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By H. R. Babitzke, H. Kato, M. D. Carver

A number of columbium and tantalum alloys were investigated to determine their suitability for use at elevated temperatures . Columbium-vanadium , tantalum-vanadium , and tantalum-hafnium alloys , and also columbium- 10 wt pct titanium alloys modified with additions of 0.1 to 2 mole pct ZrO2 , TiO2 , ZrB₂ , TiB , ZrC, or TiC were prepared and examined . Workability , tensile properties , and oxidation resistance were tested . Of the columbium alloys studied , the columbium- 12 at . pct vanadium exhibited the best properties ; it compared closely with the columbium- 10 at . pct vanadium alloy studied in a previous investigation.

Jan 1, 1964

By Nan C. Jensen, Oliver Bowles

"INTRODUCTION Limestone (which consists essentially of calcium carbonate) and dolomite (calcium magnesium carbonate) occur widely in the United States. Their presence is of vast economic importance, because they are used much more extensively than any other form of rock. In 1945, limestone (which, broadly, includes dolomite) was quarried in every State except Delaware, New Hampshire, North Dakota, and Rhode Island, and also in Hawaii and Puerto Rico. Total production (including that used in cement and lime manufacture) exceeded 151,700,000 tons, or 79 percent of the quantity of all kinds of stone sold or used during that year.Important well-known uses of limestone are as concrete aggregate, road material, railroad ballast, for liming the land, for cement manufacture, as riprap for shore protection, harbor work, and spillways at dams, and as building stone.. None of these uses, however, are considered herein. The purpose of this paper is to discuss the industrial and chemical uses that are less widely known and yet are of tremendous importance in a great variety of processing industries. Important examples are dolomite as a refractory furnace lining and limestone as a fluxing agent in blast furnaces, and as a raw material employed in sugar, paper, glass, and alkali manufacture.PRIOR REPORTIn May 1941, the Bureau issued a report 4/ that described these uses in some detail. As new and important developments have taken place during the ensuing years, a revision and representation of the salient features of these uses seem desirable. Asphalt filler and mineral wool uses included in the earlier report are omitted from this paper because they are identified more closely with the highway and building industries, respectively, than with the industrial applications."

May 1, 1947

By V. F. Parry

The major industrial uses of char or semicoke produced by low-temperature carbonization of coal4/ are as fuel for generating electric power, for blending with metallurgical coking coal as a substitute for low-volatile coals, and for gasification to produce synthesis gas for chemical purposes. This paper discusses various methods for carbonizing coal, emphasizing processing of the noncoking coals to produce char for thermal power-plant fuel and for blending with metallurgical coking coals and tar for chemical use. Low-temperature carbonization is a relatively simple processing step involving heating coal to about 900° to 1,200° F. to decompose the coal into 4 main products: (1) Semicoke or char; (2) complex, partly oxygenated liquid hydrocarbons or tar; (3) fixed gases; and (4) water. If the coal is heated rapidly under conditions that prevent decomposition of the primary products, 68 to 87 percent of the net heat in the raw coal is left in the char and 10 to 23 percent of the potential heat appears in the primary tar. Fixed gases represent approximately 7 percent of the heat and approximately 2 percent is lost or dissipated in the reactions of decomposition. Considering the different ranks of coal in the United States, the yield of tar will vary from about 9 to 44 gallons per ton, therefore it is important that each coal be carefully considered if it is to be carbonized for industrial use.

Jan 1, 1955

By S. H. Ash

THE MAGNITUDE of the drainage problem of the anthracite industry in Pennsylvania's Western Middle field is realized when it is known that in 1951 nine pumping plants in this field pumped nearly 36 billion gallons of water to the surface. This is almost 68,000 gallons per minute pumped against an average hydrostatic head of 350 feet for that year alone. In 1948 over 20,000 gallons per minute was pumped by relay pumps against an average hydrostatic head of 265 feet. In addition to the water pumped to the surface, it is estimated that 15,000 gallons per minute overflows to the surface from underground pools in idle mines. The volume (second-feet) of water pumped and overflow water is almost 1;z times the, average mean flow of the Schuylkill River at Pottsville for the 8-year period 1944--51 (7, 13).4 Mahanov and Shamokin Creeks drain an area of 99 square miles in the Western Middle field, and all surface drainage in this area must traverse some part, of the coal measures before entering these streams. On the basis of 46.03 inches of rainfall (the weighted average of 6 recording stations for 1948), the runoff from the drainage area during that period was 51 billion gallons, approximately 1 times the volume of water pumped by all mine-pumping plants in the Western Middle field. In other words, because of the pervious strata overlying the mine workings, approximately two-thirds of the total runoff in the drainage, area becomes mine water tributary to the pumping plants.

Jan 1, 1953

By S. W. Parr, T. E. Layng

There is presented below the results of experiments made on six samples of Utah coals furnished through the U. S. Bureau of Mines , under an agreement dated June 16th , 1920. The details of all values for all runs are tabulated and presented herewith . Clear The samples, consisting of approximately 150 pounds each, were received at the University of Illinois , on June 15 , 1920 , and are listed as follows : Creek , Wattis , Castle Gate , King , Standard , and Aberdeen . The proximate and ultimate, analyses of the various ccals from that region , representing all the types included in these samples , have already been made by the Bureau of Mines , and are available . * Similar determinations were also made on the particular samples forwarded for purposes of these experiments . The results obtained on the coal as received did . not very in any material feature from the values reported by the Bureau, they are shown in Table 1. It is of importance to note only that the oxygen content is uniformly high , namely approximately 9.5 to 11.5 per cent of the as- received coal , while the oxygen - hydrogen ratio is also high, being on the average approximately 2 ( oxygen) to 1 ( hydrogen) .

Sep 1, 1921

By Robert E. Barieau

General expressions for evaluating various thermodynamic properties applicable to the van der Waals equation of state have been derived. These formulas were subsequently used to evaluate various thermodynamic functions in the two-phase region. The results indicate that, for a van der Waals fluid, there is a finite discontinuity in the second derivative of the vapor pressure curve, in the second derivative of the chemical potential or Gibbs free energy at the critical point, and in the heat capacity at constant volume measured at the critical density. Numerical values are tabulated and graphs are presented for all functions calculated.

Jan 1, 1967

By Charles A. R. Lambly

This paper, which describes the mining practices of the Pend Oreille Mines & Metals Co. at Metaline Falls, Wash., is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in various mining districts of the United States. ACKNOWLEDGMENTS Acknowledgment is made to L. P. Larson, president, and Jens Jensen, secretary, of the Pend Oreille Mines & Metals Co. for permission to publish this paper. information was supplied by E. Berglund, mine superintendent; Earl Miller, chief engineer; Lynn Kinney, John Currie, and Wally Frick, engineers; Arthur Newman, chief clerk; and Jack Crampton, assayer.

Jan 1, 1941

By Frank E. Cash

"INTRODUCTION The iron—ore ranges in the Lake Superior district are the Marquette in Michigan, Menominee and Gogebic in Michigan and Wisconsin, and the Cuyuna, Mesabi, and Vermilion in Minnesota. These ranges produce about 85 percent of the iron ore mined in the United States. Accident experience in connection with this production is better than that of the regions producing the remaining 15 percent. Production and shipments vary slightly from year to year but closely approximate each other over a period of years.This information circular supplements, continues, and combines the data in Information Circular 7321,2/ including figures of 1944 and 1945.During the 6—year period 1940 to 1945, inclusive, 481,485,475 long tons of iron ore was shipped from the Lake Superior district. 4/ Michigan and Wisconsin shipped 93,787,648 tons, or 19,5 percent of the total, and employed annually an average of approximately 14,300 men; Minnesota shipped 387,697,827 tons, or 80,5 percent, and employed annually an average of approximately 9,300 men. The tons produced per man employed is much greater in Minnesota than in Michigan and Wisconsin, owing to the large open-cut production in Minnesota."

Jul 1, 1947

By Richard F. Hewlett

Numerous populations of assays have been simulated for a range of assay values representative of low-grade mineral deposits to facilitate the study of problems encountered in evaluating these deposits. Analysis of these simulated populations of assays (obtained by using statistical probability models for the simulation) makes possible the quantification of the effects of (1) various composite assay intervals, (2) ore reserve computational methods, (3) uneven assay intervals, and (4) various cutoff grades on both the precision and the accuracy of the estimated average grade and tonnage of ore.

Jan 1, 1964

By E. C. Lane

This paper is the first part of a report giving the results of the Bureau of Mines' twenty-third semiannual survey of motor gasoline marketed in the United States. A companion report, Part II, is in preparation and will give a more detailed discussion of the whole survey. Results of the determination of copper-strip corrosion, color, sulphur content, copper-dish evaporation residue, and gum content as given by the Bureau of Mines steam-oven method will be presented in the second paper, which will also include the prevailing retail price and the tax at the time the sample was taken. This paper deals specifically with data relative to gravity, Reid vapor pressure,5 and distillation (method 100.13).6 The samples tested were divided into "competitive-price gasolines" and "premium-price motor fuels," a method of presentation that was begun with the twenty-second semiannual survey.7 A total of 312 samples were collected from service station pumps in 20 cities throughout the United States. Of this number of samples, 207 were "competitive-price gasolines" and 105 were "premium-price motor fuels." All of the samples were collected in March, 1931, and analyzed at the Petroleum Experiment Station of the United States Bureau of Miner at Bartlesville, Okla.

Jan 1, 1931

By J. R. Ruark

Because of the importance of oil-shale reserves the Bureau or Mines resumed research investigations in this field beginning in 1944. The Bureau early decided to build a Large-scale demonstration plant to accomplish the dual purpose of obtaining design data and to produce crude shale oil for refining studies. Two 40-ton-Capacity batch N-T-U (Nevada-Texas-Utah) retorts were completed for this purpose in 1947. After a preliminary operation, the plant was used to investigate process variables of air rate, recycle gas rate, and shale particle size and crude. Correlations obtained from these variables are presented in this report. Researchers concluded that recycle gas was not necessary for efficient operation of the process. Short comings of the batch method of processing the oil shale are pointed out in the report. Several periods of prolonged production operations were carried out. During these periods, the retorts were operated to produce as much crude oil per day as possible. The lifetime operation of the N-T-U retorts was divides into three periods, namely, preliminary operation, process variable study, and production operation. During the preliminary operation, 187 runs were made with a total of 7,596 tons of raw shale used to produce 3,688 barrels of crude shale oil. During the process variable study, 179 runs were made with a consumption of 7,494 tons of raw shale and a production of 4,218 barrels of crude shale oil. The production operation consisted of 554 runs in which 22,457 tons of raw shale was used to produce 12,359 barrels of crude shale ail. The overall total for the lifetime operation of the retorts consisted of 920 runs with a total consumption of 37,547 tons of raw shale and a production if 20,265 barrels of crude shale oil.

Jan 1, 1956

By C. M. McCulloch

The natural vertical fracture system in bituminous coalbeds is called cleat. Cleat orientation commonly controls the direction of mining with major development paralleling the face cleat. Previous researchers have categorized the origin of cleat as endogenetic, relating the origin of cleat to compaction and coalification, and exogenetic, relating the origin of cleat to tectonic forces. In the coalbeds studied for this report it was found that tectonic forces were the controlling factor of cleat formation. Face cleats were formed as extension fractures during structural deformation, and butt cleats, as release fractures during erosion and uplift. The face cleat of the Pittsburgh coalbed rotates from N 80° W in north-western West Virginia to N 57° W in southwestern Pennsylvania; the face cleat maintains a perpendicular orientation to the shifting axial trend of local structures. Cleat orientation in other bituminous coalbeds in Virginia, Utah, Oklahoma, and Central Pennsylvania showed a similar relationship to local structure. Directional permeability of coal is directly related to cleat. Holes drilled perpendicular to the face cleat yield from 2.5 to 10 times the amount of gas released as compared with holes drilled perpendicular to the butt cleat.

Jan 1, 1974

By Larry Gsellman

This report presents the results of a benefit/cost analysis of the Bureau of Mines' Coal Extraction RCD Program for the period FY 1977 through FY 1982. The analysis is an update of the analysis performed on the Coal Extraction R&D Program for EY 1975 - FY 1980 and presented in a MITRE report, MTR-7225, published in May 1975. Major changes included: new production scenarios and an update of R&D cost estimates.

Jan 1, 1977

By David C. Oyler

The U.S. Bureau of Mines studied the interaction of longwall shield supports and adjacent strata at the Meigs No. 31 Mine in southeastern Ohio. Twenty-three legs of twenty shields at midface were instrumented with pressure transducers and monitored for 11 weeks. During the project, leg setting pressures were reduced twice to determine the effect of setting pressure on shield-strata interaction. No correlation was observed between setting pressure and leg loading rates. The shield loading profiles were consistent with a model in which the roof consists of two zones, a thin immediate roof loading the shields well below the typical setting force and a main roof zone essentially supported by the coal and gob and loading shields through its convergence. This model was used to develop an equation for estimating average loading rates at the site. The only variable of the equation is time, and the equation consists of an exponential term to account for the immediate roof loading and a linear term to account for main roof loading. The equation gave good correlation with average loading rates, but the variation in loading from cycle to cycle was too great for the equation to give good predictions of individual cycle loading rates.

Jan 1, 2010

By G. E. McElroy

The purpose of tins paper is not to present new date on the pressure losses due to bends and chances of area in mine openings through which air flows, but rather to correlate existing data, determined mainly on small duct systems and expressed in a variety of ways, according to uniform methods that facilitate their use in pressure-loss computations. These are required in such, air-flow problems as determining the quantity that will flow through is mine openings under a certain pressure difference or, conversely, the pressure difference that will be required to maintain a certain rate of flow. Air flowing through h ducts, such as mine airways, encounters resistance to flow due to interference of the individual air streams with each other caused by the wall surfaces. The result is that part of the kinetic energy of the flowing stream is converted to heat; and constant renewal of the kinetic energy from the total energy of the flow is required to maintain it. This process manifests itself by a decrease of the total pressure (static pressure plus velocity pressure; of the air in the direction of flow; in order that flow pray occur, there must necessarily be a differences in total pressure between the two cads of the air-ay equivalent to the pressure losses occasioned by the flow, which automatically adjusts itself in magnitude to the pressure difference maintained.

Jan 1, 1932

By Keith L. Harris

Real gross national product3 (GNP) grew at a seasonally adjusted annual rate of 4.2% in the fourth quarter compared with a revised 4.3% rate in the third quarter, according to the most recent estimates released by the U.S. Department of Commerce (table 1). Expanding inventories, Government purchases of goods and services, residential fixed investment, and a narrowing of the trade deficit fueled the growth. Significantly reduced consumer demand led to the heavy inventory growth. Almost half of the buildup in inventories consisted of automobiles because consumers reduced purchases when Detroit ceased most incentive programs in late summer. Reduced consumer demand also affected imports, however, and the narrowing of the trade deficit resumed after widening in the third quarter. Nonresi- [ ] dential fixed investment also declined after a strong gain in the third quarter. On a year-to-year basis, the economy grew at an inflation-adjusted rate of 2.9%, the same as that of 1986. However, on a fourth-quarter-to-fourth-quarter basis, the real growth reached 3.8%, the highest growth since 19M, and exceeded the Reagan Administration's estimate of 3.4%. Rising merchandise exports accounted for about one-third of the growth in GNP for all of 1987 and are expected to continue to grow as domestic manufactures benefit from the lower value of the dollar vis-a-vis other major trading country currencies. Consumer demand became a less important factor of economic growth, but employment continued to grow (table 2), and civilian unemployment declined by 0.9 percentage points (December to December) as the industrial sector geared up to increase exports. Inflation, as measured by the fixed-weighted GNP price index, remained low at 3.4%.

Jan 1, 1988

By J. A. Eisele, D. J. Bauer, D. E. Shanks

As part of its effort to produce cell - grade alumina from clay , the Bureau of Mines investigated the hydrogen chloride gas - sparging crystallization of aluminum chloride hexahydrate ( ACH ) from aluminum chloride liquor , to provide information for optimizing the crystallization operation . Four parameters important in controlling the crystallization of the aluminum chloride hexahydrate and the concentration of impurities , particularly phosphorus and magnesium , in ACH crystals are ( 1 ) aluminum chloride concentration in the feed solution to crystallization , ( 2 ) hydrogen chloride gas flow rate , ( 3 ) temperature , and ( 4 ) concentration of phosphorus and magnesium also in the feed solution . Parameters 1 , 2 , and 3 affect crystal formation . The combined effects are very important because the phosphorus and magnesium concentrate in the crystals during the early stages of crystal growth . Aluminum chloride hexahydrate of cell -grade purity was crystallized from saturated aluminum chloride solutions containing less than 0.003 wt - pct P205 and 0.010 wt - pct Mg0 . Crystallization temperatures less than 60° C decreased crystal purity .

Jan 1, 1965

By H. M. Cooper

The determination of moisture in coal is an empirical test, because the time, temperature, and equipment are specified. The essential features of the equipment and details of the procedure are given in A.S.T.M. Designation: D271-44.:2. According to the specifications, the following features should be incorporated in the equipment used: 1. Oven must have uniform temperature in all parts. 2. Oven must be constructed with minimum of air space. 3. Oven must have means of changing the air two to four times per minute. 4. Air must be dried over sulfuric acid (sp. f-7. 1.84). The analytical procedures governing most of the nation's coal purchases are those given in A.S.T.M. Standards referred to above. These standards are general arid of such scope as to cover all ranks and types of coal. In cases where only the moisture is required, a faster method than the standard procedure is desired.

Jan 1, 1948

By E. L. Singleton

The electrochemical reduction of aluminum chloride to aluminum was investigated in a closed, two-compartment cell utilizing a molten chloride electrolyte. The externally heated cell was divided into a reduction compartment and a combination AICl3 feed and metal removal compartment. Aluminum was deposited at 700° C on a molten aluminum catbode from a KCI-NaCI-AICI3 electrolyte. The AICl3 content of the electrolyte was replenished by either vapor or solid additions. The chlorine evolved was collected and measured to give a quantitative evaluation of AICl3 reduction. The effects of anode and cathode current densities and AIC13 concentration on anode current efficiencies were studiedo A range of 64 to 84 percent anode current efficiency was obtained with the 25-pound electrolyte capacity cell and related auxiliary equipment.

Jan 1, 1968

By J. L. Reuss

The Bureau of Mines investigated the technical feasibility of smelting copper concentrates containing chalcocite (Cu2S) and native copper using nonpyritic sulfur-bearing materials to aid matte formation. The procedure consisted of combining various proportions of commercial chalcocite concentrate, smelter slag, fluxes, and matte-forming constituents to produce charges of comparable compositions. The mixtures were charged in fire-clay crucibles and smelted in an induction furnace at 1,300° C. The research proved that either sulfur or gypsum can replace pyrite as a matte-forming material, and that gypsum produces an exceptionally high-grade copper matte. The addition of small quantities of metallic iron to the nonpyritic smelting charge furthers the removal of sulfur, improves the recovery of copper, and makes it possible to utilize gypsum as the exclusive flux and matte-forming ingredient, thereby eliminating the necessity of adding limestone.

Jan 1, 1968