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By T. L. Joseph

The size and accessibility of the Minnesota manganiferous iron ore deposits make them attractive as a potential source of ferromanganese, which is essential in the production of steel. For several years the Bureau of Mines has been conducting experiments to determine the feasibility of producing ferromanganese from these ores by a three-step process which involves (1) the smelting of the ores in the blast furnace to produce a high-phosphorus spiegel; (2) the treatment of the spiegel produced from step 1 in an electric or open-hearth furnace to separate the manganese from the phosphorus and the iron; and 3) the smelting of the high-manganese slag from step 2 to produce ferromanganese. The details of the first two steps of the process and the results of tests with the experimental furnaces have been given in previous reports.

Jan 1, 1931

By Robert L. Skaggs

Sixteen nonaqueous techniques conceived to replace the current aqueous scheme for separating hafnium and zirconium tetrachlorides were re- viewed and evaluated by the Bureau of Mines. The methods are divided into two classes: separation by fractional volatilization of the tetrachlorides, which takes advantage of the higher volatility of hafnium tetrachloride; and separation by chemical techniques, based on differences in chemical behavior of the two tetrachlorides. The criteria used to evaluate separation methods were temperature, pressure, separation factor per equilibrium stage, complexity, compatibility with existing technology, and potential for continuous operation. Three processes were selected as being most promising: (1) high-pressure distillation, (2) extractive distillation from a molten salt, and (3) preferential reduction of gaseous ZrC14. Any of the proposed nonaqueous Hf-Zr separation schemes must be supplemented with additional purification to remove trace impurities.

Jan 1, 1984

By E. G. King

Many of the existing thermodynamic values for the titanium halides are estimates, including all the entropies and high-temperature heat contents of their crystalline and liquid phases. This report contains the results of low-temperature heat capacity measurents (which lead to entropy values at 298.15° K,) and high-temperature heat-content measurements of four halides - trichloride, tribromide, tetrabromide, and tetraiodide. The new data are combined with selected heat-of-formation values at 298.15° K. to obtain improved values of the heats and free energies of formation of these halides at high temperatures, thus supplementing the previous data of Kelley and Mah.5/ ACKNOWLEDGEMENTS This investigation was conducted under a cooperative arrangement between the Federal Bureau of Mines and the Department of the Navy, Office of Naval Research. The work was done by Bureau of Mines personnel using Bureau of Mines calorimetric equipment. The Office-of Naval Research supplied the supporting funds and arranged for procuring the samples of the titanium halides. The samples were prepared and analyzed by the Inorganic Chemistry Section, Division of Chemistry, National Bureau of Standards.

Jan 1, 1961

By W. A. Young

Vermiculite deposits on the. Platt ranch, 12 miles southeast of Encampment Carbon County, Wyo., were investigated by the Bureau of Mines early in 1949. Major activity was centered on property held under lease by the Mikolite Mining & Development Co. (figs. 1 and 2). Vermiculite occurs in masses and lenses of varying size and as disseminations in altered hornblende diorite. Alteration of the host rock probably resulted from the proximity of dikes and irregular masses of pegmatite. Investigation of the Mikolite property consisted of surface trenching, diamond drilling, and sampling. Four trenches totaling 5,401 linear feet were excavated with a bulldozer and Diesel power shovel. Three diamond-drill holes totaling 600 feet were drilled from the surface to determine the character of mineralization at depth. Eighty-one bulk samples were obtained from the trenches, and 130 sludge samples were collected from the drill holes. Samples were analyzed, and ore-dressing tests were made in the Bureau of Mines laboratories at Salt Lake City.

Jan 1, 1952

By C. H. Schack, K. C. Dean

An investigation was made to devise and evaluate a flexible flotation method for beneficiating typical tactite types of calcareous scheelite - bearing ores ; these scheelite - bearing ores are available in large tonnages in deposits containing 0.2 to 0.3 pct tungsten trioxide . The objective was to achieve a high recovery of the tungsten in concentrates , containing a minimum of 10 pct WO3 , that would be suitable for chemical processing into high- quality synthetic scheelite . The principal problems encountered and resolved by bench- scale flotation tests on ore samples from five different deposits were to define the conditions and reagent combinations essential for ( 1 ) achieving selective flotation of a small amount of scheelite from a large amount of calcite and ( 2 ) controlling the effect of small amounts of calcium , magnesium , and iron salts in the ores and water used . The flotation process was evolved from batch tests and continuous runs in a pilot - scale mill with a capacity of 100 lb per hour . The flotation process comprised ( 1 ) removal of sulfide minerals , ( 2 ) conditioning the residual ore pulp with sodium carbonate , quebracho , and trisodium phosphate , and ( 3 ) rougher flotation and single - stage cleaning of a scheelite concentrate . In a pilot plant run , over 91 pct of the tungsten was recovered from ore containing 0.27 pct WO3 , in a concentrate containing 11.2 pct WO3 .

Jan 1, 1964

By D. N. Tallman

The Bureau of Mines has completed 4 yr of deep-bed filtration research comparing the efficiencies of granular magnesium oxide (MgO) and conventional filter sand in single- and dual-medium filters when filtering mineral-processing and mine waters. Bench and field evaluation tests were conducted using water types ranging from synthetic suspensions of asbestos, kaolin, metal hydroxides, and milled sand to process waters from magnetite beneficiation, iron ore flotation, granite cutting, and a steel mill. Even though the turbidity reductions were similiar, MgO filters were found to be advantageous when filtering water pretreated with alum because the volume throughput before breakthrough (turbidity > 1 NTU unit) was much more for the MgO filter than for the sand filter. Reduced head loss owing to the greater porosity of the MgO filter beds is potentially the most beneficial advantage in employing MgO as the filter medium, especially when filtering water pretreated with polymer flocculants. Granular MgO (periclase) is durable and can be backwashed Like sand. It is compatible with anthracite in a dual-medium filter and apparently is not poisoned by dissolved metals in the process water. No single solid-removal mechanism could be identified for the improved filtration observed with granular MgO.

Jan 1, 1987

By J. L. Wiley

[NOTE. - P before the number indicates that the ab tract appears in patent section. Abstract numbers without. P appear in literature section. A Abietic acid, hydrogenolysis - 404 Acetone, recovery - P-4024 Acetylacetonate catalyst - P-3352, P-3664, P-6067 Acetylene, production - P-2556, P-3169, P-4064, P-4221, P-4222, P-5002 Acid catalyst - P-4584 Salts - P-4555 See also Specific acid. Acid treatment. See Procedure. Adsorption. See Hydrogen, adsorption. Agitation. See Equipment, agitators; Procedure. Alcohols: Decomposition -1128 Hydrogenation - P-3288, P-4743 In motor fuel - 1486]

Jan 1, 1952

By Edward L. Wilson

A general computer program is given for the linear elastic static analysis of complex structural systems. These elements have special advantages for the analysis of massive underground structures such as mine structures and above ground structures such as arch dams. New finite elements are developed which are useful in the analysis of two and three dimensional solids. Examples are given which illustrate the accuracy of the elements. A description on the use of the program and a FORTRAN IV listing are given in the Appendices.

Jan 1, 1971

By Ronald S. Conti

The Bureau of Mines conducted a comprehensive laboratory study of the thermal ignitability of various carbonaceous dust clouds with particular emphasis on various ranks of coal dust. The tests were conducted using a new 1.2-L furnace. Autoignition temperatures of dust clouds were obtained as a function of coal volatility and particle size. Dust particles and gas samples were collected by a rapid-sampling system in order to study the reactions involved in preignition and postignition processes. The autoignition temperatures measured in the new 1.2-L furnace were significantly lower and therefore more conservative than those measured previously in the Godbert-Greenwald furnace. The combined effects of thermal and electrical ignition of dust clouds were also studied in the 1.2-L furnace using electrical discharges of varying energies at ambient and elevated temperatures. The minimum spark energy necessary to ignite a dust cloud decreased significantly as the temperature of the dust cloud increased.

Jan 1, 1983

By J. P. Hansen

Wustite beds were reduced with carbon monoxide and mixtures of hydrogen and nitrogen in the temperature range 900° to 1,300° C to determine the effect of temperature, gas flow, and surface area on the rate of reduction to iron. The composition of the gas stream as it passed through the wustite bed was continuously measured with infrared absorption cells and heated-wire methods. The change in composition was used to calculate the reaction rates. Arrhenius plots of the data give heats of activation of 34 kcal for particles using CO, 27 kcal for particles using H2, 24 kcal for pellets using C8, and 6 kcal for pellets using H2. The velocity of reduction is dependent on the area of reacting interface and the driving potential of the gas (reducing gas concentration minus equilibrium concentration) as well as the exponential temperature effect. The reaction rate was independent of the gas velocity over the range of conditions studied.

Jan 1, 1965

By L. C. George

The Bureau of Mines measured vapor pressures of selected mixtures in the binary system SnCla-ZnC12 by the static pressure method. Equations expressing the vapor pressure) and the heat and free energy of vaporization) as functions of temperature were developed by numerical analysis based on the sigma-plot method. It was found that the vapor pressure of any SnCl2-ZnCl2 mixture) at any temperature within the range of this investigation) could be accurately calculated from the derived values for the heat and free energy of vaporization for the mixture, with a probable error of 0.01 cm Hg or less.

Jan 1, 1967

By Lee Blackman

The Malheur-Jordan Resource Areas (MJRA?s) is a tract of approximately 6.5 million acres of federal and non-federal land in the southeast corner of Oregon. This study evaluated the Resource Areas' economically recoverable mineral potential based on geological estimates provided in the USGS report (Smith, 1994). The mineral terranes are believed by geologists to contain undiscovered resources. The geological data is probabilistic; with estimates of the possible number of deposits and their grades and tonnages. Possible future development scenarios range from no development to numerous mines. Based on the analysis performed on these terranes, the most likely (in a statistical sense) future scenario for the resource areas would include the potential for two medium sized, predominately gold, mines. These would supply direct and indirect employment of up to about a thousand workers.

Jan 1, 1995

By D. G. Leddy, J. B. Johnson, L. D. Gratz, S. T. Bagley

"Studies have been conducted at Michigan Technological University (MTU) for over twenty years on methods for characterizing and controlling particulate emissions from heavy-duty diesel engines and die resulting effects on regulated and unregulated emissions. During that time, control technologies have developed in response to more stringent EPA standards for diesel emissions. This paper is a review of: 1) modem emission control technologies, 2) emissions sampling and chemical, physical and biological characterization methods and 3) summary results from recent studies conducted al MTU on heavy-duty diesel engines with a trap and an oxidation catalytic converter (OCC) operated on three different fuels. Control technology developments discussed are particulate traps, catalysts, advances in engine design, the application of exhaust gas recirculation (EGR) and modifications of fuel formulations. Methods for dilution tunnel sampling, particle size analysis, chemical analysis with emphasis on polynuclear aromatic hydrocarbons (PAH) and nitro-PAH, and biological characterization using mutagenic activity (Ames) assays are described, along with statistical approaches to experimental design and data analysis.In studies at MTU, both particulate traps and an OCC have been shown to be effective for the reduction of total particulate mauer (TPM), with the OCC being better al reducing all forms of hydrocarbon emissions, including PAH and nitro-PAH, and with the traps being better at removing the solids (SOL). The use of low sulfur fuel (0.Ql % by mass) has led to additional reductions in TPM; the low sulfur fuel has been shown to reduce the number of small, nuclei-mode particles for one of the engines tested. PAH, nitro-PAH, and mutagenic actively levels generally decreased with use of either the traps or the OCC.INTRODUCTIONDuring the 1980s and the early 1990s there have been significant advancements in the development of technology to control diesel particulate emissions. Efforts have been focused on internal control of the engine by design, the use of after-treatment devices, and improvements in fuel formulations to reduce all the diesel emissions. The research and development activities have been driven by the need to meet the US EPA heavy-duty vehicle standards shown in Table 1. The important standards for new technology are the 1994 heavy-duty vehicle 0.1 gm/bhp-hr particulate, the new urban bus 0.05 gm/bhp-hr particulate standard for 1996 and the heavy-duty vehicle 4.0 gm/bhp-hr NOx standard for 1998."

Dec 1, 1995

By W. A. SLOAN, G. L. Oldright, J. D. Sullivan, E. K. PRYOR, A. F. HALLET, R. S. Dean, S. L. BROWN, F. S. Wartman, A. J. Thompson

Lack of sufficient publication funds has resulted in the accumulation of considerable unpublished experimental work on copper metallurgy by the Bureau staff . The present report gives extended abstracts of this work , as well as a discussion of the best direction for future efforts . The experimental work reported in this series of papers was done in cooperation with the University of Arizona , Tucson , Ariz . The investigations covered in the third , fifth , and seventh papers were done under the direction of G. L. Oldright and the remainder under the direction of V. H. Gottschalk .

May 1, 1934

By R. V. Lundquist

This report describes results of tests on the desilication of solutions resulting from the leaching of lime-soda sinters. Desilication was accomplished by heating the solutions in an autoclave. A liquor relatively free of silica was obtained after 30 minutes of heating at 200 p.s.i.g. in the presence of lime. The addition of lime improved desilication, but the rate and efficiency of desilication was effected by the quality of lime used. The optimum quantity of lime for effective desilication was about 6 grams per liter. A lesser quantity gave poorer desilication, and a greater quantity increased the alumina loss without improving desilication. The alumina loss was approximately proportional to the lime added. A complex structure, called artificial noselite in this report, was the only silica bearing compound detected in the desilication precipitate. Other compounds present were Ca(OH)2 (calcium hydroxide), CaCO3 (calcium carbonate), and Ca [A1(OH)6]2 (hydrated tricalcium aluminate). Sodium carbonate in the leach liquor retarded the formation of the calcium aluminate; hence it decreased the alumina lost to the precipitate. The extraction of alumina from aluminum silicate materials by the limestone soda-sinter process has been investigated by the Bureau of Mines for many years. The process consists of the following major operations: Blending the aluminum silicate with limestone and soda ash in such proportions that dicalcium silicate and sodium aluminate are formed on sintering; leaching the sinter in a carbonated caustic solution to extract the soluble alumina; purifying the leach liquor by the precipitation of soluble silica (this precipitate is designated desilication precipitate in this paper); precipitating alumina trihydrate from the purified liquors by carbonating with carbon dioxide gas; and calcining the trihydrate to alumina. Commercial grades of

Jan 1, 1962

By J. M. Mutmansky, C. Lee

"This paper outlines some of the work associated with a research study into the relationship between the characteristics of coal mine dust and the incidence of coal workers' pneumoconiosis (CWP). The project involves study of the chemical, mineralogical, and morphological characteristics of the dust. Early stages of the study have dealt primarily with the size analysis and elemental composition of airborne dust in continuous miner sections. This paper outlines the procedures and findings of the elemental analysis portion of the study.Most of the previous elemental analyses of coal were made available in the quest for information on the combustibility of coal dust or on causal agents and prevalence of CWP. However, no extensive studies have been performed to date, primarily due to the limitations of the analytical methods. A review of the analytical methods for elemental characterization of coal and coal dust particles is presented. TI1e comparisons are made based on the sample mass required, the sample preparation required, the destructivity of the test, and the capability of providing an easy multi-element analysis. The reasons for selecting the proton-induced x-ray emission spectroscopy (PIXE) method are outlined.The PIXE method was applied to both the airborne coal mine dust and channel samples collected from seven continuous miner sections in six different mines. Channel samples of the coal, roof and floor were collected and analyzed. Airborne dust sampling was performed using multi-stage cascade impactors and permissible 2.0 I/min pumps. Sampler locations were fixed in the sections with respect to the continuous miner and roof bolter or with respect to the intake and return airways. Sampling times varied from 45 minutes to 6 hours, depending on the dust concentration.The statistical analysis of the resulting elemental data is presented. Of particular importance are the analyses of the variation of elemental composition with size and the variation in elemental composition over the working section. One interesting finding is outlined showing the multivariate statistical analysis of the trace elements and its implications in the identification of the dust sources. The paper concludes with an analysis of the ramifications of the elemental data to related medical studies."

Mar 1, 1989

By John C. Edwards

To increase the capability to predict the effectiveness of a flame arrester in the cooling of hot combustion gases expelled through a flame arrester, the U.S. Bureau of Mines developed an equilibrium. model and one-and three-dimensional transient thermal models of a flame arrester, which were used to predict the temperature evolution within the arrester and the maximum temperature at the external surface of the arrester. The models account for convective and conductive heat transport within the arrester and radiative losses at the exit surface. The gas flow through the arrester is established from an empirically derived relationship between the gas velocity and the pressure gradient across the arrester. Lateral heat loss from the arrester to the enclosure wall is accounted for in the three-dimensional model. The model calculations for maximum outside surface temperature of the arrester showed an approximate agreement with measured values for vent-area-to-enclosure-volume ratios between 12 and 28 in2?ft-3.

Jan 1, 2010

By W. H. Carrington, A. C. Richardson

"INTRODUCTION The Powhatan mine of the Franklin Coal Mining Co. is located in the western part of Jefferson County, Ala., on the Louisville and Nashville Railroad, 40 miles west of Birmingham. The Mary Lee bed at this point yields coal with fair coking qualities, but with an ash content as mined so high as to prohibit its use in the production of metallurgical coke. At present the entire output of the mine is washed in single-compartment jigs and marketed as locomotive and domestic fuel.Figure 1 gives a typical seam section of the Mary Lee bed at the Powhatan mine. This section shows that the bed is divided by rock partings into three benches. In many parts of the mine, particularly in the older workings the roof rock is so weak that it can not be held without excessive timbering. This condition has restricted the operation in many parts of the mins to the middle and bottom benches of coal. The 6 inches of draw rock between the top and middle benches is very strong and makes an excellent roof requiring only a normal amount of timbering to support it. In the newer workings of the mine the character of the rock above the top bench is strong and it is believed that in the future it will be possible to work all three benches. This study was undertaken for the purpose of determining the washing characteristics of the Mary Lee bed at Powhatan and the effect on these characteris-tics of including or omitting the coal from the top bench. It was also the purpose of the study to show whether it would be possible to produce a washed product sufficiently low in ash to be used for the manufacture of metallurgical coke. This paper is one of a series of reports on the washability of Alabama coals which is being prepared by the U. S. Bureau of Mines and tin University of Alabama. With the cooperation of the coal producers of Alabama. It contains the results of screen sizing and float-and-sink tests of representative samples of run-of-mine coal, and the results of table tests on the minus 3/16-inch sizes of the raw coal."

Apr 1, 1933

By Charles W. Huggins

The Bureau of Mines investigated palygorskite, a natural asbestiform material, to accumulate knowledge that might serve as a foundation for future synthesis of a similar material. Unit cell, chemical analysis, DTA, TGA, optical constants, and electron microscopy data were obtained. Selected palygorskite samples of bettor than 97-percent purity were used to obtain this information. Chemical analysis revealed the following formula: (OH2)4 (OH)2 Ca0.01Fe0.02K0 .c3Mg2.10A12.00Si7.93020.3.91 H2O. The optical constants for sodium light are a = 1.522; S = 1.530; ?=1.533; biaxially (-). The following orthorhomibic unit cell constants were determined: ao = 12.690 A, Z = 2, bo = 17.857 A, Dx = 2.327. co = 5.207 A, Identical diffraction patterns resulted from the three palygorskite samples that were studied. X-ray, chemical, DTA, TGA, and optical data were compared with literature values for similar fibrous materials. X-ray diffraction lines were indexed. Several electron micrographs were made to compare the structures of palygorskite and attapulgite with that of chrysotile. The micrographs revealed extremely short laths for attapulgite, very long flexible laths for palygorskite, and tubular structure for chrysotile.

Jan 1, 1962

By R. F. Tenney

The performances of four anthracite-burning stokers have been observed under identical 74-hp. steam boilers. Fifty runs of 12 and 24 hours' duration were made in accordance with the test code of the American Society of Mechanical Engineers (ASME). The capacity of each stoker for burning anthracite has been determined, the heat efficiency at each fuel rate has been computed, and the various significant items of hear loss have been estimated. The operating data and results from each run are tabulated in this report in the form used in the test code. The heat efficiencies and most significant operating data for each run are also presented graphically for each stoker to establish the trends with increasing boiler outputs, The tests show that rice anthracite can be burned on stokers adapted to its use at heat-conversion efficiencies of 82 percent or more under continuous firing. These high efficiencies are maintained with fuel inputs 30 percent higher and lower than the peak efficiency rate. Moreover, a heat efficiency of 70 percent or more is obtained at 50 percent of the optimum fuel rate, even though the excess air into the furnace cannot be held below 150 percent.

Jan 1, 1960