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By T. T. Campbell

This investigation was undertaken by the Bureau of Mines to determine if high-purity ductile molybdenum of uniform quality can be prepared by bomb reduction techniques. Molybdenum trioxide (Mo03) and mixtures of molybdenum dioxide (Mo02) and trioxide were reduced by magnesium in closed steel bomb reactors. Very high pressures in excess of 5,000 p.s.i. developed during magnesium reductions of Mo03. The addition of calcium oxide to the bomb charges caused a significant reduction in pressure. Reaction efficiencies higher than 95 percent were obtained during magnesium reductions of either Mo03 or mixtures of Mo02 and Mo03, but high pressures were encountered when the charges contained from 30 to 60 percent Mo02. Reaction efficiencies were usually low (less than 80 percent) when the bomb charges contained more than 40 percent Mo02. The charges with the best composition considering operating pressure, yield, and purity contained from 10 to 30 percent Mo02. The addition of small amounts of carbon to the reaction charges was helpful because some deoxidation occurred during the reduction and also during subsequent arc-melting of the regulus metal. The purity of the bomb-reduced, arc-cast molybdenum metal ranged from 99.2 to 99.8 percent and in some instances the metal contained as little as 5 parts per million oxygen.

Jan 1, 1962

By Michael Rieber

Commodity transportation by barge is possible on about 25,000 miles of navigable inland waterways in the contiguous 48 states. Barge operations are used chiefly for the movement of bulk raw materials ranging from farm products to iron ore, coal, and other bulky semi-finished as well as finished products such as steel, chemicals and petroleum [3,p.7-9]. The barge industry, unlike other transportation industries, is largely unregulated. This is because all liquid bulk commodities most dry bulk commodities transported by for-hire carriers and companies engaged in private transportation of their own commodities are exempted from Interstate Commerce Commission regulations. As a result, about 15 percent of the total ton-miles of barge traffic each year is under Interstate Commerce Commission regulation [13,p.14-25].

Jan 1, 1977

By Kent W. Hawley

An improved visibility system was developed for use on the large (100 ton+) haulage trucks typically operated in open pit and surface mines. The improved visibility system provides the truck driver' with a means of viewing hazardous situations that occur in the extensive blind areas adjacent to his true. The cost effective, reliable, visibility system consists of a closed-circuit television three unique fresnel viewers, and two improved mirrors. This report describes the visibility problems of Large trucks in the surface mining environment, shows the performance of existing mirrors, substantiates concept selection, and describes the prototype improved visibility system.

Jan 1, 1978

By Thomas O. Meyer

Laboratory test results are presented for the determination of elastic modulus made with the NX borehole jack. Determinations were made in massive pieces of aluminum so as to satisfy conditions of linear elasticity, homogeneity, and isotropy. Results indicate a large discrepancy (approximately 200 percent) betwen material modulus as determined by laboratory block-loading tests and that indicated by the jack under relatively ideal circumstances. Effects due to interface friction, finite block size, incomplete plate-bore contact, and other factors were examined and found not to be significant. Finite element results indicate that assumed loading conditions for the jack differ from those actually occurring, at least in materials of high elastic modulus (approximately 10 million psi), such as quartzite.

Jan 1, 1974

By Sidney Katell

Philippine laterite and serpentine ores can be utilized in an electric furnace operation to produce both a steel ingot and a ferronickel product. Figure 1 is a schematic interpretation of a plant in which laterite and serpentine ores are processed separately to obtain both ferronickel and steel as products. A relationship of estimated capital requirements and probable returns has been established in this study for a plant of this type. No attempt has been made to evaluate the risks involved in commercial operations. At such time that the project might be constructed and placed in operation, changes in the costs of material, labor, and power may materially affect the profitability aspects of this study. One of the uncertainties involved in the economic evaluation is the cost of mining, handling, and shipping the ores. It is on this basis that the cost of ore delivered at the plant is assumed to be variable at $3, $5, and $7 per net ton (dry basis). For all other costs a plant site at Iligan City, Philip-pine Islands, has been assumed in preparing the economic characteristics for a plant that will process 2,000 tons4/ of ore per day. Results of the study, for the 2,000-ton plant, with all monetary values expressed in terms of United States currency (Philippine peso valued at $0.50), are summarized as follows:

Jan 1, 1962

By Mandeep Singh

The smelting of lead ores has been carried out in southeast Missouri for centuries, and modern smelting practices have generated a variety of waste products. Lead blast furnace slag is one such product, which typically contains 10% zinc, 25% iron and 2% lead. This slag has often been stockpiled on the producing smelter site and accumulations have now reached several million tonnes. It is possible that in the near future these slags will be classified by the federal Environmental Protection Agency as hazardous, and therefore there is considerable interest in possible treatment processes to render the slags non-hazardous by removing the offending metallic elements. To ensure that the overall slag processing costs are kept to a minimum, it is imperative that lead and zinc be recovered in a form suitable for sale or further processing. There are two generic routes for processing blast furnace slags and they involve hydro-metallurgical or pyrometallurgical techniques. With hydrometallurgy, the slags would be leached directly and the metal values recovered from purified leach solution(s) by electrowinning. One problem with processes of this type is that the zinc and lead grades of the slags are low and the iron content is high, and thus the economics of metal production are often not favorable. For pyrometallurgical processing (1), it has been shown that the slags can be fumed to produce an oxide dust containing all the lead and zinc, and representing only a fraction of the weight of the initial slag. The oxide dust may then be processed hydrometallurgical to recover zinc and lead.

Jan 1, 1992

By Diane M. Doyle-Coombs

In late July 1985, air samples from a sealed portion of the Quinland coal mine in West Virginia showed the presence of carbon monoxide (CO). Mine Safety and Health Administration (MSHA) personnel concluded that a fire was burning behind the seals. Since an imminent danger existed, the mine operator was given a closure order. The gases behind the seals were monitored and almost 2 million ff of carbon dioxide (C02) gas was pumped into the sealed area to stabilize the environment. Sixteen days after the closure order was issued, MSHA allowed the mine to return to production. Approximately 1 yr later, mine management submitted a seal breaching request to MSHA in order to drive a set of entries to further develop the mine. The Bureau of Mines established a sampling strategy and monitored gases from behind the sealed area during the breaching operation until the atmosphere was safe. This report is an account of the seal breaching conducted by the mine, MSHA, and the Bureau. The logistics of this event, the sampling strategy, and the equations applied could be used by the mining industry in future breachings or mine recovery operations. Time to reenter the area was calculated by using the methane (CH4) concentrations sampled at the discharge of the seals. Tracer gas was used to verify the ventilation flows through the area.

Jan 1, 1988

By Terry R. Neumann

During 1983, U.S. Bureau of Mines personnel examined mines, prospects, and mineralized zones to evaluate the mineral resources and potential of the Funeral Mountains Wilderness Study Area (WSA), Inyo County, California. Eleven mineral properties and two mineralized zones were examined during this study. Of these, six are within the study area and seven adjacent. There are no active mines, in the WSA, nor is there evidence of past production from any claim within the study area. The WSA contains no identified mineral resources. However, occurrences of bentonite, zeolites, and strontium were found in the area. There is little likelihood for resource development of any occurrence in the WSA. The area, in the Basin and Range Physiographic Province, is dominated by a Paleozoic marine sequence. Segments of Tertiary continental fluviolacustrine sediments, including volcaniclastic rocks, abut and overlie the Paleozoic rocks in fault controlled basin areas. Significant concentrations of bentonitic clay and zeolites occur as alteration products in Tertiary tuffaceous sedimentary rocks. However, they are generally low-grade, thin, and discontinuous, precluding commercial development. Limestone, quartzite, and sand and gravel in the area are suitable for many types of construction uses, but similar deposits outside the WSA are closer to markets. No energy resources have been identified in the WSA.

Jan 1, 1984

By Kim B. Shedd

The U.S. Bureau of Mines Particulate Mineralogy Unit examined the habits of six zeolite minerals commonly occurring in domestic zeolite deposits. Mineral habit is of interest because current theory on the potential for sarcoma production in test animals emphasizes the size and shape of mineral particles, without regard to composition or structure. A scanning electron microscopic study revealed that, of these six minerals, only mordenite and erionite crystallized in acicular to fibrous habits, The fibrous varieties of these two minerals were characterized by size and shape on the transmission electron microscope, and their dimensions were compared with those of asbestos and amphibole cleavage fragments. When comminuted, these two minerals possess "fibrosity indices" similar to those of amphibole cleavage fragments. One sample, a rare woolly erionite, has uniform widths, large aspect ratios, and a "fibrosity index" similar to those of asbestos.

Jan 1, 1982

Electrical trailing cable used to power coal mining machinery is frequently damaged by tensile strain or crushing by mining machines running over the cable. A major problem is finding the exact location of a short or open in this cable so it may be repaired. A major problem is finding the exact location of a short or open in this cable so it may be repaired. FMC Corporation was awarded modification III to USBM Contract H0122011 to continue development and testing of cable fault locators, resulting in delivery of: 1. A prototype electrostatic/electromagnetic/ TDR transmitter and an electrostatic/electro-magnetic receiver sot that: o Locates cable faults by time domain reflectometry o Locates opens by detecting electrostatic signals o Locates shorts by electromagnetic coupling. 2. A prototype infrared detector and an infrared detector power supply that heats a shorted area by applying high current (at low voltage) and locating a short by infrared output. 3. Twelve production infrared detectors. 4. Detail drawings for all of the developed instruments.

Jan 1, 1973

By J. A. Holmes, EDWARD C. FRANKLIN, RALPH A. GOULD

The commission may be permitted to express its earnest hope that the litigation which comes to an end with the findings and recom- mendations herein set forth will be considered by both parties to the action as definitely and equitably decided. The commission trusts that its work will show the value of the commission form of settlement and that its work will serve as a prece- dent to be followed in disputes relative to technical subjects. If the work of the commission is productive of a tendency on the part of technical litigants to avoid the use of the courts for the settlement of disputes it will not have been done in vain. Such tendency will surely grow and ultimately such differences will be arbitrated by technically trained men without recourse to the courts of law. Appended to the report of the findings of the commission are to be found the detailed reports covering the several lines of inquiry and investigation carried on by the commission and upon which its findings are based, and also a detailed statement of the fiscal affairs of the commission. A word of explanation is necessary in regard to the fiscal statement. While each party to the litigation has agreed to bear one-half of the expense of the investigations of the commission, it will be noted that the Selby Smelting & Lead Co. is credited with $21,000, while Solano County is credited with but $6,000. In order that the investigations of the commission might go forward without interruption the Selby Smelting & Lead Co. has generously supplied funds at the times they were needed. This assistance has been

Jan 1, 1915

By J. P. Morris

The Bureau of Mines investigated the mechanics of fuming of iron-carbon melts during top-blowing with oxygen. Melts weighing 45 lb were prepared in an induction furnace and blown with oxygen by means of water-cooled lances. The rate of fuming was measured and correlated with the operating variables. The data showed that the primary cause of fuming was a boil at the bath surface in the impingement zone of the oxygen jet. Nucleation of the carbon monoxide bubbles producing the boil was apparently brought about by the precipitation of an oxide phase. The actual fuming mechanism involved partial oxidation and vaporization of bubble films and fine metal spray generated by the bursting of the bubbles. Bubbles that formed outside the impingement zone produced little fume. The distribution of trace elements between the metal and fume strongly indicated that the fume contained fine spray particles as well as particles that had condensed from vapor. The rate of fuming was found to be proportional to the carbon content of the metal) the concentration of oxygen in the jet) and the bath temperature) provided that a continuous boil occurred. In the absence of a boil) very little fume was produced.

Jan 1, 1967

By J. H. Nixon

A three phase program evaluated commercial proximity warning devices, developed and designed a microprocessor-based electrostatic field measurement instrument, and utilized this instrument to investigate the electro-static fields about power lines. The Phase I program consisted of test and evaluation of these commercially available proximity devices. The evaluation results were reported in the Phase I report entitlted "Evaluation of Proximity Warning Devices II dated 22 February 1980. The Phase II program resulted in the design and development of a microprocessor-based Distributed Sensor A.C. Electrometer which measures the electrostatic field present at 17 discrete locations along a crane boom. Operator control of the measurement system allows simultaneous electric field measurements from 17 probes, print out of the electric fields measured, and data archiving on magnetic tape for post measurement analysis. Under the Phase III program, electro-static fields around a crane boom were measured by the instrument at 17 high voltage power lines of various voltages and geometries. The electric field data was processed and plotted versus boom distance from the power line. Analysis of the electric field data indicate that the distances at which a single sensor alarm will activate, vary by a factory of 3 to 1. This is due primarily to variations in boom orientation. The results also indicate that in the case of multiple power lines, a single electrostatic field sensor cannot reliably be used to determine the distance from a power line.

Jan 1, 1982

By W. W. Adams, T. D. Lawrence

"The National Safety Competition conducted by the Bureau of Mines, United States Department of the Interior for the promotion of safety in mines and quarries, has just been closed for seventeenth consecutive year. Enrollment covered more plants than in any previous contest. Moreover, a larger volume of employment was represented than in the contests of previous years, and several new plants were enrolled for the first time. Six safety trophies are awarded annually in these competitions one to the leading plant in each of six groups. An anthracite, mine in Pennsylvania, a bituminous-coal mine in West Virginia, a metal mine in Tennessee, a nonmetal mine in Virginia an open-cut mine in Minnesota, and a quarry in Alabama won the 1941 trophies.To be eligible to win a trophy, a mine or quarry must have had at least least 25 men working under ground or in the pit for not loss than 100 days. The number of man-hours worked must total 30,000 or more. Mines or quarries having no accidents during the year are rated according to the number of man-hours worked. If there are no plants with accident-free records, the mines and quarries in each of the six groups are rated according to their accident-severity rates; the plant having, the lowest rate is declared the winner.The Sentinls of safety trophies presented to the winning mines and quarries in the six groups were donated by the Explosives Engineer magazine to promote safety in the mineral industry. They are held by the winning companies for 1 year or until won by other mines and quarries."

Jul 1, 1942

The inherently explosion-proof mine (EPM) concept is based upon the non-flammability of certain combustible-oxidant-inert gas mixtures, and the effect of partial pressure of gases on physiological reactions. In a properly controlled underground environment, gas explosions are impossible, men can do work, and relatively high concentrations of methane would be permitted. A systems analysis has been performed to examine the physiological, engineering, and economic feasibility of such a concept, and methods and equipment are recommended for maintaining an EPM atmosphere in a bituminous coal mine producing a nominal two million tons of clean coal per year. It is concluded that: engineering feasibility can be demonstrated using subsystems and components that can be designed and built within the present state-of-the-art, that economic feasibility is possible within approximately five years, and that physiological feasibility is sufficiently promising to warrant continued investigation.

Jan 1, 2012

By ROLLIN THOMAS CHAMBERLIN

The studies herein reported were begun as a part of researches undertaken by the United States Geologü;al Survey looking to the more effcient utilization of the coal in the United States through the reduction of waste in its extnidion, and were continued as part of further researches having regard to the conservation of the fuel resources of this country and to the lessening of injuries and fatalities in coal mining. Among other phases of the general problem to be studied were the origin of the gas whidi escapes into coal mines, its modes of occurrence in the coal and rock strata, and the conditions governing its outflow into the mines. The subject of relative danger from destructive explosions due to gas and coal dust in different mines belonging to different coal fields was to be one of the principal lines of investigation. But this work was barely under way when the series of unusually disastrous explosions in the Naomi, .Monongah, and Darr mines of Pennsylvania and West Virginia, in December, 1907, afforded an exceptional occasion to observe the behavior of explosions on a large scale. Because of the opportunities for study afforded by these terrific explosions, the inquiry originally planned was d ¡verted to the more specific investigation of the conditions in tl10SC mines, and the examinations have been directed toward finding those qualities of gas and dust which were concerned in these explosions. The following discussion, therefore, consists essentially of a report on that subject; but it is far from being exhaustive, and is to be regarded as a preliminary outline of investigations which are still in progress. The first of the three mine explosions mentioned occurred in the Naomi mine of the United Coal Company, near Bellevernon, Pa., on Sunday, December 1, at 7.40 p. m. All the men who were within the mine at the time, fortunately only 34, were killed. Less than a week later there occurred in mines Nos. fì and 8 of the Fairmont Coal Company at Monongah, W. Va., the most disastrous mine explosion yet recorded in the annals of American mining. The mines were comparatively new and well laid out. Mine No.8 had been in operation only about two years and was the pride of the Fairmont Coal Company. Mine No.6 was first opened ahout four years earlier. In order to make it possible, in case of emergency, for either mine to be ventilated by the ventilating system of the other, the two sets of workings were connected underground. The F face heading of mine K o. 6 led direetly into No.2 north heading of No.8 mine. On Friday, Dcccmber 6, at about 10.30 in the morning, an explosion of unusual violcnce swept completely through both mines, pursuing its course throughout the numerous ramifications and bursting out of the two pit mouths, located It miles apart, nearly simultaneously. The slope of mine No.6 was only slightly damaged, but at the mouth of No.8 the destruction was very great. The fan was wrecked, the engine house was demolished, and mine timbers were blown across Monongahela River: As nearly as can be determined, 361 men were killed in the two mines by the explosion. .While the inspection of the Monongah mines was still in progress, on Thursday morning, December 19, at about 11.20, a similar explosion wrecked the Darr mine of the Pittsburgh Coal Company ut Jacobs Creek, Pu.; 238 men lost their lives in this explosion, which in number of casualties is second only to the :Monongah disustcr in the history of American mining. Of ull thc men in the mine at the , time of the explosion, only one mun, who happened to be within 100 feet of the ~iUrface on an old manway in a wet, unexploded portion of the mine, succeeded in escaping alive. The underground investigation of these mines was made in cooperation with Clarence Hall and ""Valter O. Snelling, of the United States Geological Survey, and James ""V. Paul, now of the Survey but at that time chief of the department of mines for vVest Virginia, to all of whom the author is greatly indebted for valuable assistance, suggestions, and advice. Mr. Paul will rcport on the nature of these explosions, the precipitating causes, their destructiveness, and the general cüliditions in these mines following the disasters. The present report is confined essentially to the laboratory examination of some of the explosive materials collected from these mines directly ufter the explosions.

Jan 1, 1911

By M. J. Ferrante

The preparation and subsequent reduction of vanadium trichloride was investigated as a process for the production of high-purity vanadium metal. Chlorine was reacted with vanadium oxide in the presence of carbon to vanadium tetrachloride. The contaminant vanadium oxytrichloride was also formed and later converted to tetrachloride by reaction with chlorine in the presence of activated charcoal. Vanadium tetrachloride was stirred continuously during thermal dissociation to vanadium trichloride powder from which volatile contaminants were removed by distillation. The vanadium trichloride powder was reduced to vanadium sponge by controlled feeding of the trichloride into molten magnesium. Excess reductant and byproduct salt were removed from the vanadium sponge by high-vacuum distillation. Batches as large as 6.5 kilograms of sponge metal were prepared at an average reaction efficiency of 98 percent. Vanadium sponge after consolidation by arc-melting contained 820 to 11330 ppm of interstitial impurities and had a hardness between Rockwell B 40 and 70, This metal exhibited excellent workability at room temperature. The purification of impure vanadium metal by electron-beam melting resulted in lowering interstitial impurities from 1,890 to 504 ppm and hardness from Rockwell B 87 to 28.

Jan 1, 1968

By T. A. Lang

The objective was to develop a Program Plan of analytical studies and tests for determining ( 1) the optimum installation tension of a coal mine roof bolt, (2) the most valid bolt support theory or theories, and ( 3) the most valid roof failure theory or theories. On this basis a comprehensive literature search was made and significant material dealing with coal mine roof behavior, roof bolting and roof support was collected, reviewed, classified and analyzed. Emphasis was given to the influence of rock reinforcement on the control of deformation, stress field modification and mine roof stability. An assessment was made of the effect of various parameters including bolt tension, bolt pattern and time of installation, on the effectiveness of rock reinforcement systems, and equations developed for bolt tension as a function of these parameters, and rock properties. From these studies, a major program plan of tests and studies was developed for verifying and validating the most tenable theories of roof behavior and roof support and for determining optimum bolt installation tension.

Jan 1, 1979

By Wilton Johnson

The development and use of minerals and mineral fuels are essential to national security and to the maintenance of an expanding economy. As a Nation, we often met these needs but failed to recognize and assess the impact that mining and mineral processing activities have on other natural resources. Currently, the growing demand for energy and minerals is accompanied by an increasing awareness that the provision of these resources must not conflict with society's demand for a clean and habit-able environment. Although present mining and mineral processing activities incorporate, or have under development, technology capable of minimizing environ-mental impacts on land, air, and water, many older operations, particularly in the first half of this century, lacked the technological, social, and environmental insights that exist today. Consequently, a substantial backlog of damaging and potentially damaging conditions remains from such problems as mine subsidence, acid water generation, burning and nonburning waste banks, abandoned surface-mined lands, abandoned underground mine fires, and abandoned mine shafts and oil and gas wells.

Jan 1, 1979

By Dick T. Atkinson

This report describes the Foster-Miller program that designed, developed, built and tested an automatic, remote control mine car coupler. This new coupler gives the motorman the capability to selectively couple and uncouple cars from the locomotive, to transmit braking intelligence to the coupled car s and to determine if the trip is intact. Hazards due to derailment and runaway cars will be reduced as the brakes are automatically applied in any uncoupled car. Laboratory tests described herein have been completed on the coupler set. Applications include, but are not limited to, the unit train system.

Jan 1, 1976