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By D. Harrington

Notwithstanding all the effort maa.e to introduce wet drills to prevent dustiness of air of metal-mine workint;s pl2.ces, there has during the pa.st few years arisen in Australia and South Africa an impression that wet drills, in­cluding the Leyner typa, actuali"y cause und..ue quantities of finely divided ore and rock to rise into the air, these fine particles being chiefly attached to · P=i-rticles of fog or spray escc:.ping frow holes using water drills. This fs saia. to have created consternation in the ranks of the min operators who have com­piiei With drastic wet dri llin rf,ubtions, 2nc:i. purchased and operateC1. various types of wet drills at no inconsiderable expeniiture in both money and effort.

Mar 1, 1922

By L. J. E. Hofer

The Bureau of Mines determined rates of adsorption and desorption of methane as a function of particle size and temperature, using coals from the Pocahontas No.3 seam (lvb) from the Bishop mine of western Virginia, and the Pittsburgh seam (hvab) from the Pursglove No. 15 mine of northern West Virginia. For a given coal sample and temperature, the rate curves for adsorption and desorption are essentially the same when expressed on a fractional approach to equilibrium basis. The rates of adsorption and desorption increased eightfold as the particle size was decreased from 6-8 to 270-325 mesh per inch. The adsorption process appears to be diffusion controlled. Rate of sorption processes increased with increasing temperature; however, the amount adsorbed at equilibrium decreased.

Jan 1, 1966

By Spencer P. Howell

One of the important problems in metal mining , tunneling or quarrying is the most economical method of bringing down the ore or rock . The two factors having great influence in determining this are arilling and blasting costs . In considering the efficiency of the explosive used , the diameter of cartridge has always been supposed to play an important part . However , the Bureau's attention has been called to the lack of definite data on the effect of cartridge diameter on the strength and sensitiveness of high explosives . This information is especially valuable to the user of explosives as it assists him to determine what diameter of borehole is most economical . A paper* on "The effect of cartridge diameter on the strength and quickness of high explosives " was submitted to the sub- committee on Drills and Drill Steel of the 24th Annual Convention of the American Mining Congress by Charles S. Hurter , Technical Representative of the E. I. duPont deNemours and Co. In this paper Mr. Hurter points out that the physical characteristics of an explosive most affected by the diameter of cartridge are rate of detonation and sensitiveness to explosion by influence , and that both increase with increase in diameter . As there is a continuing tendency to the use of smaller diameter drill holes in order to lower drilling costs , and as the smaller drill hole requires a smaller diameter of explosive cartridge than larger drill holes do , this paper has been prepared to show the effect the diameter of cartridge will have on the strength and sensitiveness of the high explosives which may be used . Accordingly , the Bureau of Mines , in cooperation with the Institute of Makers of Explosives , has carried out a series of tests to show the effect of cartridge diameter on the strength and sensitiveness of certain high explosives .

Jan 1, 1923

Many USBM research and information products are available through the systems or formats listed below: Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219 3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button o your fax machine. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. CD-ROM: This USBM disk is updated quarterly and sold by GPO's Superintendent of Documents. For information on the latest product, please contact Rodger Wedgeworth, 202/501-9557. Internet/World Wide Web: Text and graphics. Access via PC-based browsing software such as Netscape or Mosaic. Universal Resource Locator (URL) is: http:/www.usbm.gov Internet/Gopher Server Text and tables only. Using Gopher client software, access via port 70 as follows: gopher.usbm.gov Internet System Administrator: webmaster@usbm.gov (or contact your local System Administrator).

Jan 1, 1995

By A. Y. Lee

Prior work at the Bureau of Mines resulted in the successful development of a bench-scale, combination electrorefining-electrowinning method for recycling the lead from scrap batteries using waste fluosilicic acid (H2SiF6) as electrolyte. This paper describes larger scale experiments. Anodes cast from scrap battery lead were electrorefined in a 20-L multielectrode cell for 3 to 7 days. The anodes, containing 2 to 2.5 pct antimony, were ideal for obtaining firm and adherent slime blankets. Cathode deposits, assaying 99.99 pct Pb, were obtained, with current efficiencies near 99 pct. Sludge leaching was done in 100-L tanks followed by filtering in 61 cm square vacuum pan filtersu Lead of greater than 99.99-pct purity was recovered from the filtrate by electrowinning in a 20-L multielectrode cell using insoluble Pb02-Ti (lead dioxide-coated titanium) anodes and pure lead cathodes. The fluo-silicic acid electrolyte depleted in lead was repeatedly recycled to leach more sludge, and there was no problem with impurity buildup. The amount of Pb02 formed on the anodes during electrowinning was less than 1 pct of the total lead deposited on the cathodes, as long as the phosphorus concentration in the electrolyte was greater than 1.3 giL. Emissions of lead in air were less than 10 ~g/m3, well below the proposed OSHA limit of 50 ~g/m3.

Jan 1, 1984

By F. M. Boler

The U.S. Bureau of Mines has configured a flexible data acquisition and analysis workstation, which incorporates control and analysis software written in-house for use in mining research experiments conducted in the laboratory and in operating underground mines. This data acquisition system combines computer-automated-measurement-and-control (CAMAC) modular instrumentation with a Unix-based graphics workstation. The data acquisition front-end hardware can be interfaced to almost any computer. CAMAC instrumentation modules adhere to mechanical, electrical, and digital interface standards and can be custom designed or purchased off the shelf. Communications along the CAMAC bus are regulated by the crate-controller module, which contains the only hardware link to the computer interface. Software support for the data acquisition and analysis workstation consists of a series of functions and programs written in the "C" programming language designed to provide flexible and fast data acquisition, processing, and analysis. The user can interactively control the digitizers and other CAMAC modules by sending standard CAMAC read, write, and command function codes from a menu-driven program. Automated data collection is achieved through software that responds to hardware interrupts triggered by acoustic emission or microseismic events. Graphics display routines are used to plot part or all of the data and provide the ability to process and store signal information selectively.

Jan 1, 1990

By Charles A. Steen

Publication of this information circular results from an invitation extended to the Bureau of Mines by the Utex Exploration Co. to visit the company mine, on the Mi Vida claim about 39 miles southeast of Moab, in the Big Indian mining district, San Juan County, Utah. The Bureau is pleased to present this record of the Utex mine -- a property that in the relatively short period of 4 months has become one of the major uranium-ore producers on the Colorado Plateau. The ore deposit was discovered in July 1952 by Charles A. Steen, a geologist-prospector, now chief geologist of the Utex Exploration Co., in tae course of drilling the first diamond-core borehole in the Big Indian district. High-grade ore, 14 feet thick, was penetrated by the borehole. Sinking of a shaft, from which to develop the ore body, was begun in October, and the first shipment of ore left the property December 6, 1952. Ore production, as recorded on ore-settlement sheets received by the company up to July 15, 1953, totaled 16,000 tons averaging, 0.51 percent U305 and 1.25 percent V205. Discovery of the ore body and the large production of ore were achieved without any financial assistance from the Government.

Jan 1, 1953

Southeast Alaska's mining industry has come to life after nearly 50 years of relative dormancy. Commencement of operations of the Greens Creek Mine in 1989 marked a turning point in the industry as the first large scale mining operation in the region since closure of the Alaska-Juneau Mine in 1944. The Greens Creek Mine is now the nation's largest silver producer. Other large scale mining projects are now on the drawing board, including development of the Kensington Mine and reopening the Alaska-Juneau Mine, which could become North America's largest underground gold mine. The region's mining industry includes more than these large scale projects, however. For example, a significant level of mineral exploration occurs each summer in Southeast Alaska. In addition, mining operations in British Columbia and Yukon Territory are generating jobs and income in Southeast Alaska.

Jan 1, 1992

By J. O. Jones

[Willis Mountain in southeastern Buckingham County is one of several kyanite deposits its central Virginia. It is composed principally of kyanite resulting from metamorphism of siliceous sedimentary beds rich in alumina. The mountain, which trends north-south, is 2 miles long and is topped by a narrow ridge with sleep rugged sides rising to an altitude of 1,160 feet and projecting 500 fast shove the surrounding countryside. Bureau Mines engineers examiner Willis Mountain early in 1949, when bonded concentrations of coarsely crystalline kyanite were observed in the kyanite-quartzite on the northern end of the mountain and in loose boulders on the eastern slope. Commencing in late July 1949, the investigations continued on the Long Mountain segment for 11 months, ended in June 1950. A total of 600 samples from 32 diamond-drill holes, aggregating 3,876 feet of drilling, and from 255 feet of sampling in 3 trenches was assayed for kyanite and ferric oxide.]

Jan 1, 1954

By P. C. Good

The Bureau of Mines conducted a laboratory investigation of a sinter-leach method to recover aluminum and fluorine from waste carbon potlining residues from secondary cryolite recovery operations in aluminum reduction plants. After removal of carbon by burning, the residue was sintered at 900° to 1,100° C with silica and N2CO3, then crushed and leached with dilute NaOH solution, dilute Na2C03 solution, water, or water containing residual Na2O which remained in the sinter after reaction and decomposition of Na2CO3. Over 90 percent of the contained aluminum and up to 87 percent of the contained fluorine were extracted from this waste product in the form of a mixed alkaline solution. Treatment of the alkaline solution with CO2 yielded a white precipitate containing 89 percent of the original aluminum and 61 percent of the original fluorine as a mixture of synthetic cryolite and alumina, together with a variable excess of soda.

Jan 1, 1969

By William W. Adams

Not since complete records of accidents first became available has the safety record of the quarrying and related industries of the United States been as favorable as it was in 1940. The combined accident-frequency rate was lower and therefore better than in any year since 1916, the first year for which complete and comparable figures are available. Although operating companies began to furnish accident reports to the Bureau of Mines in 1911, the reports for that year and the next few years were obviously incomplete as to number of accidents reported, especially slight injuries involving only 1 or 2 days of disability of the injured employees. By 1916 the reports from operating companies appeared to be reliable as to completeness of coverage of slight injuries. Although the number of men employed in 1940 was by no means a record, it represented a gain over each of the 2 preceding years. Likewise, the number of man-hours worked during 1940 was larger than in 1938 and 1939.

Jan 1, 1942

By D. K. Steele

The domestic primary copper industry generates in excess of 600 million t of mining and mineral-processing waste annually. Most of the waste poses negligible environmental threat, but a small fraction, because of toxic or corrosive characteristics, may be subject to regulation under Subtitle C of the Resource Conservation and Recovery Act (RCRA) or other pertinent regulations. Among the wastes generated by various copper producers are flue dusts, slags, refinery-bleed solutions, and. acid-plant wastes. The U.S. Bureau of Mines (USBM) has researched methods to mitigate the environmental threat posed by copper-processing wastes while recovering valuable metals from these materials. Acid-leach processing of flue dusts has been demonstrated feasible along with sulfide treatment of liquid refinery wastes and acid-plant-bleed and gas-cleaning solutions to precipitate dissolved metals. In, addition, the feasibility of removing copper and molybdenum from slag, as well as stabilization of precipitated sulfide wastes by vitrification, have been investigated.

Jan 1, 2010

By M. R. Geer

Traditionally, fine coal is more troublesome than the coarser sizes at every step of the coal-preparation process--screening, cleaning, dewatering, and drying. Therefore the present trend toward a higher proportion of fines in the run-of-mine product, brought about by changes in mining practice necessitated to increase productivity, has added greatly to the task of preparing coal for the market. One of the more difficult and costly problems involved is that of recovering fine solids from the washery water. These fine solids should be recovered in the interest of conservation, and they must be removed to provide recirculating water of proper quality. If there is a plant effluent, it must meet increasingly stringent requirements against stream pollution. Vacuum filtration has been used for years at a few plants to recover the extreme fines, but its additional cost discouraged general adoption until recently. Now, with growing emphasis on better solids recovery, filtration is becoming more widespread. Many coal slurries filter readily, giving high cake rates and clean filtrates. Others, however, particularly those containing either a high proportion of material finer than 200-mesh or an appreciable amount of clay, are much more difficult to filter. Many of these refractory slurries can be rendered more filterable by flocculation. A previous report of Bureau of Mines research dealing with flocculation alone was published in 1940.5/

Jan 1, 1959

By J. J. Shields

This is the Seventh of a series of publications that describe methods and practices used in mining bituminous coal mechanically.3/ This report deals with the operation referred to in coal mining as continuous mining, and the interest shown by mining companies in this method is the reason for this study. Only continuous mining as it applies to the room-and-pillar system of mining, or a modification thereon, is discussed in detail in this report. Although not always as continuous as the name implies, it is a system of mining in which a machine is used to cut and load coal in one continuous operation without drilling and blasting the coal. With the mining equipment in most general use today, the usual cycle of operation in mining of coal is: (1) Timber, (2) cut, (3) drill, (4) blast, and (5) load. As the phases of this type cycle cannot be performed simultaneously in the same working place, it is necessary to operate from 3 to 7 working places so that at least 1 place is available for coal loading at all times. Even if the schedule of the phases in a cycle is maintained, coal production ceases during the time required to move the loading equipment from one loading place to the next. In 1920 a continuous-type mining machine4/ was installed in an Illinois coal mine to drive entries. Several other companies used these entry drivers for short periods in the following few years. In 1927 a southern Illinois coal company installed 2 of these machines which, in the next 25 years, were reported to have driven over 200 miles of entries. The machines did not attain widespread usage.

Jan 1, 1954

By Hillary W. Clair

An equation is derived for the rate of reaction of a sphere of metal oxide in a restricted enclosure through which a reducing gas is flowing . The equation takes into consideration the reaction rate coefficient , transport through the gas and through the porous shell of reduced oxide , the rate of gas flow , and the volume of the enclosure . The equation serves as a model for predicting the course of reduction of a particle of metal oxide in a shaft furnace .

Jan 1, 1964

By James S. Browning

Research by the Bureau of Mines demonstrated that organic heavy liquid adhering to or adsorbed on fine mineral particles can be effectively removed by a novel method embracing pulping or displacement washing with hot water alone or in combination with a detergent. Displacement washing with steam alone or in combination with a detergent also was effective for removing the heavy liquid. In tests of sized minus 48-plus 200-mesh mineral charges, both the hot water washing with detergents and detergent steaming effectively reduced the heavy liquid losses on the particles to about 0.2 pound per ton of mineral or less. Centrifuging of the wash solutions permitted an almost complete recovery of heavy liquid from the solution as a pure heavy liquid product.

Jan 1, 1966

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 Sidney Katell

This report covers the period January 1962 through December 1962; it is a continuation of the series that began with the publication of Information Circular 7510 in October 1949. Also, it is the fourth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load evolved in the preparation shared equally. The abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related subjects, are from tile following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal Utilization. 9. Cost Engineering. 10. Hydrocarbon Processing and Petroleum Refiner. 11. Industrial and Engineering Chemistry. 12. Nucleonics. 13. Oil and Gas Journal. 14. Petroleum Management. 15. World Oil.

Jan 1, 1963

By L. C. IlsLey

A list of permissible mine equipment approved by the Bureau of Mines before January 1, 1940, was published in Bureau of Mines Information Circu- lar 71103. Information Circular 71584, published as a supplement thereto, listed equipment approved during the calendar year 1940. The present list contains the information given in those two circulars, as well as approvals issued during the calendar year 1941. It embraces electrically operated air compressors, coal drills, conveyors and loading machines, electrical equipment for mine fans, mining machines and trucks, mine pumps, rock- dust distributors, room hoists, storage-battery gathering and haulage locomotives, storage-battery power trucks and shuttle cars, mine telephones, junction and distribution boxes, electric cap lamps, flame safety lamps, electric hand and trip lamps, electric flood lamps, flashlights, methane detectors, and single- and multiple-shot blasting units. The equipment listed is not approved by the Bureau of Mines until found by inspection and test to comply with minimum standards of safety as outlined in "schedules" prepared upon the basis of many years of ex- perience in dealing with safety problems confronting the coal-mining in- dustry. The use of such equipment in mines that are known to be gassy,. as well as in those that may become so, is earnestly recommended in the interests 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 incidental to coal mining.

Apr 1, 1942

By W. M. Myers

The U. S. Bureau of Mines conducted an investigation to determine the cause of the deterioration of Portland cement during storage and transportation , and to discover a means of preventing it . All available printed sources of information on this subject have been examined and a bibliography has been compiled . The subject has also been discussed with the leaders in the cement industry ; the present report is the result of their cooperation , and is based principally on information thus obtained . Deterioration of Portland cement during storage over any considerable period of time has long been noted ; closely related to it is deterioration of cement during transportation, which involves not only the time factor of storage but also exposure to varied climatic conditions . Deterioration in both cases is due to hydration of the cement by absorption of moisture from a humid atmosphere , or by exposure to actual rain-fall . After hydration cement possesses no cohesive power ; the degree of deterioration is directly proportional to the degree of hydration . The amount of deterioration of Portland cement during storage has been accurately determined in an investigation by the Structural Materials Research Laboratory , in cooperation with the Portland Cement Association . Cement stored in a shed in cloth sacks retained 80 per cent of its original strength after three months storage ; 71 per cent after six months ; 61 per cent after one year ; and 40 per cent after two years . The deterioration of Portland cement during storage and transportation was noted particularly in France during the World War . Information concerning cement used by the American Expeditionary Forces was furnished by Lt. Col. H. S. Spackman and Major E. C. Eckel , U. S. R. , who had charge of practically all matters concerning cement used by the A. E. F. The cement used by the A. E. F. came from the following sources : 42,000 tons was French , Swiss , and Spanish cements ; 120,000 tons was English cement ; 55,000 tons made in plants operated by the A.E.F .; 500 tons ( Not over) from America . Deterioration was most marked in cement from the first source .

Jun 1, 1922