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By Maria I. De Rosa

The Bureau of Mines performed experiments to determine concentrations of toxic gases and liquids, and smoke-particle diameters and diameter-concentrations evolved during degradation of PVC-derived brattice with and without nylon-woven fabrics, fiberglass, cotton, and jute brattices, and other mine materials. The samples were exposed in a 20-L chamber at temperatures of 1500 to 4500 C, with a chamber airflow of 10 L/min; 27.3 cm3/s of which was directed into a submicrometer-particle detector-analyzer. During the degradation of PVC-derived brattice, large concentrations of hydrogen chloride (TLV, 5 ppm; STEL, 100 ppm) evolved at a temperature as low as 2000 C. The minimum toxic load of 3.1 mg or 40 ppm in 50 L of dilution air, with O.l~g weight loss, may be reached at a mine face with 314,000 L of dilution air, at the 5th min, during which less than 1 kg of brattice undergoes combustion. Fiberglass, cotton, and jute brattices, pine wood dust, and coal dust showed small concentrations of carbon monoxide evolving during early stages of combustion. Hydrogen cyanide gas evolved from the PVC-derived, nylon-reinforced brattice; at a later stage of combustion, large concentrations pf carbon monoxide and dense smoke evolved from all PVC-derived brattices. Experiments to characterize smoke particles showed that marked differences exist in particle diameter-concentrations among the materials.

Jan 1, 1986

By P. A. Surgeon, R. R. Sayers

It is not the purpose of this report to try to describe all the work done during the past year for the improvement of health or the prevention of illness among miners , but to call attention to a few of the more outstanding investigations in which progress has been made . Among these , the investigations on the physiological effects of carbon monoxide , dust and ventilation , and temperature and humidity will be discussed . Carbon Monoxide . During the years 1920 and 1921 , much more work has been done on the various A survey phases of carbon monoxide than has been carried on for a number of years . of carbon monoxide poisoning in the American steel works , metal mines , and coal He conmines was made by Dr. Henry S. Forbes , of the Harvard Medical School . ** cludes from his survey that late after- symptoms following acute severe gassing rarely occur , and that almost always there is evidence of pre - existing pathological conditions when such effects do appear . He further states that he found no evidence of cumulative harmful effects resulting from frequent exposure . Dr. Forbes , Dr. Forbes , assisted by Louise Hompe , made a laboratory investigation in which anesthetized animals were exposed to carbon monoxide , illuminating gas , and benzol *** . The investigators conclude that , under the conditions of their experiments , there is no change in the coagulation time of the blood . It has been stated by many investigators that the blood of those affected by carbon monoxide does not clot as quickly as normal blood . While the investigation referred to above may not cover all the conditions , it is a valuable contribution to the subject as it indicates that the small hemorrhages found in the membranes covering the central nervous system , abdominal organs , etc. , at autopsy of those dying of carbon monoxide poisoning is probably not due to direct toxic action of the gas upon the blood .

Feb 1, 1922

By J. M. Mutmansky

"The objective of this study was to produce coal dusts for laboratory research that are similar to mine airborne dusts in chemical, mineral, and physical characteristics. In this investigation, dusts produced in laboratory comminution equipment were compared with continuous miner- generated dust for similarity in physical characteristics. Mining-generated dust (MGD) and bulk coal samples were first collected from an underground mining operation. The bulk samples were then processed in the laboratory for size reduction in various comminution devices. These laboratory- generated dust (LGD) samples were subjected to size and microscopic analyses. Physical properties of the dust particles were studied on a scanning electron microscope (SEM ). A numerical shape coordinate system (SCS) was also developed and applied to 300 particles from each sample. Statistical analysis was then performed on the collected data and characteristics of the MGD and LGD samples were compared. IntroductionIn many biomedical studies, researchers routinely introduce a dust mass into an experimental environment to assess the response of a biological entity, usually lung macrophages in vitro or a live laboratory animal, to the dust mass. To provide data of maximum usefulness, it is highly desirable to use dust with characteristics of actual mine airborne dust. The primary objective of this research was to produce dusts in the laboratory similar in chemical, mineralogical, and physical characteristics to mine airborne dusts. This paper outlines the evaluation of the physical characteristics of the lab-generated dusts.Particle shape analysis is perhaps the least-developed area in mineral-related particle science and technology. There are still no standard methods or instruments to scientifically quantify particle shapes. To date, many attempts have been made to characterize particle shapes. These procedures can be roughly classified into three categories:"

Dec 1, 1995

By Fred N. Kissell

A self-sealing brattice intended for use during coal mine rescue and recovery operations has been designed and tested by the Bureau of Mines. The major design difference between self-sealing and conventional brattice is that the fabric is cut and sewn BS a hemisphere instead of as a flat sheet. This new type of brattice offers reduced weight, leakage, and installation time. Preliminary testing indicates that the concept is worthwhile, but that further developmental research is required.

Jan 1, 1976

By Jeffrey B. Osmint

The Bureau of Mines Information and Analysis Directorate 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. The Bureau's data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), which placed the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines survey 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, 1991

By E. R. Cole

Bench-scale research at the Bureau of Mines has resulted in the successful development of a combination electrorefining-electrowinning method for recycling all the lead in scrap batteries. The method reduces energy consumption and eliminates toxic emissions, in contrast to present pyrometallurgical smelting, and the lead produced is pure enough for use in maintenance-free batteries. Anodes cast from molten lead scrap were electrorefined in 1-and 2-liter plastic cells using an electrolyte composition of 70 g/l Pb and 90 g/l free H2SiF6 (fluosilicic acid). Both reagent-grade and waste H2SiF6 were used. Cathode starting sheets were made from refined lead. Aloes, and later bone gelatin, and calcium lignin sulfonate addition agents were employed. The sludge remaining after separation of the lead metal was treated in a two-step leaching operation to solubilize the lead for recovery by electrowinning. Conditions for electrowinning were essentially the same as for electro-refining, except that insoluble Pb02-Ti (lead dioxide-coated titanium) anodes were used. The best results for both electrorefining and electrowinning were obtained with a current density of 170 amp/m2 and a cell temperature of 25° to 35° C. Cathode purity ranged from about 99.9 to 99.99+ pct Pb. Maximum energy consumption after 3 days, for electrorefining and electrowinning, was 90 and 700 kwhr per metric ton of refined lead, respectively.

Jan 1, 1981

By R. L. Handy

The goal of this research was to adapt the highly successful rock borehole shear test for use in deep, small-diameter boreholes. Operating somewhat on the principle of a rock bolt, the borehole shear test measures both the expansion pressure and pulling force to give discrete measures of rock shearing strength as a function of the applied normal pressure. A new instrument was designed and built to fit into a 2-3/8 inch diameter hole. Unfortunately the design became so complicated, the operation is nut reliable. This is attributed to constraints of the small hole, and added requirements of an in-hole anchor to push against, and a rotating shear plate cleaner for repeated tests down-hole. A clue to the d: vice complexity is its length, which is over 10 feet. Furthermore it employs concentric cylinders and one hydraulic cylinder bored into the piston of another, or it would be even longer. Meanwhile drilling technology has advanced to greatly reduce costs of drilling 5- or 6-inch diameter holes. The downhole tester therefore should be redesigned and simplified for use in a larger diameter drill hole.

Jan 1, 1982

By Roger L. King

The Bureau of Mines has developed probes to be used in emergency mine rescue operations by being lowered through a borehole drilled into an underground mine. Various probes can provide two-way voice communication with trapped miners, continuous mine atmosphere monitoring, temperature indication, and television searching capability. At present, an infrared imaging probe is being developed for "seeing" through coal smoke.

Jan 1, 1976

By Thomas Varley

"Concentration, ore-dressing, or the dressing of minerals are common terms used in metallurgy and indicate processes of separating valuable minerals from worthless gangue. It is understood, of course, that the products from such processes, being separated from the various minerals and gangue, are ready for commercial sale or for further treatment by smelters and refineries.Gravity concentration takes advantage of the difference in specific gravity of the various constituent minerals and gangue of waste material in the ore. The two most common forms of concentration by this means are jigging and table concentration. Jigs usually are used in the separation of relatively coarse material and the tables for the finer material, the line of division in general being about 20 mesh.There are mar factors to be considered .before a decision can be made as to what method would be best adapted to the successful treatment of an ore and only by careful experiments can this be determined. Among the important factors to be considered are. The nature of the minerals present, their physical and chemical relations to the gangue material, and the gangue material itself. Perhaps the most important is the number of minerals present and their relation to each other.Metals exist in ores in three principal forms -- sulphides, oxides or carbonates, and native. Concentration by gravity methods is in general best suited to sulphide ores, although in some places considerable success has, been obtained in the concentration of oxide ores by gravity methods."

Apr 1, 1920

By A. W. Kbair, L. D. Gehl

"INTRODUCTION The rock-bit interaction during the cutting process in underground mines has been a matter of great concern to mining operators, researchers and manufacturers, particularly after the passage of strict environmental laws. Coal cutting bears directly on airborne coal dust generation and rock cutting generates frictional sparks which may cause face ignitions, jeopardizing the productivity, safety and economy of the industry. It is imperative to investigate into the factors which have influence on bit we.ar. Hurt and Evans (1981) concluded that the point attack bits have greater ignition potential than the conventional wedge shaped bits, and also worn bits were more responsible for ignition than the new bits. The results of a study (Khair et al., 1992) suggested that after 7% weight loss, the bit should be replaced. The polycrystalline compact diamond (PDC) tipped bits are reported to be cost effective in a study done by USBM (Twin Cities Research Center), and it was stated that the PDC tipped drill bits had 80 to 100 times longer life than the ordinary tungsten carbide (WC) tipped bits.This paper presents the results of the experiments which were conducted utilizing a coal cutting simulator at the laboratory of the Department of Mining Engineering, West Virginia University, USA. The description of the machine and the experimental set-up have been described elsewhere (Khair et al., 1989; Gehi & Khair, 1994), and therefore, will not be discussed here. The rock types which were used in experimen~ are Tennessee sandstone, Berea sandstone and Indiana limestone. The operating parameters include (1) drum speed, (2) water spray pressure and (3) bit type. Besides studying the wear characteristics influenced by the above mentioned variables, the effect of these parameters on the required cutting force, specific energy consumption, acoustic emissions rate and rise in temperature of the bit were also studied. A preliminary study was also done to compare we.ar characteristics of the WC bits with those of the poly-crystalline compact diamond tipped bits."

Dec 1, 1995

By L. A. Readdy

No text. A set of geophysical well logs for U.S. B.M. Pilot Hole "X", Piceance Creek Basin, Colorado.

Jan 1, 1977

By J. F. Barkley

The following questions and answers were prepared principally to supply information in answer to general inquiries received by the Bureau from those contemplating the use of propane and butane fuels . Primary or basic information only is covered; this usually gives enough guidance for most inquirers . To those who wish information of the treatise type , the handbook , Butane- Propane Gases , published by the Jenkins Publications , Inc. , 1709 West 8th Street , Los Angeles 14, Calif . , is suggested .

May 1, 1949

The Bureau of Mines Minerals Information 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. 829) to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information 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, 1987

The Bureau of Mines Minerals Information 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. 329), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information 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, 1985

By S. R. Wilson

[The Anniversary-Bucky pegmatite is one of the largest, dikes in the Quartz Creek district, 21 miles east of Gunnison, Colo. The major dike consists of quartz-albite pear pagmatite and graphic granite with many quartz masses as individual cores occurring within the dike. A mining operation on one of the largest core areas has exposed several mineralogic cones directly associate with the core. These zones, including the large- units of the dike, are quartz pegmatitc, quartz-perthite pegmatite, perthite pegmatite, muscovite-feldspar -quartz pegmatite, quartz-albite pegmatite, and perthite-quartz (graphic granite) pegmatite. Muscovite and beryl are found in the muscovite-feldspar-quartz zone and are the only two products that have been marketed. Other potential products are perthite, graphic granite, and possibly small quantities of columbite-tantalite, monazite, and related radioactive minerals. The Bureau of Mines drilled two diamond-drill holes during April 1950 to investigate the largest and cost promising core area. This, report describes the results of this drilling.]

Jan 1, 1953

By John Gross

"Introduction.Southern Illinois and Kentucky are credited with approximately 90% of the fluorspar production of the United States. A small amount of high-grade acid, spar is obtained from the ore by band sorting; the greater part, however, is recovered by jigs and tables as gravel spar containing approximately 85% calcium fluoride. In the jigging and tabling operations, galena is recovered, and enough silica and calcite are removed to raise the calcium fluoride content of the gravel spar to 85%. However, the removal of silica and calcite results in a large loss of spar. With increasing depth in the mines, zinc sulphide, sphalerite, is encountered in increasing quantity and the removal of this has become a serious problem. While the sphalerite can be fairly well removed from the spar by present milling methods, a marketable zinc concentrate can not be made. The experiments described below were made on fluorspar ore from Southern Illinois, by the mining experiment station of the U. S. Bureau of Mines, at Rolla, Mo., in cooperation with the Missouri School of Mines and Metallurgy.The ore tested contained. 7.3% lead, 27.9% zinc, 35.7% calcium fluoride, 9.5% silica and 4.7%. calcite.Tests and Results. In some preliminary tests it was noticed that a portion of the finely crushed ore adhered strongly to the sample pans, and upon investigation it was found that the adhering material was practically clean spar. By utilizing this property of adhesion 46.8% of the spar was recovered as a product containing 98.3% calcium fluoride. This suggested the possibility of using electrostatic separation."

Jul 1, 1921

By R. K. Clifford

Chalcopyrite (CuFeSz) concentrates produced on the Lead Belt of Missouri typically contain 28 pct Cu and from 0.5 to 1.5 pct each of nickel and cobalt. Most of the nickel and cobalt are present as the mineral siegenite, (Ni,Co)3S4, almost none of which is recovered presently. The Bureau of Mines, U.S. Department of the Interior, has been conducting research on the chalcopyrite to produce a marketable fraction enriched in cobalt and nickel. Ferric chloride leaching of various chalcopyrite (copper) concentrates has yielded residues containing from 10.2 to 16.2 pct Ni and 8.3 to 11.4 pct Co with recoveries of approximately 79 pct. In another approach, laboratory froth-flotation tests have been conducted to investigate the effects of regrinding, roasting, baking, and steaming prior to flotation, with a variety of reagents. The best laboratory results were obtained after regrinding the copper concentrate to 94 pct minus 400 mesh and floating the chalcopyrite at natural pH (6.5) with 0.48 pound of sodium diethyldithiophosphate and 0.01 pound of sodium cyanide per ton of concentrate. This procedure yielded a tailings assaying 20.4 pct Cu, 5.2 pct Ni, and 3.45 pct Co. The tailings contained 67.2 pct of the nickel and cobalt and 15.9 pct of the copper originally in the copper concentrate; the remainder of the values reported to the flotation concentrate, which analyzed 29.6 pct Cu. To verify the laboratory flotation results, a 60 kg/hr process demonstration unit (PDU) was constructed in the Cominco American Magmont mill, Bixby, Mo.

Jan 1, 1978

By Thomas C. Ruhe

The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs. Low ambient temperatures may cause these recycled oils to become too viscous for proper absorption by ammonium nitrate (AN) prills and result in poor blast performance, safety hazards, and environmental problems. To help quantify and resolve these issues, viscosity, mixing, and performance tests were conducted at various temperatures. Diesel fuels No. 1 and No. 2 were studied separately and in blends with 25,50, and 75% RO. Good quality ANFO mixes (94-6) were produced with dry absorbent prills and blended fuel (No. 1 diesel plus RO) at temperatures as low as -40°F (-40°C) with 75% No. 1/25% RO, and at -20°F (-29°C) with 50/50. Diesel fuel No. 2 also made good mixes as low as -30" F (-34°C) with 75% No. 2/25% RO, and at 0°F (-18°C) with 50/50.

Jan 1, 2008

By Howard E. Parkinson

In 1969, new coal mine health and safety legislation was enacted in the United States. As a result of this legislation, the Department of Interior, Bureau of Mines has carried out communications research aimed at developing whole mine communications for increased safety and efficient operation. The research has advanced and many promising results are now being demonstrated to the mining industry. However, there remains a challenge to further improve wireless communications within the mine workings, and through the overburden above the workings. The objectives for future research and development will be discussed, together with the physical and operational constraints that new mine communication systems must face.

Jan 1, 1973

By T. D. Moore

The use of a partially slotted 6.5-inch-inside-diameter vertical pipe to remove methane from a longwall gob area at a depth of 2,260 feet in the Pocahontas No. 3 coalbed was investigated. The value of gas removed by such a pipe under free-flow conditions was found to equal the cost of the installation in this case. Approximately 25 percent of the available methane passed through the pipe without the use of an exhauster; an additional 10 percent was removed when an exhauster was employed. The diversion of methane through a vertical slotted pipe to the surface permitted the use of increased mining rates and decreased the ventilation air requirements.

Jan 1, 1972