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By McMillan W. D.

Vermiculite is the name of a group of micaceous minerals characterized by their property of exfoliating when heated and thereby increasing many times their original volume. The resulting product has excellent heat-and sound-insulating properties, is used as a lightweight aggregate, and has numerous other industrial applications. Deposits of vermiculite occur in areas of pre-Cambrian rocks of the Llano uplift of central Texas, particularly in Burnet and Llano Counties. Because of the growing economic importance of vermiculite products, the Bureau of Mines undertook a detailed investigation of several deposits in Llano County. This investigation was completed in February 1947. The work comprised topographic surveys of five deposits, drilling with a 4-1/4 inch Parmanco power auger drill, and laboratory evaluation of samples. 342 drill holes, aggregating 4,905.5 feet, were completed, and 377 samples were taken. Laboratory evaluation of the vermiculite comprised expansion tests on both crude and beneficiated samples. The products obtained were compared with commercial-grade vermiculite from Montana.

Jan 1, 1949

By Irven A. Jacobson

This literature survey consists of references dealing with gaseous state thermal decomposition reactions of organic nitrogen and sulfur compounds. The reference source for the survey was the Chemical Abstracts from 1930 to 1956, inclusive. Original articles were not studied. The starting date was set at 1930 because previous to this time much of the work is questionable. This report is in three parts: Part I lists nitrogen compounds; Part II, sulfur compounds; and Part III, compounds containing both nitrogen and sulfur. The organization of the classes of compounds is alphabetical: Part I - amides, amines, amino acids, ammonia, azides, azines, azo compounds, heterocyclic nltrogen compounds, hydrazine, nitrates, nitriles, nitrites, nitro compounds and miscellaneous nitrogen compounds; Part II - disulfides, sulfides (including double and triple sulfides), thiols, thiophenes and xanthates; Part III - thioacid amides, thiazoles, thiocyanates and thiuram disulfides. A class formula is included with each class name. The R's used in these class formulas may refer to hydrogen or to the same or different radicals when more than one R appears.

Jan 1, 1960

By F. W. Smith

This paper is based largely on a study of experimental data obtained by the Bureau of Mines in its comprehensive 25-year survey of the carbonizing properties of American coals. Although the Bureau was interested in and conducted carbonization research-from time to time ever since it was organized in 1910 (1),4/ no systematic studies of the coke-, gas-, and byproduct-making properties of American coals were undertaken until 1927, when the American Gas Association appointed an advisory committee (2) to cooperate with the Bureau in developing equipment and techniques to obtain-data for the accurate assessment of the behavior of coals on carbonization. It was found, in general, that small-scale laboratory tests were unsuitable for the complete evaluation of the coking properties of coal; hence, larger pilot-plant-scale equipment was designed and used (3). It was decided that the scale of the test should be large enough to determine both the yield and quality of the products and yet small enough to maintain adequate control of the process variables (4). These considerations led to development of a carbonizing retort and furnace-of 80 to 200 pounds of coal capacity, suitable for operation at various temperatures up to 1,100° C. (2,0120 F.) and equipment for recovery and measurement of gas and byproducts. This apparatus and the standardized procedure for its operation became known as the Bureau of Mines-American Gas Association (EM-AGA) method or retort (5).

Jan 1, 1955

By David Schlain

This Bureau of Mines report describes a method for electrodepositing titanium diboride from a molten salt bath. Initially, the electrolyte is a mixture of LiBO2, NaB02, Na2 Ti03 , Li2Ti03, and Ti02? The cell is operated at 900° C in a dry, inert atmosphere with consumable anodes of titanium or hot-pressed titanium diboride (TiB2) powder. Agitation of the electrolyte is essential. Current densities may be 6 to 9 amperes per square decimeter (amp/dm2) with titanium anodes and 9 to 30 amp/dm2 with titanium diboride anodes. A current density of 6 amp/dm2 is equivalent to a plating rate of about 35 micrometers per hour. The adherence of the TiB2 deposit varies with the substrate material. It is most adherent on molybdenum and on 4130 steel that has been preplated with copper and nickel, less adherent on nickel, and still less adherent on Inconel and on 4130 steel without the preplate. Cathode and anode reactions are suggested.

Jan 1, 1976

By S. McGinn, G. Schnakenberg, D. Petrie, A. Bugarski, M. Grenier

As part of the Diesel Emissions Evaluation Program (DEEP) consortium, Noranda Inc. has undertaken a field project to evaluate the overall performance of the latest diesel particulate filter technology (DPF) at its Brunswick Mine in Bathurst, New Brunswick. Performance of the filtration systems is evaluated with respect to their ability to reduce tailpipe emissions and concentrations of diesel particulate matter (DPM) and noxious gases in mine air, efficiency of filter regeneration process, maintenance requirements, reliability, and acceptance. Four different particulate filter systems deployed on heavy production vehicles are subjected to an 18-month field evaluation. Over the evaluation period the vehicles will have accumulated approximately 4000 operating hours in production. This paper presents the results of testing conducted mid way through the 18-month field trials. The 400- meter section of the mine drift at 525-5 sub level, hereinafter referred to as the "isolated zone" was isolated between intake and exhaust fan systems and sealed with bulkheads against leakage. The isolated zone was ventilated at the rate required per CSA Standards and issued by CANMET for the engines tested. Four vehicles, two load-haul-dumps (LHDs) and two trucks, retrofitted with particulate filter systems were tested along with a new identical model LHD and truck equipped with exhaust systems consisting of a catalytic converter (DOC) and muffler. The test vehicles were operated individually inside the isolated zone for approximately 4 hours over simulated production duty cycles. Measurements of ambient concentrations of particulate matter, tailpipe emissions, and engine parameters were performed for each of the tested vehicles. The DPM samples for carbon were collected at the most up- stream end of the isolated zone, at the vehicle next to the operator, and at the most downstream or exhaust end of the isolated zone. The DPM samples were analyzed for total (organic and elemental) carbon using NIOSH Analytical Method 5040. Ambient concentrations of particulate matter at the exhaust end of the zone were also measured using Scanning Mobility Particle Sizer (SMPS), and real time PAH monitor (PAS 2000). Efficiency of the filters was also evaluated on a basis of tailpipe measurements performed using raw exhaust instruments the NanoMet and the UGAS. In addition, relevant engine parameters were obtained using Detroit Diesel Diagnostic Link (DDDL) and from exhaust backpressure and temperature measurements. Results from the tests proved conclusively that diesel particulate filters can significantly reduce the concentrations of air- borne DPM, but not without careful monitoring of both ambient and tailpipe emissions and not without careful attention with respect to maintaining the integrity of the DPF systems.

By Gordon E. Fletcher

This Bureau of Mines report outlines the atomic absorption analysis of oilfield brines for barium, calcium, copper, iron, lead lithium, magnesium, manganese, potassium, sodium, strontium, and zinc, using the method of additions. The advantages of using atomic absorption are discussed. The method of additions was chosen to overcome large matrix interferences usually found in brines; techniques of overcoming chemical, ionization, and background interferences are also described. The method was used to analyze several hundred oilfield brines and found to be rapid and reasonably accurate. A solvent extraction method was used to concentrate lead, copper, zinc, and iron in low-level samples.

Jan 1, 1974

By E. G. Noble

The effects of hydrogen chloride (HCI) concentration and temperature on the solubility and hydration state of the alkali chlorides LiCI, NaCI, and KCI and the alkaline-earth chlorides, MgCI2, and CaCl2 were investigated by the Bureau of Mines. Saturated aqueous solutions of the chlorides were sparged with HCI gas at temperatures of 20°, 40°, and 60° C. Increased HCI concentration caused decreased salt solubility be-cause of the common ion effect. Aqueous solubilities for the chlorides of Ca, Li, Mg, K, and Na ranged from 42.6, 45.2, 35.2, 25.5, and 26.1 pct, respectively, at 20° C to 56.9, 49.4, 37.6, 31.0, and 27.0 pct, re-spectively, at 60° C. In solutions sparged to HCI saturation, solubili-ties for these chlorides ranged from 22.4, 26.5, 3.0, 1.3, and 0.05 pct, respectively, at 20° C to 53.2, 48.8, 28.3, 2.6, and 0.8 pct, respec-tively, at 60° C. The solubilities of LiCI and CaCl2 in HCI solution were high because HCI solubility is low in these solutions. The chlo-ride salts of Ca, Li, and Mg formed hydrates, which depended on tempera-ture and HCI concentration. Monohydrates for LiCI, tetrahydrates and hexahydrates for MgCI2, and dihydrates, tetrahydrates, and hexahydrates for CaCl2 were obtained.

Jan 1, 1985

By C. E. Coleman, Joseph D. Davis

During some distillation experiments conducted by the Bureau of Mines in cooperation with the Trent Process Corporation it was observed that amalgams of heavy petroleum oils and finely pulverized coal tended to produce a denser coke than that obtainable from the coal when retorted alone . Even anthracite coal when retorted with oil yielded a coke . This led the writers to believe that by mixing a lowrank coal ( sub-bituminous or even lignite ) - with asphaltic oil and retorting it, a coke suitable for domestic fuel could be made . Thus there was contemplated the production of domestic coke and the utilization of a low- grade oil in one operation . - In order to decide on the practicability of this process , it was necessary to know the value of products obtainable by such a method , as compared with those obtained by separate distillation . A laboratory method was therefore devised , and while it was realized that no small - scale testing apparatus for destructive distillation gives results that are directly applicable to commercial - scale operations , by keeping distillation conditions uniform for comparative tests , results were obtained valuable for purposes of comparison . The plan was to distill mixtures of coal and oil in a laboratory retort , and then distill the constituents separately under the same conditions . The comparative quantities of products yielded were thus directly obtained , and their quality was determined by analysis . The following are the main points investigated : ( 1 ) Quantity and quality of coke ; ( 2 ) Quantity of oils boiling below 221 °C . ( gasoline stock) and oils boiling at 221 to 300° C . ( kerosene stock) ; and ( 3) Quantity and quality of gases .

Jan 1, 1922

By Oliver Bowles

"Score of the Bureau's Investigations.There has been outlined in a previous report* the results obtained regarding the adaptability of pulverized waste slate as a filler in road asphalt mixtures. As pointed out in that report the percentage of waste at slate quarries is very high, and the Bureau of Mines has undertaken the problem of discovering new and enlarged outlets for the waste material.Many products such as paper, rubber, road asphalt, floor coverings, paints, etc., require as one of their important constituents a considerable percentage of finely pulverized inert mineral matter to give ""body"", to obtain the desired consistency, or to supply the necessary wearing or other qualities demanded. Such materials are known as ""fillers"". The possibility that slate flour might be used as a filler with advantage in several products other than road asphalt led the Bureau to undertake further investigation.The Importance of Discovering Advantageous UsesIt has been found that in some products slate may be substituted for materials now in use without any marked effect on the quality of the products. A wider use of slate in such products could result only from a definite price advantage as compared with other fillers. Mile it is probable that waste slate may be placed on the market at prices which will encourage its wider use, it is evident that a waste slate utilization industry can never attain sufficient magnitude to definitely assist the slate producers unless it is demonstrated that some definite advantage in quality may be gained when slate is substituted for fillers now in use. The main purpose kept in view throughout the inquiry has been, therefore, to find advantageous uses for waste slate in order that both producer and consumer may be benefited."

Sep 1, 1921

By Carl F. Wingquist

In support of Bureau of Mines studies of thermal fragmentation of rock, the elastic moduli of four types of rock were measured at temperatures ranging from room temperature up to 1,500° F (1,089° K). The sonic method was employed to determine the resonant frequencies of the rock specimens and from these frequencies, the elastic moduli were calculated. Data for Young's modulus, shear modulus, and Poisson's ratio are given as a function of temperature for Dresser basalt, Reserve taconite, Jasper quartzite, and Charcoal granite. Young's modulus and the shear modulus decreased with increasing temperature up to about 1,200° F and then became relatively insensitive to temperatures from 1,200° to 1,500° F.

Jan 1, 1969

By Claude W. Sill

In the usual volumetric determination of uranium, the solution containing uranium is reduced in a Jones reductor, yielding a mixture of trivalent and tetravalent uranium; the trivalent uranium is oxidized to the tetravalent state by bubbling a stream of air through the solution. The resulting solution of. Tetravalent uranium is titrated with a standard oxidant, generally sulfatoceric acid, dichromate, or permanganate; It seemed likely that the, same general procedure could be used in determining semimicro quantities of uranium if the conditions affecting the variables involved were understood more clearly than at present. In the method described below, the use of ferric sulfate to oxidize tetravalent uranium allows the titration to be made at room temperature in an essentially colorless solution with sulfatoceric acid. The latter oxidant its turn permits the use of the very stable indicator, ferroin, with its sharp color.., change and exactly reproducible blanks. Solutions of uranyl sulfate were prepared by diluting a stock solution that had been standardized gravimetrically according to the method of Lundell and Knowles (8).3/ Solutions of sulfatoceric acid were prepared according to the directions of G. F. Smith (12) and were standardized against arsenic trioxide in the presence of osmic acid according to the directions of Gleu. The cerium solutions were stored in 18-liter carboys fitted with siphon arrangements so that the bottles did not need to be opened and protected from light in a dark cupboard. Under these conditions, even the 0.01 N solution changed by less than 1 part per thousand over a period of about 6 months.

Jan 1, 1952

By J. G. Donaldson

Binary alloys of molybdenum and tungsten were prepared by the Bureau of Mines in laboratory-scale experiments by hydrogen reduction of their vaporized hexafluorides. Near-optimum deposition parameters were determined, and the nature of the deposited alloys was investigated. Dense, homogeneous alloys were codeposited between 650° and 750° C with a reduction efficiency of more than 75 percent. The alloy composition was uniform when the hydrogen ratio in the gas feed mixture did not exceed 3 times the stoichiometric requirement. Regulating the proportions of the metal hexafluorides in the gas feed provided a large degree of control over the composition of the deposit. Hardness of the deposits varied directly with the proportion of excess hydro,,,, in the gas feed and with the weight-percent of tungsten in the alloy. Hardness was not affected by deposition temperature over the range 650° to 750° C for specimens of similar composition. Extreme brittleness and unsuitable physical shapes of the alloys prevented tensile strength measurements.

Jan 1, 1966

By J. K. Whyatt

Researchers at the U.S. Bureau of Mines have been exploring recent advances in the use of strain-softening constitutive laws that approximate shear fracturing. The purpose of these tests is to investigate shear-fracture-related rock bursts in hard-rock mines. The capabilities and remaining problems in the use of strain-softening laws in finite-element, distinct-element, and finite-difference methods are reviewed. Performance of the finite-difference implementation of strain softening is compared to classic experimental results and observations of rock mass behavior in the Coeur d'Alene Mining District of northern Idaho. The results show promise for developing methods to identify the general location and orientation of shear fractures and their sequence of occurrence, but such methods cannot be relied upon to quantify post-fracture loads or displacements accurately. Uncertainty over the amount of energy consumed by failing rock and the dependency of energy consumption on model mesh definition prevent direct application of the results to analyses of rock bursts.

Jan 1, 2010

By O. C. Blade

A comparison of certain properties of the commercial aviation gasolines produced in the United States during October 1949, 1950, and 1951 is presented in table 1, the 1951 data being average values from tables 3 through 6 of the present report. Trends in the average values of certain characteristics of these fuels may be seen in figures 1 through 4 which also indicate the minimum and maximum values. As may be observed, with the exception of changes in kinematic viscosities, the properties of commercial aviation gasolines have not varied greatly during recent years. A list of aviation-gasoline survey reports published by the Bureau of Mines is given on page 6. A summary of the average values of the properties on jet fuels is shown in table 2.

Jan 1, 1952

By D. L. Nussear, W. E. Wallace, N. N. Clark, M. Gautam, G. Hong-Guang

"Results from a study directed towards identifying and measuring the mutagenicity of diesel exhaust particulate matter involved in mining exposures, especially those which may synergistically affect genotoxic hazard, are presented in this paper. Particulate matter emissions from a diesel engine, representative of the ones found in underground mines, were sampled and assayed to determine the genotoxic potential as a function of engine operating conditions. Diesel exhaust was diluted in a multi-tube mini-dilution tunnel and the particulate matter was collected on 70 mm fluorocarbon coated glass fiber filters as well as on 8"" x 10"" hi-volume filters. A six mode steady state duty cycle was used to relate engine operating conditions to the mutagenicity potential.Protocols developed for using a primary component of pulmonary surfactant as a medium for collecting and applying respirable particulate material to cells for mutagenicity testing offer a true representation of in-vivo delivery of such respired aerosols to pulmonary cells and the genetic material within . The surfactant dispersion technique is discussed in this paper. Methods have been developed to sample and assay the diesel soot and diesel soot/mineral dust complexes which would not compromise the surface and physical properties of the particulate material."

Nov 1, 1995

By E. P. Youngman

The rapidly growing demand for titanium pigments has aroused new interest in actual and potential sources of supply of titanium- bearing ores , which only a comparatively few years ago were almost unmarketable . This paper , which supplements a general circular entitled " Titanium" ( Information Circular 6365 ) , represents a summary of current trade literature and Government reports , together with some hitherto unpublished material that has accumulated in the files of the Bureau of Mines . The purpose of this pamphlet is simply to indicate the commercial possibilities of the deposits , and the discussion is confined almost entirely to the three commercial ores , ilmenite , rutile , and magnetite ( titaniferous iron ore ) .

Oct 1, 1930

By Martin J. Gavin

During the recent study of lubricating oils carried on in the San Francisco laboratory of the United States Bureau of Mines, it became desirable to distill the oils used in the experimental work at pressures as low as 10 millimeters (mercury column) absolute. In the effort to Overcome difficulties and eliminate sources of error, certain changes were made in the apparatus for vacuum distillation used by the Bureau of Mines for crude petroleum.4 These changes were described in R.I. 2819, issued in July, 1927. Subsequent to the publication of R.I. 2819 several other changes have been made, and the present form of the apparatus for vacuum distillation of lubricating oils is described in this revision of R.I. 2819. These changes were found to give more accurate checks on duplicate distillations. The major part of the credit for the laboratory work which developed the changes in the apparatus and method revised herein is due to Boyd Guthrie, assistant petroleum chemist, and R. V. Higgins, junior chemist, o the San Francisco laboratory, United States Bureau of Mines. DESCRIPTION OF APPARATUS The distilling flask employed is essentially the Hempel flask as used by the United States Bureau of Mines for the analytical distillation of petroleum.5 he complete apparatus is shown in Figure 1. The fractionating column and exposed portion of the flask is wrapped with 4 inch asbestos rope and then surrounded by a cylindrical hood of 1/8 inch pliable asbestos sheet with a narrow air space between the wrapping and the cylindrical hood. This was found necessary to prevent any radiation or convection heat losses from the column, and resulted in obtaining a more even and constant fractionation by eliminating any dephlegmating action caused by temperature changes around the column.

Jan 1, 1930

By J. M. Stuve

Thermodynamic properties were determined by the Bureau of Mines for the intermetallic compound, TiA13. Heat capacities were obtained from 5 to 303 K by adiabatic calorimetry. The derived value of S2 1s is 22.08±0.07 cal/deg¬mole. Enthalpies relative to 298 K were obtained from 298 to 1,413 K by copper-block drop calorimetry. No anomalous thermal behavior was noted in the temperature ranges investigated. Low- and high-temperature data were combined with a known enthalpy of formation at 298 K to give values of enthalpy of formation and Gibbs energy formation, 0 to 1,400 K.

Jan 1, 1974

By A. B. Whitehead

A spectrographic method for the determination of 18 impurities in cerium is presented. The carrier distillation technique is utilized to separate the spectra of impurities from the complex spectrum of cerium. Metal samples are ignited to the oxide, mixed with silver chloride carrier containing an internal standard, and excited with a 20-ampere direct-current arc. An additional exposure, made after carrier depletion, provides for the determination of refractory elements. Experiments to determine the best carrier, sample-carrier ratio, electrodes, arc current, exposure conditions, internal standards, and any matrix effect are described. The relative standard deviation of the method at the 20- and 200-part-per-million levels is about 25 and 15 percent, respectively. The average relative error is about 20 percent in the 10- to 1,000-part-per-million concentration range.

Jan 1, 1962

By M. J. Ferrante

Enthalpy and entropy increments above 298.15° K were determined for cop-per sulfate between 298° and 1,000° K and for copper oxysulfate between 2980 and 1,146° K by the method of copper-block drop calorimetry. Enthalpies, entropies, and heat capacities are tabulated for both compounds. In addition, free-energy functions are tabulated for the sulfate. Equations representing the enthalpies are given for each compound.

Jan 1, 1972