Search Documents

By Almon F. Robertson

The floor of Shady Valley, Johnson County, Tenn., is underlain by the Shady dolomite formation. In places the residual clay derived from this formation contains considerable manganese oxides. Nine properties in Shady Valley and two in Doe Valley were prospected by the Bureau of Mines from January 1943 to April 1943. The results obtained indicate that the ore bodies are small and spotty and, that the ore is not well-adapted to gravity concentration. The work of the Bureau was confined to the open end of the valley. One mile northeast of the Ham Greer property, Beaverdam Creek enters a rocky gorge, and it was believed that the few prospects in this area were of secondary impor-tance and, owing to the steep slope and general roughness of the terrain, that exploration with the rite', bucket-drill would be impracticable. A total of 4,398.5 feet was drilled in 131 holes. In addition, 235 lineal feet of bulldozer trenches were cut and 4.5 feet of test pits were sunk. The following nine properties were explored in Shady Valley: Bentley, Walker, Blevins, Scott, North Ham Greer, South Ham Greer, Lipford, Blackburn, and Steagall In Doe Valley, the Gerd Shoun and Brookshire properties were explored.

Jan 1, 1949

By W. W. Culter

"This paper is the outcome of thorough investigation into the value of the previous methods used for deriving production decline curves. It is highly important that methods be employed that are fundamentally sound and also practicably applicable. Six methods commonly used were studied. Some of these were found to be fundamentally in error; some save reliable curves but involved much work and time in the preparation; others gave reliable curves with less time and effort.It was found that of the methods previously employed the ""family curve"" method described in Bull. 134 Amer. Inst. Feb. 1918, pp. 499-500 by Lewis and Beal, was probably the most satisfactory. The now method given in this paper ploys the same principles as the ""family curve"" method, but is mathematical instead of graphical,The engineer and the oil man should carefully boar in mind both the use and the limitations of the average production curve such as is derived by the ""family curve"" method or other methods mentioned. Estimations of future productions or of underground oil reserves of a particular tract or well should be made from the production records of the tract or the well itself wherever such records are satisfactory. The use of the average curve of a district or field should be applied only to those properties or wells where there are not sufficient data to construct individual or tract production records, or where the productive life so short that a satisfactory individual record can not be obtained."

Jul 1, 1920

By E. E. Maillot

In 1943, diamond drilling by the Bureau of Mines, comprising 11 holes which totaled 1,295.6 feet, showed that the pegmatite at Black Mountain consisted of shallow lenses in interbedded biotite-quartz-schist and impure quartzite. The average thickness of the pegmatite was 9.7 feet. Mineralization had a zonal arrangement. Beryl was most abundant near the footwall contact of the pegmatite. The average estimated beryl content of the pegmatite exposed at the surface was 0.81 percent, and the highest content of any pegmatite area was 1.75 percent. Other economic minerals were scrap mica, feldspar, spodumene, and lepidolite. Representative samples of the Black Mountain deposit failed to yield high-grade boryl concentrates by straight flotation owing to the presence of considerable spodumene. By employing heavy medium separation to remove the spodumene, 75.4 percent of the. BeO wan recovered in a flotation concentrate assaying 10.4 percent BeO.

Jan 1, 1949

By H. P. Hermance

The Ely mine, which at one time was the largest producer of copper in the United States, has been idle for the past 30 years. A remarkably continuous ore shoot probably averaging 100 feet wide and 19 feet thick was mined on about a 25° slope for 3,400 feet on the incline. The ore was massive sulfides containing chalcopyrite, pyrrhotite, pyrite, and sphalerite. The estimated production of the Ely mine is 400,000 tons of ore averaging 3.3 percent copper. Because of the critical position of copper during the recent war, a search for extensions and recurrences of parallel ore shoots at the Ely deposit seemed warranted. The Bureau of Mines surveyed selected areas by geophysical methods, diamond-drilled nine holes, and sampled mine dumps during its investigations, which began in 1942 and terminated in 1946. The diamond drilling totaled 5,229 feet. The logs of the holes include chemical analyses of mineralized sections.

Jan 1, 1949

By Frank E. Cash

Accident prevention is an integral part of the operating procedure of the petroleum industry, and refinery officials and employees throughout the United States are exerting concerted effort to reduce the frequency and severity of accidents and are realizing definite results. In other words, the petroleum industry is safety conscious to a much creator decree than most of the other mineral industries. On January l, 1936, there were 11 operating, refineries in Louisiana with a crude-oil capacity of 199,750 barrels per day.4/ This report deals with safety in four of these refineries representing. 72 percent of the refinery capacity of Louisiana.

Jan 1, 1940

By F. D. DeVaney

[In the course of the investigation by the U. S. Bureau of Mines and the Missouri School of Mines and Metallurgy at the Mississippi Valley experiment Station at Rolla, Mo., on the beneficiation of the low-grade manganese ores of the country, some samples from the Cuyuna District, Minn., have been examined. The work was done under the direction of W. H. Coghill, supervising engineer of the Mississippi Valley Experiment Station. Josoph and Kinney5 in venting about the relative importance of Minnesota deposits of low-grade ore compared to the total reserves say:]

Jan 1, 1930

By A. L. Peyton

The Brewer mine, near Jefferson, Chesterfield County, S. C., was originally operated as a gold mine. As late as 1890 this mine was reported to have been one of the large gold producers in the southeast. Occurrence of topaz on the Brewer property was not reported until 1935, when it was discovered, by Parks3/ and Parks of the Federal Geological Survey while they were investigating gold deposits in the Piedmont province.

Jan 1, 1953

By J. W. Town

The Bureau of Mines conducted phosphate beneficiation studies to determine the influence of mineralogical and textural features on the recovery of phosphate from select bed and composite samples representing different phosphate rock types of the western Phosphoria Formation. Batch heavy-liquid tests showed that ore grade) pellet size, and type of interstitial material were significant parameters affecting concentrate grade and recovery. Recoveries at acid grade (31.5 percent P2O5) ranged from 98 to 56 percent. Liberation was essentially complete at 28 mesh, and recoveries tended to drop when overgrinding occurred.

Jan 1, 1966

By J. W. Griffith, J. L. Stauffer, L. M. Demers, D. C. Kuhn, S. Riliog

"The relative activation of eicosanoid production which results from the exposure of the alveolar macrophage (AM) to mineral dusts is thought to be a key factor in the pathophysiology of occupational lung disease. We compared in vitro basal and silicastimulated production of prostaglandin E2 (PGE2) and thromboxane A2 (TXA2) by AM from normal humans and non-human primates (Macaca nemistrina). In addition, we instilled mineral dusts directly into one lung of the non-human primate and evaluated AM eicosanoid production at two week intervals following dust instillation. Unstimulated AM from humans produce more PGE2 and TXA2 than do AM from M. nemistrina. However, in vitro exposure of AM from both species to silica dust produced a qualitatively similar increase in TXA2 production accompanied by no change in PGE2 production. Sequential analysis of AM eicosanoid production following a single bolus exposure to bituminous or anthracite coal dusts, titanium dioxide (Ti()i) dust or crystalline silica showed marked variability among individual non-human primates in qualitative and quantitative aspects of dust-induced eicosanoid production. However, the rank order of potency of the different dusts (silica> anthracite> bituminous) correlated with epidemiological evidence relating the type of dust mined to the incidence of pneumoconiosis. These studies suggest that the non-human primate may serve as a model for the study of both the role of eicosanoids in the etiology of dust-induced occupational lung disease and the biochemical basis for individual variability in the response of lung cells to mineral dust exposure. IntroductionOccupational inhalation of mineral dust can lead to chronic debilitating lung disease ( 1,2). One of the key components of the disease process is thought to be the interaction of mineral dust with the alveolar macrophage (AM) and the subsequent release by the AM of inflammatory and fibrotic substances (3,4). Chronic inhalation of mineral dust, depending on the type and amount of dust, may then produce a situation in which ongoing inflammation, accompanied by the destruction of functional lung tissue by products of activated AM and polymorphonuclear neutrophils, stimulates the production of nonfunctional matrix by lung fibroblasts.The AM produces several oxygenated derivatives of arachidonic acid (AA) which may play important roles in dust-induced lung pathophysiology (5,6). In previous studies in the rat, we found that prostaglandin E2 (PGE2). thromboxane A2 (TXA2) and leukotriene 84 (L TB4) were the major AA metabolites produced by AM (7). PGE2 is associated with pro-inflammatory activity (8) as well as anti-fibrotic activity since it downregulates interleukin -1 (IL-1) and tumor necrosis factor (TNF) release by AM (9-11). TXA2 is known to stimulate platelet activity, cause bronchial and vascular smooth muscle contraction (12) and to possess chemotactic activity (13). LTB4 is chemotactic for neutrophils and monocytes (14) and has been suggested as an additional regulatory factor in the release of TNF by AM exposed to silica dust ( 15)."

Nov 1, 1995

By R. D. Leitch, C. A. Taylor

Trinitrotoluene is made by the direct nitration of toluene by a mixture of nitric and sulphuric acids . The exact procedure varies , but the product , where Grade I of TNT is desired , is similar , and consists largely of material that has a melting and setting point of 80.6 °c . The purification consists of draining off the liquid portions , including the acid and liquid nitro compounds . The mass is crushed and washed until the TNT is acid - free . It may still have a low-melting point due to the presence of material of lower nitration. Other isomers also have the same effect . The crystal mass may be washed with a solution of sodium sulphite , thiosulphate , sulphuric acid , or with an organic solvent such as alcohol , benzene , or carbon tetrachloride , Where a very pure product is desired , the TNT is separated by fractional crystallization from solution in organic solvents . The TNT is If it forms In some cases the material is melted during purification . agitated as it cools to prevent solidification in a solid mass . in a solid mass , this is broken up and screened . There has been some question as to the effect of the different methods of purification on the strength and sensitiveness of TNT , although all methods left a product that would give satisfactory tests .

Sep 1, 1923

By C. V. Davis

In the lnvestlg::ìt1on of mAthods for aSS8.7ing platin",. conducted by the Bureau ot MinAs, reoent experiments have d~velopad tha~ with ce..tain orei, especially when thr, quantity Of platinum 1s eonlidarablfl, nit'!le acid w111 not etfßct a iepard-Han of platinum and pa11adium. 'lhe following m;lthod has been found to be accurate and to reiu1 t in a complete S''lun''ation of' th~3:l metals. It is therefo 1" '!eeommei:ed that 1 t ba followed rath::r- than the method of separation with nitrio acid, givèn in Technical Pape'! 270.* At line 22, pagi 14, of that paper, bAglnnlng with ~tarm th,~ metals '.'ith dilute¡ nitrio acid," strikE out the rest of the paragraph, and substttutt~ the pro_t cedure g1 ven below. ?lunder and Thuringer.. have developed mnt¡iods for th"i sflparation of palladium from all the platinum metals exoept platinum bj m ,ans of dlmethy- 19lyoxlme. They state that the~ is no action for several hours if an excess of dimeth¡lglyoxime is added to an aqueous solution of ohloroplatinic acid in the cold, alio that only on boiling is the platinum pTecipi ated ¡~d than only PST't of the platinum i srenoved from the sUut1on. They found that palladium 1s p~ecipi tated quati tat! vely in the oold as (CaH 4N40 Pd) which is insoluble tn water, dilute hydroohlorio acid, dilute acetIc aofd or in 50~ ethyl alcbhol. All of their pT'90ipi tations we~p Carl". ied out ~hile the solutions were being heated. This caused a pal"tia~recipltation of the platinum along wi th the

May 1, 1922

By I. AITKENS

The precious stones rubies and sapphires are transparent varieties of the mineral corundum . Essentially they are aluminum oxide , but the aluminum is often replaced. by small amounts of chromium , titanium , or iron . The chromium is said to give a red color , titanium a blue , and iron a yellow . True rubies range from rose to a somewhat purplish red and are sometimes termed " oriental rubies " to distinguish them from spinel rubies , stones of inferior hardness , density , and value . " Oriental rubies " are very rare , and the so-called " pigeon's blood" variety is the most valuable . Sapphires normally range in color from palest blue to deepest indigo , but actually all precious varieties of corundum of any other color than red are called sapphires . The most esteemed tint is like that of the blue cornflower . Colorless corundum of gem quality is called white sapphire ; the yellow variety is described either as yellow or as golden sapphire ; and the pale pink is classed as pink sapphire . The word " oriental " is also used as a prefix in naming varieties of corumdum of less popular colors . For instance , oriental emerald is used for green corundum, oriental topaz for yellow , and oriental amethyst for violet to purple varieties . The chief physical characteristics of rubies and sapphires are hardness , adamantine luster , and moderately high specific gravity ( 3.9 to 4.1) . Next to the diamond, corundum is the hardest of all minerals ; in fact , the sapphire is number 9 on Moh's scale , ranking between the topaz and the diamond. Rubies crystallize in 6-sided prisms terminated by flat faces and other varieties of corundum with twelve inclined faces , six above and six below , meeting in a girdle . Corundum is doubly refractive , with a direction of single refraction running parallel to the edge of the prism . The refractive indexes are very constant, the ordinary index ranging from 1.766 to 1.774 and the extraordinary index from 1.757 to 1.765. The double refraction always remains the same.

Aug 1, 1931

By J. E. Chilton

The Bureau of Mines has examined the operation of an oxygen sensor manufactured by the City University, London, England. The sensor produces a current proportional to the oxygen concentration by reacting oxygen at a nonconsumable cathode. The sensor design is unique in that the primary mode of oxygen transport to the cathode is by diffusion through a capillary, The sensor using this design has a stability of 0- to 0.02-pct reading change per day over a 4.7-month test, small temperature coefficient of 0.29-pct reading change per °C, and small pressure coefficient of 0.34-pct reading change per 1,000-ft altitude change, If this sensor were incorporated into an oxygen detector or monitor, this would be a distinct improvement in electrochemical-type oxygen analyzers and would be useful to the mining industry.

Jan 1, 1983

By T. OnIin, F. F. ApIan

"A study has been made of the surface properties of coals of differing ranks, in their natural state and as modified by the addition of collectors. The evaluation of their surface properties has been done by captive bubble contact angles, water and methylene iodide sessile drop contact angles, zeta potential, point-of-zero charge (PZC) shift, and flotation. .changes in the hydrophobicity of coal is a function of both the rank of the coal and the collecting reagent.INTRODUCTIONThe chemical and physical properties of a raw coal will determine its response to a given beneficiation process. .For such processes as flotation, filtration, flocculation, dispersion, handling, dust supression and agglomeration, however, it is also necessary to consider the surface properties of the coal and mineral matter constitutents of the raw coal. In the case of a specific particle to be floated, it is also necessary to consider the properties of the coal as modified by the addition of some reagent designed to modify (usually increase) the hydrophobicity of the coal surface. General properties of the coal have been well summarized by Van Krevelen (1) and Elliott (2), while the data for the surface properties of coal are much more scattered in the literature (see, e.g.: Parekh and Aplan (3), Gutierrez-Rodrigues et al. (4), Aplan (5), Arnold and Aplan (6), Hogg and Chander (7) and Rosenbaum and Fuerstenau (8)). While a knowledge of the inherent surface properties of a sample are important, of much greater practical significance are the properties of the particle in the presence of a reagent, such as a collector, designed to enhance the hydrophobicity of the particle. This study will focus on the surface properties of coals of various ranks in the presence of a variety of collectors."

Jan 1, 1989

By K. K. Kelley, W. W. Weller

This report contains experimentally determined heat capacity data for four crystalline sulfides -- AsS , GeS , NiS , and Ni3 S₂ -- over the temperature range from 50 ° to 298.15 ° K. The heat capacity data were used to evaluate the entropies of the sulfides at 298.15 ° K. Entropies of formation from the metals and rhombic sulfur and from the metals and diatomic sulfur gas are also included .

Jan 1, 1964

By Irving Hartmann

The record of safety in the use of permissible explosives in United States coal mines has been excellent, due in great measure to the persistence with which research has been carried on in the Bureau of Mines, to the development of permissible explosives, and to the cooperation of mine operators and workers in using permissibles in a recommended manner and in the effective though gradual replacement of black powder and other nonpermissibles. The demand for increased rate of coal production, changes in mining conditions and minim methods, and introduction of new mining machinery have resulted in modified or new blasting practices. To keep abreast of these developments the Bureau of Mines conducts investigations under actual mining conditions at the Experimental coal mine near Pittsburgh, Pa. Several years ago an extensive study was complete to determine conditions under which the allowable charge limit for permissible explosives per shot hole might be raised from 1.5 to 3 pounds without undue risk of gas or coal-dust ignitions. As a result of the study, this increase in the charge limit was authorized under certain specified conditions in 1948,5/ greatly facilitating production schedules.

Jan 1, 1954

By Herbert R. Babitzke

As part of a project to develop refractory metal alloys suitable for high-temperature structural applications, the Bureau of Mines applied solid solution and precipitation-hardening techniques to columbium and tantalum alloys. Thirty-three alloys were evaluated to determine their formability, strength, and oxidation resistance. Three alloys had tensile strengths near 40,000 psi at 1,200° C: Cb-1N-5W-5V-10Hf (No.4), Cb-15Hf-5W-0.5B (No. 31), and Cb-15Hf-SW-IB (No. 32). Oxidation resistance of the high-strength alloys was good. Alloy4 gained only 34 mg/cm2 at 1,200° C, and 21 mg/cm2 at 1,000° C in 2 hours. Hot forming was done without any protection from oxidation.

Jan 1, 1968

By R. L. King, J. Cervik, A. A. Campoli

The Bureau of Mines performed laboratory experiments to evaluate the triboelectric effect of particulate-laden gas streams on polyethylene pipe at various velocity, humidity, dust-size, and dust-load conditions. Charges in excess of 10 kV were produced on the outside and inside surfaces of laboratory pipe samples, when exposed to 40 pct relative humidity (RH) gas stream containing coal dust. However, no charges were produced in laboratory tests that duplicated the over 75 pct RH and dust-free gas streams found in working underground pipelines. Bare cop- per wire, which is wound around the polyethylene pipe in a 1-ft (31-cm) spacing and grounded, eliminated the charge on the outside surface of the pipe, but not on the inside of the pipe surface,

Jan 1, 1986

By E. L. Sweeney

The mine and mill of the Davis-Dunkirk Lines, Inc., are about 16 miles by road south of Prescott, Ariz., which is the nearest railroad point for receiving mine and mill supplies and for shipping concentrates to smelters. A good trucking road reaches within 2 miles off the property, but from that point the grade is very steep. Outgoing loads are limited to 2 tons. The topography near the mine is exceedingly rugged, and the area is slightly wooded. The climate is mild excepting in a few winter months, when the snowfall is heavy. Electric power is secured by way of a 4 1/2-mile, high-tension line connecting with the main line of the Arizona Power Co. The concentrator was intended to treat 60 tons or more daily of gold-silver-copper ore and make a single gold-silver-copper concentrate for shipment to a copper smelter.

Jan 1, 1933

By M. Clair Smith

This report is one of a series describing exploration, development, mining, and processing of mineral deposits in the United States. The reports are prepared and published by the Bureau of Mines in cooperation with various mining companies The purpose of the reports is to promote development and conservation of our natural reserves by disseminating technological information on mining and milling procedures and related practices at operating mines. Simplot Silica Products, Inc., mines and processes a friable silica sandstone. The finished products are sold for use in glass manufacture, foundries, chemicals, and special applications.

Jan 1, 1959