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By F. P. Miknis

Previous studies at the Bureau of Mines have shown that broad-line nuclear magnetic resonance (NMR) techniques have potential applications for rapid evaluation of oil-shale deposits. In a continuation of this study the techniques of pulsed NMR have been applied in a similar manner. The basis for the pulsed NMR oil-shale assay method lies in the assumption that the free induction decay (FID) amplitude following a 90° pulse is proportional to the potential oil yield. This assumption was tested on two groups of oil-shale samples, numbering 141 and 263 samples, from two different oil-shale cores. For both groups of samples a small number were selected as calibration samples. Free induction decay amplitude measurements were made on the 141 and 263 samples. The best least-squares regression line was obtained for the calibration samples, and the oil yields of the remaining samples were calculated using the slopes and intercepts obtained in the regression analyses. The agreement between measured and calculated oil yields was good, the indexes of determination being 0.93 and 0.89 for the groups of 141 and 263 samples, respectively.

Jan 1, 1974

By G. L. Cook

The design of a dual-inlet system for a Consolidated model 21-103C mass spectrometer is described in detail. The system permits both high-mass and low-mass samples to be run by using a single instrument. The difficulties of using a single instrument for both purposes are given and a method of minimizing these difficulties through the use of the present design is discussed, After examining the experience of five years of use, the conclusions are that the bimodal operation is practical and the low-mass analyses had nearly the same precision as before the modifications to the instrument were made. In 1951, O'Neal and Wier.5/ published the first description of the modifications made to a mass spectrometer so that the spectra of hydrocarbons with molecular weights up to 600 could be obtained. Further discussion of the equipment of O'Neal appeared in 1953.6/ Also, Brown, Melpolder, and Young7/ described a parallel inlet system designed to reduce sorption effects at room temperature.

Jan 1, 1960

By R. V. Mrazek

The heat of formation of vanadium trichloride was determined at 298.15° K. Measurements were made in a solution calorimeter in which an aqueous hydrochloric acid-potassium dichromate solvent was employed. Data are presented for the heats of solution of vanadium trichloride and the vanadium trioxide "backup" compound, and for appropriate dilution reactions needed to preserve stoichiometry. The resulting heat of formation of vanadium trichioride (VCI3) at 298.15° K was found to be ?H°298.15° K = -138.89 ±0.37 kcal/g mole.

Jan 1, 1968

By D. A. Reynolds, L. P. Rockenbach

"The method of analyzing light oil for benzene is fully described by Fieldner and others 4/ and Kester and Kolmes 5/. In this procedure, benzene is determined by shaking 20 cc. of the 79º to 81º C. boiling point cut from the fractionation of the refined light oil with 3 volumes of 98—percent sulfuric acid in an A. S. T. M. separator funnel of the type used for determining water in bitumi¬nous materials. After the mixture has been shaken 5 minutes it is allowed to settle at least half an hour and the acid is drawn off; the residual oil is reported as paraffins and the decrease in volume as benzene. The method has been found satisfactory for light oils from coals carbonized at 5000, 600°, and 7000 C. but does not give accurate, reproducible results for oils from the 800° C. tests.The content of benzene of the 790 to 81° C. cut is high, 90 to 95 percent, for 800° C. light oils, whereas for lower—temperature light oils it is considerably less. Benzene is the most difficult of the aromatics to sulfonate, hence the acid concentration must be maintained above 95 percent to insure complete sulfonation. Sulfuric acid (98 percent) reacts with benzene, but its reaction with paraffins at ordinary temperatures is negligible; however, more concentrated acid will attack paraffins and give erroneous yields of benzene. The reaction between benzene and sulfuric acid forms water that will dilute the acid. The effect of this dilution may be overcome by increasing the acid-to-oil ratio or increasing the strength of the acid. The latter, however, must not be used, because the stronger acid reacts with paraffins."

Mar 1, 1942

By Gerald R. Smith

Because of continuing concerns regarding the effects of cumulative quantities of materials in the environment, the Bureau of Mines has initiated a series of studies to evaluate, to the fullest extent possible, all aspects of the materials flow sequence fur selected commodities. Although tungsten and its compounds do not pose a significant health hazard to the environment, they do represent valuable resource materials to which appropriate conservation considerations must be given. The present study includes a description of recent trends in the consumption, loss, and recycling of tungsten-containing materials in the United States during the period 1974 to 1991 and an estimation of the cumulative loss of tungsten to the environment since 1910. Obsolete tungsten is recycled primarily as cemented tungsten carbide components that have been used in cutting and wear-resistant applications. The quantity recycled, as a of annual U.S. consumption of tungsten, was estimated to have increased from 10% in 1974 to 341a in 1991. An estimated 58% of the 148,000 metric tons of primary tungsten consumed since 1910 was lost to the environment through means such as dissipation, discard, and dilution.

Jan 1, 1994

By R. K. Koch

The vapor pressures of liquid columbium and liquid hafnium were deter-mined by the Langmuir free evaporation method as a part of the Bureau of Mines program on the study of transition metals. An electron-beam furnace with a water-cooled copper crucible was used for melting. Temperature was measured with a two-color ratio pyrometer. Least-squares analyses of the vapor pres-sure data gave the following equations: [Logp (atm) = 5 .429 -31,310 T] for liquid columbium in the range 2,740° - 3,140° K, and [Log p (atm) = 5,690 28 T] for liquid zirconium in the range 2,500° -2,810° K. Third-law evaluations of each data set gave mean heats of sublimation (298.15° K) of 175.1±3.2 kcal/mole and 148.3±1.2 kcal/mole for columbium and hafnium, respectively. Second-law standard heats of sublimation determined from sigma plots and from sigma-prime plots agreed fairly well with the third-law values. The sigma-prime plots gave standard entropies of sublimation of 30.96±0.84 eu and 33.S6±0.44 eu for columbium and hafnium, respectively.

Jan 1, 1968

By E. D. Gardner

This paper is one of a series on mining methods and costs being published by the United States Bureau of Mines. In April 19.74 the St. Joseph Lead Co., at Atlanta, Elmore County, Idaho, was mining and milling about 225 tons of gold ore daily with a total force of 150 men. The mine, which comprises the old Boise-Rochester and Monarch properties, is at an elevation of about 6,000 feet. Snow lies on the ground about 5 months each year but does net interfere greatly with local operations. However, the road to Mountain Home, the shipping point 80 miles distant, passes over a high range and usually is closed by snow from about November 15 to June 15. Heavy supplies are brought in and concentrates trucked out during the summer. In winter the district is served by a biweekly mail plane and a passenger and express plane making 4 to 6 trips weekly. Mine timber is cut locally. A plentiful supply of water is obtained from a stream brought to the property through 7,500 feet of plume.

Jan 1, 1935

The first phase of our work for PMSRC on this contract was devoted to a comprehensive and in-depth assessment of electromagnetic (EM) noise measurements and data taken by several contractors for use in the design of operational and emergency mine communications. Pertinent measurements and data of other selected investigators were also included in the evaluation. This assessment treated the measurements and instrumentation used, the data analysis and presentation methods, and the utility of the final results. This phase concluded with the identification of the most useful results and methods, the remaining data gaps, the contractor most qualified to fill these data gaps, and the definition (with PMSRC and this contractor - NBS, National Bureau of Standards) of a follow-on noise measurement program, instrumentation system, and data processing methods tailored to obtain the necessary but missing noise data. A partial bibliography of references related to electromagnetic and seismic noise and propagation in the frequency bands of interest was also compiled during this first phase. The body of this Part of the final report presents a summary of the findings of our EM noise assessment, together with detailed recommendations regarding the new noise measurements to be taken and the instrumentation and data processing methods to be used. This work was done during the latter part of 1971 and the early part of 1972. During subsequent phases of the contract ADL was asked to perform on-going evaluations of the continuing program of electromagnetic (EM) noise and propagation measurements made by Bureau contractors, and to utilize pertinent data from these measurements to make performance estimates for

Jan 1, 1974

By Stephen D. Cramer

The solubility of methane, carbon dioxide, and oxygen was measured in brines at temperatures from 0° to 300° as part of Federal Bureau of Mines research on the corrosion of metals in high-temperature geothermal and mineral processing environments. Solubilities were measured by the technique of extracting pure gas, dissolved at pressures where Henry's law was applicable, from known volumes of brine. The results were smoothed with respect to temperature. The solubility, expressed in terms of the Henry's law constant, reaches a maximum at temperatures ranging from 60° to 100° C for methane and oxygen, and from 160° to 170° C for carbon dioxide. The Henry's law constant increases, that is, gases are salted out of the brines, in the presence of dissolved salts. Salting-out coefficients are strongly dependent upon temperature. The temperature dependence of the Henry's law constant for geothermal brines is different from that for sodium chloride brines owing to the more complex chemistry of the geothermal brines. The solubility of oxygen and carbon dioxide in brines exposed to air saturated with water vapor and at a total pressure of 760 mm Hg is reported for temperatures from 0° C to the normal boiling point.

Jan 1, 1982

This part of the final report treats some problems related to coal mine carrier frequency communication systems using the trolley wire/track transmission line. This work was undertaken for a brief period of time during the summer of 1972 to help understand, quantify, and improve some of the trolley wire carrier system behavior observed and/or predicted. Calculations and estimates of transmission line characteristic impedance, inductance and capacitance per unit length, mine motor loading effects, parallel line effects, and connection impedances are presented in Chapter I. Chapter II treats the design of r-f isolators for reducing the undesired and troublesome r-f loading that mine motors present to the trolley transmission line. Chapter III treats a diversity method for combatting standing wave nulls. I. CALCULATIONS RELATED TO TROLLEY WIRE COMMUNICATIONS A. ESTIMATION OF INDUCTANCE AND CAPACITANCE PER UNIT LENGTH OF TROLLEY LINES To estimate the L and C per unit length of trolley lines, we use the eccentric line model of Section G of this Chapter, "Characteristic Imped¬ance Estimates for Mine Trolley Lines." The capacitance per unit length for an eccentric line is given by (1)

Jan 1, 1974

By S. J. Page, W. R. Reed, J. A. Organiscak

NIOSH continues to conduct respirable dust control research for surface mine blasthole drilling operations. Research areas have included testing variables (shroud leakage area, drill deck cross-sectional area, shroud height, collector-to-bailing airflow ratio, etc.) that have the most impact on respirable dust control, development of a dust collector inlet hood, development of a dust collector dump point shroud, and testing of a small diameter water separating sub. This paper summarizes the results of the aforementioned research that has been completed. Additionally, past dust control research for drilling operations of both underground and surface mines completed by the U.S. Bureau of Mines, created in 1910 and incorporated into NIOSH in 1997, is reviewed.

By Dennis A. Long

Slip and fall accidents are a major cause of lost-time injuries associated with large mobile equipment in surface mines. An evaluation of the safety hazards associated with getting on and off large surface mining vehicles showed that most of the accidents occur at the point where personnel attempt to mount or dismount the machine at ground level. The major hazardous design conditions were identified as excessively flexible supports for lower steps or rungs, inappropriate ground-level-to-first-step distances, poor step designs, access designs that use vehicle components as steps or walkways, and inadequate hand- rail and guardrail designs, Additional hazards are introduced by the lack of proper maintenance of ladder hardware and the work practices of operators in carrying articles while mounting and dismounting the vehicle. This Bureau of Mines report describes the design and in-mine testing of improved access system for large mobile mining equipment.

Jan 1, 1984

By Charles A. Kumbe

"INTRODUCTION The Sullivan Mine was examined by Thomas L. Chapman, an engineer of the Bureau of Mines, in March 1943. Samples taken from the few mineralized exposures justified further investigation of the property. To determine whether extensive exploration of the property would be warranted, the Bureau did a small amount of trenching and underground work during April 1943, 3/ under Bureau project 1462.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its, primary objective the, more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratary project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurigical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests.The investigations of the and Metallurgical Branches of the Bureau, as reported in this paper, were supervised by J. Hedges, district engineer for Arizona, and S. R. Zimmerly, regional engineer for the Western Region, respectively."

Feb 1, 1947

By Charles L. Kimbell

Comprehensive data on market prices for crude minerals and mineral products for the world as a whole do not exist, and even the data that are available are not necessarily compatible between countries, particularly between the market economy countries and the centrally planned economy countries. Further, it should be evident that the actual delivered price for a small quantity of any specific commodity at some point substantially removed from a production facility or a seacoast port will differ appreciably from that for a large volume of the same product at or near its production source or a major import center. Nevertheless, the regularly published prices of selected major mineral commodities in key market areas can be regarded as indicative of general world price trends.

Jan 1, 1992

By Paul R. Amyotte, Omotayo Kalejaiye, Kenneth L. Cashdollar, Michael J. Pegg

The Siwek 20-L chamber is widely used throughout the world to evaluate the explosibility of dusts. This research evaluated the quality of dust dispersion in the Siwek 20-L chamber using Pittsburgh coal, Gilsonite, and purple K dusts. A Pittsburgh Research Laboratory (PRL) optical dust probe was used to measure optical transmittance through the dust cloud at various locations within the chamber. A total of 540 tests were performed, with triplicate tests at five nominal dust concentrations and six locations. The two standard dispersion nozzles (rebound and perforated annular nozzle) were compared. The transmissions corresponding to the normal ignition delay period were used to: (a) determine variations in spatial uniformity of dispersion obtained with both nozzles; (b) make comparisons between the experimental transmission data and those calculated from theory for the three dusts; and (c) make comparisons with transmission data measured in the PRI, 20-L and Fike 1 -m3 dust explosion chambers. The uniformity of dispersion for the three dusts was similar with both nozzles, despite the differences in nozzle geometry and mode of operation. Transmission data of the three dusts were all significantly lower than those calculated from theory. This was discovered to be, in part, due to significant reduction in particle size that occurred during dispersion. By measuring particle sizes before and after dispersion, values of 60%, 50%, and 20% reduction in particle size (based on the surface weighted mean diameter) were obtained for Pittsburgh coal, Gilsonite, and purple K, respectively. Transmission data from the PRL 20-L, Fike 1 -m3 and the Siwek 20-L chambers indicated comparable results in terms of uniformity of dispersion. However, transmission data from the Siwek 20-L chamber were significantly lower than those of the PRL and Fike chambers. Again, this was attributed, in part, to the significant reduction in particle size that occurred during dispersion in the Siwek chamber. The design of the outlet (dispersion) valve of the Siwek 20-L apparatus charge vessel was largely responsible for the particle break-up. The contribution to particle break-up by the dispersion nozzles and the high level of turbulence in the chamber were found to be minimal. This is a significant finding in that the dust particle size tested for explosibility in the Siwek chamber is considerably smaller than the original dust sample.

By McHenry Mosier

Diamond -drilling blast holes at Eastern Magnetite Mine C is proving economical in boundary shrinks , in removing pillars not readily accessible for percussion drilling , and in driving scraper drifts . The cost per foot drilled is greater than for percussion drilling , but savings in associated factors outweigh this handicap . The rocks drilled include trap rock and magnetite ore . The mining method is the panel , block- caving system utilizing scraper sublevel drifts instead of branch raises to convey the ore to the haulage level . Diamond -drilling blast holes was begun early in 1945. Three rigs equipped with noncoring bits are now in active operation two shifts per day . They are owned by the company , and the drill operators are paid by the day . In shrinkage stopes the drill is mounted on a horizontal bar set against opposite walls of the stope . Stoping holes are horizontal , which gives better results in blasting and requires fewer set ups . In scraper drifts the drill is mounted on a horizontal bar clamped to two columns about feet apart . Trim holes around the periphery of the drift and reliever holes are drilled 50 to 80 feet in length . A 10 - foot wedge cut drilled with a stoper is blasted in conjunction with a corresponding length of the trim holes to effect a 10 -foot advance of the full- sized drift . Recent drilling averages 97 feet per machine shift , excluding time utilized in setting up and moving the machine , hand mucking , and barring down . The feet drilled per bit at present is 417. These data represent the average for drilling in both rock (waste) and ore . Percussion drilling utilizes three types of wet drills . Detachable bits are standard . Gage changes for new bits is 1/8 inch and for reconditioned bits 1/16 inch . The life of a bit is five uses . Resharpening is on contract . A drill carriage is used in haulage headings .

Feb 1, 1948

This chapter summarizes data on crude mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are tables that show the principal mineral commodities exported from and imported into the United States, and that compare world and U.S. mineral production. Except for the mineral fuel commodities, the detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume II of this edition of the Minerals Yearbook. In October 1977, responsibility for the collection of data on mineral fuels-coal, petroleum, natural gas, and natural gas liquids-was transferred to the newly created Department of Energy. Although chapters covering these commodities will no longer appear in Volume I of the Minerals Yearbook, quantity and value data have been included in most of these summary tables to maintain statistical consistency in State and national value of overall crude mineral output. This shift in responsibility has also resulted in changes to the composition of the "Nonmetals? and "Mineral Fuels" groups in table 1 and table 2. The commodities-asphalt and related bitumens (natural), carbon dioxide (natural), helium, and peat-have been removed from the ?Mineral Fuels" group, and are now included under the "Nonmetals" group. There has been no change in the components of the "Metals" group.

Jan 1, 1981

By Francis X. Cannaday

The Bureau of Mines developed equipment to measure the sonic velocity of pulses transmitted through rock samples varying in size from laboratory specimens to mine pillars in place. Pulses are produced by electronically excited piezoelectric ceramic transducers. Special equipment components were developed by Bureau facilities; other components are commercially available. The technique permits a nondestructive, repetitive, stable, shaped pulse to be used in place of explosive caps or hammer blows. Longitudinal wave travel time measurements were taken on an oscilloscope screen; transverse wave measurements were taken under special field conditions. Results were consistently repeatable within the accuracy of the oscilloscopes utilized.

Jan 1, 1966

By Jeffrey S. Walker

Abandoned underground mine openings are susceptible to collapse because of the mining methods used, the character of the overburden, and the typically large, wide entries with minimal roof support. The final effect of the collapse of the underground workings is surface subsidence. To reduce the probability of subsidence, methods to backfill the mine void with various types of materials have been developed. This U.S. Bureau of Mines report describes the available technologies for subsidence abatement and discusses their operation and application. The basis of these abatement methods is the replacement of the mined material with mine waste. Backfilling of mine voids is the most common method of stabilization used to abate subsidence and protect surface structures. Hydraulic flushing and grouting, using remote methods from single or multiple boreholes, are the most often-used methods for the placement of backfill material. Other subsidence abatement techniques are available and may be more appropriate under different conditions. These other techniques include pneumatic stowing, either by in-mine or remote methods, and various point support methods that do not completely fill the mine void and are used for the protection of small areas of the land surface and surface structures.

Jan 1, 1993

By W. M. Weigel

"The use of sand for the filtration of municipal water supplies is comparatively recent use in this country, although at the present time, most cities of any size that draw their water supply from surface sources use sand filters in their purification system. Not only are sand filters employed to remove sediment and suspended matter, but they also take out most of the bacteria in the water.The first comprehensive research and study of sand for this purpose was probably that of Hazen for the Massachusetts Board of Health in 1891 and 1892, although sand filters had been employed for a considerable time before, specifications for filter sand drawn since then have been largely based on the results of Hazen's work,The general requirements for filter sand are more exacting than for any of the different kinds of sands, except the chemical specifications for glass sand. Filter sand must be uniform in size and within certain limiting sizes. In addition, it must be clean and free from clay and organic matter and of fairly high purity. Early investigations established the fact that an excess of fine materiel increased the friction and decreased the rate of flow through the filter, and that the size of the finer particles rather than the courser, determined the effective size. Also, that large grains tended to cause irregularities in flow in different parts of the bed. There is no requirement as to grain shapes, except that they be not flat or elongated, since, so far as known, either rounded or angular grains are equally efficient.Based on Hazen's investigations, two factors are quite generally used to control the average size and uniformity of size of the sand. These are defined as follows: The ""effective size"" of a sand is such that 10 per cent by weight of the seed is finer than this size, end 90 per cent is coarser. It is expressed in millimeters, The ""uniformity coefficient"" is defined as the ratio of the size of grain which has 60 per cent finer than this size to the size which has 10 per cent finer (the ""effective size""). It is evident that the smaller this coefficient, the more uniform is the seed. If all the grains were exactly the same size, the coefficient would be 1."

Jul 1, 1924