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By V. E. Homme

Low- and high-temperature reduction techniques were employed by the Bureau of Mines in study of conditions favorable to the formation of massive titanium crystals. '1,1,2 low-temperature method, feeding molten sodium to solidified titanium lower chloride-sodium chloride, produced higher quality and high quantity crystalline metal. The percentage of crystalline titanium was increased with increasing reactor diameter, melt depth, and titanium dichloride concentration. The high-temperature technique, feed molten sodium to melts above 8000 C, producing needle-type crystals of lower quality and with less consistent results than the low-temperature method. Layers of titanium foil, sponge, fine needles, wool, and crusts of sin-tered granules were formed during the earl, -art of the low-temperature reduction, and massive crystals were produced beneath this barrier in the latter part of the reduction. Crystalline titanium having an average hardness of Bhn 76 and representing 58 percent of the total titanium was obtained. Lamellar crystals up to 1 1/2 inches long with a hardness as low as Bhn 54 were also produced. A second-stage reduction for reclaiming titanium from offgrade sponge is described. Titanium produced by this method was comparable in quality to that from sodium reduction of titanium tetrachloride.

Jan 1, 1966

By M. R. Geer, H. F. Yancey

Fuel requirements of the Pacific Northwest have been increased greatly by the war . To the normal peacetime demands for fuel have been added the requirements of new industrial and metallurgical plants engaged in war production , the increased demand arising from expansion of existing industrial establishments , increased amounts of railroad fuel required to handle wartime traffic , and increased quantities of domestic fuel required by the influx of war workers . In the face of these augmented demands for fuel shipments of fuel oil have been curtailed , wood fuel which normally is an important factor in both industrial and domestic markets of the area is less abundant , and the production of coal in Washington has decreased sharply . The fuel requirements of the region have been met so far by shipping large tonnages of coal into the Pacific Northwest from Utah , Wyoming , Montana , and Colorado ; the quantity received from these States and Canada in 1943 amounted to 2,688,9124/ tons , 175 percent of the Washington production . or The proximity of the Washington coal mines to large centers of war production has resulted in widespread migration of miners to employment in shipyards and aircraft plants ; the ensuing shortage of miners largely accounts for the decreased production of coal in the State . Hence , strip mining , which requires relatively few workers and a shorter time for development , offers an attractive means of alleviating the local coal shortage and obviating the necessity of shipping coal from the producing areas of the Rocky Mountain States to the Pacific.coast . So urgent has been the necessity for augmenting local coal production that any coal property that promises to be amenable to strip mining , even though the coal may be inferior in quality , has warranted examination . Even low- grade coals that cannot compete in the normal market can be used locally , thus releasing better coals for shipment to critical centers. of consumption ... One such deposit of low- rank fuel examined by the Bureau of Mines is in western Lewis County , about 9 miles east of Toledo , Wash . The coal is lignitic and on the as - received basis has a heating value of 6,000 to 6,500 B.t.u. per pound . The property is of interest primarily because the physical conditions favor operation by stripping and offer opportunities for low- cost production with very low manpower requirement .

Jan 1, 1945

By J. P. Bennett

The Bureau of Mines is investigating the acid resistance of ceramic materials to identify construction materials for emerging technology in chemical and metallurgical processes. Eight commercial ceramic materials, including two red shale, two fireclay, a silica, a silicon carbide, a carbon, and a high-alumina brick, were evaluated. Samples were exposed to 40 wt pct HN03 at 70° and 90° C and 60 wt pct HN03 at 50°, 70°, and 90° C for time periods of 110 days. Statistically significant changes in cold crushing strength were generally small or not detected, except for a strength drop in the high-alumina brick, which decreased in strength when exposed to the chosen acid concentrations at 90° C. Vol-ume and weight changes were also measured. The leach rates of Al, Ca, Fe, K, Mg, Na, Si, and Ti were monitored. Increasing temperature or a decrease in the acid concentration resulted in an increased ion leach rate. Of the conditions tested, the most severe corrosion occurred at 90° C for a 40-wt-pct-HN03 solution. The silica brick had the best overall acid-resistant properties, followed by a red shale and a fire-clay brick. The carbon and silicon carbide bricks are not recommended for service.

Jan 1, 1984

By Joan C. Biordi

[Composition profiles for atomic, radical, and stable species, as well as temperature and area expansion ratio profiles, have been determined for a nearly stoichiometric CH4-02-Ar flame and one to which 0.3 percent CF5Br inhibitor had been added. Net reaction rate profiles were calculated for all the observed species. For the normal flame, these and the mole fraction profiles gave rate coefficient information about the elementary reactions in the methane flame, for example, CH. + 0 4- H2CO 0 H, k4 = 1.05 X 1014CM3 mole-1sec-1 for 1,550§T 0,725' K; CO + OH 4 C02 + H, k6= 4.7 X 1011 for 1,350{T X1,750° K. Comparison between the inhibited and normal flame showed that A] and [CH3] were significantly reduced at the lower temperatures in the inhibited flame even though in the hot gas region the [E] [OH!, and [0] were essentially the same in both flames. The CF3Br disappears very early in the flame, relative to the fuel, and the reaction primarily responsible for its disappearance is H v CF3Br 4 HBr + CF3, where k7 is found to be 2.2 X 1014 exp(-9460/RT) for 700-1,550° K. Reaction of the inhibitor with methyl radicals provides for the relatively small amounts of CH3Br observed, but CH3 + Br2 - CHs Br + Br must also occur. The HBr formed reacts rapidly with H atoms to form H2 and Br, but the reaction is soon "balanced" in the flame as may be demonstrated by calculation of the equilibrium constant at various temperatures. The fluoro-carbon fragment produced in reaction (7) also reacts rapidly, in part with methyl radicals to give the observed elimination product CH2CF2 Later in the flame, above -1,400' K, F2CO is formed from the reaction CH2CF2 + 0 P F2CO + CH2 and k., -1.5 X 1013 at 1,600° K. The rather slow decay of carbonyl fluoride is attributed to reaction with H atoms according to the sequence F2CO I H - HF + FCO and FCO + H HF + CO.]

Jan 1, 1975

By C. M. Mason

The current Bureau of Mines active list of permissible explosives includes 95 brands. Twelve are gelatinous and the rest are the more commonly used granular ammonium nitrate type. The list of permissible blasting devices comprises five Cardox models.

Jan 1, 1968

By Graham W. Mark

A chemical method of analysis for beryllium was developed recently in Bureau of Mines laboratories. In this method, quinalizarin (1-2-5-8 tetrahydroxyanthraquinone) in N/4 NaOH is used as a colorimetric titration reagent. This solution has a reddish-purple color, whereas the solution containing equivalent amounts of beryllium and the dye is rather blue. In the titration procedure, standard quinalizarin solution is added to the unknown beryllium sample and to two standard beryllium samples of different but known concentrations. Then adjustments in concentrations of BeO in the two known and of quinalizarin in all three are made until the red-violet shade of the unknown is halfway between that of the two knowns. The amount of BeO in the unknown is calculated from the known BeO content of the solutions between which it lies. It is extremely difficult to distinguish the slight differences in shade of these solutions without the use of a proper light filter, especially when the concentration is over 0.1 mg. of BeO, so a study was made of the transmission characteristics of quinalizarin in N/4 NaOH and of the corresponding beryllium complex to determine what filter would give the most contrast.

Jan 1, 1950

By J. J. Burns

Disasters such as occurred at Oppau, Germany, in 1921, at Tessenderloo, Belgium, in 1942, and in this country at Texas City, Tex., in 1947 clearly indicate the explosive hazard associated with the manufacture, storage, and transport at ion of ammonium nit rate The importance and extent of the hazard may be Judged from the large amount of ammonium nitrate produced and transported annually in this country. Between July 1, 1947, and June 30, 1948, it was estimated that the United States produced 461,528 tons of ammonium nitrate commercially for agricultural purposes alone .5/ In addition, U. S. Army Ordnance plants have manufactured and shipped 779,730 tons of ammonium nitrate fertilizer to Germany, Japan, and Korea.6/

Jan 1, 1953

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 Mark S. Sanders

This report discusses the development and testing of prototype gloves for underground mining work. An analysis of HSAC hand-finger injuries revealed three high-risk jobs: laborer, mechanic, and roof bolter. Laboratory tests of dexterity and protection were performed using six off-the-shelf gloves. Two prototype gloves were developed. Both were Kevlar-cotton blend knit gloves. One had polyvinyl "Ks" screened on the palm and fingers, and a hand pad sewn into the palm. The other prototype had the palm and fingers coated with a sol id layer of polyvinyl and had no hand pad. Field tests revealed that the solid-coated gloves were preferred by workers, but that the polyvinyl melted when working with hot drill steels.

Jan 1, 1985

By S. J. Schatzel, P. W. Jeran, W. P. Diamond, F. E. McCall, F. Garcia, J. C. LaScola, T. P. Mucho

The National Institute for Occupational Safety and Health, Office for Mine Safety and Health Research, is investigating the geologic and mining factors influencing the migration of longwall gob gas. One goal of these studies is to optimize methane drainage strategies to reduce the volume of gob gas that reaches the underground workplace. As part of this research effort, longwall gob gas flow paths in a mine operating in the Pittsburgh Coalbed, PA, were investigated using SF6 tracer gas. Tracer gas released into the ventilation airflow underground generally stayed in the bleeder system and was vented at the associated bleeder fan shafts. Tracer gas injected into an inactive (intaking) gob gas venthole migrated to the two inby producing ventholes on the study panel, indicating that all three ventholes were in communication. The tracer gas that was injected into the gob generally stayed in the gob and only migrated to the ventilation system in response to the venthole on the study panel closest to the injection hole going off production. Tracer gas flow velocities in the longwall gob reservoir and factors influencing the production performance of gob gas ventholes in the study area are also discussed.

By L. A. Grant

This paper describing the concentrator practice of the Montana Mines Corporation at Helena. Mont., is one of a series of articles on milling methods and costs being prepared by the United States Bureau of Mines. The Spring Hill mine and mill are located 4 miles south and west of Helena, Mont., near the head of Grizzly Gulch. The mine portal is on the east slope of the gulch, and the mill is directly opposite on the west slope. Grizzly Gulch is one of the tyro gulches which unite at the south end of Helena to form Last Chance Gulch, on which the main street of Helena is built.

Jan 1, 1931

By S. H. Lorain

This paper is one of a series on mining methods and costs being published by the U. S. Bureau of Mines. The operations of the Quartz Hill Mining Co., near Dewey, Mont., afford an interesting example of the cost of mining small bodies of direct shipping ore; they also illustrate the effect of the unavoidable periods of unusually high exploration and development costs in this type of mining upon the cost per ton of producing ore. The importance of skilled geological guidance and the necessity of avoiding unnecessary overhead and capital expense at small mines are shown. Operating conditions at Quartz Hill are typical of those in many other mining districts of southwestern Montana. It is believed that the costs presented here may be of value in the preliminary estimation of costs to be expected by conservative operators under similar conditions elsewhere. The information contained in this paper was obtained during a visit to the Quartz Hill mine in August 1936.

Jan 1, 1937

By T. L. Joseph

The size and accessibility of the Minnesota manganiferous iron ore deposits make them attractive as a potential source of erromanganese, 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 furnaoe 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 forromanganese. The details of the first two steps of the process and the results of tests with the experimental furnaces Lave been given in previous reports.5 The m$ or part of the experimental work on the second step has been conducted in a half-ton open-hearth furnace. Some preliminary tests showed, however, that the electric furnace has some distinct advantages over the open hearth for producing, from high-phosphorus spiegel, a slag containing from 45 to 55 per cent manganese and phosphorus and iron in amounts required for ferro-grade ore. The electric furnace tests described in this paper were made to get more information as to the possibilities of the electric furnace in connection with this problem and to study the fluxing effect of alumina on high-manganese slags. Herty, Conley, and Royer have reported' results of laboratory tests which showed that slags containing from 60 to 75 per cent MnO, from 8 to 10 per cent S102, and small amounts of CaO MgO, and FeO, were sufficiently fluid at 1,450° to 1,550° C. to pour readily if 12 to 14 per cent alumina was present. With a normal A1203 content resulting from the A1203 in the

Jan 1, 1931

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

"This paper presents the results of the eleventh yearly accident-prevention contest, the National Safety Competition of 1935, conducted by the United States Bureau of Mines. Participating in the competition were 336 mines and Quarries in 37 States. Five mining or quarrying companies, each the leader in its group for having established the best safety record during the year, were awarded the national safety trophies 'Sentinels of Safety.Since these annual contests were begun 11 years ago the scope of the competition has been broadened materially, both as to the number of plants participating and as to the number of man-hours of exposure to accident hazards. Moreover, marked progress in the pre¬vention of accidents has been achieved, as is indicated by an almost constant downward course in the accident-frequency rates for the contest group as a whole during the past 11 years. On the other hand, the accident-severity rates for the group showed an upward trend during the first part of the period and a downward trend during the latter part, except in 1930 and 1934, when two disastrous explosions occurred with heavy loss of life, and in 1935, when there was an increase in the number of fatalities although no major disasters occurred. The accident rate for 1935, both as to frequency and severity, was higher than for 1934.The National Safety Competition is conducted by the Bureau of Mines in the interest of safety in the mining and quarrying industries. This object is accomplished directly through the efforts of the competing companies and their employees to win first place in the competition and thereupon receive well-merited and national recognition for their achievement. Indirectly the purpose of the contest is accomplished through studies by the Bureau of Mines of the fasts contained in the accident reports which the competing companies furnish to enable the Bureau to compute the accident rates that are the basis for determining the winners of the contest.The statistics that constitute the basis for determining the winning companies and the relative standing of all companies are prepared uniformly without regard to the States in which the companies operate, or to differences in classes of accidents covered by State laws relating to compensation for injuries resulting from industrial accidents."

Jul 1, 1936

By G. W. Elger

This report describes pilot-plant studies and an economic evaluation of a process developed by the Federal Bureau of Mines, Albany Metallurgy Research Center, to produce synthetic rutile from a rock-type ilmenite concentrate. In this process, ilmenite blended with coke and lime is smelted in an electric arc furnace to separate most of the iron as salable pig iron and to form a titania-enriched slag of low iron content, which is treated with oxygen and titanium pyrophosphate. The titanium oxides are converted to crystalline rutile; the phosphate glass contains most of the associated impurities. The treated slag is ground and leached with sulfuric acid to liberate rutile crystals, which are concentrated by physical methods. In pilot testing conducted to obtain data for a cost estimation, a synthesized product containing about 88 wt-pct TiO2 and less than 2 pct FeO was extracted from a rock-type ilmenite concentrate containing about 45 wt-pct TiO2. The estimated fixed capital cost (on a mid-1975 basis) of a plant producing 500 tpd of synthetic rutile is $28,290,100. Based on 330 operating days per year, the estimated operating cost for this process is $351 per ton of synthetic rutile. The estimated selling price of synthetic rutile made from rock-type ilmenite is $344 per ton, based on a credit of $160 per ton of pig iron and a 20 pct interest rate of return on investment after taxes.

Jan 1, 1976

By Steven J. Page

Longwall double-drum shearers frequently have difficulty complying with the 2.0 mg/m3 dust standard and, therefore, require the use of effective dust controls. However, before dust controls can be implemented effectively, the major individual dust sources must be determined and their relative severity evaluated. The Bureau of Mines has recently developed a sampling strategy, based upon short-term gravimetric sampling, that can identify the major dust sources contributing to the shearer operator's exposure. This technique utilizes approved gravimetric sampling equipment already available to all mine operators and can be performed by two people in 2 days. Five examples, including data analysis, are discussed with respect to various cutting sequences. In addition, typical dust source contributions obtained from studies of double-drum shearer operations regularly in compliance are included. Mine operators can thereby compare their dust source evaluation results with those from these longwalls.

Jan 1, 1982

By H. W. St. Clair

In about 1930, Degussa applied for a patent on a process for the of oxides, carbides, sulfides, and other nonmetallic impurities by filtration in the molter state. The filtering media listed were wire screen, coke, and ceramic materials, and quartz. It was also suggested that filtration might be combined with chemical reaction between the metal and the filter medium or that might be added to the system. No patent was granted on the general scheme, but several years later a patent was granted on a continuous process purification of crude light metals, especially or alkali earth and their alloys. The melt was stirred at 1 temperature at which the impurities (such as oxides and salts) remained solid and the metal was drawn through a filter tube. The impurities collected under the filter and were removed by a screw conveyor. Crude sodium was purified by this process in Degussa's Knapsack plant. During the last war, when the refining of scrap became a very urgent Problem in Germany, experimental investigations were extended to separation of other metals and metallic compounds by filtration. Preliminary experiments seemed to confirm the opinion of Dr. L. Weiss that the principles of wet chemical filtration might be applied to a great extent in the purification of metal and alloys.

Jan 1, 1949

By Constantine C. Popoff

During 1946 several limestone deposits near Fortson, Snohomish County, Wash., were examined by the Bureau of Mines. These examinations were part of a long-range investigative program of regional mineral supplies required by the anticipated industrial development of the Pacific Northwest. The .study outlined in the following paper was specifically undertaken to disclose new sources of high-purity limestone and to appraise, their economic aspects. The deposits examined -namely the Galbraith, Climax, and Hi, Hi -are somewhat similar in physical features and geologic environment. They are lenticular and belong to the same formation of metamorphosed sediments that underlies the prominent Whitehorse Ridge.

Jan 1, 1949

By H. J. Heinen

A technique offering promise as a metallurgical processing sequence the recovery of molybdenum (Mo) from the sulfide mineral--molybdenite?was investigated. The method consists of two steps: (1) electrosynthesis of pure dimolybdenum carbide (Mo2C) from molybdenite (MoS2) and (2) interaction of Mo2C and molybdic oxide (MoO3) to produce pure molybdenum metal. Two molten salt systems were satisfactory for electrosynthesizing Mo2C. The first was a mixture of potassium chloride (KCl), potassium fluoride (KY), and sodium metasilicate (Na2SiO3), and the second consisted of sodium fluoride (NaF), KF, sodium tetraborate (Na2B4O7), and sodium carbonate (Na2CO3). Yields up to 0.42 gram of Mo2C per ampere-hour were obtained. The carbide, mixed with monitored amounts of MoO3, was converted to molybdenum metal of 99.9 percent purity by sintering at 1,500° C.

Jan 1, 1965

By B. J. Scheiner

Extraction of silver from silver mill tailings by an electrolytic oxidation procedure was investigated by the Bureau of Mines. Various parameters affecting silver extraction, such as electrolysis time, particle size, and dissolution of the silver as the tetrachloro or cyanide complex, were studied at 30° C with an electrolyte concentration of 20 weight-percent sodium chloride. Resulting silver extractions ranged from 77 to 90 percent, depending on the tailings being treated. Concomitant extraction of mercury ranged between 90 and 95 percent. Power consumption was 52 to 90 kilowatt-hours per ton for the tailings investigated. Comparative experiments using direct cyanidation resulted in extraction of 46 to 82 percent of the silver and 20 percent of the mercury. Cyanide consumption ranged from 3.3 to 9.4 pounds per ton of tailings, depending on the tailings being treated. Silver and mercury were recovered from leach solutions by precipitation on iron powder, followed by conventional distillation and fire refining steps.

Jan 1, 1972