. The metal and nonmetal-mining industries have recognized the impor-dma tance and need for disposing sewage properly; accordingly, facilities of some sort are installed and need today in most large mines. The coal-mining industry has given little thought to the disposal of sewage underground; however, in most mines of the anthracite industry, the inflow of large vol- unes of highly acid mine water and the extensive drainage system required to remove this water provide a natural means for disposing of sewage.

Dec 1, 1946