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Develop new technology to encourage domestic processing of automobile catalytic converters for recovering platinum -group metals. Background Automobile catalytic converters are used to convert pollutants in automobile exhaust into water vapor, carbon dioxide, and nitrogen, About 1 million troy ounces of platinum-group metals arc used each year in the. United Slates to manufacture catalytic converters. It has been estimated that about 60 pct of the used catalytic converters arc being collected. Most of these used catalytic converters were not processed in the United States but were exported to Japan or Europe for processing. In 1991, about 250,000 troy ounces of platinum-group metals were recovered from scrap catalytic converters collected in the United States. Each short ton of decanned catalyst may contain 30 troy ounces of platinum-group metals valued at over $15,000. Development of an economic process for the recovery of platinum-group metals that can be operated on a small or large scale may increase, the percentage of catalytic converters collected and encourage domestic processing to recover a platinum-group metal concentrate. This would significantly decrease the dependence of the United States on imports for these critical and strategic metals.

Jan 1, 1992

By Todd M. Ruff

Researchers at the National Institute for Occupational Safety and Health (NIOSH) are studying methods to prevent workers from being entangled in machinery used at mining operations. An analysis of mining accidents in the United States that resulted in a fatality or permanent disability from 2000 through 2005 showed 438 severe incidents that involved contact with machinery or equipment, an average of 73 per year. Researchers determined that the most common machinery involved in these severe accidents was conveyors. Also, a significant portion of the accidents occurred during machine maintenance and repair. Researchers are focusing on improved methods to prevent unintentional machine startup during maintenance activity and methods to detect workers near moving machine components. One new technology that shows promise for this application is intelligent video. Popular in the surveillance and security industries, these systems use cameras and computerized video analysis techniques to automatically detect the presence of people in preset zones within the camera?s field of view. A preliminary study has been initiated to determine if this technology could reliably detect the presence of workers in hazardous locations near machinery. Possible advantages of the use of this technology include improved detection zone demarcation and improved ability to distinguish between hazardous and non-hazardous proximity, compared to conventional proximity sensor techniques. Initial tests to detect a person near a conveyor system in daylight conditions showed promising results. A description of the technology, test procedures and results, implementation challenges, and future research needs are discussed.

Jan 1, 2008

By Walter K. Utt

The U.S. Bureau of Mines conducted research to develop an accurate, real-time, position monitoring and warning system for the vehicles used in surface mining. The product of this research will be technology to reduce accidents and injuries associated with the operation of surface mining haulage equipment. The position monitoring system should reduce accidents related to vehicle position and also increase the efficiency of haulage operations. This research was conducted in preparation for development of an accurate, real-time position monitoring and warning system, which notifies equipment operators when they deviate from a known safe course and are approaching a fixed hazard. A radar positioning system designed for marine applications was evaluated and a series of tests was run to determine the accuracy of the radar positioning system when used in a land vehicle. The radar position determination was compared to surveyed values. Both static and dynamic (moving vehicle) tests were conducted. The static test results were marginal and the dynamic test results were not accurate enough for the position monitoring and warning system. Although a promising technology, the system tested needs to be modified to meet the accuracy requirements of mobile mine equipment.

Jan 1, 2010

Reduce the number of accidents caused by slips and falls from large mining equipment. Approach A powered lift was developed that provides operators with a safer way of getting on and off large machines. How It Works The powered step is designed to lift personnel and materials to working levels on large machines. It eliminates hazardous blind steps and makes it unnecessary to climb on irregular surfaces made slippery by mud, ice, snow, and accumulations of grease. The step is powered by a self-contained electric/hydraulic unit which is connected to a vehicle's auxiliary power supply. When in the "down" position, the step rests about 15 inches above ground level. When the power unit is activated with an electrical switch located on the step, a Single cylinder attached between two lifting arms smoothly lifts the step. In conjunction with the lifting motion, a linkage and bearing arrangement on the mounting end of the lift arms causes the step to rotate towards the machine, so that the step moves in an arc from ground to platform level. When the machine Is operating, the step is automatically locked in the "up" position, protecting it against any damaging contact with obstructions. The step is lowered by activating a pressure release solenoid. An in-line orifice controls downward speed and prevents free fall. On most machines, additional control switches are conveniently located at ground level and in the operator's cab. Visual alarms and machine interlocks are provided where necessary to prevent machine operation when the step is In the "down" position. The powered step can be easily adapted to any type or model of large machinery.

Jan 1, 1981

By H. R. Shell

Variations between laboratories on the silica and alumina content of calcined kyanite led to this Bureau of Mines study of the extent and nature of the differences. In particular, Bureau scientists hoped the study would lead to correction of the causes of the dissimilarities. A sample of calcined Kenya kyanite was analyzed by seven different laboratories familiar with silicate analysis. The compiled data indicated differences originating from lack of recovery of silica after two acidic dehydrations, from high alumina caused by several factors, from loss or gain of iron during sample fusion, and from indifference regarding the accurate determination of minor constituents.

Jan 1, 1959

By Howard E. Parkinson

An environment monitoring and communication system has been installed in the Bruceton Mine, and research is under way to improve mine safety. Standard day-to-day mine communications are available, along with additional systems installed to permit experimentation with wireless radio, through-the-earth phones, along-the-roof paging, and mine face machinery communications. Research is continuing and the essential concepts for a dependable whole mine communication system, providing simple environment monitoring, improved day-to-day communications and post-disaster communications, will be demonstrated in a larger mine with about 900 feet of overburden.

Reduce mine worker dust exposure by capturing airborne coal and quartz dust generated by a continuous mining machine. Approach Install a water-powered scrubber system operating at 1,000 psi on the side of a continuous miner boom. Dusty air under the boom is drawn through the scrubber, and cleaned air is discharged into the face return. How It Works Most coal mines use exhaust face ventilation to send fresh air over the miner operator, and contaminated air behind the line curtain to the section return. The difficulty with exhaust face ventilation is that the line curtain should be within 10 feet of the face for maximum effectiveness. If the line curtain is not extended properly, or water sprays for dust control are poorly installed, dust rolls back toward the operator. A scrubber mounted on the mining machine will effectively reduce this dust rollback and the dust in the return airstream.

Jan 1, 1989

Develop a new method for coal mint pillar stability evaluation and design based on pillar load measurements. Approach A novel approach to chain pillar stability evaluation and design for longwall coal mining panels has been developed by the Bureau of Mines. The evaluation approach uses an INTEGRITY FACTOR as the criterion for stability. Hydraulic borehole pressure cells developed by the Bureau are used to measure stresses in a pillar for stability evaluation. The results are used to improve the pillar design.

Jan 1, 1989

By James C. Cawley

A summary is presented of existing leaky feeder communications systems currently in operation in North America. Background information pertaining to previous use of leaky feeder technology is discussed along with the survey methodology. A review of some pertinent facts concerning propagation in tunnels and specific reference to mine tunnel propagation is presented. A summary of the characteristics of each mine visited is presented in tabular form, and methods of procurement and maintenance are discussed. The role of user training in efficient system use is presented. Seven sites representing eight mines are included in the survey. Economic and technical topics are considered.

By Joseph C. Zelanko, Anthony T. Iannacchione

One of the most difficult and longstanding engineering problems associated with coal mining is the catastrophic failure phenomenon known as coal mine bursts (known in the United States as bumps). For more than 70 years, researchers and practitioners have attempted to determine whether this destruction observed underground is caused by stress conditions within the coal pillar or from distant seismic sources in the mine roof and floor strata. The role of confinement and the extent of failure in solid pillars and panels have also proven difficult to define. These are important issues, since control solutions need to be based on a fundamental understanding of the problem. Obsenations by U.S. Bureau of Mines researchers over the last decade have helped to clarify certain aspects of these issues. Microseismic sensors and geomechanic field measurements have located areas of excess energy release, identified stress conditions in coalbeds close to failure, and recorded the response of mine structures prone to bursts. In the present study, data available for a range of U.S. bursts were considered in an effort to evaluate both common and distinctive features. Although the attempt revealed little commonality, encouraging results were produced by categorizing coal bursts by source mechanisms. When a coal burst is thus categorized, differences in environmental factors-such as geology, stress fields, and mining methods-are highlighted, and viable control strategies are readily recognized.

Provide roof to floor closure rate measurements during underground mining, especially retreat mining of coal pillars, thereby helping the miners predict an imminent roof fall. Approach An electronic device and rugged potentiometric extensometer were developed to provide a means fur measuring total closure and the rate of closure. How It Works An intrinsically safe, battery operated instrument is enclosed in a rugged, hand carried field case. The unit is constructed using low-power, integrated circuits to provide minimal battery drain. Two digital Light Emitting Diode (LED) readouts are used; one displays the rate, the other displays the total closure. The unit will measure one extensometer continuously or two extensometers alternately. Two potentiometric extensometers with a closure measurement range of 6 inches are attached to the readout unit. As the roof to floor closure changes, the potentiometric resistance

Jan 1, 1982

By Charles F. Weber

Premature blasts of charges of explosives have caused many deaths in anthracite mines, and the causes of many of the blasts were not determined satisfactorily. Investigators often found fairly high potential differences between such metallic objects as rails, pipes, conveyor lines, or sheet-iron chutes in the working place where an accident had occurred. At one mine where a premature blast occurred in a rock tunnel, one workman was killed and two others were injured, and several days later a potential difference large enough to explode an electric squib was detected between the compressed-air pipe and the track rail; the voltage fluctuated and appeared to change with the movement of a locomotive. At another mine, a. workman was killed when a primed cartridge that he was about to load in a blast hole exploded in his hand. During the investigation, a potential difference was found between the conveyor line and the sheet-iron chute. During a 5-year Period, 61 fatalities and 771 nonfatal injuries were caused by explosives accidents in anthracite mines, and one of the chief causes of these accidents was premature blasts.

Jan 1, 1950

By J. F. Barkley

"In the course of the Government's Fuel Economy Survey of its own power plants, studies and tests have been made of various oil-burning equipments under power-plant boilers. There are now many types of burners being offered in the relatively limited field of power-plant use. The majority of the types used may be grouped into two general classes- those using steam to effect the atomizing of the oil, and those using mechanical means.Burners using steam have had the most prominence in this field for a long period. The mechanical atomizing type of burner successfully applied on shipboard, however, pointed to a possible betterment in land work. The vision presented itself of a burner that would need no steam for atomizing that would permit of air inlets or registers compactly arranged as a part of the entire burner, and that would only require the natural stack draft usually available in land boiler furnaces. Hence, rather recently there has been much development along this line, resulting in various types of burners.In Table 1 are grouped test items chosen from many tests showing representative analyses of the products of combustion obtained with various burners installed in various types of furnaces. In all these tests the burners were handled by experts and represent practically the best attainable for that particular arrangement. The boiler efficiencies ranged from 70% to 80%. It will be noted that the burners using steam for atomizing were able to secure slightly better 002 and less 02 without the presence of CO."

Feb 1, 1926

Control respirable dust in underground coal mines through selection of optimum water spray pressures. Approach Through underground trials at longwall and continuous mining operations, the relationship between operating water spray pressure and respirable dust levels at the machine operator's location was determined. Defining the Application Water sprays are used for two significantly different control applications. On longwall mining machines, sprays are commonly installed both on the body of the machine and on the cutting drum. Sprays on the body of the machine are used to redirect dust which has already become airborne away from the machine operator. Each spray acts as a small fan, directing the primary airflow over and around the machine and towards the face, away from the operator. The energy of this system is directly related to the spray pressure. Higher pressures move more air, but care must be taken not to cause turbulence and boilout into the walkway. Sprays mounted on the drum are, effective at suppressing the respirable dust at the bit/coal interface and preventing it from becoming airborne. Again, these sprays must not impart excessive energy to the dust particles thus stirring up more dust than they suppress. While mounting sprays on the shearer drum is standard industry practice, there is no reliable technology available to successfully mount water sprays on the cutting drum of continuous miners. Instead, sprays are mounted on the machine body, close to the drum, and directed at the cutting head. This allows the water to reach the bit/coal interface and mix with the cut material. Here again, care must be exercised to prevent these sprays from imparting excessive energy to the dust particles and stirring up more dust than they suppress. These sprays can also cause dust "rollback" from the face, toward the operator, if operated at too high pressures.

Jan 1, 1986

By D. G. RUNNER

Information Circular 6148R, " Selected Bibliography of Minerals and Their Identification ," was issued in June 1929 , revised in July 1937, and again in October 1938. The popularity of this circular , combined with the desire to make it more comprehensive , has occasioned the preparation of this compilation of references . Where possible , date of publication , publisher, current price , and number of pages are given, although prices are subject to change at intervals . The references are grouped under the following headings : minerals , gems , rocks , geology, geomorphology, engineering geology , prospecting, mining . engineering, microscopy, technical dictionaries , and miscellaneous . For ready reference, the authors ' names are arranged alphabetically under each grouping . This list is not comprehensive, but contains only those references in most common use and which are generally available in public college libraries .

Sep 1, 1949

Provide a method for obtaining in situ measurements of coal cutting forces which are needed for mining machine design. Approach A portable in-seam testing device is carried to the face of an underground coal mine heading to measure the cut-ting force encountered by a continuous miner pick directly at its maximum depth of cut. How It Works The tester frame is attached directly to the coal surface with four one inch diameter threaded studs resin-bolted into 1-1/4 inch diameter holes which are drilled 30 inches deep. Spherical nuts and washers compensate for misalignment between the bolts bearing plate, and traverse beams. Spacers can be placed over the studs to assure that the traverse beams remain in the same plane. Cutting forces are applied by a hydraulic cylinder that moves the pick of the tester through a twin-chain arrangement which gives a 20-inch cutting stroke with

Jan 1, 1982

By Carlton E. Brown

The purpose of this report is to present results of tests on the effectiveness of a spray of water mist, commonly called compressed-air water blast or water blast, in reducing the concentration of dust present in the air shortly after blasting and during mucking of the blasted material. Many observations have been male on the effectiveness of such ,sprays, but published quantitative information on comparative dust concentrations with and without their use, obtained by dust-sampling methods in use in this country, is rare if not absent. Tests conducted in South Africa about 19164/ and more recently in England5/, 6/ have shown that such sprays reduce the dust concentration to very low values within a fen minutes after blasting,

Jan 1, 1938

By T. L. Joseph

"In the January 3 issue of Iron Trade Review, Sweetser2, in referring to the problem of coke combustibility, points out that, ""Someone should formulate a rule for the rate of flow of coke through the zone of coke combustion that now appears to be confined to a comparatively restricted volume in front of the tuyeres,"" In formulating such a rule it is necessary to distinguish clearly between combustibility, a property of the fuel, and rate of combustion, which is determined by the rate at which air is supplied to the fuel bed. The rate of carbon gasified at the tuyeres of a blast furnace is independent of coke combusti-bility. A fast-burning coke will burn in a more restricted volume than a slow-burning coke, but both types of fuel will be consumed at rates determined by the supply of oxygen,A number of the definitions of combustibility that have appeared in technical literature relate more closely to rate of combustion than to combustibility. Perrott and Kinney) have correctly defined it as follows: ""Combustibility of coke from the standpoint of its use in, the blast furnace is inversely proportional to the mean rate of gasification per unit volume of the combustion zone, assuming other factors remain constant,"" Combustibility of coke refers therefore to those properties that determine the size or extent of the combustion zone. Relative differences in these properties can be measured by the depth of the fuel bed required to convert oxygen from the air into carbon monoxide."

May 1, 1924

Investigate the use and placement of lightweight concrete to improve ground control technology in deep mines where deformation occurs under heavy ground conditions and where there is danger of rock bursts. Approach Investigations of lightweight concrete properties and placement methods were conducted in the laboratory and in the field. Three test sections were completed: a monolithic, portal-type structure with integral walls and arch constructed aboveground; an underground test section constructed in a mine drift using plywood forms; and a test section constructed in a mine drift using an air-supported formwork. In the two underground test sections, the light-weight concrete was placed using a piston pump with concrete discharge line. A cooperating mine also used lightweight concrete, in the density range of 25 lb/ft3, to replace timber blocking in a raise preparation structure (the enlarged area across a vein where chutes and manway access arc placed). Other experiments included the use of precast lightweight concrete blocks in situations where ground support was needed, such as fur mine, ventilation doors, stoppings, and barricades.

Jan 1, 1990

Rapidly identify unstable mine waste embankments and similar dam structures. Approach Aerial photography, geotechnical instrumentation, and telephone or satellite data transmission are used to supplement walk-around inspect ions. How It Works Embankment stability and other indicators of structural integrity are evaluated using aerial photography, and on-site unattended instruments and data transmitting systems. Evidence of external movement and water seepage is obtained from aerial photography and photogrammetric evaluation techniques. Surface points marked by stake- mounted targets are monitored photographically at time intervals of several weeks or months. Photographic measurements of x, y, and z coordinates of these points are obtained from flying a series of photo-runs over the dam.

Jan 1, 1979