Search Documents

By Donald F. Reed

During the first 6 months of 1948 the Bureau of Mines investigated the titania, deposit on the Wynn 0. Christy property in northern Hot Spring County, Ark. The property is situated in Magnet Cove, about half a mile north of the Magnet Store and U. S. Highway 270 (fig. 1). The purpose of the investigation was to determine the extent and grade of the ore body and to obtain a representative sample of the ore in as nearly natural condition as possible for use in metallurgical testing. All of the titania that has been marketed from Arkansas mines has been in the form of rutile from a deposit about 2 miles west of the Christy property. The titania in the Christy property occurs principally as brookite, which, with fragments of novaculite, quartz, and limonite, is imbedded in red clay. It is difficult to recover a core of the material. Three types of drills - a diamond drill, a bucket drill, and a Baker cable-coring tool operated on a churn rig - were employed in an effort to procure proper samples in their natural state. The Baker tool was found to be the most efficient and to be capable of drilling to a depth of 150 feet, making 80 to 100 percent core recovery (fig. 8). Total footage drilled was 1,536.9 in 21 holes, of which 7 were diamond-drill holes, 13 were bucket drill holes, and one was drilled with the Baker tool. The ore body was found to be 900 feet long, 500 feet wide, and more than 141 feet deep and contained 5.8 percent TiO2 and 0.52 percent 1720. Most of the deeper drill holes bottomed in ore, and there is a possibility that the ore may persist to a depth of several hundred feet. The Metallurgical Division of the Bureau of Mines is conducting experimental work at the Mississippi Valley Experiment Station at Rolla, Mo., for the purpose of developing methods of concntrating and utilizing the ore.

Jan 1, 1949

By Arcy R., D&apos George

A process for removing sulfate from Great Salt Lake brines and other natural brines, including sea water, has been developed. Sulfate is quantitatively removed by precipitation as barium sulfate in a cyclic process employing ion-exchange techniques. Barium is continously recovered and recycled, and sodium carbonate and sulfur or sulfuric acid are produced as byproducts in quantities sufficient to more than defray the cost of desulfation.

Jan 1, 1967

By John E. Pahlman

An increasing number of gold and silver mining operations are employing cyanide solutions to effectively dissolve silver and gold from finely disseminated ores. Many of these operations use small, packaged processing systems like the State of Maine filter system, which employs zinc precipitation of gold and silver. Solution-clarifying filters in these systems become blinded with calcium carbonate (CaC03) scale and require frequent (every 2 to 10 days) dismantling of the filter units for acid cleaning, This is a hazardous operation as it is not compatible with the alkaline cyanide leach solutions and may result in the evolution of toxic hydrogen cyanide (HCN) gas during cleaning and during any accidental acid spill. The Bureau of Nines has investigated an alternative, nonacidic method of cleaning blinded State of Maine filters that employs ethylene- diamine-tetraacetic-acid (EDTA) type chelating agents to dissolve the scale. In situ cleaning of a 150-st/d State of Maine filters with EDTA- type chelating agents was successfully demonstrated. Greater than 90 pct of the CaC03 scale was removed in about 10 min with circulation of 31 L of 2.5-pct-EDTA solution through the filter unit. The EDTA cleaning method not only eliminates the cyanide hazard in filter cleaning but is advantageous from the standpoint of operating costs and productivity.

Jan 1, 1986

By C. A. Alien

The increasing activity in oil shale has had a tendency to direct the attention of the industry to any substance from which gasoline or other oils can be secured . Cannel coal for many years has been known, as a source of oil and formerly it was the only substance from which kerosene was obtained . The name of coal oil was given to kerosene because it was derived from cannel coal before any flowing wells were brought in in the United States . In an isolated region in Southern Utah there is an unusually thick and clean bed of cannel coal which laboratory experiments indicate can be made to yield about seventy gallons of oil to the ton . This coal was first described in Bulletin 341 of the United States Geological Survey under the title of Colob coal field . This field lies at the western and southern base of the Colcb plateau and extends from the town of Cedar City southward to Kanarra and then southeastward to the town of Mount Carmel . Cedar City is 35 miles south of east from Lund on the Los Angeles and Salt Lake Railroad which is the nearest railroad point . Mount Carmel is about 90 miles south of Marysvale , on the Denver and Rio Grande Railroad , which is the nearest railroad point from the eastern end of the field . The Colob coal occurs in Lower Cretaceous rocks and a number of wagon mines have been opened on the seam in the vicinity of Cedar City , Kanarra , and Mt. Carmel , but between these places the field has been very little prospected . The cannel coal , so far as known at present , is limited to a small area on the head waters of the north fork of the Virgin River in Township 39 and 40 South , Range 9 East . In this region it occurs as a bed 5-1 /2 feet thick over which lies a layer of bituminous coal 2 feet and 5 inches thick .

Feb 1, 1921

By D. Bienstock

A rig was constructed to burn 100 to 125 lb of coal per hour at 4,000° F in a cyclone burner with oxygen-enriched air preheated to 1,500° F to ascertain the problems in the coal-fired MHD generation of power. Potassium carbonate was added to the coal at several concentrations up to 1.23 g-moles/kg of coal (17 lb K2C03/100 lb coal). Boiler-tube materials maintained at wall temperatures of 800° to 1,500° F were exposed to the combustion effluent of 1,800° to 2,500° F. Practically complete removal of sulfur dioxide from the stack gas was achieved with the seed addition. Nitric oxide formation followed theoretical expectations at combustion temperatures with some decomposition of the NO occurring as the gas cooled flowing through the system. Nitrates in the fly ash were less than 1.7 percent of the total fixed nitrogen. With aqueous extraction of the fly ash a maximum recovery of 75 percent of the potassium was obtained. Haynes 25 was unattacked at a wall temperature of 1,500° F in combustion gas at 2,500° F; the stainless steels 310, 316, and 446 were resist-ant at a metal temperature of 1,100° F in gas at 2,100° F.

Jan 1, 1970

By Oliver Q. Leone

The effect of oxygen content in the anode metal on titanium electrorefining characteristics was studied. Increasing quantities of oxygen in the anode resulted in increased anode scale formation, decreased anode and cathode current efficiencies, lower titanium recovery efficiencies, and higher oxygen content of the cathode products. The titanium electrorefining process performed best when the anodes did not contain more than 0.5 percent oxygen, although anode dissolution was recorded for alloys containing up to 25 percent oxygen. Back emf affords a useful index of an alloy to electrorefining.

Jan 1, 1965

By Perry G. Cotter

The objective of this investigation was to synthesize and investigate the properties of a high-temperature refractory material based on a combination of boron, silica, and magnesium. A magnesium-thermic reaction was used for the synthesis. X-ray examination of the product indicates that the crystalline portion of the composition is a combination of magnesium borides, magnesium silicate, and magnesium orthoborate. Chemical analysis of a representative sample shows, in weight-percent, boron 17.6, silicon 23.9, magnesium 17.8, and chromium 0.5. The balance is largely oxygen. The composition is resistant to high temperatures under oxidizing conditions and is stable in water, hydrochloric acid, and hydrogen. It has a low density (less than 3 grams per cubic centimeter) and a hardness value in the range of quartz. It has a melting point above 1,700° C. and can be hot-pressed to shape in the temperature range between 1,200° and 1,350° C. The properties described in this paper indicate that the material may have some uses as a high-temperature refractory, and because of its boron content it may have some value as a thermal-neutron-absorption material.

Jan 1, 1961

By Gerald R. Smith

Because of continuing concerns regarding the effects of cumulative quantities of materials in the environment, the Bureau of Mines has initiated a series of studies to evaluate, to the fullest extent possible, all aspects of the materials flow sequence fur selected commodities. Although tungsten and its compounds do not pose a significant health hazard to the environment, they do represent valuable resource materials to which appropriate conservation considerations must be given. The present study includes a description of recent trends in the consumption, loss, and recycling of tungsten-containing materials in the United States during the period 1974 to 1991 and an estimation of the cumulative loss of tungsten to the environment since 1910. Obsolete tungsten is recycled primarily as cemented tungsten carbide components that have been used in cutting and wear-resistant applications. The quantity recycled, as a of annual U.S. consumption of tungsten, was estimated to have increased from 10% in 1974 to 341a in 1991. An estimated 58% of the 148,000 metric tons of primary tungsten consumed since 1910 was lost to the environment through means such as dissipation, discard, and dilution.

Jan 1, 1994

By Irving Hartmann

1. Under the conditions of the tests described herein, the proper use of an incombustible stemming plug of the type discussed prevented ignitions of gas in all tests during the firing of 21 single shots of permissible explosive in cool. In two tests with multiple blasting (four and five shots each) no ignitions resulted. 2. The results of a few tests in this investigation and of numerous tests made previously indicate that fire-clay stemming of the same weight as an incombustible plug provides about the same degree of protection as the plug against gas ignitions during blasting of coal by permissible explosives. 3. The hazard of gas ignition on firing charges of non-permissible 40-percent gelatin dynamite in coal was reduced but not eliminated when the shot holes were stemmed with one or two incombustible plugs or with an equivalent weight of fire clay. 4. On the basis of this investigation, the Bureau of Mines considers the proper use of incombustible stemming plugs of the design tested, under the conditions of the tests described in this paper, to be of equivalent safety as the same weight of fire-clay stemming. This report does not constitute approval or disapproval of the incombustible stemming plugs by the Bureau of Mines. 5. The test data indicate that misfired charges in shot holes stemmed with the incombustible stemming plug cannot be disposed of with certainty by the procedure recommended by the manufacturer. In this investigation the misfired charges failed to detonate in 30 percent of the trials.

Jan 1, 1950

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 Clyde M. Pearce

The Lake Superior iron-mining district includes parts of the States of Michigan, Minnesota, and Wisconsin. The laws of each State provide for an industrial commission and for inspection of mines. The following extract from the General Orders on Mines, effective October 25, 1937, issued by the Industrial Commission of Wisconsin, is the only reference to the use of safety catches on mine cages or skips found in the laws and regulations in the Lake Superior iron-mining district: Order 316 - Cages for Hoisting Men. (c) Sides, Gates, and Safety Catches. ***Every cage shall be provided with safety catches of sufficient strength to hold the cage with its maximum load at any point in the event the hoisting cable should break. (d) Testing Safety Catches. The safety catches of cages and skips used to hoist men shall be kept well oiled and in good working order. They shall be tested at least once each month by tying up the cage or skip with hemp rope, lowering a few feet of hoisting cable on top of cage, then cutting the hemp rope, provided that any other system of testing, which is equally effective, may be used.

Jan 1, 1945

By Fred N. Kissell

This U.S. Bureau of Mines report is a guide for the control of air contaminants during tunnel construction. Topics discussed are calculating air quantity requirements, types of ventilation systems, planning ventilation systems, control of methane gas, control of dust, control of diesel emission, ventilation to remove blasting fumes, measuring airflow, and measuring gases. This report does not provide detailed design information, but seeks to answer practical questions on air contamination issues.

Jan 1, 1995

In 2006, a total of 280 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Metal mines were the smallest mining commodity sector, comprising 1.9% of all mining operations. ? Gold mines comprised 46.8% (n=131) of all metal mining operations. Other common types of metal mines were copper ore (n=34; 12.1%), and iron ore (n=33; 11.8%). Nevada had the largest number of metal mines (n=53; 18.9%), followed by Alaska (n=31; 11.1%).

Sep 1, 2008

By Francis Crowley

Elementary concepts of seismic wave properties are reviewed to establish a framework for discussing seismic noise and its suppression. A liberal number of references is included for those who wish to pursue the topic in detail. A base motion noise level is established for a single surface seismometer. It is argued that simple array processing and seismometer burial should regularly permit us to approach this base noise level which is found in areas free of conspicuous man-made seismic noise sources. The sensitivity of the base seismic level to a number of common disturbances is presented. Solutions that promise to hold the "effective" seismic noise at a site near the base level are given for acoustic, meteorological and fixed local surface sources. Guidelines are suggested for controlling other local man-made sources, e.g. vehicular traffic, by keeping them at sufficiently large distances away from the seismometers to keep noise at permissible levels. These guidelines are speculative and conservative. They should be the subject of future study. The ability to process against general local activity, drilling, and intra- mine sources is limited. Certainly no dramatic gain is to be expected. When strong man-made and/or intramine noise sources are not controllable, detection may well be impossible to achieve, unless the seismometer can be moved close enough to the suspected miner position, i.e. via very deep holes, to compensate for the likely vast differences in strength of the miner signal and the uncontrollable man-made noise sources. However, many intramine sources, e.g., falling water, rock bursts, explosions, etc., may well preclude the existence of a hale miner in their vicinity, and therefore any need to attempt detection of a miner at such locations. The following recommendations are made to enhance the detection and location of a miner signaling seismically. They are: 1. Seismometer burial in slim holes. 2. Narrow band detection, using multiple narrow band filters to cover the likely signal band. 3. Broadband recording and analysis for time-of-arrival estimation.

Jan 1, 1974

By R. W. Dougherty

From time to time interest has been evidenced in transporting coal with water in pipe lines. About the year 1895, United States patents broadly covering a method of pumping coal with water through pipelines were granted to W. C. Andrews. His process was used to some extent in pumping anthracite culm and waste back into the worked-out portions of the mines. About 1905, W. T. Donnely was granted patents relating to pumping anthracite silt away from the breakers. From about 1913 until 1924, a British engineer, Gilbert G. Bell, used a short pipeline to convey coal with water from barges on the Thames River to the Hammersmith Electricity Generating Station, London. Minus 5-inch coal was transferred 660 yards through an 8-inch pipe. Some trouble was experienced with fine coal, which tended to plug the line. Bell made several proposals to transport coal by pipeline overland from the Midlands to London, a distance of about 100 miles, but these were never adopted. This survey is concerned mainly with the problems presented by actual pipeline transportation of coal with water. It is assumed that the coal will have been processed to remove most of the abrasive impurities by conventional methods prior to introduction into the line, and that it has been crushed to the required top size. Dewatering at the discharge end of the line is considered part of the conventional cleaning process. There still remain many pump-performance and behavior of water-coal mixture problems that can be solved only by actual performance tests. It is recognized that the distribution of coal to other than very large users is not changed. Large storage areas would be required to supply seasonal markets. Large users, such as power plants and heavy industries, could be supplied by branch lines directly to the point of use, It is also recognized that pipe lines might not be able to carry a full range of sized coal to meet market demands in many areas.

Jan 1, 1951

By E. R. Bauer

Noise-induced hearing loss (NIHL) continues to be a concern of the mining industry. A new noise standard (30 CFR, Part 62) is aimed at reducing NIHL in mining through engineering and administrative noise controls. However, the difficulty and expense of implementing engineering controls can make administrative controls an attractive alternative for reducing worker noise exposure. Over the last three years, the National Institute for Occupational Safety and Health (NIOSH) has conducted worker noise exposure surveys in underground and surface coal mines and in coal preparation plants. The surveys revealed numerous possible administrative controls and an approach to implementation and analysis. The surveys have shown that worker dosimetry, time-motion studies and equipment noise profiling are important aspects of effectively utilizing administrative controls. A description of the approach for selecting, implementing and evaluating administrative controls and a list of possible administrative controls are reported.

Jan 1, 2007

By Raymond M. Stateham

The Bureau of Mines evaluated temperature increases on the heads of resin-grouted bolts as indicators of the integrity of the anchoring of the bolt. Expected increases were calculated by the finite difference method; the calculations were checked by bolthead temperature measurements, both in the laboratory and in the field. The accuracy of the calculations varies with the validity of assumptions necessary to the process. Measurements in the laboratory produced a temperature rise of about 4.00 F on the head of a 4-foot bolt when installed with a full column of resin. This increase remained for about 30 minutes. Similar increases were noted on bolts installed at the White Pine mine, White Pine, Mich., but bolthead temperature increases in the mine lasted only about 10 to 15 minutes. When partial columns (reduced amounts) were used, the temperature increases were smaller.

Jan 1, 1976

By Charles A. Seitz

This Bureau of Mines report describes an automatic and continuous transducer-drift compensator. The compensator formed a part of the instrumentation used to indicate the saturation by hydrogen of a cryogenic, adsorption column. It has a variable delayed-response characteristic and will respond only to signals having rise times faster than component drift times. Zero drift due to varying ambient conditions and component aging is nullified. Equations relating the output as a function of the input signal are given.

Jan 1, 1981

By P. G. Kovalchik

Safe electrical operation of shuttle cars depends upon maintaining the trailing cable's conductor temperature below 90° C. However, trailing cables are wound on and off reels, which changes the heat transfer characteristics of the cable-reel system. Derating factors for trailing cables are an attempt to adjust for this changing heat transfer mechanism in a practical way. The U.S. Bureau of Mines conducted research to determine acceptable derating factors for reeled mine trailing cables, using four cable-reel combinations, representative of industry usage. Cables were continuously and intermittently loaded at different duty cycles with direct currents of different magnitudes. Relationships between the average temperature rise and current load were established for each layer of each cable. Two models were constructed; one used empirical data from the continuous and intermittent load tests, and the other was based on thermodynamic theory. Results obtained from the theoretical model were compared with those from the empirical model for the rated temperature rise of the cable. Both models can be used to simulate a variety of test conditions including those that normally cannot be conducted in the laboratory. This information was used to determine acceptable derating factors for each layer of these cable-reel combinations.

Jan 1, 1994

By Stewart W. Towle

In 1989, the u.s. Bureau of Mines initiated a contract to gather engineering, operating, and environmental cost data for 1988 for 30 major foreign primary copper smelters in market economy countries. Data were collected for 29 of the designated smelters together with information on applicable environmental regulations. Materials balance data obtained were used with available data for the eight U.S. smelters to determine the approximate extent of copper smelter sulfur emission control in 1988. A broad characterization of the status of sulfur emission control regulation was made. The 37 U.S. and foreign smelters represented roughly 73.2% of world and 89.3% of market economy primary copper production in 1988. The 29 non-U.S. smelters attained 55.3% control of their input sulfur in 1988. Combined with the 90.4% control of U.S. smelters, an aggregate 63.4% sulfur control existed. Roughly 1,951,100 mt of sulfur was emitted from the 37 market economy smelters in 1988. Identifiable SO2 control regulations covered 72.4% of the 29 foreign smelters, representing 66.5% of smelting capacity. Including U.S. smelters, 78.4% of the major market economy smelters were regulated, representing 73.1 % of smelting capacity. Significant changes since 1988 that may increase sulfur emission control are noted.

Jan 1, 1993