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By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

C. 7 Emergency Rescue Hoists There is a need, especially in mine development areas, for portable, on-call, man-rated equipment capable of lifting men through several hundred feet. Wire rope climbing equipment as shown in Figure 37 appears particularly suited to this need. It is portable, weighing approximately 100 lbs. , is currently man-rated for numerous above ground applications and can be electric or air powered. Commercial units currently have a lifting capacity of 1000 lbs. , and can be fitted with bosun' s chairs. Lifting speeds are in the 20-30 FPM range and the equipment is not depth limited. In a situation where miners are unable to climb to the top of a shaft this equipment could rapidly be anchored to the top of the shaft and lowered to them by hand. Since the self contained unit is controlled by the person travelling in the shaft he would be able to negotiate shaft obstruction himself. This would not be possible with other forms of easily deployed free-hanging equipment. Typical manufacturers of this type of equipment are Ohio Hoist Mfg, Co, 321 South Beaver St. Lisbon, Ohio 44432 216-424-7283 Sky Climber Inc. 17311 South Main St. Gardena, California 90248 213-321 -6414

Jan 1, 1976

By C. B. Manula, R. L. Sanford, R. A. Rivell

The large amount of computer code required for this simulation model dictates that reasonable limitations be placed on some of the input variables. The program permits the following maximum sizes: 1. Ten mine car stations 2. Twenty track intersections 3. Three hundred mine cars 4. Eight motors 5. One hundred profiles 6. Twelve intersections between stations 7. Forty-five profile changes between stations 8. Thirty station pairs (routes) These may be changed by the user providing the particular computer in use has available core storage. Major Array Descriptions This section is a detailed description of four of the major arrays used in the rail haulage simulator for data storage and logical control. Other arrays are used; however, they may be considered sub¬servative to the major ones. These major variables are explained on the following pages. Motor Control Array (XXXDEF). The first 99 locations in this array are arranged according to and are developed by data input. Unit conversions are made at input time which include: 1. Tons to pounds. 2. Rolling resistance in pounds/ton to percent/100. 3. Miles per hour per second (mphps) to feet per min. per minute. 4. Miles per hour to feet per minute. The following information is stored for each motor at the array

Jan 1, 1974

By Louis A. Turnbull, JOSEPH J. SHIELDS

The Bell & Zoller Coal & Mining Co. recently completed construction of two slopes at Mine 3 near Zeigler , Ill . The slopes are in the Big Muddy River Valley , and construction was particularly difficult because the strata from the surface to a depth of 70 feet comprise water saturated sandy clay and sand . Many mining companies have similar shaft- and slope - sinking problems , and because these slopes were satisfactorily completed and now are in use the methods followed during construction are described in this information circular . It is believed that other companies with similar problems . will benefit by adopting the methods followed at Mine 3 .

Apr 1, 1949

By Christopher Mark

Since it was first introduced, the Coal Mine Roof Rating (CMRR) has been widely accepted as a tool for geologic characterization and mine planning. This paper discusses the application of the CMRR to another practical ground control problem. Extended cuts (cuts greater than 6 m (20 ft) in length) are commonly used with remote control continuous miners. Extended cuts can greatly increase productivity, but they have been associated with a number of fatal roof fall accidents. When extended cuts are attempted in weak roof, the roof may collapse before it can be bolted, causing hazardous conditions. Until now, it has not been possible to predict where conditions may not be suitable for extended cuts. In this study, data on the CMRR and extended cut experience were collected at 36 mines in 7 states. It was found that when the CMRR was greater than 55, deep cuts were routine in nearly every case. When the CMRR was less than 37, extended cuts were almost never taken. Between 38 and 55, extended cuts were feasible sometimes but not others. The data also shows that extended cuts are less likely to be stable if either the entry span or the depth of cover increases.

By Edward A. Barrett, Lynn L. Rethi

Recent studies have shown that miners performing construction, maintenance, and repair (CMR) work activities in the conduct of their jobs incur from 39 to 65 percent of all reported injuries in the mining industry, The number is particularly high at surface aggregate operations; however, the problem exists at all mining locations and commodities. To address this issue, an interactive, (3-D) slides training exercise, Hazard Recognition Training Program for Construction. Maintenance and Repair Activities, was developed. The purpose of the exercise is to teach work& to recognize CMR hazards in the workplace and to deal with them using accepted safe work procedures. It was field tested using a total of 340 persons from surface mining operations in six states. The subjects were tested before and after the training intervention to determine if objectives of the instruction were achieved. Results indicated that 7 1 percent of the participants showed improvement in ink test scores. Following the posttest, subjects responded to a seven question Likert scale. These questions related to the validity of the exercise and the utility of the training program. More than 93 percent of the miners reported that they "learned something new from the training" and over 94% said they "would use these practices to work more safely".

By R. K. Koch

The vapor pressures of liquid columbium and liquid hafnium were deter-mined by the Langmuir free evaporation method as a part of the Bureau of Mines program on the study of transition metals. An electron-beam furnace with a water-cooled copper crucible was used for melting. Temperature was measured with a two-color ratio pyrometer. Least-squares analyses of the vapor pres-sure data gave the following equations: [Logp (atm) = 5 .429 -31,310 T] for liquid columbium in the range 2,740° - 3,140° K, and [Log p (atm) = 5,690 28 T] for liquid zirconium in the range 2,500° -2,810° K. Third-law evaluations of each data set gave mean heats of sublimation (298.15° K) of 175.1±3.2 kcal/mole and 148.3±1.2 kcal/mole for columbium and hafnium, respectively. Second-law standard heats of sublimation determined from sigma plots and from sigma-prime plots agreed fairly well with the third-law values. The sigma-prime plots gave standard entropies of sublimation of 30.96±0.84 eu and 33.S6±0.44 eu for columbium and hafnium, respectively.

Jan 1, 1968

Reduce costs of recontouring surface mined land by improving bulldozer blades. Approach A specialized 48-foot-wide bulldozer blade set at an angle, a 13-foot bulldozer blade with swept-forward end sections, and a 24-foot grading bar are used in conjunction with conventional bulldozers to reduce the cost of recontouring surface mined land. How They Work The angle blade is used to do the initial and intermediate leveling of long spoil banks. It is mounted at an angle on two 410-horsepower crawler tractors in a side-by-side offset configuration, but requires only one operator since both tractors are controlled by a single set of controls. The angle blade usually begins its cycle at one end of the spoil bank where the operator fills the blade and moves forward, continuously cutting and casting the material to the repose slope. At the opposite end of the spall bank, the angle blade turns around and begins cut-ting and casting material to the opposite repose slope. This action continues until adjacent banks meet or the lateral distance from the center line of the spoil bank to the repose slope exceeds approximately 40 to 50 feet. At this distance, the sidecasting angle blade is no longer effective, and conventional bulldozers are used to do the final land shaping.

Jan 1, 1981

By Anthony T. Iannacchione

The Bureau of Mines developed data on the methane content of the Hartshorne coalbed, Haskell and Le Flore Counties, Okla. The methane content is calculated to be between 1.1 and 1.5 trillion cubic feet, based on an estimate of total coal in place of 2.4 to 3.2 billion short tons. Methane increases with depth, but the rate of increase decreases with greater depths. Degasification in advance of mining is recommended for all mines operating at depths greater than 500 feet to reduce hazards and methane explosions, decrease mine ventilation costs, and conserve the natural gas that would be otherwise wasted.

Jan 1, 1979

By S. R. B. Cooke, F. D. DeVaney

"INTRODUCTION The potash mineral receiving the most attention in the newly discovered. New Mexico-Texas potash district near Carlsbad, N. M. is sylvite (potassium chloride). Sylvite contains more potassium than any other mineral. Merchantable high-grade deposits have been found, and those of lower grade may be enriched to a high degree of purity by refining methods. Deposits containing sylvite were the first to be developed and axe the only ones being mined.However, many other minerals that contain potash occur in the salt beds of the Carlsbad District. Of these the more important are polyhalite, carnallite, langbeinite, leonite, and kainite. The nature of the deposits and their mineralogy have been described in detail by members of the United States Geological Survey. 4/Langbeinite, although not so abundant in these deposits as carnallite and has particular interest because the potash is in the form of the sulphate and as such commands a premium in terms of K20 unit. This is explained by Fox and Turrentine 5/, who state:"

Feb 1, 1936

By R. D. Leitch

"REASONS FOR AND PURPOSE OF WORKIn 1924 the United States Public Health Service was requested to undertake a special study of stream pollution. At that time the proposal that the United States Bureau of Mines take up the study was made by the Public Health Service because in point of training and experience the personnel of the latter was considered not to be as well, suited to this type of investigation as was that of the Bureau of Mines. H. Foster Bain, then Director of this bureau, promised to undertake the work, and, accordingly, field investigations were begun in the spring of 1925. The problems of mine-drainage wastes and of gas-house and coke-oven waste were investigated in the laboratory, and a method of treatment by sodium hydrate and benzol was found to be promising. The idea was obtained by A. C. Fieldner, chief engineer of the Bureau of Mines experiment stations, while in Germany in 1924, where he was shown a practical application of the process, but no information was obtained as to definite chemical or mechanical processes. Because of the then pending American patent application by the German firm, we made no attempt to develop our findings further. Shortly after, a similar method of treatment was developed in the United States, and since that time we have devoted our attention entirely to mine drainage. This paper is a presentation of some general facts and information gathered during the past five years on coal-mine drainage.SCOPE OF WORKAt the time our work was begun there was such a diversity of opinion on the whole subject and apparently so little was accurately known, that it was decided to undertake a basic study from which (1) certain definite information might be evident, and (2) what might be considered side issues of the original investigation would be suggested for subsequent study.A stream in a district thought to be representative of those in low to average sulphur bituminous coal fields and another in a high sulpbur district were selected for study, A fair (weber of factors entered into the tentative selection of these streams, the chief ones being their accessibility and freedom from other industrial or domestic pollution, besides, of course, the presence of mine drainage in these streams."

Apr 1, 1931

By L. B. Pankratz

Enthalpies were determined for synthetic chalcopyrite (CuFeS2) between 298° and 1,050° K and for synthetic bornite (Cu5FeS4) between 298° and 1,100° K by copper-block drop calorimetry. Two transitions were found for each compound. The lower transitions were both crystal transformations from tetragonal (low-temperature form) to cubic (high-temperature form). The chalcopyrite transformation occurred at 830' K with a heat of transformation of 2,405 cal/mole; the bornite transformation was at 485° K with a heat of 1,430 cal/mole. The other transitions were of the second order and were presumed to be magnetic in character. The second-order transitions for chalcopyrite occurred at 930° K, and the one for bornite at 540° K. Enthalpy increments, entropy increments, and heat capacities are tabulated at even temperatures above 298.15° K. Equations of enthalpy are also given.

Jan 1, 1970

By D. A. Doughty

The Bureau of Mines developed two methods for determining iron II and iron III in 2- to 5-mg samples of coal using electron paramagnetic resonance (EPR) spectrometry. One method used solid coal samples; the other method used aqueous solutions. The method using solid samples was more simple, technically, but required the use of X-ray fluorescent analysis, or another independent method, for determining total iron in the samples, and the results were subject to some uncertainty. The method using aqueous solutions appeared capable of greater certainty and did not require additional methods of total iron analysis but was more involved procedurally. The coals analyzed were found to contain much more iron II than iron III.

Jan 1, 1973

A prototype EM Location System was fabricated and tested at the Geneva Mine near Dragerton, Utah. This system consisted of six manpack transmitters and six manpack receivers covering the frequency band from 900 Hz to 2900 Hz as well as a six channel receiver designed for use in a helicopter. Tests showed that EM signals from lightweight (314 lb) transmitters could be detected both on the surface and from a helicopter through -2 as much as 1650 ft of relatively high conductivity (2 X 10 mhos/m) over- burden. Furthermore, the resulting field strength profiles could be used to determine source location to within 150 ft of the actual surveyed location in the mine. Modifications were made to a Monitoring, Locating and Communications System being tested at the Bruceton Mine, Pittsburgh, Pennsylvania. These modifications have improved the performance and quality of the paging and voice telephony mode of the system. Subsurface receiver modifications have improved reception of voice downlink signals.

Jan 7, 1973

Provide a full-scale test facility where the effectiveness of all types of subsidence abatement techniques can be evaluated under controlled conditions. Background Subsidence is ground movement resulting from the collapse of overlying strata into a mine void because of failure of the mine roof, mine floor, or support pillars. The failure may propagate to the surface and be expressed as a depression, cracks, or a sinkhole. The surface expression of such features may be delayed until long after mining has been completed. Subsidence has the potential to affect more land area than any other type of abandoned mine land problem. Subsidence also causes direct damage to real property, with significant financial loss and more importantly, presents a danger to public health, safety, and general welfare. Subsidence-related problems are considered to be one of the most important abandoned mine land issues. Backfilling of mine voids is the most common stabilization method used to abate subsidence and protect surface structures. Backfilling or placement of material is performed by hydraulic flushing or pneumatic stowing, using either in-mine or remote methods. The majority of the past subsidence abatement projects has been performed using remote methods from single or multiple boreholes. Other subsidence abatement techniques arc available. For example, various point support methods are used to protect small areas of the land surface and surface structures, without completely filling the mine void. These may be more appropriate under different conditions. Little documented information is available concerning the capability of the various backfilling methods for completely filling a mine void or providing long-term structural strength. Therefore, the Bureau of Mines developed a laboratory for controlled evaluation of backfilling technologies.

Jan 1, 1991

By L. B. Pankratz

High-temperature heat-content values of gallium and scandium sesquioxides were measured over the temperature range from 298° to 1,800° K. The results fill gaps in the thermodynamic information for these compounds; no previous similar data existed. The heat-content values were combined with heats and entropies of formation to obtain free energies of formation of gallium and scandium sesquioxides to 2,000° K. The thermodynamic stabilities of the sesquioxides of aluminum, gallium, scandim, and yttrium were compared.

Jan 1, 1963

By D. Debasis, Christopher Mark, Gregory M. Molinda

The stability of any underground opening is, in large part, a function of the strength of the rock mass which surrounds it. The Coal Mine Roof Rating (CMRR) has been developed to quantify the defects in the rock mass and compile a strength value which can be used for engineering design. The CMRR has been applied to a number of ground stability problems, including chain pillar design, roof bolt selection, hazard assessment, intersection design, and numerical modeling. The CMRR procedure and some of these applications are described in this paper. The CMRR will soon be available in a Visual Basic computer program, allowing easy integration into exploration programs and standard roof fall assessments.

By T. E. Ackman

The Bureau of Mines conducted a study of current trends in methods employed by the coal industry to dispose of acid mine drainage (AMD) treatment sludge. Thirty-three AMD treatment plants, operated by 11 Pennsylvania coal companies, were randomly surveyed. These plants provided data for calculating sludge volumes, as well as information on sludge settling, transportation, and disposal. Onsite visits allowed observation of problems associated with the various methods of sludge disposal: (1) disposal into a deep mine, (2) permanent retention in ponds, (3) disposal at an active coal refuse area, and (4) onsite burial. Method 1 is the most frequently used and the most environmentally sound. It is apparent, based on this representative sampling of AMD treatment plants, that the magnitude of sludge production is such that an aggressive and directed effort in reduction of sludge volume is seriously needed. The areas of major concern are (1) the amount of surface land required for sludge storage and disposal, (2) reclamation of these disturbed surface areas, and (3) effective and efficient means of removing, transporting, and disposing of AMD sludge. In this report, an engineering approach to the practical problems associated with the existing disposal methods is presented, together with recommendations for future research.

Jan 1, 1982

By Ludwig Schmidt

The attention of operators of oil-producing properties long has been directed toward methods of' disposing of petroleum wastes as well as the disposal of oil-field brines. The problem of disposing of' petroleum wastes is not easy to solve, and although many operators are to be commended for the efforts they have made, much work remains to be done before the problem can be considered solved. Petroleum wastes include emulsions of petroleum and brine or mixtures of petroleum and sand that cannot be "broken down" or treated economically by known methods of separating petroleum from deleterious matter; crude petroleum that escapes from pipe lines, fittings, and tanks because of holes in the lines, leaky connections, or some accident; and oil-saturated materials that accumulate accidentally or otherwise an the normal operation of an oil-producing property.

Jan 1, 1938

By Ludwig Schmidt

[The attention of operators of oil-producing, properties long has been directed toward methods of disposing of petroleum wastes as well as the disposal of oil-field brines. The problem of disposing of petroleum wastes is not easy to solve, and although many operators are to be commended for the effort they have made, much work remains to be done before the Problem can be considered solved. Petroleum wastes include emulsions of petroleum and brine or matures of petroleum and sand that cannot be "broken down" or treated economically by known methods of separating petroleum from deleterious natter; crude petroleum that escapes from pipe lines, fittings, and tanks because of holes in the lines, leaky connections, or some accident; and oil-saturated materials that accumulate accidentally or otherwise in the normal operation of an oil-producing property.]

Jan 1, 1938

By K. K. Kershner

The purpose of this investigation was to develop methods on a laboratory scale for recovering tin from metallurgical slime, Tin chlorides were volatilized using mixtures of hydrogen chloride and reducing gases, such as hydrogen, carbon monoxide, hydrogen sulfide, ethane, propane, and butane. Optimum conditions were found to be n mixture of 3:1 of hydrogen and hydrogen chloride at 475° C. Over 95 percent of the tin was volatilized as chlorides. Low temperatures and relatively rapid rates of reaction are distinct advantages of the chloride volatilization process. Research is being continued with various slimes and will be extended to tin ores, where the method offers interesting economic possibilities in comparison with current tin-smelting practice.

Jan 1, 1957