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By L. P. Purtell

The performance of ten anemometers of several types has been measured at low air speeds. Multiple calibration runs provided sufficient data for measuring random error about the mean calibration curve in addition to the difference between indicated and true speeds. Measurements were also performed of the minimum operating speeds of the anemometers.

Jan 1, 1979

By M. D. Aldridge

The results of a four-year research effort aimed at developing a practical and effective electronic system for monitoring safety conditions throughout a coal mine by displaying, at a central location, remotely measured parameters are described. This document presents the general philosophy of an experimental system in an operating coal mine. The conclusions drawn from this experience are presented and a typical design for a large coal mine is described.

Jan 1, 1974

By Floyd D. Everett

The J. B. fluorite deposit is in the Washington mining district, southwestern Beaver County, Utah (fig. 1). Fluorite outcrops were found during 1942, and three lode claims wore located. Little work was done on the property until October 1943, at which time the Bureau of Mines started development to determine the subsurface extent of the fluorite mineralization exposed at the surface. The most prominent rocks in the J. B. mine area are porphyries, which vary considerably in composition. Dacite porphyry appears to be the most common host rock for the fluorite-quartz-calcite lenticular masses. The dacite porphyry in the area is highly brecciated over a strike length of more than 1 mile. Fluorite deposits in the brecciated zone cover a strike length of approximately 400 foot. The fluorite lenses range in length from 40 to 200 feet and in width from 4 to 10 feet (fig. 2). The Bureau of Mines work on the J. B. property was started in October 1943 and completed in October a year later. The work consisted of surface trenching by bulldozer and hand methods, shaft sinking, drifting, and crosscutting. Eleven trenches totaling 1,800 linear feet were excavated. An inclined shaft was sunk to a depth of 105 feet, and from thin shaft 577 feet of drifts and crosscuts were driven to outline the extent of the mineral deposit (fig. 3). Two hundred ninety-seven samples were taken in the surface trenches and underground workings. The locations of the samples and analyses arc shown in accompanying figures and tables. Results of metallurgical tests comprise the concluding section of this report.

Jan 1, 1950

By C. C. Anderson, H. H. Hinson, H. J. Snhroeder

"INTRODUCTION The Eunice field is one of a group in southeastern New Mexico producing oil and gas from so-called limestone-type reservoirs in which the productive strata are dolomite or dolomitic limestone ordinarily, wells in reservoirs of this type show wide differences in their productive characteristics, indicating erratic variations in porosity and permeability. Often there is a large difference in total footage of actual ""pay"" penetrated in neighboring wells and the vertical distribution of the ""pay"" within the productive strata varies. In the Eunice field there are few easily recognizable geologic markers to indicate true structural conditions of the oil-productive section, due to horizontal and vertical gradation in chemical compositions and lithologic characteristics of the strata. Geologic markers are found some distance above the oil-producing zones in this field and consequently they indicate only the general structure. Furthermore, no direct relation has been found between the general structure and the accumulation of oil within the reservoir.Many problems in well-completion and production practice have been met in the Eunice field because of erratic variations in porosity, permeability, in vertical distribution of ""pays,"" and the apparent departure from ordinarily accepted relations of oil accumulation to structure. A detailed study of the position and characteristics of the oil- and gas-producing zones aids production procedure. The methods employed in studying the Eunice field, discussed in this paper, may be applicable to other limestone-type reservoirs."

Jul 1, 1939

By Richard L. Rains

During this study in 1983, the U.S. Bureau of Mines examined one mine and five prospects in the Greenwater Valley Wilderness Study Area (WSA). No mineral resources were identified within the WSA. Principal mineral commodities in the WSA are gold and silver with minor lead, and zinc. Two properties have significance; sample analyses indicate the Salsberry Prospect may have gold-silver-lead-zinc resources, and the Graham Jem Mine may have gold resources. The likelihood for development is greatest at the Salsberry Prospect, although the only recorded production from the study area was from the Graham Jem Mine; in 1908 less than 1 ton of gold-bearing ore valued at $25,000 per ton was produced. Gold, silver, lead, zinc, and copper minerals in the WSA are associated with rhyolite dikes and quartz veins in Precambrian gneissic rocks, commonly concentrated in sheared zones along the dikes and veins. Although known to contain silver-lead deposits elsewhere, Precambrian Noonday Dolomite sampled inside the WSA contained no significant mineral values. Much of the WSA is covered by relatively unmineralized Tertiary and Quaternary volcanic rocks. The Bureau collected 140 rock samples at four adits, nine shafts, four trenches, and 33 prospect pits in the WSA. In 1983, 14 lone claims and one millsite within the study area were current. No patented claims, placer claims, or coal, mineral, oil and gas, or geothermal leases were in the WSA.

Jan 1, 1985

By F. W. Wessel

This report summarizes Bureau of Mines laboratory tests of four tungsten¬-bearing materials of various grades, The test work has demonstrated that the dry reaction between sodium carbonate and scheelite is best conducted at 900° C. or a few degrees less. The sodium carbonate requirement, in addition to the stoichiometric equivalent of the scheelite, is in some inverse relationship to the grade of tungsten in the ore. Residence time and particle size exert a definite but minor control on the reaction. Pressure-digestion tests on an impure concentrate indicate the technical feasibility of extraction by this process. INTRDUCTION Over 100 years ago Oxland discovered that tungstic oxide could be removed from wolframite and converted to a soluble form by reacting the mineral with a soluble alkaline salt at elevated temperatures. He patented this discovery, and this patent 4/ since has been the basis for most tungsten extraction. Much literature exists on this process and its modifications, and the characteristics and possibilities of the reaction are quite well defined.

Jan 1, 1956

By G. B. Shea

In the search for possible future sources of petroleum products, the recovery and utilization of bitumens from the large outcropping deposits of bituminous sandstones in the United States have been under study by the Bureau of Mines for the past several years. The results of laboratory research in the adaptation of the hot-water separation process to recovery of bitumen from bituminous sandstones were reported in an earlier publication, on the Edna deposits near San Luis Obispo, Calif. This publication included analytical data on the cracked products and asphalts obtained from the extracted bitumen and on the cracking and distillation of the bitumen. Comparable hot-water separation tests have been run in the San Francisco, Calif., laboratory of the Bureau of Mines on quarry samples from the large deposits of bituminous sandstones near Vernal and Sunnyside, Utah. The bitumens were isolated from the extracts of the separation plant and analyzed at the Petroleum and Oil-Shale Experiment Station of the Bureau of Mines, Laramie, Wyo. Part I of this report summarizes the general characteristics of the Vernal and Sunnyside deposits and discusses the hot-water separation process as applied to those bituminous sandstones and the results obtained. The separation tests showed that these bituminous sandstones also respond to treatment by the hotwater method of separation. The bitumen in the Vernal sandstone was extracted more readily by the action of hot water than was the Edna bitumen, which greatly simplified plant operation. The Vernal sandstone contains no water-soluble iron compounds, such as were found in the Edna sandstone, and, therefore, required no preliminary water washing. Recovery of bitumen from the Vernal sandstone was about 96 percent.

Jan 1, 1952

By E. C. Lane

This paper is a preliminary report of the results of the Bureau of Mines' twenty-second semiannual survey of motor gasoline marketed in the United States. A more detailed discussion of the whole survey is in preparation and will be published as a companion, report. The second paper, in addition to giving a more complete summary of the data included in this report, will present results of the determination of copper-strip core lion (method 530.22), color (method 10.11), sulphur content (method 520.11) evaporation residue (method 530.1), and gum content as given by the Bureau of Mines steam oven method.9 The retail price at the time the sample was taken and tax will also be stated for each sample. The present paper deals specifically with data relating to gravity, vapor pressure, and distillation. It has been the feeling of some investigators that the practice, followed in previous semiannual surveys, of grouping all types of motor fuel together without discriminating between "competitive price gasoline," benzol blends, Ethyl gasoline, "high-test" fuels, etc., has detracted from their usefulness because the data did not permit drawing conclusions in regard to any one type of fuel, and tended to obscure differences between fuels of the various types. Therefore, in order to remedy this condition, the samples of the present survey have been divided into two groups; one called "competitive-price gasoline" and a second group called "premium-price motor fuels."

Jan 1, 1930

By E. C. Lane

This paper is a preliminary report of the results of the Bureau of Mines' twenty-second semiannual survey of motor gasoline marketed in the United States. A more detailed discussion of the whole survey is in preparation and will be published as a companion, report. The second paper, in addition to giving a more complete summary of the data included in this report, will present results of the determination of copper-strip corrosion (method 530.22),5 color (method 10.11),6 sulphur content (method 520.11) copper-dish evaporation residue (method 520.11),7 and gum content as given by the Bureau of Mines steam oven method.9 The retail price at the time the sample was taken and try will also be stated for each sample. The present paper deals specifically with data relating to gravity, vapor pressure, and distillation.

Jan 1, 1930

By J. A. Cavallaro

The heats of formation of anhydrous barium carbonate (witherite), strontium carbonate (strontianite), and lead carbonate (cerussite) were determined by solution calorimetry. The solution mediums were hydrochloric acid for barium and strontium carbonates and perchloric acid for lead carbonate. The heats of formation at 298.15° K are as follows: BaCO3 -297.5 ± 0.8 kcal/mole; SrCO3 -294.6 ± 0.5 kcal/mole; and PbCO3 -168.0 ± 0.3 kcal/mole.

Jan 1, 1966

By Robert H. Bedford

The New Almaden mine was discovered in 1824, and since that date production of quicksilver has exceeded 1,000,000 flasks. Because of this high production record, the New Almaden area was, upon passage. by Congress of the Strategic Minerals Act of 1939, immediately considered by the Bureau of Mines as a promising location for exploration. In 1941, the Federal Geological Survey undertook a survey of the entire district. R. R. Trengove, an engineer of the Bureau of Mines, made a preliminary study for a project in 1942, and in August 1943 the Bureau, in close cooperation with the U. S. Geological Survey, began the development project described herein. The Bureau of Mines drilled 36 holes, totaling 6,807 feet of diamond drilling, along the contact between the serpentine and Franciscan, sandstones and other sedimentary formations. The ore bodies are found along this contact and occur in the carbonate-silica rock. This report briefly describes the location, history, and ore deposits of the property. The recent operations are outlined, and the work performed by the Bureau is explained in detail.

Jan 1, 1950

By M. R. Geer

The use of the cyclone as a dense-medium cleaning device was first described by Driessen6/ in 1945, after development of the process in the Netherlands during the German occupation of World War II. A pilot plant was built in the Netherlands soon thereafter, and the first commercial plant was built in 1948. By 1958, 18 plants were operating or under construction.7/ Thus, economic factors in Europe, where the high cost of coal places a premium on efficient cleaning, dictated rapid adoption of the cyclone. American reception of the process differed. The Bureau of Mines presented the results of its own small-scale cyclone experiments in 1946;8/ showing a sharp separation between coal and impurity; adoption by industry now is taking place. There is now much greater emphasis on the efficient cleaning of fine coal, and the first American cyclone plant has begun operating; others are planned or under construction. With the present interest in improved treatment of fine coal, the Bureau of Mines felt that additional performance data on the cyclone would be helpful to industry. Therefore, a complete, open-circuit pilot plant was built to make cleaning trials on American coals covering a wide range of washability characteristics. Five raw coals and one middling product were included in the investigation, and each was cleaned at several densities; 17 cleaning trials are reported.

Jan 1, 1961

By R. M. Becker

As part of the Bureau of Mines program for examining the Nation's iron and titanium resources, magnetic, gravity, and geologic surveys were made to permit an estimate of the extent and magnitude of the Iron Mountain, Colorado, titaniferous magnetite deposit. Gabbro is the dominant rock type of the area. Within the gabbro are lenses of titaniferous magnetite, 5 to 25 feet wide and as much as several hundred feet long. These lenses comprise a zone which has scattered occurrences of magnetite for 2,200 feet. To the west, the gabbro grades into a strip of pyroxenite that in turn borders a large monzonite mass. A wedgelike broadening of the pyroxenite with depth accompanied by little or no increase in the titaniferous magnetite is considered a reasonable interpretation of the field data. The iron deposits appear to be limited and discontinuous.

Jan 1, 1961

By Elmer W. Pehrson

The recent establishment of an official price of 64.64 cents per ounce for silver by the President's order of December 21, 1933, has provoked discussion as to the effects of this move on the various metal-mining industries. To assist those of the mineral industry who are interested in this problem, the Bureau of Mines presents the following analysis of basic statistical data concerning; the relation of the silver price to the value of copper ores mined in the United States. The term "copper ore" as used herein includes all ores in which copper is the most abundant base metal paid for. In 1928, this class of ore contributed 98 percent of the total copper output of the United States.

Jan 1, 1934

By G. A. Appell

"INTRODUCTION During the summer of 1945, the Bureau of Mines conducted an investigation and program of churn drilling near the village of Tennyson in Grant County, Wis. The work was undertaken as part of a general investigation of the zinc-producing area of southwestern Wisconsin at a time when all effort was being made to increase the production of metals important to the war program.The area for special investigation was selected on the basis of favorable structural disclosures, evidence of widespread zinc mineralization, absence of any great amount of exploration to depth beneath the productive shallow workings, and the favorable results of several churn-drill holes in the village of Tennyson.During the Bureau's investigation, 30 churn-drill holes aggregating5,888 feet were completed.ACKNOWLEDGMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to-the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual. Investigative work, and prepares the final report.The work described herein was accomplished under the direct supervision of Francis C. Lincoln and the author, mining engineers of the Bureau of Mines. Final data on the investigation were prepared under the direction of Edward F. Fitzhugh, Jr., chief Minneapolis Division, Mining Branch."

Jun 1, 1947

By John H. Perry

The Bureau of Mines has developed several techniques for draining methane from coalbeds in advance of mining. Drilling long horizontal holes from an underground location is one such technique, which was successfully demonstrated in the Pittsburgh and Sunnyside Coalbeds. The same technique has now been applied in the Mary Lee Coal bed at Jim Walter Resources, Inc.'s No. 4 Mine, Brookwood, Ala., where two holes were drilled horizontally--one to a depth of 1,010 feet (308 m) and the other to 540 feet (165 m). The 1,010-foot (308-m) hole proved successful in degasifying a portion of the Mary Lee Coalbed. The hole drained methane for 1 year, during which time the initial gas flow of 200,000 ft3/d (5,663 m3/d) declined to 65,000 ft3/d (1,840 m3/d). Total gas production was 40 x 106 ft3 (1.1 x 106 m3). The gas was of commercial quality, with 98 pct methane and a heat rating of 990 Btu/ft3 (36.89 Mj/m3). The methane emissions from the faces of the mine section advancing into the degasified zone were reduced by 60 pet. The 540-foot (165-m) hole was terminated prematurely when it became impossible to maintain an open hole. Because of caving, very little gas was drained through this hole.

Jan 1, 1982

By B. W. Jong

As part of the Bureau of Mines program to develop substitutes for critical and strategic materials for metallurgical applications, the Tuscaloosa Research Center has evaluated the effect of additives and starting materials on the sintering and strength properties of sialon (silicon-aluminum-oxynitride) compositions fabricated by conventional pressing and sintering techniques. Sintering and MOR (modulus of rupture) data were developed for sialon compositions produced from three components, Si3N4, A1203, and AIN. When doped with Y203 to aid in sintering, the highest MOR values were obtained with compositions containing between 20 and 30 mole-pet (A1203 + AIN). The effect of the crystalline phase of the Si3N4 and Al203 used in the three-component system on MOR also was investigated. Alpha-Si3N4 and ?-A1203 were found to be the best starting materials. A sialon composed of 67.4 mole-pct a-Si3N4 plus 32.6 mole-pct (?-AI203 + AIN), doped with 5 wt pct Y203, had MOR values at 25°, 1,200°, and 1,400° C of 40,300, 40,300, and 31,100 psi, respectively. Samples of this composition doped with Gd203, MgO, Zr02, and ZrSi04 also were evaluated. The ZrSi04-doped sialon had higher MOR values than Gd203-, MgO-, and Zr02-doped materials but lower MOR values than the Y203-doped sialon. The MOR values of ZrSi04-doped sialons were 25,000 and 25,900 psi, respectively, at 25° and 1,400° C.

Jan 1, 1981

By J. Douglas Causey

In 1987, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied 13,374 acres of the 14,994-acre Ireteba Peaks Wilderness Study Area (NV-050-438) in order to evaluate its identified mineral resources. The study area is located in Clark County, NV, about 4 miles south of Nelson, NV. No identified resources were found within the Ireteba Peaks study area, although there are identified subeconomic resources just outside of the study area boundary. Most of the area is underlain by Tertiary granitic rocks, which apparently postdate mineralization. The area is virtually surrounded by mining districts with mines developed in older rock units. On the north side, quartz monzonite, volcanic tuff, and tuffaceous sediments in the Eldorado mining district host deposits of gold, silver, copper, zinc, and mercury. On the south side, Precambrian gneiss, intrusive andesite porphyry, and hornfels in contact with Quartz monzonite in the Searchlight mining district host gold, silver, copper, and lead deposits. The Newberry mining district to the southeast had copper, gold, and silver mineralization in Precambrian gneiss and andesite.

Jan 1, 1988

By R. V. Lundquist, H. Leitch

The solubility characteristics of mono calcium aluminate (CaO A₁₂ 0 ) in water and in NaOH , Na₂ CO₂ , and NaOH - Na₂ CO₂ solutions were measured by determining the changes in Al2O3 concentrations in solution over a period of time at a specified temperature . The monocalcium aluminate was synthesized by sintering its starting components for 72 hours at 1,375 ° C. Distilled water and aqueous solutions of technical grades of NaOH and Na₂ CO₂ were used as solvents . The extraction of alumina from the monocalcium aluminate was dependent on the composition of the solvent and partially dependent on temperature for leaching . About 98 percent extraction of alumina from the aluminate occurred in Na₂ CO3 solutions containing 10 to 12 percent NaOH . Other solution compositions produce lesser extractions .

Jan 1, 1963

By John A. Breslin

Size distributions and concentrations of particulates emitted from diesel engine exhausts were measured with cascade impactors. Samples were taken from the exhaust of two types of engines using three types of fuel and operating under five different engine speed and load conditions. The measured mass median diameters of the diesel particulates were typically about 0.3 um. There was no significant difference in mass median diameter between engines or fuels and only a slight dependence on operating mode. Concentration measurements ranged from 14.2 to 250.9 mg/cu m, and calculated mass outputs, from 64 to 10,000 mg/min. Significant differences in mass output were found between engines, fuels, and especially between different operating modes. The quantity of clean dilution air that would be required to reduce the particulate mass concentration below the 2.0 mg/cu m respirable dust standard for coal mines was greater than the dilution air required to meet the standards for noxious gases for both engines tested.

Jan 1, 1976