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By C. E. Schmidt

Condensate waters from the Bureau of Mines Synthane process for coal gasification have been investigated by mass spectrometric methods to determine the organic contaminants. Waters from the gasification of six coals were extracted with methylene chloride, yielding 0.6 to 2.4 weight-percent extractable material. Using high-resolution mass spectrometry (HRMS), combined gas chromatography-mass spectrometry (GC-MS), and low-voltage mass spectrometry, 60 to 80 percent of the extract was found to be phenolic. About 20 organic contaminants have been identified and are present in the condensate waters from each coal gasified. The relative distribution of contaminants in the condensate water was nearly the same for the six coals gasified under various conditions; phenolic compounds were the most abundant in all cases.

Jan 1, 1974

By Wilbert J. Huff

The organization of the Explosives Division has been outlined in two preceding publications.3/ The activities of the various units for the fiscal year 1939 are described hereafter: I. INFLAMMABILITY OF GASES AND VAPORS DETERMINATION OF EXPLOSION HAZARDS OF COMBUSTIBLE GASES AND VAPORS IN MINES AND INDUSTRIES (a) Determination of Limits of Inflammability of Gases and Vapors The following hitherto unpublished limits of inflammability were determined during the past fiscal year.

Jan 1, 1939

Several federal and state agencies have promulgated regulations that require the installation of operator protective structures on mobile equipment used in mining, construction, agriculture and logging industries. These regulations cover many different types of vehicles, from small farm tractors to large rubber-tired front-end loaders, and require structures that help protect the operator from death or injury from vehicle overturns, from falling tree tops and logs, from falling rocks, and from tree limbs in clearing operations. Two general types of vehicle operator protective structures have evolved over the past twenty years. The first of these is the "Roll-Over Protective Structure'' or "ROPS" that is essentially a "roll bar" or "roll cage" that provides a relatively safe area for the vehicle operator if the vehicle should tip over and roll. The second protective structure is the "Falling Object Protective Structure" or "FOPS" that provides overhead protection against falling material. The terms "ROPS" and "FOPS" are often used interchangeably (sometimes inaccurately) with "cabs", “canopies” , "roll bars" , protective structures" and other such descriptive names. In this report, "ROPS" describes the function of the structure; "FOPS" also describes a particular function. Thus a ROPS/FOPS could describe a cab or a canopy that provides both roll-over protection and falling object protection. “MESA” is used as an abbreviation for the Mining Enforcement and Safety Administration; "USBM" is used to abbreviate the U, S. Bureau of Mines.

By H. H. Schrenk, Carlton E. Brown

"INTRODUCTION The question as to whether or not the flow of water through pneumatic rock drills commonly used in this country keeps to a minimum dust disseminated into the air during drilling arose during a study of the dust-in-air conditions in Butte mines from February to July 1936 and December 1936 to June 1937 made by the Bureau of Mines in cooperation with the Anaconda Copper Mining Co., Butte, Mont, The purpose of this report is to describe the study, including some experimental work on the subject, and to give test results.ACKNOWLEDGMENTSThe help of the ventilation department of the Anaconda Copper Mining Co. in planning the study and collecting the data is gratefully acknowledged.EXPERIMENTAL CONDITIONSTests were conducted in an untimbered 6- by 8-foot crosscut in medium-hard granitic rock near the shaft station on an inactive level of one of the active Butte mines. Figure 1 shows the plan and section of the test location. Air was drawn from the shaft at the station, through the crosscut, and up through another shaft. The flow of air through the crosscut was decreased by a brattice downstream from the sampling location, so that relatively high, easily measurable dust concentrations would be obtained in the tests. Impinger samples for determing concentration of dust in the air were collected in an opening 51 inches wide, 29 inches high, and about 4o inches from the top of the rails in a wooden stopping about 16 feet downstream from the place where the test holes were drilled."

Apr 1, 1938

By S. H. Lorain

The Minah silver-lead mine in the Wickes district, Jefferson County, Mont., produced substantial quantities of silver-lead ores in the 1890's. The mine has been abandoned since the "silver panic" of the early 1900's. As a part of the Bureau of Mines: program to develop new sources of lead to overcome the growing shortages of that metal, a development project was started at the Minh mine in April 1946 and continued until June 1947, during which 5,600 feet of angledozer trenching and. 1,093 feet of core drilling were completed on the main vein and nearby parallel veins: As a result of this work, interest in the property was stimulated and private operators are now engaged in reopening the mine. This report discusses the past history, geologic setting, and the recent and early operations of the mine.

Jan 1, 1948

By M. A. Trvits, M. Cummins, A. C. Smith, T. P. Mucho

This paper evaluates the effectiveness of remotely applied nitrogen-enhanced foam to aid in efforts to isolate and suppress a mine fire. The foam, in combination with a remotely-installed cementitious mine seal and a novel borehole pressure sampling methodology to determine the location of the suspected ignition source, was used to help control ventilation and inert the area surrounding the suspected ignition source by isolating it from oxygen. This allowed mine rescue teams to safely enter the mine, seal the area, and begin recovery operations to successfully return the mine to full production.

Cutter roof failure, a ground control problem that frequently results in massive roof failure, is common in coal mines of the Northern Appala-chian Coal Basin, causing delays in production and posing a safety hazard to mine personnel. The Bureau of Mines is conducting research on the causes of cutter roof failure to gain a basis from which to predict and prevent its occurrence, and to support such roof when failure occurs or is imminent. Research conducted at the Greenwich Collieries North and South Mines, in central Pennsylvania revealed a correlation between the presence of clastic dikes and formation of cutter roof failure. The research con-sisted of in-mine mapping of geologic and deformational features, rock pressure monitoring, core recovery and evaluation, and in situ stress measurement. It was found that roof failure increased in areas where the occurrence of clastic dikes was most frequent, especially where two or more clastic dikes intersect. Staggering of crosscuts prevented the extension of cutters and deterred the occurrence of large falls extending over several break-throughs. In addition, trusses and cribbing were effective in stabilizing clastic dikes and inhibiting the development of cutter roof failure when employed immediately or shortly after mining.

Jan 1, 1987

By Louis C. Brichta

The rapid depletion of known deposits of high-grade ore and the need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores in the Tri-State District, led the Bureau of Mines to examine likely mining sites. Underground operations failed to remove all of the ore in a number of areas, and it appeared possible that some of them might be reworked successfully by low-cost open-pit methods. The South Carthage or Hull tract in Jasper County, Mo., was selected by Bureau engineers as favorable for the development of an open-pit mine.

Jan 1, 1949

By Kent Volkmer, Mark Sanders, Gregory Krohn, Tyler Blake, Daniel Wick, Barry Beith

This report describes a study designed to evaluate a proposed modification in the cap lamp battery cord intented to reduce the incidence of snagging and catching of the cord. A three phase evaluation as performed comparing a prototype with the standard, currently available cord. First, a "pull test" equipment was run. The second evaluation was a body conformity study. The third evaluation involved subjects performing common tasks in a low seam coal mine simulator. The results of these evaluations clearly demonstrated significant safety advantages of incorporating coiled cord into the design of the cap cord. The coil cord presented less of a snagging hazard, allowed the wearer more time to respond to a snag, and transmitted lower levels of force to the helmet when snagged. The research team recommended that cap lamp cords be commercially developed which incorporate coiled cord at the battery and helmet.

Jan 1, 1980

By George J. Carter

Data obtained from field and laboratory examinations were used by the Bureau of Mines to evaluate 82 silica deposits in the Pacific Northwest. A total of 94 field samples was taken from 64 deposits, and an additional 18 deposits were investigated that did not warrant sampling. Of the 37 deposits found to be of high quality, only 16 were large enough to be classified as industrial silica resources. Another 27 deposits did not meet quality requirements. Methods of simple low-cost beneficiation and rapid classification of a large number of samples were investigated in the laboratory. These tests indicated that high-intensity electromagnetic separation was equal or superior to either high-or low-intensity electrostatic separation. In general, the electromagnetic method gave higher recoveries and produced equal or better grade concentrates. A glass button method developed for estimating iron oxide content of silica samples proved to be highly satisfactory as a means of classifying field samples and evaluating beneficiation tests.

Jan 1, 1962

By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

4. Preliminary Study - Remote Seal Checker 4.1 Introduction Determination of the completeness of each individual seal at the time of its emplacement is essential for an effective remote sealing system. A satisfactory seal checking technique should provide a signal which: (1) indicates percentage completion as the seal is emplaced (2) provides a definite indication of a complete seal (3) indicates the size of the unsealed area if a complete seal is not feasible This information is required to establish the need for additional seal material, the need for additional seals, and the risk likely involved in entering the mine., In many situations it is as important to know the quality of a seal as it is to build an effective one. It is likely that with repeated use the remote sealing technique developed by Foster-Miller Associates will be sufficiently reliable and predictable to preclude the seal checking requirement. It is recommended, however, that each seal be checked during construction to insure its completeness and increase the level of confidence so necessary in reopening the mine. 4.2 Description of General Problem Several characteristics of remote mine seals are important in considering techniques for evaluating the effectiveness of these seals. These include:

Jan 1, 1973

By Wilbert J. Huff

This is the sixth of a series of annual reports describing the work of the Explosives Division, Bureau of Mines, United States Department of the Interior.3/ It deals particularly with the activities of the division from July 1, 1940 to June 30, 1941. The studies outlined in this and preceding reports of the series have been conducted under the direction of the author and the respective unit leaders, to whom specific credit is given.

Jan 1, 1942

By J. W. Paul

The material that composes the roof in coal mines differs in strength according to variations in its physical nature and characteristics. Some material such as limestone and massive sandstone, (free from slits) and carbonaceous shale or bone, will often remain in place in narrow work without the use of timber or other means of support, but in wide places the use of supports becomes a real necessity. Roof material composed of shale, fire clay or small laminations of sandstone, or shale or sandstone interspersed with laminations of thin coal, presents conditions that call for timber support in both narrow and wide work. However, in narrow work such unstable roof material may be taken down until the strata assume an arch that is self-supporting for overlying firm strata such as a roof coal, a touch weather-resisting, shale, sandstone, or limestone. The proper support of the roof in roadways used for haulage or travel adds to the economy of operation by preventing delays in transportation and increases the safety of those who travel these roadways.

Jan 1, 1930

Rock mass classification is widely used throughout the underground mining industry—in both coal and hard-rock mines. The technique has been successful because it— • Uses simple measurements to rate rock mass strength. • Helps mine planners to make the best use of geologic information in mine design. • Makes it possible to compare ground control experiences between mines, even when the geologic conditions are very different.

Jul 1, 2007

By P. M. Brown

The Bureau of Mines is investigating a dewatering technique for coal-clay waste that uses a flocculant, polyethylene oxide (PEO). This flocculant forms strong stable flocs that can be dewatered on a static screen. A field test unit (FTU) using this technique was operated at approximately 400 gal/min, using a waste stream from the flotation circuit of a coal preparation plant. Consolidated coal-clay material con-taining 55 to 60 pct solids was produced when the flotation circuit slurries of 2.7 to 8 pct solids were treated with 0.1 to 0.3 Ib PEO per ton of solids. The FTU was also operated at 64.5 and 87.5 gal/min using a portion of the underflow slurry from the preparation plant's thickener. Consolidated coal-clay material containing 55 to 60 pct solids was produced when the thickener underflow slurries of 19 to 24 pct solids were treated with 0.08 to 0.2 Ib PEO per ton of solids. PED-treated materials continued to dewater when placed in a pit.

Jan 1, 1983

This report describes the development of training materials for the operators of underground mining equipment in the underground metal and nonmetal mining industry. The objective was to determine the effectiveness and acceptability of these training materials and to provide the validated training materials to the industry. Ten modules were developed, based on industry need according to accident frequency, accident severity and exposure to the equipment. The final modules were an average of 20 minutes in length and used slides with synchronized narration on cassette tapes. Testing materials are included for use by the mines.

Jan 1, 1984

This report describes a U.S. Bureau of Mines investigation into the removal of gate road chain pillars in conjunction with longwall retreat mining. The research objective was to determine, through evaluations of the loads imposed on the gate road pillars and supplemental support elements in the entries, how the pillars, supplemental support, and entries were affected by the longwall abutment pressure. To achieve this goal, vibrating wire stressmeters and hydraulic flat jack pressure cells were installed in the support elements to monitor stress change caused by abutment pressure as a function of longwall face advance. The findings documented in this report are the result of information collected from instrumentation and observation at the mine. Pillar and support loading measurements and stability observations revealed that the roof and the support elements remained stable during panel retreat, while the face progressed at a normal rate of advance. The ability to safely and efficiently mine chain pillars during panel retreat increases resource recovery and can provide several other benefits described in this report.

Jan 1, 2010

By F. Fraas, J. E. Conley

"The problem of recovering potash from the mineral polyhalite (K2SO4.MgSO4.2CaSO4.2H2O), occurring in large quantities in the salt beds of Texas and New Mexico, has been under investigation at the Nonmetallic Minerals Experiment Station of the U. S. Bureau of Mines continuously since 1928. Most of the results previously obtained have been published in technical journals and in a series of Bureau of Mines Reports of Investigations.The experiments described in the present report were performed to ascertain whether a continuous countercurrent extraction of calcined polyhalite by hot water would yield satisfactory recoveries and concentrations of sium sulphate in the top liquor. Previous investigation by Storch 4 had shown that the rate of solution of uncalcined polyhalite was too slow to be of value in an industrial process, and Storch and Clarke 5 had demonstrated that calcination of the polyhalite greatly, accelerated the rate of solution in hot water, allowing most of the potassium sulphate to be readily extracted."

Sep 1, 1933

By C. H. Herty

"The work on the physical chemistry of steelmaking, as carried out at the Pittsburgh Experiment Station of the United States Bureau of Mines in cooperation with Carnegie Institute of Technology and, the Metallurgical Advisory Board, has covered a series of fundamental studies on the action of oxygen in liquid steel and the application of the findings to open-hearth operation. The staff has varied from 14 to 23 men per year, some of whom have been Bureau of Mines physical chemists and metallurgists, others research engineers of the Metallurgical Advisory Board, and the remainder graduate students employed as research fellows at the Carnegie Institute of Technology. The work on the laboratory studies, and particularly on slag systems, has been in charge of G. R. Fitterer, associate metallurgist, Bureau of Mines, while the plant work has been under the direction of C. F. Christopher, research engineer of the Metallurgical Advisory Board. In all, some 16 physical chemists and metallurgists and 24 research fellows have taken part in the experimental work. Advantage has been taken of the opportunity for cooperation with the University of Pittsburg to have certain phases of this program made the subject of graduate work, particularly the laboratory studies on the deoxidation of steel with manganese-silicon alloys.The general method of studying oxygen has been, first, to determine the solubility of the various oxides in liquid steel. To date the solubility of Fe0 in steel has been determined, over a wide temperature range.3 The straight-line relationship in the plot of solubility versus temperature indicated that under a slag of 100 per cent Fe0 the oxygen was present in the steel as dissolved FeO. A further conclusion drawn from this work was that the solubility of FeO in the metal was proportional at a given temperature to the mol fraction of Fe0 in the slag if the slag contained a large excess of basic constituents. This result was determined from a study of the solubility of Fe0 under slags containing lime and iron oxide in various proportions. These data have been used extensively in determining the saturation of a bath of open-hearth steel under any conditions of slag composition, and results to be given later showed that the solubility curves are consistent with the results obtained in practice."

Dec 1, 1930

By T. Bajpayee, J. Ellenberger

Microseismic monitoring and evaluation is one aspect of the National Institute for Occupational Safety and Health (NIOSH) research program. Roof falls are often preceded by a period of elevated microseismic activity, but not all periods of elevated activity result in a roof fall, nor do all roof falls occur after some amount of elevated activity. The objective of this study is to review periods of elevated microseismic activity and determine whether fracture activity rate can be used to anticipate the initiation of roof falls. The study was carried out at an underground limestone mine where major roof falls are associated with excessive horizontal stress. The progression of roof falls was detected by the microseismic signature produced by the rock falling from the mine roof onto the mine floor, which is termed a roof fall impact event. A total of nine elevated fracture activity periods that resulted in seven major roof falls were examined. It was observed that elevated fracture activity preceded the initial roof fall impact event in three out of four major roof falls. The initial impact event was not identified for the remaining three roof falls. Fracture event rates were analyzed and a roof fall alarm trigger of five fracture events in a ten minute time period was established for this test case. The fall alarm trigger was tested against six of the elevated activity periods. Four roof falls occurred in the six periods of elevated activity, and two would have triggered the alarm before the roof fall occurred, while two false alarms were generated. The results show that limited success would have been achieved by the microseismic system as a roof fall alarm trigger. However, the trigger would have been successful at warning of the onset of elevated activity, allowing mine employees to respond appropriately. The study highlighted some issues with implementing such a system in an operating mine, including the need for real time identification of fracture related microseismic signals among mining induced signals, and accurate location and identification of fracture clustering.