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By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Bolivia has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State. SYNOPSIS OF LAW All useful substances of the mineral Kingdom belong originally to the State. The soil and subsoil are regarded as two distinct parts, the latter extending indefinitely in depth (Art. 2). The subsoil is under the dominion of the State, which may either abandon it to common use, grant it gratuitously to the owner of the soil, or alienate it, in return for an annual fee, to any individual or association that applies for it. (Art. 1-3.)

Jan 1, 1929

By Stephen D. Cramer

A nondestructive procedure for measuring electrodeposit porosity has been developed which records the location and number of deposit defects including pores, pits, and voids. The procedure involves the passage of an X-ray beam through the deposit-substrate system onto suitable film. The defects are recorded as images on the film. Variables studied included intensity and spectra of the X-ray beam, composition and thickness of deposit and substrate, film type and developing procedure, and limits for detecting defects. At an X-ray tube voltage of 40 kv, pores several mils thick were easily detected in copper-nickel specimens more than 20 mils thick. To illustrate the utility of the procedure, the effect of substrate oxidation and of current density on electrodeposit porosity was briefly studied.

Jan 1, 1970

By Michael G. Zabetakis, Israel Liebman, Henry E. Perlee

Flammability studies conducted to date on stratified methane - air and pentane - air mixtures in air indicate that location and extent of a flammable layer are affected by molecular diffusion , gas motion , and propagation of flame . In initially quiescent mixtures , the lower limit - of - flammability zone may be determined by assuming molecular diffusion alone governs mixing rate . The upper limit - of - flammability zone can be predicted in this manner only for stratified layers with small concentration gradients ( less than 0.2 volumepercent per inch ) ; where large concentration gradients are encountered ( for example , as much as 30 volume - percent per inch ) , the initial - mixture methane concentrations that yield flammable mixtures are larger than anticipated . Flames propagating through heterogeneous quiescent methane - air atmospheres in the direction of the concentration gradient exhibit flame speeds at any point that corresponds to the flame speed of the homogeneous gas mixture having the same gas composition as that of the point in the heterogeneous system . In flowing mixtures with large concentration gradients , the degree of mixing prior to ignition does not appear to affect the flame velocity and emitted radiation appreciably in a 6.5 - ft - diameter gallery .

Jan 1, 1964

By R. V. Ramani, J. Qin

"During the mining process, the insitu material is broken into different size ranges, from very, large pieces to very fine particles. Some of the fine particles become airborne. In underground coal mining, airborne respirable. dust is associated with health and safety of the miners: The amount and size distributions of airborne dust are important parameters to effective dust control measures. The design of underground mine experiments, including sampling procedures and sample analyses methods to determine these parameters are presented in this paper.. A total of fifteen continuous miner cuts were sampled. The amount of dust generated during the cutting process and the relationship between total and respirable airborne dust concentrations and amounts are examined.The amount of respirable dust airborne is on the average only. 0.016% of the respirable dust generated. On the average, 61% of the total .airborne dust measured is in the respirable size range. The amount of respirable airborne' is on the average 36% of the respirable size fraction in the total airborne dust. For equal proportion of rock and coal material cut, rock contributes about twice as much fines (<0.22 mm) as coal. Additional fundamental research is necessary to further the understanding of 'the airborne propensity of respirable dusts in mine atmospheres.INTRODUCTIONMining is a sequential process of breaking, gathering, loading, and transporting the in-situ .materials.' In underground coal mines, duet in both the non-respirable and respirable size ranges is generated and entrained in every phase of the process. Even though large amounts of dust particles' adhere to run-of-mine coals, part of the dust generated becomes airborne (Cheng and Zukovich, 1973). Studies have shown that bit type affects the amount of dust generated'(Evans and Pomeroy, 1966; Kurth et al., 1975; Roepke et al., 1976; Stecklein et al., 1982; and Khair and 'Reddy, 1986). Deep cutting can reduce airborne dust generation (Black and Schmidt, 1977 arid, Black et 1978). Mechanical properties of. coal seams are also important factors in dust generation. Laboratory studies have shown that Hardgrove Grindability Index (HGI) of the coal has a relationship with the amount of respirable. dust generated (Beafi and Ramani, 1979; Moore and Bise, 1984; and Moore, 1986). However, these relationships have not yet been validated with' data from the mines. The amount of dust airborne depends on a number of factors. Suppression of the airborne propensity of dust by water sprays is'widely practiced and is very effective. Water flow rate; pressure and configuration of water sprays have been identified as major factors affecting dust capture by sprays (Courtney and Cheng, 1977; Courtney et al., 1978; and Kissell et al., 1979). Ventilation is a very important means of controlling the dust level at the coal face (Jayaraman, 1977). According to a National Academy of Sciences study (1980), the mechanism of dust generation and the process by which the generated dust becomes airborne are complex and not yet completely understood coal seams are also important factors in dust generation. Laboratory studies have shown that Hardgrove Grindability Index (HGI) of the coal has a relationship with the amount of respirable dust generated (Beafi and Ramani, 1979; Moore and Bise, 1984; and Moore, 1986). However, these relationships have not yet been validated with data from the mines. The amount of dust airborne depends on a number of factors. Suppression of the airborne propensity of dust by water sprays is widely practiced and is very effective. Water flow rate; pressure and configuration of water sprays have been identified as major factors affecting dust capture by sprays (Courtney and Cheng, 1977; Courtney et al., 1978; and Kissell et al., 1979). Ventilation is a very important means of controlling the dust level at the coal face (Jayaraman, 1977). According to a National Academy of Sciences study (1980), the mechanism"

Jan 1, 1989

By Steven J. Page

Accurate measurement of workplace respirable dust concentration is an essential step in eliminating lung disease in any occupational setting. In the United States (U.S.) coal mining industry, this measurement process has relied upon a personal sampler that includes a 10 mm Dorr-Oliver (DO) nylon cyclone operated at a flow rate of 2.0 L min-1 to collect a respirable dust sample. Dust concentrations measured with this sampler are multiplied by 1.38, which was empirically derived, to convert them to measurements approximating the United Kingdom British Medical Research Council (BMRC) definition of respirable dust upon which the health effects of coal mine dust are based. The International Organization for Standardization (ISO) subsequently refined the respirable dust definition and the U.S. National Institute for Occupational Safety and Health (NIOSH) 1995 Criteria for a Recommended Standard presented a conversion multiplier of 0.857 to apply to the 2.0 L min-&apos; DO (in addition to thel.38 multiplier) to obtain equivalent ISO concentrations, as approximated by the 1.7 L min-1 DO. However, the conversion multiplier 0.857 was derived indirectly from a limited size distribution data set rather than a direct comparison of the DO samplers. The present analysis focuses on providing a more accurate conversion multiplier derived from direct comparisons of the 2.0 L min-1 (with 1.38 BMRC equivalency multiplier) and 1.7 L min-1 DO cyclones. A weighted linear regression analysis of this database suggests that a more accurate estimate of the conversion multiplier is 0.815.

Jan 1, 2009

By J. J. Shields

This is the Seventh of a series of publications that describe methods and practices used in mining bituminous coal mechanically.3/ This report deals with the operation referred to in coal mining as continuous mining, and the interest shown by mining companies in this method is the reason for this study. Only continuous mining as it applies to the room-and-pillar system of mining, or a modification thereon, is discussed in detail in this report. Although not always as continuous as the name implies, it is a system of mining in which a machine is used to cut and load coal in one continuous operation without drilling and blasting the coal. With the mining equipment in most general use today, the usual cycle of operation in mining of coal is: (1) Timber, (2) cut, (3) drill, (4) blast, and (5) load. As the phases of this type cycle cannot be performed simultaneously in the same working place, it is necessary to operate from 3 to 7 working places so that at least 1 place is available for coal loading at all times. Even if the schedule of the phases in a cycle is maintained, coal production ceases during the time required to move the loading equipment from one loading place to the next. In 1920 a continuous-type mining machine4/ was installed in an Illinois coal mine to drive entries. Several other companies used these entry drivers for short periods in the following few years. In 1927 a southern Illinois coal company installed 2 of these machines which, in the next 25 years, were reported to have driven over 200 miles of entries. The machines did not attain widespread usage.

Jan 1, 1954

By Launa Mallett, Charles Vaught, Michael J. Bmick

Since 1991 the Pittsburgh Research Center (PRC formerly part of the U. S. Bureau of Mines) has been tapping u valuable resource-researchers have recorded extensive interviews will, 30 individuals who are recognized as experts in the area of mine emergency response. These veterans related stories and observations from events experienced during as many as 47 years of response activities. Overall, the response veterans averaged 29 years of mine emergency response experience and 35 years mining experience. Individuals [ ] interviewed included representatives from mining companies, the UMWA and state and federal government agencies. This information was gathered so dial it could he provided to today&apos;s miners and to tomorrow&apos;s emergency response personnel. It is hoped the collective wisdom that has been obtained can be used to help train new responders and guide those decisions which mill have to be made on the scenes of future events. During interviews file emergency response experts were asked to discuss lessons they had learned through experience. The interviewers asked them to tell what they had learned that would cause them to handle similar situations differently and to tell about things they saw at past events shat the would warn others not to do in the future. In response the experts discussed a variety of things. Most of their responses, however, touched on some of the same topics including: preparedness, experience people on-site mine rescue teams, and decision making. A summary of their responses provides alt overview of [lie lessons learned on-site at tile largest mine disasters in the country.

By J. C. Edwards

To have the capability to predict the development of localized spontaneous heating within a porous coalbed that is subjected to forced air ventilation or in an otherwise quiescent environment in which buoyancy develops, the Bureau of Mines developed three time-dependent mathematical models, which were used to calculate the temperature increase associated with chemisorption of oxygen by the coal. In each model, spontaneous heating is driven by an Arrhenius first-order reaction between the oxygen and coal. Two models are two-dimensional, and one is one-dimensional. In the first two-dimensional model, a constant-velocity forced convection airflow is specified; and in the other, buoyant flow is allowed to develop in the absence of forced convection. The third model evaluates the airflow from Darcy&apos;s law and a specification of the pressure at the surface of a one-dimensional porous coalbed. Numerical computations demonstrated how each model could be used to predict the onset of spontaneous heating when the porous coalbed was subjected to constraints of an imposed internal heat source or a high temperature airflow. The effects of particle size and coalbed compaction upon spontaneous heating were examined with the third model.

Jan 1, 1990

By G. A. Apell

Completion of 18 churn-drill holes totaling 2,218 feet and 3 diamond-drill holes aggregating 421.5 feet of drilling in the M.C. mine area, near Truman, Wis., provided information indicating the existence and trend of a zone of zinc mineralization extending for 1,000 feet west of the old M. C. shaft.

Jan 1, 1949

By Emory Smith

The preface of the United States Bureau of Mines Manual of First Aid Instruction contains the following paragraphs: One of the most important inquiries that Congress has authorized the Bureau of Mines to conduct relates to health condi- tions among those engaged in the mineral industries. Investigations made early with a view to bettering these conditions demonstrated the need of prompt care of injured miners, as, under the difficulties inherent to mining and other mineral industries; wounds seemingly unimportant, if not treated promptly, may become infected and possibly cause permanent crippling or even death of the porach. In the past many seriously injured persons have been treated by fellow workers ignorant of approved means of treatment and transportation and have been handled in such a manner as to cause suffering and to accentuate injuries to such a degree as to bring about permanent disablement. Accordingly, the need of general instruction in first aid became apparent. It must be recognized that the conditions in and about the mines, mills, smelters, quarries, oil fields, etc., usually present difficulties not found in large industrial centers where experienced surgeons are available and hospitals close at hand. Many mines are isolated and, when an accident occurs several miles underground, there may be a serious lapse of time before the injured person can be brought to the surface and taken to the hospital or given attention by a sur- geon who may have to come a long distance. Under such conditions it has been frequently demonstrated that, if effective first aid is not given, the injured person may die or become permanently crippled... First-aid instruction has been found to be an excellent aid3in pre- venting accidents. In addition to the immediate relief of injured persons, it has been found that most persons while in the act of practicing dressings for

Apr 1, 1931

By J. G. Croeni

The high thermal-neutron cross section of gadolinium and the good mechanical and corrosion properties of titanium suggest that alloys of these two metals might be useful as control rod material. To aid in establishing the feasibility of this combination, the Federal Bureau of Mines investigated the titanium-gadolinium system. The results indicate that the system is composed of a single eutectic reaction and a peritectoid reaction involving the alpha-beta transformation of titanium. The eutectic isotherm extends from 1 to 99 pct, gadolinium at 1,240° C. The established eutectic composition is about 95 pct, gadolinium. The peritectoid reaction occurs at 885° C. and extends almost over the entire composition range. Hardness increases slightly with additions of gadolinium, and little change is obtained by heat treatment. Alloys containing less than 10 pct. gadolinium are amenable to extensive cold-working, but alloys having higher percentage of gadolinium content are only moderately cold-workable. All alloys can be hot-worked in iron sheathing at 750° C. Observation indicates that all compositions possess good machinability. Corrosion resistance to water at room temperature is apparently poor, especially in the gadolinium-rich alloys. INTRODUCTION A combination of the good mechanical and corrosion properties of titanium and the variety of thermal-neutron cross sections characteristic of the rare-earth metals suggests that alloys of these metals may be used for control rod materials. For this reason the Bureau of Mines proposed a study of the titanium-gadolinium alloy system, and the Atomic Energy Commission sponsored the investigation.

Jan 1, 1961

By Potts J. D.

Installation of a horizontal air-blocking shelf around the inside perimeter of the surface mining drill deck shroud is proposed to improve dust capture. Without the use of this shelf, a strong Coand? effect airflow pattern results in dust leakage to the environment, especially at the shroud-to-ground interface. Bailing air exits the drill hole and travels along the drill steel to the underside of the table, where it fans out across the bottom of the drill table and continues down the sides of the shroud. This dust-laden bailing air then strikes the ground and fans out under gaps between the shroud and the ground. The proposed shelf prevents dust-laden air from striking the ground by redirecting it toward the center of the enclosure, where it can be captured. Laboratory tests demonstrated that the shelf reduced dust levels outside of the shroud by 81% under operating conditions consisting of a 1.9:1 collector-to-bailing-airflow ratio and a 51-mm (2-in.) gap between the shroud and ground. The shelf was 152-mm (6-in.) wide and was located at a height equal to 2/3 the distance measured from the bottom of the shroud to the bottom of the drill table. The air-blocking shelf was also capable of overcoming the adverse impact of vertical leakage along the shroud seams as long as this leakage was confined to an area below the horizontal plane defined by the shelf location.

Jan 1, 2008

By Wm. W. Odell

For a number of years there has been a very appreciable annual,, increase in the production and recovery of natural gas and natural-gas gasoline2 in the United States the latter product being used largely for blending with gasoline from petroleum in the production of motor fuel. On account of the increased amount of oil cracking in the production of gasoline and the accompanying increased percentage of low-boiling constituents in the resulting product, the specifications for the natural gasoline suitable for blending have been altered, that is, the amounts of propane and butane which it can contain have been limited. The result has been that large quantities of the latter materials are wasted because there has been no ready market for thorn in large quantities. Because of this wasteage and because it is probable that large quantities of there and similar materials will be produced in the near future us a result of the more general use of oil cracking processes, a study was made by the Bureau of Mines, under a cooperative agreement with the assistance of the Phillips Petroleum Company, of the suitability of these materials alone or in mixtures for use as gas enricher in the carburetion of water gas for city distribution. This investigation included: (a) A study of the properties of the low boiling members of the paraffin series including pentane with particular reference to their utilization as gases.

Jan 1, 1927

By Gary L. Hundley

As part of the U.S. Bureau of Mines program to reduce the Nation&apos;s reliance on foreign supplies for critical metals, a procedure was devised to separate and recover critical metals from mixed and contaminated super alloy scrap. The process uses both pyrometallurgical and hydrometallurgical methods to treat the scrap. The mixed scrap is converted to a matte containing 4 to 7 pct S by adding S directly to the molten metal. This matte is then granulated and ground to a minus 35-mesh particle size and leached with an HCI-CI2 solution. This process takes essentially all the Ni, Co, Cr, Fe, AI, and Mo into solution in a 3-h leach, leaving W, Ta, Ti, and Nb (Cb) in the residue. The Mo is recovered from the chloride leach solution by solvent extraction, and the Cr and Fe are recovered together by precipitation. The Ni and Co can be recovered individually by an existing solvent extraction-electrowinning process. The W is recovered by a caustic leach of oxidized Cl2 leach residue.

Jan 1, 2010

By H. O. Poppleton, F. E. Block

This investigation was made to develop a method of preparing high - purity thorium metal in quantities up to 20 kilograms per batch . Several methods for the preparation , purification , and reduction of thorium tetrachloride are discussed . Thorium tetrachloride was prepared by chlorination of decomposed thorium nitrate or oxalate with carbon tetrachloride or phosgene . tion of the crude tetrachloride was achieved by multiple distillations or by filtration of the molten chloride . It was found that high - purity thorium metal could be prepared by sodium reduction of thorium tetrachloride if chloride of sufficient purity were available . Byproduct salts and excess reductant were removed by vacuum distillation , and the resultant thorium metal sponge was consolidated by consumable - electrode or fixed - electrode arc melting . It was demonstrated that metal prepared by this method could be fabricated into bar , rod , or sheet , at room temperature .

Jan 1, 1964

By R. V. Ramani, R. Bhaskar

"An airborne dust cloud is an ensemble of particles of varied size, density, shape and states of aggregation. An understanding and quantifying of the dispersion and deposition of the du.st generated in mines is essential to the development of measures for reducing worker exposure to dust.In coal mining, the major portion of the dust is generated during the cutting of coal using a shearer or a continuous miner. The major phenomenon affecting ambient concentration is the deposition of dust. Panicle deposition may take place due to the effect of gravitational, inertial, electrostatic, and thermal forces, and mechanisms such as Brownian and eddy diffusion and inenial impaction. The three major mechanisms of deposition in turbulent flow in mines are diffusion (Brownian and eddy), sedimentation and inertial impaction. The mechanisms determining panicle deposition are size dependent.From a review of the literature, there appears to be a knowledge gap in the understanding of the deposition phenomena in mine airways. In order to obtain a better understanding of the deposition of dust for various particle sizes, and to develop a set of data for evaluating predictive mathematical models/or dust flow in mines, a series of dust-flow experiments was performed under controlled conditions in mine airways. It appears that the deposition data generally follow the theoretical behavior of dust based on the combined effect of diffusional and gravitational deposition. Jn this paper, the findings of the study on the deposition of dust in mine airways and its dependence on size, velocity and concentration are discussed. A set of deposition equations that could be used to determine the approximate deposition at various points in a mine airway are presented.IntroductionThe major factor affecting ambient dust concentration in mine airways is the deposition of dust. Particle deposition may take place due to the effect of gravitational, inenial, electrostatic, and thermal forces, and mechanisms such as Brownian diffusion, eddy diffusion and inertial impaction. The major mechanisms of deposition in turbulent flow in mines are diffusion (Brownian and eddy), sedimentation and inertial impaction. Inertial impaction is significant only during changes in direction, but the change in direction of flow with resultant powerful eddies may cause increased re-entrainment of the particles, thus having a compensating effect. While the literature in aerosol sciences contain several references on deposition, most studies were done in small diameter tubes for diffusional deposition (Liu and Agarwal, 1974). The deposition data from small diameter, short tube experiments may not be applicable to studying deposition in mine airways that have large areas and extend several hundred meters. Further, the change in concentration along the length of a mine airway may significantly affect the deposition an aspect that may not be easily determined in short tubes in laboratory experiments."

Mar 1, 1992

By Phillip R. Moyle

A basic precept in mineral exploration is that the best places to prospect are where minerals have already been found. The California desert has many old mining districts once thought to be "played out" that are currently producing more mineral wealth than at any time in the past. Because no "crystal ball" exists that will enable us to predict the Nation&apos;s future mineral needs, land management plans must be flexible enough to respond to these often unforeseen needs. MANAGEMENT ISSUES The California Desert Conservation Area (CDCA) (figure 1) encompasses 25 minion acres, nearly one-quarter of the total area of California. Passage of the Federal Land Policy and Management Act of 1976 (FLPMA) launched an intensive program by the Bureau of Land Management (BLM) to study this vast area. Painstaking scientific investigations were made of wildlife and plant populations, soil, air, and mineral resources, range use, and wilderness characteristics, among other environmental concerns.

Jan 1, 1992

By A. P. Grossman

&apos;This report was prepared by Shell Oil Company, Mining Ventures Department in accordance with Cooperative Agreement No. 14-09-0070-b53 dated September 10, 1976, between the United States of America, Department of the Interior, Bureau of Mines and C(b) Shale Oil I Project, Ashland Oil Inc., Shell Oil Company, Operator. After completion of this report the Shell Oil Company withdrew from participation In the C(b) Shale Oil Project and advised the Bureau of Minus that plans for publication of this report had also been withdrawn. The Bureau of Mines acting under terms of the Cooperative Agreement hereby releases this report for general information.

Jan 1, 1976

By August J. Kwitowski

The U.S. Bureau of Mines developed and tested a teleoperating system to control a new highwall mining system. A remote operator was provided out-of-sight sensory information and control of coal extraction and haulage equipment. Surface and production testing proved that the teleoperating system supplied the operator with sufficient sensory information to operate the mining system. Details on the teleoperating system provided in this report include (1) sensor selection, (2) a description of the electronic control system, (3) equipment selection and modifications, (4) the positive test results, and (5) recommendations for system improvements.

Jan 1, 2010

By B. T. McClure

Oxidizing catalytic converters are sometimes used by underground mine operators as an emission control device to reduce odor, hydrocarbon (HC), and carbon monoxide (CO) emissions from diesel equipment. The objectives of this report are to quantitatively assess the effects of catalytic converters on diesel exhaust emissions and to make recommendations for their use. Information in this report is from a literature survey and contract research supported by the Bureau of Mines. Catalytic converters are effective in reducing CO, HC, and odors when the exhaust temperature is high enough so that the converter remains above 250° C. Converter temperature is dependent upon engine duty cycle. Catalytic converters increse sulfate emissions and slightly in- crease oxides of nitrogen (NOx) emissions. If low sulfur fuels are not used, the increase in sulfate and nitrogen dioxide (NO2) emissions can offset any advantages of the catalytic converter as measured by the emissions quality index (EQI). In addition, in vitro bioassays have shown that catalytic converters produce soluble organic compounds, which have increased mutagenic activity with respect to untreated exhaust. Based upon criteria recommended by a joint Canadian-United States research panel, catalytic converters should only be used in special circumstances in underground mines. Vehicles equipped with catalytic converters should operate under moderate to heavy load conditions, and use fuel with a sulfur content less than 0.1 pct.

Jan 1, 1988