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By R. D. Leitch

The work of the United States Bureau of Mines on stream pollution by coal-mine drainage has included a study of seasonal variations in acidity and volume of several streams in Pennsylvania. The acidity of these streams has been determined during the two or three years prior to 1930 and the results may be considered to represent "normal" low water conditions. The summer of 1330, however, was unusually dry and represents what may be termed "extreme low water conditions on these streams. This report is a comparison of the results obtained for extreme low water of 1930 and for other years. The streams investigated were Buffalo Creek in Somerset County, Indian Creek (lower 5 miles) in Westmoreland County, Little Toby Creek in Elk and Jefferson Counties, Daguscohonda Run in Elk County and West Creek in Elk and Cameron Counties. These will be treated separately in the order given. Most of the descriptive matter and physical data pertinent to the streams and drainage basins are taken from published reports of the Pennsylvania State Water Supply Commission, 1917.

Jan 1, 1931

By M. E. Tyrrell

Research objectives were to determine the reasons for erratic behavior of semisilica horizontal zinc retorts in service; to investigate potential corrective measures including the possible utilization of more refractory materials in the retort body; and to delineate laboratory tests suitable for process control in the manufacture of retorts. Correlation of laboratory test results and data supplied by the cooperating smelters indicated that structural failures due to thermal shock and laminations in the retort body are largely responsible for the erratic behavior of horizontal zinc retorts in service. The most promising modifications made in the retort body and evaluated on a laboratory scale included finer grinding of the plastic clay fraction, substitution of mullite grog for calcined fire clay and grain alumina for silica, plus the use of an organic binder. Lamination-free extrusions having excellent thermal shock resistance were prepared from a mixture composed of 50 percent low-silica Missouri plastic clay through 100 mesh, 25 percent mullite grog through 6 mesh, and 25 percent alumina through 100 mesh. The mix was pugged under 28-inch vacuum with 1 percent ligno sulfonate binder in 12 percent tempering water. Laboratory tests suitable for process control in the manufacture of retorts are described.

Jan 1, 1969

By R. Van A. Mills

[In previous contributions** the writer has called attention to important relations that faulting bears to the migration and accumulation of oil end gas. It has been pointed that favorably situated parts of oil and gas bearing, sands have been enriched by migration art segregation incident to faulting. The escape of water through natural passages such. as fault fissures has induced wide spread hydraulic currents through the beds toward these, points, of diminished pressure and these water currents, plus buoyancy hove contributed largely toward the migration of oil to favorable rock entrapments in the vicinity of the faults.*** The propulsive force of expanding gas has been one of the contributing causes for the hydraulic currents. Paradoxical as it may seem, the escape of gas with entrained oil through fissures has been on important factor In the migration, and accumulation of oil in many faulted areas. Compressed gas is the propulsive force by which oil generally moves to producing wells. It is also one of the propulsive forces by which oil has moved with or even ahead of water under conditions: of differential pressure brought about by faulting.]

Jan 1, 1922

By R. L. Soderberg

Large open stopes mined by vertical crater retreat or sublevel s are sometimes backfilled with uncemented sand to support the stope walls and alleviate rock bursts. The failure of bulkheads in two different mines prompted a research project at the Bureau of Mines to prevent a recurrence of these failures. A series of laboratory tests with drains and sand filters was conducted to measure the bulk-head pressures when adequate drainage was maintained. Results showed that bulkhead pressure was reduced to near zero while drains were in operation, as compared to full hydrostatic pressure when drains were blocked or drainage was restricted. A relatively simple, free-draining bulkhead was shown to be adequate.

Jan 1, 1985

By S. H. Ash

In the early nineties it was observed by several European investigators and by C. S. Rice4 that an explosion could be checked and would not propagate in the parts of a mine where shale or other inert dust was present in large amounts.5 After the disastrous Courrieres explosion in France that killed 1,100 men, coal-dust explosion tests were made in France in 1907 and in Great Britain in 1908 which resulted in the conclusion that if enough incombustible dust were properly spread throughout passageways charged with coal-dust, the propagation of an explosion by the coal-dust could be prevented. In 1908 the Federal government authorized the investigation of the causes of mine explosions and of possible methods of preventing them, with the result that during 1911 the United States Bureau of Mines, after making several tests, suggested that rock-dust be used in gassy or dusty bituminous coal mines. Since that time, experiments and investigations6 have proved conclusively that widespread explosions can be prevented in coal mines by efficient rook-dusting.

Jan 1, 1930

By R. Clark Lantz, Charles Stanley, David E. Hinton

Morphometric examination of lung alterations following exposure to toxic and pathogenic substances is invaluable in detecting subtle changes which might otherwise be overlooked. Results, from evaluation of initial structural alterations, support and guide subsequent nonmorphological techniques and, when coupled appropriately, can lead to a better understanding of the pathogenesis of a disease. Morphometry is a technique which can be used to determine, quantitatively, the site, extent, development, and progression of a disease state. Determination of the extent of tissue and cellular involvement in the response to inhalation of silica has been performed in order to gain a better understanding of the development of fibrosis following inhalation of this toxicant. In addition, since silica has been postulated as one of the important pathogenic minerals in coal mine dust' it is important to understand the lung tissue response to silica prior to evaluating the effects of inhaled coal mine dusts. Male Syrian golden hamsters were placed in Hazelton 1000 inhalation chambers and were exposed to either filtered air (controls, n = 24) or filtered air plus 30 mg!m3 silica (Min-U-Si110,95%ofparticles < 5 um,n =24)for16hours per day, five days per week, for two weeks. Animals were returned to the animal quarters prior to subsequent tissue processing at 1, 4, and 12 weeks following exposure. This schedule was designed to allow time for the development of fibrosis. Lungs were fixed by intratracheal perfusion of ½ strength Karnovsky's fixative at a pressure of 20 cm H20 and tissues were taken for embedment and analysis at the light level. Determination of site, extent, and development of alterations was performed using a multitiered approach. Changes in large structures (airways, blood vessels) was determined prior to evaluation of changes at the septal tissue level. Data will be presented outlining the progression of changes. Results indicate the usefulness of morphometric analysis of lungs following inhalation of toxic substances in quantitatively defining the structural alterations.

Mar 1, 1989

By D. F. Walsh

A study of damping capacity was made on a number of magnesium-base alloys, commercial types and experimental compositions. Hardness and tensile properties were determined, and the microstructure of each alloy was examined. Alloys of low yield strength, in general, possessed high damping ability. A correlation was established between damping capacity and composition.

Jan 1, 1962

By M. E. Volin

The Buckeye manganese deposits are in Stanislaus County, Calif., about 33 miles south of Tracy. From 1917 to 1919 the deposits produced 13,370 tons of ore reported to average 46 percent manganese and 14 percent silica. The deposits are confined to two areas of&apos; development, known as the north mine workings and the south mine workings, about 700 feet apart horizontally. Mineralization occurs chiefly as rhodochrosite and psilomelane interbedded in cherts of the Franciscan formation. As a part of the Bureau of Mines program of investigation and development of domestic mineral deposits, a development project was started November 25, 1940, and completed June 27, 1941. The Federal Geological Survey cooperated by mapping the topography and geology and logging the drill cores. The program included road and. trail building, trenching, underground excavation, diamond drilling, and sampling. The following pages mention the location, brief the history, and note the physical .features of&apos; the district. Mine workings are sketched, the deposit is described, and the plan of the project is noted. The work performed by the Bureau of Mines is explained in the concluding pages with a summary of the drill-hole logs.

Jan 1, 1949

By Noel N. Moebs

Five LANDSAT lineaments in the coal mining region of southwestern Pennsylvania were investigated by the Bureau of Mines to determine their geologic character, relation to subsurface conditions, and the means of discriminating one from another. The investigation included earth resistivity and very low frequency (VLF) electromagnetic traverses, soil moisture sampling, and a correlation with coal mine roof conditions. The lineaments could not be detected by the methods used, suggesting that they might be a surface phenomenon unrelated to subsurface geologic structures or roof stability in coal mine workings beneath.

Jan 1, 1987

By Fun-Den Wang

Finite-element structural analyses were performed to determine the stress distribution and displacements around a single rectangular coal mine opening in a multilayered rock system. The effects of changes in mechanical properties of roof and coal layers, roof layer and mine opening geometry, horizontal-to-vertical load ratio, and structural geologic features on the stress distribution about the opening were studied. Variability in the stiffness and relative thickness of the immediate roof layers can produce a considerable difference in the stress distribution about the opening as compared with that of a homogeneous material. Changes in opening width and horizontal-to-vertical load ratio have different effects on the stress distribution about the opening depending on the composition of the roof layers. In general, where a stiff layer exists in the roof at the surface of the opening, the stresses are higher in the roof and ribs around the opening. Horizontal changes in facies in the roof layers produced by structural geologic features can also greatly alter the stress distribution about the opening compared with the simple layered cases.

Jan 1, 1974

By F. K. McIntosh, A. F. Robertson, T. J. Ballard

"INTRODUCTION Molybdenum deposits occur in Halifax County, N. C., near the eastern border of the Piedmont province. The deposits are associated with a small granite body about 2 miles long and half a mile wide. Molybdenite is the principal ore mineral and is found as disseminations or thin stringers in quartz veins and occasionally in the enclosing granite or schist wall rock.The deposits were investigated by Almon F. Robertson and Charles J. Cohen, engineers of the Bureau of Mines, in 1942 and 1943, who recommended that the deposits be explored to supplement reserves of critical war minerals.The Bureau made the initial exploration of the deposits in July 1943 and continued its work to January 1944. Drilling was resumed from July to December 1946 to test the deposits at &eater depth than had been attempted during the previous exploration."

Dec 1, 1947

By M. J. Kovalik

The effects of the process variables on the production of chemical coke on a chain grate stoker, a type of traveling grate, were studied. Six bituminous coals, ranging in volatile matter from 16.7 to 43.8 percent, were successfully carbonized, yielding chemical coke with acceptable physical properties. The coke yields were dependent on the volatile-matter content of the coal. The air fuel ratio had the most marked effect on the yield and characteristics of the resultant coke, and the general furnace performance. Results can only be predicted; the actual yield and quality of coke obtained from any given coal can only be determined by actual tests using the optimum processing variables to obtain a coke with minimum volatile-matter content and to retain as much of the fixed carbon in the original coal as possible.

Jan 1, 1967

By Jennifer A. Slatnick

The U.S. Bureau of Mines estimated the potential availability of titanium from 39 mines and deposits in 12 market economy countries. The evaluated properties account for 76 pet of the market economy country demonstrated resources, which total 603 Mt of contained titanium dioxide (Ti02) in the minerals rutile, ilmenite, leucoxene, and anatase, and represent 95 pct of current production. Approximately 250 Mt of contained Ti02 could be economically recovered from evaluated titanium operations at January 1992 market prices. In terms of mineral concentrates, this equals approximately 19 Mt of rutile concentrate, 110 Mt of ilmenite concentrate, 47 Mt of synthetic rutile concentrate (in addition to the ilmenite), and 160 Mt of titanium slag that could be recovered. Over the past decade, the titanium minerals industry has adapted to the changing market. In the 1980&apos;s, titanium producers expanded production because of the rising demand for titanium products. Today, the titanium industry is in a state of overcapacity, and byproduct revenues, such as that from zircon, have become essential in keeping operations profitable. The industry has also witnessed a greater dependence on upgraded ilmenite products, such as titanium slag and synthetic rutile, because of the expense of rutile and the lower wastes emitted from these upgraded products. As a result of this dependence on upgraded ilmenite products, South Africa has become a leading titanium producing country and has displaced Australian production.

Jan 1, 1994

By V. Vallyathan, Xianglin Shi, N. S. Dalai

While Cr(VI) is a known carcinogen, the underlying biochemical mechanism is still not fully understood (1). In a pioneering study Jennette (2) utilized electron spin resonance (ESR) spectroscopy to demonstrate that a long-lived Cr(V) species is generated during the reduction of Cr(VI) by microsomes in the presence of NADPH. Later Wetterhahn and co-workers (3, 4) showed that incubation of chromate with isolated rat liver mitochondria causes the reduction of Cr(VI), as well as the formation of a Cr(V) species. Analogous Cr(V) species have also been detected in the reduction of Cr(VI) by other cellular systems such as Hanserulla polymorphared (5) and blood cells (6, 7). All these as well as other studies (8-12) have suggested that this Cr(V) species plays a significant role in the mechanism of Cr(VI) toxicity. Thus far, however, the chemical structure of this dominant Cr(V) species formed in cellular systems has not been identified, and this observation provided an impetus for the present investigation. Another reason for undertaking this study was that some recent reports (10-16) suggest that hydroxyl ('OH) radicals may also play an important role in the mechanism of Cr(VI) toxicity. In particular, it has been shown that OH radicals are formed in reactions between Cr(V) species and H2O2 (13-16), and that the radical yield depends on the chemical structure of the Cr(V) species (15). For example, while Cr(V)-diol complexes efficiently generate OH radicals, another Cr(V) species, the tetraperoxochromate (CrO3/8) ion, does not (15). Thus in the present study, we focused our attention on the following: (a) structural identification of the Cr(V) species generated in the reduction of Cr(VI) by subcellular as well as cellular systems, using microsomes, mitochondria, and Escherichia coli; (b) possible detection of OH radical in the same systems since there is no earlier report of chromium-mediated generation of 'OH radicals in a cellular system; (c) possible involvement of molecular oxygen in chromium-related OH radical generation since a recent report (17) indicated that Cr(VI) mutagenesis is strongly oxygen dependent; and (d) elucidation of the mechanism of OH radical formation in these systems.

Mar 1, 1992

By G. L. Neumann

"INTRODUCTION Mining in this area is inactive. The entire region is now comprised of small farms. Because approximately 1,500,000 tons of magnetite ore had been shipped from this area between 1855 and 1915, it was deemed probable that geophysical surveying and core drilling might indicate other ore bodies or sizable extensions of the previously mined ore bodies.ACKNOWLEDGEMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has, as its primary objective, the most effective utilization of our mineral resources, thus fortifying our 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 Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiatien tests.The chemical analyses and beneficiation tests included in this report were performed at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., under the general supervision of J. B. Zadra, chief, College Park Division, Metallurgical Branch, and the immediate direction of Dr. Alton Gabriel, head of the laboratory service unit.The Mineral exploration Was under the general supervision successively of G. D. Jermain, district engineer, C. B. White, district engineer, and McHenry Mosier, chief, College Park Division, Mining Branch.The geophysical section of the exploration was performed by G. B. Botsford, engineer of the Bureau of Mines. Assistance was given by the Division of Geophysical Exploration of the Bureau of Mines, Dr. F. W. Leo, chief."

Dec 1, 1947

By Richard C. Wang

The U.S. Bureau of Mines established a wire rope research laboratory to examine the factors that affect the safety and the useful life of wire rope. In the most recent work, two 32-mm 6x27H flattened strand ropes were degraded on a bending fatigue machine. The two tests were run at constant loads of 285 and 347 kN or safety factors of 2.5 and 2. Nondestructive and tensile strength tests were performed on samples of the ropes to determine the relationship between rope deterioration and rope breaking strength. Neither the area loss nor the number of broken wires measured from nondestructive tests could be used as clear indicators of the loss of strength. However, it was found from the tensile tests for both rope specimens that the strength loss was associated with the reduction of breaking strain. This suggests that measuring the strain of many short sections of a rope in the elastic region may locate the high stress sections and thus delermine the condition of the rope.

Jan 1, 2010

By John D. Corrick

The environmental and nutritional characteristics necessary for maximum copper extraction from a low-grade ore by Ferrobacillus ferrooxidans have been explored as have many of the limiting parameters. Criteria considered were oxygen consumption, copper extracted, soluble copper concentration, temperature, pH, particle size, nutrients, and other inorganic salt concentrations. A set of environmental and nutritional conditions were developed for E. ferrooxidans Which supported cell reproduction and maximum microbial oxidation of a low-grade copper sulfide ore. Percolator tests conducted under these optimum conditions resulted in an 18 percent increase in the quantity of copper microbially extracted over that extracted under conditions considered to be standard. Manometric tests determined those extremes of environmental conditions and nutritional factors Which were detrimental to the extraction of copper by E. ferrooxidans.

Jan 1, 1965

By D. L. Paulson

Electric furnace smelting of blister copper directly from copper precipitates (cement copper) was investigated by the Federal Bureau of Mines. Copper concentrations in five different lots of cement copper in the investigation ranged from 62.5 to 82.5 wt-pct. Laboratory-scale smelting tests were made in a 50-kva electric-arc furnace to establish the reductant and flux requirements. Best recoveries were realized by adding 60 pct of the carbon required to combine with the contained oxygen in the cement copper. Operating parameters established during the laboratory-scale smelting tests were used successfully in smelting 20 tons of cement copper during 12 pilot-scale tests in an 800-kva electric-arc furnace. Over 98 pct of the contained copper was recovered as blister-grade metal. The projected energy consumption for a commercial-size furnace was 380 kwhr per ton of cold charge.

Jan 1, 1978

By Gary E. Sherman

To aid the U.S. Army Corps of Engineers in their Resource Development Navigation Study of ten existing or proposed port sites in Alaska, the Bureau of Mines examined the potential for mineral development around three Alaska port sites: Iliamna Bay, Kotzebue, and Nome. The mineral deposits near Iliamna Bay include gold, copper, and iron. Development of minerals in this area will require the discovery of new deposits or the definition of additional are reserves at known deposits. The mineral deposits near Kotzebue are primarily gold, copper, coal, lead, and uranium. Based on the character of these deposits, it appears that development of a small-scale mine supplying coal for regional use is the most likely scenario in the near-term. The mineral deposits near Nome are primarily gold and copper. Development of small underground gold mines is possible, however it appears that expanded offshore gold dredging will have the greatest impact on the flow of freight and goods through the Nome port in the near term.

Jan 1, 2011

By A. C. Johnson

The Bureau of Mines explored the Three Kids deposit in 1941 as part of a strategic minerals program. Earlier mining and exploration had established the presence of a substantial tonnage of medium-grade wad ore, and drilling and sampling by the Bureau of Mines, in collaboration with the Federal Geological Survey, indicated an additional tonnage such that development and exploitation became more clearly feasible. Private interests, with Government support, undertook to produce metallurgical-grade manganese. The present paper describes the Bureau of Mines exploration and subsequent development. Manganese in the Three Kids area is found in one of the lower members of the Muddy Creek formation in a bed of fine sandstone and silt, which outcrops around the north edge of the River Mountains and generally dips 20° to 40° away from the hills. There is considerable variation in the thickness and grade of the ore. The ore is light weight, having a density of 1.2 to 2.

Jan 1, 1956