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By T. G. Carnahan

The Federal Bureau of Mines investigated, on a laboratory scale, a technique for recovery of silver from pregnant solutions generated in the hydro-metallurgical treatment of complex base-metal sulfide concentrates with oxidizing chloride media. This technique provides a means for recovery and simplified reduction of accessory silver to metal from chloride solutions. The method consists of adding NaI or KI to the solution to precipitate AgI, which is then contacted with Na2S to produce Ag2S and to regenerate the iodide salt solution. Silver recoveries range from 99 pct with 20 pct excess iodide precipitant, to 92 pct when the theoretical stoichiometric amount of precipitant is employed. The Ag2S product can be reduced to silver metal by contact with aluminum chips in NaOH solution followed by purification with conventional fire refining techniques.

Jan 1, 1980

By Howard E. Parkinson

A brief description is given of various Bureau of Mines research activities that have begun since July 1974 and are not being reported on by others at the Third West Virginia University (WVU) Conference on Coal Mine Electrotechnology. An essential feature of the various projects is that they are pragmatic. The projects are applied research and are carried out both by the Bureau in-house research group and by other research groups through contract research. Projects have been directed toward wired-type communications with a special effort to modify the wired systems so as to be more effectively used. The projects are in three groups: Pager phone systems, trolley line phone systems, and guided-wire wireless communications. Also, a brief sketch is given of research that is essential for further developments in mine communications. From the early results of these various projects, the Bureau has good reason to project that there will be improved performance of existing communication systems and that communications will be extended to other individuals working in areas that are excluded from present mine communication systems.

By R. D. Leitch

Beside many other damaging effects of acid mine drainage, corrosion of pipe lines and pumps frequently adds much to mine operating, costs. Not only is it often necessary to install special and relatively costly acid-resistant materials, but even these may require frequent replacements. It is not unusual for ordinary steel pipe to last only a few days in some highly acid waters, while other common materials, though more resistant, frequently cast only a few weeks. In the spring of 1935, local PWA authorities offered to assign a number of persons to various problems under the direction of regular employees of the Bureau of Mines. It was believed that at least some simple tests on as many different kinds of acid-resistant pipes as could readily be obtained might produce interesting; and valuable information for the mining industry. This paper describes the tests and some results that have since been noted.

Jan 1, 1938

By A. J. Forney

A high-Btu gas was made at the Bruceton, Pa., laboratories of the Bureau of Mines to demonstrate the feasibility of using the gas as a nonpolluting fuel for automobiles. The pilot plants at Bruceton were revised to combine the processes of coal gasification, gas purification, and catalytic methanation in one overall system. Tests in the Bureau's test automobiles at Bartlesville, Okla., showed the Synthane gas was less polluting than natural gas.

Jan 1, 1972

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Jan 1, 2011

By Howard E. Parkinson

Since 1969, the Department of Interior, Bureau of Mines, has carried out communications research. Research has been directed toward developing emergency and nonemergency mine communications. This paper gives an overview of the progress made in the last two years. Particular emphasis is given to the overall program, noise and signal measurements, systems studies, guidelines, products, and demonstrations now being carried on in operating mines.

By James R. Wait

It is the purpose of this paper to review theoretical model concepts in through- the -earth transmission of electromagnetic waves. While the subject is very broad in its defined scope, we will be conscious of the specific applications to mine rescue and emergency telecommunications in coal mine environments. The plan of the paper is to outline previous theoretical efforts without attempting to attach names or organizations to the specific developments. However, we include a guide to the literature as an appendix. Without pretending to be entirely impartial we include a critique of the limitations of the available analytical models. As I see it the central problem is to calculate the steady state mutual impedance of a four-terminal network that is the black box characterizing the through-the-earth path. Problems of secondary importance include the determination of the input impedances of the two pairs of terminals and the associated transient responses. [ ]

Jan 1, 1973

By G. Dale Coe, Will H. Coghill

The " periodic pincer " herein described fills a need for a device to control the rate of flow of a wet ore pulp through an orifice . Two uses of the periodic pincer to be discussed are on classifiers and on a wet ore feeder . Although the immediate necessity that brought about this device was for better operation of a miniature hydraulic classifier , in connection with an investigation of iron- ore concentration being conducted by the Federal · Bureau of Mines , with the cooperation of the University of Alabama , the device has promise of a wider field of application . In the iron - ore work , the need became so acute for a nonchoking , uniform - delivery classifier spigot that development of a suitable device was imperative .

Apr 1, 1944

By Todd M. Ruff

The lack of visibility near earthmoving equipment resulted in six fatalities in U.S. surface mining operations during 2003. These accidents were the result of either a piece of equipment striking another vehicle or worker, or the equipment traveling over the edge of an embankment. Figure 1 is an example of a recent accident that resulted in serious injuries to one worker and fatal injuries to two others when a van parked in front of a haul truck. Two fatalities occurred in separate incidents when front-end loaders struck workers. Another two workers were killed when their equipment backed over the edge of a highwall or dump point [1]. There is clearly a need to provide better information to equipment operators regarding their surroundings. [ ] Researchers at the National Institute for Occupational Safety and Health (NIOSH), Spokane Research Laboratory, are working to reduce these accidents by developing systems that sense obstacles and changes in terrain near the equipment and provide this information to the operator. Many off-the-shelf proximity warning systems that were developed for automobiles, light trucks, and recreational vehicles were evaluated on off-highway dump trucks [2]. Many limitations were found with existing systems, including frequent false alarms, limited detection range, a lack of specific information on an obstacle (e.g., location, identity), difficulties in finding suitable mounting locations, and an inability to withstand the environment. These limitations have necessitated the development of new systems designed specifically for large, off-highway, earthmoving equipment. New off-the-shelf systems available for mining equipment include radar and tag-based detection systems. Prototype systems now being developed include a proximity warning system based on the Global Positioning System (GPS) and a computer-assisted stereovision system. Development of these new systems was accomplished by working with manufacturers to modify existing systems to meet the needs of surface mining and through cooperative research with organizations to develop completely new solutions. A typical proximity warning system consists of a sensor or antenna mounted on the equipment that detects the presence of obstacles and an alarm interface in the cab of the equipment. Some systems, as described in more detail below, also require that other vehicles and personnel on the ground be outfitted with electronic tags that transmit an “I’m here” signal back to the system (e.g., radio signal detection systems or GPS). Many types of proximity warning systems are on the market, but they are not all discussed in this paper. APPROACH In past work, engineers at NIOSH evaluated several off-the-shelf proximity warning technologies in order to verify their effectiveness on off-highway dump trucks [2]. Dump trucks were chosen because of the number and severity of accidents involving this type of equipment and because extensive blind areas around these trucks are typical. This experience allowed engineers to limit the number of systems chosen for long-term tests at mine sites to those systems showing

By V. A. Nieberlein

This paper presents the results of research undertaken to recover titanium and columbium by low-temperature chlorination of low-grade columbium-bearing ilmenite concentrates, and to simultaneously remove chlorinated impurities from the volatile chlorides without resort to distillation. Coke-reduced ilmenite was chlorinated at 400° to 500° C., and the resulting TiC14 was free of most impurities before condensation. A heated purification column was used wherein various packing materials reacted chemically or physically with the impurities which passed through them in the vapor phase. A nearly water-white TiC14 product was obtained directly. The principal impurities in the titanium tetrachloride were: 0.02 percent Fe, 0.01 percent V, 0.05 percent A1, 0.04 percent Si, and 0.07 percent Cb. This is a less pure product than commercial TiC14. Most of the columbium was recovered as crude CbC15, requiring further refining.

Jan 1, 1960

By E. P. Youngman

Great Britain has never had a basic raining law such as is in force in most foreign countries. This lack may be due to the fact that, with the exception of gold and silver, all metals or minerals belong to the owner of the surface land. Even with respect to the precious metals, gold and silver, which are not abundant in Great Britain, the right of the Crown, though still technically acknowledged, is not always insisted unon. All other metals and minerals are vested in the ground landlord, who may sell, lease, or other¬ wise convey them. The State has little to do with the mining industry except in. regulatory and judicial matters. The Government must settle controversies and provide for easements, rights of way for railroads, roads, and canals, or, in general, effect the same control that it exercises over other industries. As mining was carried on in very early times in England, of necessity a certain legal procedure came into existence, which in effect was little more than a private contract between the owner of the mineral (whether an individual or the State) and the miner. The nature of such contracts, of course, has changed radically with the changed relations between classes, as England lias developed from the feudal into the modern State. From the medley of ancient procedure and custom, a concession system of mining in^its simplest form lias evolved. Of the earlier conditions. Van Wagenen says

Oct 1, 1931

"At the request of the Anthracite Institute, the United States Bureau of Mines during February, March, and April 1935, made a field survey of commercial anthracite shipped from collieries scattered throughout the Anthracite regions. In all, 268 samples were taken at 41 breakers from Carbondale at the northern end of the field to Pottsville at the south. These collieries ship approximately 50 percent of the industry’s total production. The geographical distribution of the breakers sampled was as nearly as practicable in proportion to the tonnage of the companies from each region cooperating in the plan.The following are the weighted average analyses, by sizes, of the samples taken in this survey;"

Jul 1, 1935

Compare the dust control efficiency and bit life of surface coal mine drills using standard water injection and water injection with water separation. Approach A research study was conducted to determine if a water separation technique affects wet suppression dust control. Dust control efficiency and bit life of surface coal mine drills were compared during tests using both standard water injection (wet drill bit cutting) and water injection with water separation (dry drill bit cutting). Background Surface coal mine blast hole drills typically generate a substantial amount of dust during the drilling cycle. One method used to control this dust is the injection of water into the bailing air. This is known as wet suppression.

Jan 1, 1988

By T. J. Ballard

The Rickard mine in York County, S. C., named for the original owner, Alexander Rickard, was operated about 50 years as. No records are available of the quantity of corundum shipped. Pratt states, "Many tons were picked up from the surface and shipped." The mine was visited on August 6, 1943, by the author, accompanied by Gilbert W. Withers of Atlanta, Ga. Investigation of the property was begun by the Bureau of Mines after some initial work by the Mi-Cor Corp., a company organized by Gilbert P. Withers of Atlanta to explore the property. In conducting the Bureau program, 754 linear feet of trenches were dug, 110 feet of old drifts cleaned out and examined, and 38 feet of shaft retimbered.

Jan 1, 1948

Provide the mining industry with an easy-to-use means of accurately predicting surface subsidence caused by longwall mining in the northern Appalachian Coal Basin. Approach The Bureau of Mines developed a subsidence prediction model using the novel approach of a variable subsidence coefficient. This approach had to be used because of the resistant strata types which commonly occur within the relatively thin overburden material typical in northern Appalachia. Such resistant strata precluded the use of the popular European methods that assume homogeneous overburden or overburden behaving as homogeneous from a subsidence point of view. The model is available in a BASIC computer program for use on most personal computers. The user has the options of obtaining individual subsidence calculations or may choose to develop a subsidence profile using an average overburden value. The program output can be generated in graphic or tabular form showing the location of the surface point with respect to the longwall panel edge, overburden depth, and the subsidence value.

Jan 1, 1986

By Gregory J. Chekan

In order to reduce waste and improve resource conservation, mine planning, and development, the U.S. Bureau of Mines is investigating multiple seam interactions associated with longwall mining. Longwall gate entry and panel stability have been influenced by previous mining in coalbeds above and below a mine in Virginia that operates in the Lower Banner Coalbed. Directly superjacent, approximately 115 ft, the Upper Banner Coalbed has been partially worked by room-and-pillar mining. Directly subjacent, approximately 730 ft, the Tiller Coalbed has been worked by partial room-and-pillar retreat mining. The study mine has experienced problems during development of gate entries in areas of overmining and undermining. It is anticipated that stress fields associated with adjacent mining may further affect gate entry stability and face advancement during the extraction of the longwall panel. To assess overmining and undermining effects on ground stability, the Bureau gathered geotechnical information at the site. Headgate entries and pillars were instrumented and monitored to study loading behavior as the longwall face approached and passed potential problem areas. Measurements indicate that although increases in average pillar pressure were greater than predicted values, previous mining in adjacent coalbeds had little effect on headgate stability.

Jan 1, 1989

To inexpensively monitor the ventilating airflow anywhere in underground working places. The Approach: The Bureau has developed a small self-contained monitor which sounds an audible alarm and energizes a flashing lamp if air velocity decreases below normal. How It Works: The sensing element of this inexpensive monitor is a thermistor, which is self-heated by a constant-current electrical source. Airflow over the thermistor increases heat removal and lowers the thermistor temperature. Since the electrical resistance of a thermistor is a function of temperature change, the voltage across it varies with temperature, and, therefore, the air velocity. Changes in the voltage across the thermistor are amplified, and can be used to trigger the alarms.

Jan 1, 1975

By A. Wahab Khair

"This paper presents an analysis of fracture mechanisms in coal subjected to bi-axial state of stresses, indentation of laterally confined coal specimen. Coal specimens were loaded to failure by the straight wedge indenters at various lateral confinement pressures. Strain distribution and acoustic emission characteristics of coal specimens under stress were recorded. The influence lines of vertical forces acting on the horizontal straight boundary of the coal specimen for each type of wedge indenter have been established using holographic interferometry technique. The effects of wedge indenter angle, confinement pressure, and coal anisotropy on fracture types, failure modes, and post-failure conditions were studied. The results indicated that combined application of holographic interferometry and acoustic emission monitoring techniques is not only suitable ·for studying deformability of heterogeneous and microscopically discontinuous material under stress but it also enhances the mode of fracture during the post failure stage. INTRODUCTIONOne of the relevant processes in the coal cutting technology is the application of indentation theories. Since most cutting tools in the coal industry are wedge shaped most of the indentation research is found for a wedge shaped tool.A wide range of behavior is found in different rocks subjected to the wedge penetration. A rock which is elastic brittle at standard pressure might become elastic plastic at high confining pressure (Gnirk and Cheatham, 1963). It was also observed that some rocks will merely be crushed and indented by a wedge whereas others will crack and form chips, furthermore the existence or non-existence of chips depends mostly on the geometry of the indenter, type of rock and the depth of penetration (Evans and Murrel, 1958). However, coal cutting technology is mostly explained by models which use rigid wedge to penetrate into a brittle material in which both crushing and chipping will occur (Evans and Murrel, 1958, 1962)."

Jan 1, 1988

By J. E. Wilson, J. D. Davis, C. R. Holmes

 The Bureau of Mines-American Gas Association (BM-AGA) method5/ has been used in surveying the carbonizing properties of American coals and, to date, in testing coals from 43 beds. The results in this report apply only to tests in the 18-inch retort at 800°, 900°, and 1,000° C. on coals from 32 beds. Table 1 gives the proximate and ultimate analyses of these coals and the name and location of mines. Coals from Pennsylvania, Virginia, West Virginia, Kentucky, Indiana, and Washington are considered. Seven of the coals are of low-volatile, four of medium-volatile, and twenty-one of high-volatile bituminous rank. One of the high-volatile coals (No. 45) is of high-volatile C rank, whereas all the others are of high-volatile A rank.

Mar 1, 1943

By Richard A. Winters

The 31,880-acre Battle Creek Wilderness Study Area (WSA) was evaluated for mineral resources by the U.S. Bureau of Mines in 1984. No mining district is in the area, nor were any mines or claims recorded or found. Oil and gas leases, or lease applications, covered about half the area in early 1984. No known exploration has occurred. The entire WSA is covered with thick volcanic flows. Faults in these volcanic rocks may have provided conduits for mineralizing solutions emanating from the basement rocks; however, no evidence of mineral deposits was detected from rock samples collected along the faults. Reconnaissance samples from sand and gravel deposits yielded gold at less than $0.02/yd3. The source of the gold is assumed to be intrusive rocks or the Challis Volcanics about 20 miles north of the study area near the headwaters of Battle Creek. No economic concentrations of minerals were found in the WSA. INTRODUCTION Mineral surveys of designated wilderness study areas (WSAs) 1/ are conducted by the U.S. Bureau of Mines (USBM) and the U.S. Geological Survey (USGS) at the request of the U.S. Bureau of Land Management (BLM). The USBM researches the mining and mineral exploration history and evaluates mines, prospects, and mineralized areas within or adjacent to WSAs. The USGS studies WSAs by regional geochemical and geophysical surveys and geological mapping. The USBM and the USGS investigations are summarized in a joint report used to help determine the suitability of WSAs for inclusion into the National Wilderness Preservation System. Although the immediate goal of this USBM study is to provide data for the President, Congress, BLM, and the general public for land-use decisions, the long-term objective is to help insure that the Nation has an adequate and dependable supply of minerals at reasonable cost.

Jan 1, 1985