Search Documents

By J. E. Fraley

This report describes the preliminary results of a Bureau program to develop and test an inexpensive grout for full-column support of roof bolts. Various inorganic grouts were tested in both cartridge and slurry form. Tests were also performed on methods of water packaging and on the effect of fillers on the grout strength. Results showed that some grouts had poor early strength and exceptional mid-to long-term strength. Laboratory tests have shown that rapid-setting inorganic grout could be an economical replacement for resin bolts if the short-term strength could be increased. Further development to improve its early strength would need to be tested in the laboratory and underground to prove its potential for the mining industry.

Jan 1, 1987

By Hillary W. St. Clair

The purpose of this investigation was to determine the practicability of refining crude aluminum-silicon alloy or aluminum scrap containing silicon and iron by selective dissolution in zinc of the aluminum from the alloy followed by distillation of the zinc from the aluminum.

Jan 1, 1949

By J. E. Tiffany

A stick of explosive is a package of stored energy that can be released when needed to blast rocks, coal, and other materials; but, unlike fuels such as coal and gasoline, its potential energy is self-contained, there being enough oxygen within the package to complete the almost instantaneous reaction. When an explosive is ignited or detonated, the solid or liquid materials of which it is composed are converted rapidly into highly heated gases, which, if free to expand, would have a volume many times larger than that of the original explosive. At the instant of explosion these gases occupy only the volume of the shot hole and are therefore produced at a very high pressure, which causes the material that is being blasted to be broken or disrupted. In blasting coal efficiently the proper placement of the shot hole and the confinement of the explosive therein are both of prime importance. When these are not adjusted properly, only a small amount of the energy is expended in bringing down coal, consequently the balance of the energy tends to be expended by the emission of a flame into the working place that may lead to a gas or dust explosion. Permissible Explosives Defined The term "permissible explosive", as applied by the Bureau of Mines to explosives it has approved for use in blasting in coal mines, embraces not only the requirement that the explosive, when used, shall be similar in all respects to the basic sample that passed all the tests necessary for its admission to the published permissible list, but also that the explosive shall be used under certain prescribed requirements.

Jan 1, 1938

By D. W. Bridges, R. O. Dannenberg, Laird Crocker

Preliminary solvent extraction studies , reported by the Bureau of Mines (5) , have been continued and expanded to improve on the previous estimate of process requirements . The solvent extraction portion of the process was examined at a scale large enough to enable meaningful extrapolation of the results to geometrically similar equipment of plant size . About 82 pct of the beryllium was recovered from approximately 0.5 pct beryllium oxide (Be0) Spor Mountain , Utah , ore by a process involving ( 1 ) sulfuric acid leaching , ( 2 ) counter current decantation (CCD ) washing , (3 ) iron ( III) reduction by sodium hydrosulfide ( NaHS ) , ( 4 ) beryllium solvent extraction by di - 2- ethylhexyl phosphoric acid ( EHPA) , ( 5 ) caustic stripping of beryllium- bearing EHPA, (6 ) hydrolysis of sodium beryllate - caustic strip liquor , and (7 ) calcination of beryllium hydroxide (Be ( OH ) 2 ) formed in step (6 ) . The resulting beryllia assayed 98 to 99 pct Be0 and was suitable for most nonnuclear uses . Best overall results were obtained by using pH 2 , 1.6 grams of BeO per liter of leach liquor as feed and 0.25 N EHPA in kerosine containing 2 wt vol pct (grams per 100 ml of solution ) isodecanol ( IDA ) as solvent . Analysis of the data indicated that a commercial plant would achieve 95- pct overall extraction operating at 45 ° C with 20 hp per 1,000 gal of dispersion in each of seven mixer- settlers , having 290 gal per ton of ore hourly mixer capacity and 90 gal per ton of ore hourly settler capacity . At least 79 lb H2SO4 , 13 lb sodium hydroxide (NaOH ) , 3 lb NaHS , 0.25 lb kerosine , 0.07 lb polyacrylic flocculant , 0.03 lb EHPA , and 0.007 lb IDA would be required in H2SO4 leaching and subsequent processing to recover 1 lb BeO .

Jan 1, 1964

By A. M. Kiwior

In 1969, the Congress of the United States declared that "the first priority and concern of all in the mining industry must be the health and safety of its most precious resource - the miner," Therefore, Public Law 91-173, Federal Coal Mine Health and Safety Act of 1969, was enacted. Since haulage accidents account for a high percentage of coal mining accidents, Section 314e, ?Hoisting and Mantrips,? was included in the law. This section states: "Each locomotive and haulage car used in an underground coal mine shall be equipped with automatic brakes, when space permits. Where space does not permit automatic brakes, locomotive and haulage cars shall be subject to speed reduction gear, or similar devices approved by the Secretary which are designed to stop the locomotive and haulage cars with the proper margin of safety."

Jan 1, 1975

By Herbert L. Lines

This paper is one of a series on mining and milling methods and costs published by the Bureau of Mines. The Ash Peak mine of the Veta Mines, Inc., Duncan, Ariz., is of particular interest in that the only metal of commercial value in the ore is silver. The silver is concentrated by flotation; the concentrate is shipped to a smelter for treatment.

Jan 1, 1940

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldwell Counties in western Kentucky. According to the latest available statistics, this district supplied 1/5,960 short tons of fluorspar in 1937, compared with the total domestic production of 181,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By Lloyd Williams

1. The investigation shows that the Wilder (locally known as the Bon Air No. 2) is the only known bed of commercial importance in Putnam County, although at least 5 coal horizons are known. All of the coal production now reported comes from this bed, which is found In a basin with no known coal outcrops. Further drilling in the east end of the basin should disclose the location of the eastern end of the axial trough and the lateral extent of the basin in Putnam County and adjoining areas in Cumberland County. Continuity of this deposit with that in the area in Putnam County north of Monterey is not conclusively established but may exist. 2 Known (measured plus indicated) reserves of coal, based on a minimum bed thickness of 14 inches and on 1,800 tons per acre-foot in place, are estimated at 29 million tons, as of January 1, 1953. Of this total, 28 million tons are in beds 28 inches and more thick. All born coal reserves in Putnam County me under less than 400 feet of overburden.

Jan 1, 1954

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds. The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldrell Counties in western Kentucky. According to the latest available statistics, this district supplied 165,960 short tons of fluorspar in 1937, compared with the total domestic production of 151,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By Martin Hertzberg

This Bureau of Mines study concerns the use of the tube bundle method as a sensitive and reliable detector of mine fires. The method involves the pneumatic, sequential sampling of many points in a system through branching tube bundles that lead to a single analytic station of high sensitivity, good reliability, and convenient location. Two serious limitations inhibit its use: the relatively slow response times for long lengths of narrow sampling tubes and the wall-diffusion losses for submicrometer smoke particulates. These limitations were quantitatively evaluated by measuring tube transit times and smoke particulate transmissions as a function of tube length, diameter, and pressure drop. The comparison of the data with theory offered the challenge of extending the classical, incompressible flow solutions to the two compressible cases: isothermal and adiabatic. New equations were derived for these cases, and the measured transit time data gave reasonable agreement with calculated solutions in both the laminar and turbulent regimes. The measured transmission losses of smoke particulates from several combustion sources compared favorably with those expected from Brownian diffusion losses to the interior walls of the sampling tubes. Traveltime and smoke transmission graphs are provided and, pump power requirements are estimated.

Jan 1, 1976

"Status of the Mineral Industries" provides a written and graphic view of the Nation's mineral position and its mineral industries. The report, issued annually by the Bureau of Mines, U.S. Department of the Interior, describes recent activities in mineral production, consumption, imports, exports, and uses of significant minerals and mineral raw materials. Charts profile trends for the past 28 years in supplies and uses of iron, steel, major nonferrous metals, primary nonmetallic construction raw materials, fertilizers, and plastics. Also included are current and historical financial data on the mineral industries, such as debt-equity ratios, asset-to-liability ratios, and plant and equipment expenditures.

Jan 1, 1979

By L. F. Christianson

The presence of salt in crude petroleum has been known for many years, but recently the percentage of chloride salts of calcium, magnesium, and sodium produced with some crude oils has increased to such an extent that the removal of the salty compounds is imperative for some refiners and their presence causes considerable apprehension for others. The exact reason for this increase of salts is not known definitely, but in all probability a combination of factors contributes to the condition. The most important are acidizing of wells, development of new fields producing crude oils of greater salt content, and the depletion of old fields with an attending increase in the production of emulsified brine. Due to handling

Jan 1, 1938

By L. F. Christianson

The presence of salt in crude petroleum has been known for many years, but recently the percentage of chloride salts of calcium, magnesium, and sodium produced with some crude oils has increased to such an extent that the removal of the salty compounds is imperative for some refiners and their presence causes considerable apprehension for others. The exact reason for this increase of salts is not known definitely, but in all probability a combination of factors contributes to the condition. The most important are acidizing of wells, development of new fields producing crude oils of greater salt content, and the depletion of old fields with an attending increase in the production of emulsified brine. Due to handling

Jan 1, 1938

By Charles B. Carpenter

When a drilling well strikes a horizon in which there is a large volume of petroleum or natural gas under high pressure, danger of a blowout with disastrous results is imminent unless proper precautionary measures are taken. The history of oil-swell drilling has been marked by many blow-outs and wild wells, some of which-have caught fire and burned for long periods. Such incidents nearly always make headline news, but ordinarily few persons realize that what to them is an interesting newspaper item may entail great financial loss to the operator and frequently loss of life or personal injury to members of the drilling crew and others in the vicinity of the well. The blow-out, wild well, and crater are dreaded specters to every thoughtful person in the oil industry because of danger to life and property, underground damage to surrounding wells, dissipation of reservoir energy, and waste of irreplaceable natural resources that blow to the air or migrate to barren formations. Every operator drilling in high-pressure fields must be on the alert always to forestall any conditions that may lead to a blow-out, and his vigilance must not cease until a well is completed and oil, gas, or both are flowing to storage or market.

Jan 1, 1937

By Gerald T. Homce

Accidental contact of overhead electrical power lines by mobile equipment is a leading cause of occupational fatalities in the United States, accounting for 20% of on-the-job electrocutions. Overhead electrical power line proximity warning devices (PWDs) are intended to warn personnel if mobile equipment moves within some preselected minimum distance of an energized overhead electrical power line. Two commercially available PWDs were tested at the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). The objective of the tests was to document performance capabilities and limitations for these PWDs by identifying factors that can influence their operation. The two PWDs evaluated in this research are the SIGALARM Model 210 marketed by Allied Safety Systems, LLC, and the ASE Model 2100 from Allied Safety Engineering. Both of these devices operate by measuring the electric field present around energized power lines. The PWDs were installed on a government-owned 22-st (20-mt) rough terrain crane. A purpose-built test site used for this research at PRL allowed operation of the crane near a variety of power line configurations operating at up to 25 kV. Most of the tests involved positioning the crane adjacent to one or more overhead power lines, adjusting sensitivities of the PWDs to alarm when the crane boom was approximately 20 ft (6.1 m) from the power lines, swinging the crane boom toward the lines under a wide variety of test conditions, and finally, for each unique set of test conditions, documenting the deviation from 20 ft (6.1 m) for actual alarm activation. Test results show that several factors can adversely affect PWD performance. PWD alarm accuracy generally deteriorated when operating with a boom position significantly different than that used for the device?s last sensitivity adjustment. Another factor that can affect PWD performance is configuration of the overhead power line(s) involved. Accuracy of alarm activa­tion distances was best for simple single-circuit installations, but degraded for multiple circuits on the same poles. This degradation was slightly greater for installations with different voltage levels and/or a combination of vertical and horizontal conductor arrangements. Performance also degraded for crane operation between two intersecting power line installations, especially for intersecting lines at different voltages. An additional aspect of power line configuration shown to influence PWD accuracy was phase sequence on the power line circuit(s). Specific phase con­ductor arrangements and combinations, particularly in multiple circuit installations, resulted in either improved or degraded accuracy.

Jan 1, 2008

By Piyush K. Dutta

This report describes the design, development and manufacture of production stoper drills and results of their field tests, it is shown that underground stoper drill noise level can be reduced from 118 dBA to below 100 dBA by using these pneumatic drills. The design concept of these drills is a radical departure from the standard valved rifle bar type drill machine design to a drill featuring a valveless independent rotation system, use of an integral muffler and a shroud tube. Six drills were manufactured in a standard commercial drill manufacturing setup and organization. The design and production technology proved that commercially viable quiet drills can be made available for mine use.

Jan 1, 1983

By Paul M. Tyler

"In preparing this paper the writer has perforce depended mainly upon published information, including the catalogs and pamphlets issued by importers and dealers such as the Diamond Drill Carbon Co. and J. K. Smit & Zonen. Special acknowledgment is made to various articles published by S. H. Ball. The writer of this paper, however, is alone responsible for statements herein contained and since he has often found it necessary to rationalize apparently conflicting opinions of recognized authorities on this little-known subject, he will welcome constructive criticism from the trade.Two types of diamond are extensively used for industrial purposes. One type, known as bort or bortz (boort, boart, bowr, etc.), consists of diamonds of the gem variety but unfit for cutting into gems. They may be colorless, yellow, brown, or gray. The other type, carbonado, known in the trade as ""carbon"" or ""black diamond,"" differs greatly from the white diamond, being opaque and apparently amorphous or noncrystalline. Actually, instead of forming a large single crystal as in a gem stone, carbon diamond comprises a mass of microscopic crystals that interlock to form a tough, homogeneous material with no planes of cleavage. It is found in various colors -- black, dark green, brown, and gray -- but usually it has .a dark lustrous black surface, with a resinoid or submetallic appearance, often resembling fine-grained steel. Upon exposure to the air the broken surface gradually darkens to an ash-gray color. Ballas is a special type of carbonado in which the crystals are definitely-oriented around a central nucleus. They are harder and tougher than ordinary carbonado but are much scarcer. The Cape ballas is reputed to be not quite so tough as Brazilian ballas but tougher than carbon or bort.The diamond crystals are isometric and take a variety of forms. The cleavage is octahedral and well marked. A crack is easily -started parallel to an octahedral face, and bort or gem diamonds are notoriously brittle, especially when subjected to sudden shock. Even carbonado, while it has a high resistance to slowly applied pressures, may be chipped or broken by a sharp blow.Exposed to radioactive rays, the diamond becomes phosphorescent; this property is often utilized to distinguish it from quartz, topaz, or glass. The unusually high refractive index likewise aids in its identification in the case of a more or less transparent stone. At the temperature of the electric arc, diamond is converted into graphite, another form of Carbon but one of the softest mineral substances. At a much lower temperature, as low as 1,5620 F., the diamond may be burned like ordinary carbon in an atmosphere of oxygen, and according to some authorities there is danger of burning a diamond if overheated even in air."

Mar 1, 1932

By F. L. Wideman

This report describes a computer program that is used for the calculation of the coordinates and elevations of subsidence survey pins located by intersection. This program was developed for the Federal Bureau of Mines by the Numerical Analysis Laboratory, University of Arizona. These calculations, although relatively simple, are both tedious and time-consuming when computed with a desk calculator and trigonometric tables. In this survey, a large number of pins were surveyed repeatedly, and it was evident that both time and money could be saved by using a digital computer.

Jan 1, 1962

By William R. Vogel

The Bureau of Mines Information and Analysis organization collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 3291, to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Information and Analysis activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral- material production or consumption.

Jan 1, 1989

By P. A. Croce

A total of 17 mine gallery fire tests (23 including sub-tests) were completed during this report period (10/1/76 - 11/30/77), directed at identifying a hazardous timber-set fuel-loading in a mine passageway that is otherwise free of combustibles. Results of these initial tests show that the capability of a particular fuel loading for propagating a fire is dependent upon the imposed ventilation air velocity and the ignition intensity, although this dependency needs to be better defined. It is also apparent that care must be taken when relating gallery test fire behavior to actual mine fire behavior, because of the restrictive length of the gallery. Present data indicate that some modification to the instrumentation scheme may be advantageous before proceeding with future tests.

Jan 1, 1978