Search Documents

By Spangler Ricker, F. T. Johnson

"SUMMARYThe Ione-Carbondale clays area is 2 miles northwesterly of Ione, Amador County, Calif. It was explored during the war by the Bureau of Mines to obtain data on the alumina content and to recover representative samples for beneficiation tests for alumina recovery.Seventy holes, aggregating 8,837 feet, were drilled, and about 10.3 acres of land was cleared of underbrush. Maps and cross sections were compiled showing location of holes, analyses, and other pertinent data.The clay beds vary in thickness from 13 to 196 feet, and are covered by a loose overburden, averaging about 11.9 feet in thickness. The ratio of overburden to clay is 1 : 8.2. Analysis of a composite sample showed the recoverable alumina (A12O3) and Fe2O3 content to be in the order of 23.6 percent and 2.8 percent, respectively.Topography of the clay area is ideal for open-pit mining methods and plant site.INTRODUCTIONInvestigation of alumina-rich clays for the possible production of aluminum was made during the recent war period, when the shortage of bauxite was becoming critical.Results of field examinations by the Bureau of Mines and the Federal Geological Survey indicated that one of the most promising areas for the development of alumina-rich clays is in the Ione-Carbondale district."

Mar 1, 1948

By H. L. Burmeister

This report describes the mining and milling practices used by the Eastern Magnesia Talc Co. at its Johnson, Vt., operation. The report also contains a description of the local geology and all available information on cost and performance data. Since 1925 the mine has produced continuously at an average annual rate of 54,000 tons, and the ratio of ore hoisted to finished product is roughly 2 to 1. Ore is stoped by a combination of shrinkage and sublevel methods. In any 24-hour period the mill produces an average total of 14 grades of finished talc product, 9 by dry grinding and air classification and 5 by wet grinding and flotation methods. The mine operates one shift per day, 5 days per week and the mill operates on a 3-shift, 5-1/2-day-per-week basis. Operating costs for 1958, on a percentage basis, were mining, 22.34; milling, 54.77; ore haulage, 2.89; and all other, 20.00 percent.

Jan 1, 1963

By Fremont T. Johnson

Credited with production of more than 164,000 flasks Of quicksilver from 1876 to 1944, the Oat Hill mine has ranked third in output in the United States. During World War II, when the demand for mercury was high, this property was selected for diamond drill with the purpose of increasing ore reserves so that production could be maintained or, if necessary, increased. Although the existence of marginal-grade ore (fill material) left in the stapes and possibly of virgin ore of good grade had suspected in certain parts of the Oat Hill mine, no factual information to tonnage, grade, or location was available. In close cooperation with the Federal Geological Survey, the Bureau of Mines studied old records and the few available incomplete maps. Diamond drilling began in November 1943 and was completed in December 1944. Twenty-eight holes aggregating 8,121 feet were drilled, in only parts of the promising areas disclosed by the study of the data available. Detailed data on the work done by the Bureau as well as a brief history of the property and some operating details are described in this report.

Jan 1, 1949

By Frederick W. Horton

With large deposits of low-grade molybdenum ore and a latent market for molybdenum, which with development might perhaps equal that for tungsten, the United States has for years made no pro- duction of molybdenum ore worthy of mention. In fact, during the decade previous to 1914, there was no output of molybdenum ore in this country except in 1905, 1906, and 1907, when a few small lots of molybdenite and wulfenite were marketed." To ascertain why this possible source of economic wealth should remain undeveloped, the United States Bureau of Mines undertook an investigation in 1914, with a view of assisting the establishment of a molybdenum industry in this country. A preliminary review of the situation showed the following conditions: Briefly there was a lack of any considerable demand for molyb- denum for the one known use that might consume any large tonnage of it, that is, for the manufacture to certain alloy steels to which molybdenum imparts properties roughly similar to those produced by tungsten. It was at once evident that the market for molybdenum in alloy steels must be developed, or that extensive new uses for the metal must be created, before the demand would be sufficient to war- rant any extensive mining of molybdenum ore. Investigation showed that one of the chief factors in retarding the development of any demand for molybdenum by the alloy-steel trade was that manufacturers who might use, or might investigate the possibilities of using, the metal were kept out of the market by the fear of not being able to obtain steady supplies. On the other hand, those who might be interested in the development of some of the extensive low-grade molybdenite or wulfenite deposits in this country were prevented from doing so by the small visible demand and the fear that any large production would glut the market. Owing to these conditions the mining of molybdenum has in the past been confined almost entirely to small-scale operations on high-grade streaks of molybdenite ore, and the methods of recovery have been limited largely to cobbing and hand picking.

Jan 1, 1916

By Jr. East

The Bureau of Mines conducted an investigation of the Nightingale tungsten deposit about 38 miles north of Fernley, Nev., from September 1939 to March 1940, to determine possible resources of tungsten ore. The property was owned by the Gold, Silver & Tungsten, Inc., which maintained its offices in Boulder, Colo. Ore was discovered in 1917, and some ore was mined in 1918 and treated in a mill at Toulon, a station on the Southern Pacific Railroad, 40 miles east. Same shipments were made since 1918, but no production figures are available. The ore is mined from nearly vertical tactite bodies at the limestone-granite contact. The Bureau of Mines excavated 944 linear feet of trenches, drifted 52 linear feet, sunk a shaft 20 feet in depth, sampled the underground workings by cutting 743 linear feet of channels, sampled the surface trenches by cutting 415 linear feet of channels, and drilled 9 diamond-drill holes, totaling 3,000 feet. The ensuing sections note the location and physical features of the district and specify the property and ownership. The history of the mine is briefed, and the geology and mine workings are described. The work done by the Bureau of Mines is summarized and supplemented in detail by assay maps, logs of diamond-drill holes in appendix A, and a table of sample analyses in appendix B.

Jan 1, 1950

By H. B. Brunot

A complete list of permissible mine equipment , tested and approved by the Bureau of Mines previous to January 1 , 1947 , was published as Information Circular 7432.27 A list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar year 1947 was published as Information Circular 7465.3/ The present list supplements Information Circular 7432 and includes all of the equipment approved during the calendar years 1947 , 1948 , and 1949. It therefore supersedes Information Circular 7465. The list also includes an appendix ( No. 2 ) giving the symbol that must be used by every cable manufacturer in marking trailing cables that have passed the test for flame resistance as stated in the amendment of October 21 , 1947 , to Schedule 2E . The items are numbered to indicate the consecutive order in which each type of machine or device was approved in its particular classification . Thus , Information Circular 7432 showed six air compressors on the active list ; five additional compressors , Nos . 7 to 11 , inclusive , in this category were approved during 1947 , 1948 , and 1949 . Several items that were listed in Information Circular 7432 have been repeated in this circular where it was necessary to show that approvals of such equipment were extended to cover an additional voltage rating or other changes . Equipment listed in these circulars is approved by the Bureau of Mines only when found , upon inspection and test , to comply with minimum standards of safety as outlined in schedules prepared on the basis of many years of experience in dealing with safety problems of the coal -mining industry . The use of such equipment in mines known to be gassy , as well as in those that may become so , is earnestly recommended in the interest of safety . This circular is published so that the industry may be kept informed as to the many types of machines , devices , and lamps that are available for reducing explosion and other hazards incident to coal mining . This circular and Information Circular 7432 give the complete list of permissible mine equipment that is available under the various classifications .

May 1, 1950

By George Saliba

This report disucsses the formulation of a mathematical model for the steering of a conveyor belt by a flat return idler and a troughed idler under various loading conditions. Significant parameters associated with belt training are identified. The generation of a skewed flat return idler model in terms of a steering force and self-aligning torque is presented. Development of the mathematical model for the flat return steering idler is illustrated for the case of no circumferential slip occurring and for the assumption of a bidirectional slip mechanism. Experimental results supporting the theoretical analysis is presented.

Jan 1, 1977

By J. H. Jacobs

The first authorization, in November 1940, was for a plant of only several hundred pounds capacity at Boulder City, Nev. Improvements in the process and subsequent additions to some sections have enabled the plant to produce more than 2,000 pounds of manganese per day for substantial periods. By the time pilot-plant operations were suspended in June 1945, over 1,500,000 pounds of metal had been produced. The future of electrolytic manganese production obviously depends not only on satisfactory development of methods but on availability of raw material and demonstration of valuable uses. Investigations of manganese-ore deposits in this country, made since 1938 by the Bureau of Mines, have revealed large amounts of ore suitable for making electrolytic manganese. At first the pilot plant was operated on ore from the Three Kids mine near Las Vegas, Nev. After practical features of the process had been worked out, other ores from throughout the United States were tested in the pilot plant. The purpose of this paper is to compare the results obtained on the following ores: Three Kids; Ladd mine, Tracy, Calif.; Chamberlain, S. Dak., nodules; and ore from Metals Reserve stockpiles at Deming, N. Mex.; Cushman, Ark.; and Philipsburg, Mont.

Dec 1, 1947

By Frank A. Peters

With the current renewed interest in advancing the technology for producing alumina from domestic raw materials, revisions of previous cost estimates to provide planning data are urgently needed. Completely new cost estimates on a 1973 basis are included for four alumina-from-clay processes and one alumina-from-anorthosite process. These estimates are based on new or previously calculated material balances, recalculated heat requirements, and new equipment designs. The use of larger and more modern equipment has permitted a significant reduction in labor requirements as well as equipment costs. Chemical prices, labor rates, and utility rates typical of late 1973 are used in these cost estimates. In addition to the revised cost estimates, all 21 previously published alumina evaluations compiled by the Bureau of Mines were updated to show the effect of inflation using an inflation index and late 1973 chemical prices, labor rates, and utility rates.

Jan 1, 1974

By E. M. Tignor

As a part of the program of promoting the conservation and efficient utilization of petroleum, studies are being made by engineers of the Bureau of Mines on secondary oil-recovery projects throughout the United States. In furthering that aim, engineering data concerning the reservoirs, methods of stimulating the production of oil, and other pertinent facts are collected, studied, and subsequently published so that others may profit by the experience gained. This report presents the results of a study made by engineers of the Franklin, Pa., office of the Bureau of Mines of secondary oil-recovery operations in the Boggs field, Spencer district, Roane County, W. Va., whore natural gas is injected into the reservoir to stimulate the production of oil from a so-called stripper field. The Boggs field, like most others in the Appalachian region, is one in which the major part of the natural energy that caused oil to flow through the reservoir to the producing wells during the primary stage of oil production has been dissipated. For all practical purposes, most of the oil produced in the Appalachian region at the present time can be considered to be from stripper fields. Consequently, secondary recovery methods are being used extensively in the oil-producing areas of New York, Pennsylvania, West Virginia, Ohio, and Kentucky for recovering some of the oil that was not produced by primary production methods.

Jan 1, 1949

By W. W. Weller

Heat capacities of ferrous molybdate (FeMoO4) and ferrous tungstate (FeWO4) were measured over the temperature range 51° to 298.15° K. Ferrous tungstate has a lambda type heat capacity anomaly at 74° K. The 298.15° K entropies are FeMoO4) 30.9 cal/deg mole and FeW04) 31.5 cal/deg mole.

Jan 1, 1966

By Thomas J. Peters

The Snowbank study area, which had been proposed as Wilderness, lies about 5 air mi southwest of Cascade, Idaho, and about 60 air mi north of Boise. The eastern boundary of the north-south-elongate study area lies 1-to 2-mi east of Cascade Reservoir; the western boundary is contiguous, in part, with the western boundary of Valley county. The 8,200-acre study area is underlain by Cretaceous granitoid rocks of the Idaho batholith. Three prospects were found in or near the study area during a library and field search. Gold occurs at one 30-ft adit, but the gold-bearing structure appeared too narrow to contain resources. Two other prospects appeared essentially unmineralized. No evidence of geothermal activity was observed. Rock in the area is not potentially useful as dimension stone because it does not split into flat slabs. To be used as aggregate, the rock would require crushing and hauling to distant markets. One of 18 alluvium concentrate (placer) samples contained free gold, worth $1.07 per cubic yard of gravel (at a $350 per oz gold price). No alluvial bars were seen; deposits were too small to contain gold resources or be considered gravel resources.

Jan 1, 1993

By Robert M. Cox

The objective of this study was to determine if significant relationships exist between coal mine roof stability and the time roof is left unsupported. Additional factors such as geology, opening geometry, and mining methods were also studied: to determine their relative influence on mine roof stability. The results of the study indicate that geologic factors such as shear zones (either joints or faults) and changes in roof rock lithology were the principal factors governing mine roof stability. The time lapse factor appeared to be of critical importance when poor mine roof conditions are encountered. The study pointed up the need for improved and permissible rock mechanics instrumentation for use in coal mine investigations.

Jan 1, 1974

By William C. Cooley

A literature search and survey were prepared on the technology of surface hydraulic mining, with particular reference to its possible use in the United States forstripping overburden from surface coal mines. Extensive use was made of Russian references which were translated into English. The advantages and disadvantages of hydraulic mining and hydrotransport are identified as well as criteria for selecting potential applications. At present, the major U.S. application is in the phosphate industry of Florida and North Carolina. Potential locations for hydraulic stripping of overburden from coal seams are identified in the states of Alaska, Illinois, Montana, Washington and Wyoming. Other potential applications include the hydraulic mining of peat in Minnesota, and the stripping of overburden from lignite in Texas, Montana, North Dakota and South Dakota. Further research is recommended, particularly on the subject of dewatering of fine clay slimes to avoid water pollution and to permit rapid reclamation of mined areas.

Jan 1, 1976

By Thomas C. Mowatt

Chemical and petrographic studies were carried out on selected tin-bearing rock samples of contact-metasomatic origin from the Cassiterite Creek and Brooks Mountain areas, Seward Peninsula, Alaska. The tin content of rocks ranged from 0.39 to 8.9 pct. Leaching with a 20 pct hydrochloric acid solution released from 19.3 to 67.9 pct of the tin. Cassiterite was not observed in the rock samples. These results are significant with regard to tin recovery and reserve delineation in these and similar occurrences. Part of this leachable tin may be associated with metasomatic borate minerals.

Jan 1, 2011

By Mukund O. Gangal

A deep cutting continuous miner, HH456, was tested under production-mining conditions at the Joanne Mine, Rachel W. Va., for about 1 ½ years (226 production days). The miner was run in two modes: a low head-rpm, deep cutting and high rpm, shallow-cutting mode. These tests confirmed that deep cutting and slow cutter speed reduce respirable dust significantly under production mining conditions. Quantitative reductions in dust, in deep vs shallow cutting, were 73°; in return air and 63% at the operator's location. Production rate, (tons/shift), and bit consumption rate did not show any relationship to deep or shallow cutting. Reliability and maintainability of the miner were worse in deep cutting mode due to cutter drive shaft failures; the cutter shaft problem was solved through improved material and design. Excluding the cutter shaft repairs. maintainability war similar for deep and shallow cutting,

Jan 1, 1979

By R. Hogg, T. F. Dumm

"A procedure for evaluating the size/specific gravity distribution of ultrafine coal and the distributions of sulfur and ash with respect to particle size and specific gravity is described. The procedure is essentially an extension of the conventional coal washability technique in which special precautions are taken to ensure particle dispersion in the heavy organic liquids, centrifuges are used to obtain adequate separation rates, and micromesh sieves are used for size separation at fine sizes. An example of the application of this technique to the evaluation of the extent of liberation of sulfur and ash in a coal sample ground to 90Z passing 200 mesh (74 um) is described.INTRODUCTIONIn order to determine the potential for deep cleaning of coal by fine grinding to liberate sulfur and ash-forming minerals, it is necessary to obtain data on the distributions of these species by size and specific gravity. In conventional coal processing operations, this information is obtained by means of a standard ""washability"" analysis. Attempts to extend this procedure to ultrafine coal, however, have generally been unsatisfactory and have often led to unreliable and inconsistent results [11. The present authors have described a modified washability procedure in which cumulative specific gravity fractionation is combined with sub-sieve size analysis (by laser diffraction/light scattering) to determine the particle size/specific gravity distribution of ultrafine coal [2]. Unfortunately, because this technique does not involve separation of the individual fractions, only limited information can be obtained on the specific distributions of sulfur and ash.The objective of the work described in this paper was to develop and evaluate a procedure for size and specific gravity fractionation of ultrafine coal and to use conventional analyses for sulfur and ash to determine their relative distribution in the coal. The procedure is essentially a simple extension of the standard washability analysis [3] but incorporating special precautions for treating ultrafine particles.EXPERIMENTAL Material The material used in the development and evaluation of the ultrafine coal fractionation procedure was a medium volatile bituminous coal from the Lower Kittanning seam. A sample of the coal (nominally - 1/4 inch), obtained from the Penn State Coal Data Base, was ground to 90% passing 200 mesh by the following two-stage grinding procedure: About 2 kg of the as-received coal were ground to about 30Z passing 200 mesh in a Model 4-E Quakertown mill (""coffee grinder""). About 1 kg of this product was then ground to about 90Z passing 200 mesh in a Holmes Model 300 Pulverizer."

Jan 1, 1989

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 R. H. Bedford, F. T. Johnson

"In California the history of tin mining began in Riverside County in 1853, with the discovery of the Temescal deposit. This deposit remained the only one with a production record until recent small shipments were made from Kern and San Bernardino Counties.According to the California State Division of Mines, Temescal's total output has been about 125 tons of tin, all of which was produced in 1891 and 1892. It was idle from 1892 to 1928.An extensive but unsuccessful development campaign carried on in 1928 and 1929 by the American Tin Corp. produced only half a ton of the metal, and the property again was idle until 1943, when an attempt to resume operations proved unsuccessful. After 1929 no production is recorded from California until 1944 end 1945, when small shipments of sorted ore from Kern County returned about 2 tons of tin and 1-1/3 tons was recovered from sorted ore and concentrates from San Bernardino County. The total output of tin from California has been less than 150 tons, and less than 4 percent of this was produced in the last 50 years, in spite of numerous attempts during that period to promote tin mines,So marked a scarcity of a metal essential in war makes any occurrence interesting. When some prospects were reported to the Bureau of Mines in July 1942, in a new field 10 miles east of Gorman, they were at once examined and the preliminary exploration by the owners closely followed. Eventually one was explored by bulldozing end diamond drilling as a joint project by the Bureau of Mines and the Geological Survey.To supplement this joint project, the authors undertook independently a general survey of tin in California - a survey designed to check reported occurrences and to bring their status up to date. In this work, the 37 places described in the text and spotted on the accompanying map, (fig. 1) were visited end sampled. Although traces of tin were found in many pieces, nothing that suggested a tin mine was found anywhere, and it is difficult to base much hope for appreciable future tin production upon anything found thus far in California."

Apr 1, 1946