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By L. H. Lange, F. F. Hintze

"Mineralogical Composition of Cyanite RockIn the group of minerals used in making this study, the cyanite is associated with quartz, mica, and feldspar in the schist. The amount of quartz is variable, but it is always an abundant mineral. Both large and small crystals of quartz occur in irregular masses, rarely ever showing crystal outline. Mica is of the clear and dark varieties the larger crystals being dark as a rule, and the finer crystals of light color, The present mineralogical composition of the mica is rather variable as most of the original biotite and muscovite have suffered alteration, and much secondary mica is present as a result of alteration of the original mica and other minerals present, especially the larger cyanite crystals. A large part of the mica now found in the ore is chlorite, with varying amounts of Jefferisite and others, especially sericite. These are in the form of aggregates, or felt-like intergrowths filling the spaces between the quartz, cyanile, and feldspar.The feldspar is plagioclase probably mostly albite. It is white, possesses good cleavage, and is one of the hard brittle minerals of the rock. It alters to kaolin, and sericite, and more or less of these alteration minerals are present within the feldspar crystals but not separated from them.The cyanite is of two varieties, distinguished by their colors as blue and white cyanite. The blue color varies in intensity, being a pronounced blue in some crystals and paler in shade in others. Some crystals have been seen which possess the blue color in one-half of their mass and are pure white or clear in the other half. The purity of the cyanite is probably not affected by the color, but it is difficult to detect the white cyanite in the ore by macroscopic examination, so that great care has to be exercised in the selection of the ore in the field."

Apr 1, 1931

By F. F. Hintze

In the group of minerals used in making this study, the cyanite is associated with quartz, mica, and feldspar in the schist. The amount of quartz is variable, but it is always an abundant mineral. Both large and small crystals of quartz occur in irregular masses, rarely ever showing crystal outline. Mica is of the clear and dark varieties, the larger crystals being dark as a rule, and the finer crystals of light color. The present mineralogical composition of the mina is rather variable, as most of the original biotite and muscovite have suffered alteration, and much secondary mioa is present as a result of alteration of the original mica and other minerals present, especially the larger cyanite crystals. A large part of the mica now found in the ore is chlorite, with varying amounts of Jefferisite and others, especially sericite. These are in the form of aggregates, or felt-like intergrowths filling the spaces between the quartz, cyanite, and feldspar.

Jan 1, 1931

By B. D. Sartwell

Multiple-charged beams originating from a 300-kv ion accelerator are important tools in the study of metal surfaces and thin films. A knowledge of the particle range is necessary for an understanding of the interaction processes of the ions with the targets. Utilizing a theory developed by Lindhard for determining the range of low-energy ions in solids, the ranges of H, He, C, N, 0, and Ar ions in A1203, Al, Fe203, Fe304, CuO, Cu20, Fe, Cu, Sn, and W were calculated for the energy range 60 to 400 kev using a computer program written in BASIC. The range, presented in graphical form, is given in both µg/cm2 and angstroms. In addition, heavy ion ranges were calculated for comparison with published experimental values. For ions with Z > 5, the discrepancy between the calculated values and published experimental values generally ranged from 2 to 40 percent; the largest deviations were probably due to experimental error.

Jan 1, 1970

By Kenneth M. Earl

In its program of investigation of deposits of strategic minerals, the Bureau of Mines did some development drilling at the Tapley deposit in an endeavor to find an additional source of copper. There are accounts that many years ago the property had some production; there are several old, inaccessible shafts apparently sunk on a vein in rhyolite or diabase. The waste dumps of these shafts contain considerable sulfides, chiefly pyrite and chalcopyrite. To cut the vein below the old mine workings, the Bureau of Mines? diamond-drilled five holes aggregating 1,204 feet. No significant copper mineralization was found.

Jan 1, 1950

By A. H. Warner

Sphalerite crystals occur sparingly in minor faults and pockets in a coarsely crystalline dolomite on the Brown-Tipton farm near Greenville in Greene County, Tenn. After several visits by U. S. Bureau of Mines engineers and U.S. Geological Survey geologists, a survey was r: the in the fall of 1944. Upon their recommendations, trenches on the Brown farm under Bureau of Mines supervision. In each case, the bed most favorable for zinc deposition was exposed. In the finished trench bottoms no zinc minerals are visible.

Jan 1, 1950

By G. Nuñez, M. A. Pathak, C. F. Stanley

"A 1986 report by the U.S. National Committee on Blomechanlcs (1) describes lung disease as a major national health problem. The report cites three areas that would benefit from a better understanding of the vibratory patterns of the lung. These areas are outlined below.1. In cases of respiratory distress, pressure driven artificial respirators are used. A new technique using high frequency respiration is quite promising, but the pressure distribution in the lung as a function of frequency is not yet known. At these frequencies of 1 to 60 Hz, the lung expands asynchronously (2) and a better understanding of these expansion nonunlformltles could provide valuable Information about the mechanics of high frequency ventilation.2. Listening to the sounds In the lung can yield valuable Information about the state of the lung. To improve the technique, a better understanding of how acoustic waves propagate through the lung is needed.3. The response of the lung as It Is subjected to acoustic excitation, dynamic loading or shock waves is not well understood. A better knowledge of these responees can lead to improved treatment for patients subjected to either explosive pressure waves or car crashes.4. Researchers are measuring the acoustic Impedance of the Iung to detect early states of dysfunction. Sneckenberger and Whitmoyer (3) have reported Impedances obtained at acoustic frequencies up to about 6000 Hz. However, It la not certain which parts of the lung are responding to the acoustic excitation.To Investigate the vibratory characteristics of the lung, excised rat lungs were excited via the trachea with acoustic waves at frequencies up to 6000 Hz. Thie paper describes an Instrumentation system, utlllzlng time-averaged holographic Interferometry, to detect and quantify the response of the lung surface to the acoustic excitation."

Jan 1, 1989

By Jr. Herty

Ferromanganese continues to be an indispensable requirement in steel manufacture. Approximately 470,000 of the 80 per cent ferro-alloy was consumed in 1929 and increasing amounts will be required annually by the steel industry unless some satisfactory substitute is found. An average of 14 pounds of metallic manganese is used for each ton of steel produced, The principal use of manganese is for de-oxidation of the metal in the steel refining processes, although a considerable amount is also used for the production of special manganese steels. Unfortunately, domestic production of manganese ore is inadequate to meet normal peace-time requirements, not to mention increased abnormal war-time demands. The rather large quantities of low-grade manganiferous iron ores which occur in the Coruna Range in Minnesota have for a number of years greatly appealed to those interested in the development of a domestic source of the supply. The North Central Experiment station of the Bureau of Mines has made an elaborate study of the possibilities of the pyrometallurgical treatment of ores from these deposits and much of the valuable information secured by them has already been published.

Jan 1, 1930

By C. H. Herty

[Ferromanganese continues to be in indispensable requirement in steel manufacture. Approximately 470,000 tons of the 80 per cent ferro-alloy was consumed in 1929 and increasing amounts will be required annually by the steel industry unless some satisfactory substitute is found. An average of 14 pounds of metallic manganese is for each ton or steel produced, The principal use of manganese is for deoxidation of the metal in the steel refining processes, although a considerable amount r s also used for the production of special manganese steels. Unfortunately, domestic production of manganese ore is inadequate to meet normal peace-time requirements, not to mention increased abnormal war-time demands.]

Jan 1, 1930

By K. D. Plants, J. H. Holden, L. F. Willmott

Pulverized high- volatile A bituminous coal was gasified with oxygen and superheated steam in a pressure - gasification pilot plant equipped for steampickup feeding . The pilot plant operated satisfactorily at relatively high steam- to - coal ratios , but steam- to - coal ratios could not be reduced much below 0.5 lb / lb without condensation of steam or softening of the coal . Carbon gasified , gas composition , and coal and oxygen requirements were essentially the same as for a pilot plant equipped with a fluidized coal feeder . Average results from the pilot plant equipped for steam- pickup feeding were coal requirement , 37.3 lb/M ( 1,000 ) scf of CO + H₂ produced ; oxygen requirement , 358 scf /M scf CO + H₂ produced ; and carbon gasified , 87.7 percent .

Jan 1, 1964

By C. A. Rhoades

A major contributor to the problem of short life expectancy for blade-type conveyor belt cleaners is uneven wear along the blade edge. Uneven wear results in the formation of channels in the blade edge, which allow material to be carried back between the blade and the belt. In an effort to reduce the uneven wear problem, the U.S. Bureau of Mines has studied the mechanisms responsible for effective belt cleaning. From this study emerged a design for a cleaner blade that would greatly reduce uneven edge wear. The design consists of a standard cleaner blade incorporating air passages that allow for the expulsion of air along that part of the blade edge in contact with the conveyor belt surface. The results of 18-h tests indicated that the expulsion of air on the blade edge prevents scratches from developing into deep grooves. These tests showed that effective blade cleaning life can be extended 25 times using the pneumatic cleaning blade, compared with solid metal cleaning blades.

Jan 1, 1989

By L. H. Wullstein

Bureau of Mines research on methods for reclaiming land disturbed by the minerals sector of the economy has produced a specific procedure for effectively germinating seed of Indian ricegrass, a drought-tolerant plant valuable for reclaiming arid and semiarid sites. This report describes the procedure which consists of acid-treating the seed followed by temperature and light cycling treatments. Use of the procedure resulted in an average germination rate of 29 percent, ranging from 18 to 56 percent. Seed subjected to long cold treatment but with acid treatment yielded an average germination rate of 9.2 percent, ranging from 6.6 to 14.7 percent. Untreated seeds (controls) gave germination rates less than 0.1 percent.

Jan 1, 1979

By F. F. Hintze

In the group of minerals used in making this study, the cyanite is associated with quartz, mica, and feldspar in the schist. The amount of quartz is variable, but it is always an abundant mineral. Both large and small crystals of quartz occur in irregular masses, rarely ever showing crystal outline. Mica Is of the clear and dark varieties, the larger crystals being dark as a rule, and the finer crystals of light color. The present mineralogical composition of the mina is rather variable, as most of the original biotite and muscovite have suffered alteration, and much secondary mica is present as a result of alteration of the original mica and other minerals present, especially the larger cyanite crystals. A large part of the mica now found in the ore is chlorite, with varying amounts of Jefferisite and others, especially sericite. These are in the form of aggregates, or felt-like intergrowths filling the spaces between the quartz, cyanite, and feldspar. The feldspar is plagioclase probably mostly albite. It is white, possesses good cleavage, and is one of the hard brittle minerals of the rock. It alters to kaolin, and sericite, and more or less of these alteration minerals are present within the feldspar crystals but not separated from them. The cyanite is of two varieties, distinguished by their colors as blue and white cyanite. The blue color varies in intensity, being a pronounced blue in some crystals and paler in shade in others. Some crystals have been seen which posses the blue color in one-half of their mass and are pure white or clear in the other half. The purity of the cyanite is probably not affected by the color, but it is difficult to detect the white cyanite in the ore by macroscopic examination, so that great care has to be exercised in the selection of the ore in the field. Of the above minerals, cyanite is the heaviest, having a specific gravity of 3.6; none of the others approach it in specific gravity. The usual as opiates of cyanite in the mica schists are garnet, magnetite, and tourmaline, but these have not been noted in the group of minerals treated, and their absence is a point of great value in favor of this ore, as they possess high specific gravities and interfere in separation processes, and if not separated they are detrimental because of their easily fusible character. Small amounts of apatite and titanite have been noted, but not enough to cause trouble.

Jan 1, 1931

By D. B. Dow

In collecting and dissctinating inforr:.at'ion on ir.:,provec.. practices us0i in the pr eduction cf petroleur:1 and in the r;:;.:.1.nuf __ cture of gasoline, the Bureau of Mines ha.s aidei in creatin5 an interest i-n efficient 11:ethods in all phasas of tr.e oil ani gi:i.s iniustry. In the refinin£ ir...mstry ther.:: is a growing tend.ency for incre.:l.sea. effi. ,:;iency, ana inforr;.Eition rela:tin!s to ic:;p·roved practices should be of value not only to the larger and. core efficient plants, but particularly to srr.a.11 refineries unable to carry out a lar6e experLnental pro!§.rarn. The refi?eries of the United States required 4.3,915,029 barrels cf crude oil J.uring the year 1920*, inclu.::.in1:, 611136,210 barrels of Mexican cru::...e. This yielded. 4,8821546,599 gallons of E>asoline, a.n avara.t;,e ciaily pro;.iuct1on of 13,340,291 e,allons·, Besides the easoline obtainel fro;., cruie· oil by-fr:;.cticna.1 distillation and. from heavy oils by crackini:,, this a,-r;ount incluC1.es 3,152,924 bar­rels of natural-ga.$· gasoline blended. With asoline fro,., th otha two sourcs.

Apr 1, 1922

By Kathleen M. Kowalski, Audrey Podlesny

The Maslach Burnout Inventory (MBI) was administered and scored for 154 Mine Safety and Health Administration (MSHA) employees kom the US Department of Labor. These employees serve as accident investigators for serious accidents and fatalities as part of their job duties. During a workshop on stress designed for them, subjects volunteered anonymous written anecdotes, confirming and illustrating the findings. The subjects represented locations across the USA and all mining commodities: coal, metal, non-metal, stone, and sand and gravel. The Maslach Burnout Inventory assesses three aspects of experienced burnout: emotional exhaustion, depersonalisation, and reduced personal accomplishments. The average results of the scores for each of the three subscales for the study group of MSHA accident investigators fell in the moderate range. These scores show that the subject population was at some risk for emotional exhaustion and depersonalisation, tending toward burnout. The group evidenced a lower sense of personal accomplishment in their jobs, indicating a higher risk for burnout. From this outcome accident investigators may be at moderate (note: this does not mean average) risk for burnout. The authors recommend follow-up with this population - specifically in training to work with grieving families; and greater organisational support for the accident investigators in this area would be appropriate. Keywords: Burnout; accident investigators; occupational safety and health; job stress.

By R. V. Ramani, C. B. Manula, A. Owili-Eger

Network analysis of mine ventilation systems is not new, having been traced back to 1854. A Committee Report (1970) has also reported the extensive work done in this respect in the United Kingdom, Japan, U.S.S.R., South Africa, United States, and other countries. Wang, et al (1970) developed a computer program which is an improvement over the earlier one developed by Wang et al (1967). The program has been recently modified and extended to include methane emission features by Owili-Eger (1973). This computer program incorporates all the novel features of the earlier programs. These include the capabilities of mesh selection, free splitting, internal or external fans, natural ventilation pressure and fixed quantity branches. The program is written in Fortran IV and, in effect, is an experimental mine in which many ideas can be tried out. The computer produces, besides the input data and certain computational data, the quantities and head losses in the branches, the head losses to be adjusted in the fixed quantity branches and the fan operating point. The last named program, hereafter to be referred to as the PSU/MVS, is presented in Appendix I. The application of this program is demonstrated in this manual through a series of selected examples. Application of the methane generator program is not included here as a detailed report on the subject is available elsewhere (Ramani et al, 1975).

Jan 1, 1975

By Lloyd A. Morley, Alan M. Christman

Presented below is a review of how the objectives, as outlined in the statement of the problem, were achieved. 1. Methods of evaluating the performance of grounding systems must be described. These methods are the subject of Chapter III. 2. Field trips to operating mines should be undertaken, and a cri¬tique of their grounding systems made upon the basis of obser¬vation and the application of the above techniques. An analysis of field trip data, along with practical recommendations, is in¬cluded in Chapter IV, while a complete review of all field trips is given in Appendix I. 3. Because of their thoroughness, present coal mine regulations should be evaluated, and their applicability to open-pit environ¬ments appraised. This has been done in consultation with governmental agency, manufacturing, operating mine, and consult¬ing engineers. As stated in Chapter IV, insight gained through field observations has served to amplify and extend the base of knowledge from which the recommendations were made. 4. The results of these investigations should lead to suggested Federal standards. Such recommendations comprise Appendix II. In addition, several important factors, which are discussed in Chapter IV, were brought to light as a direct result of the field research. 5. Seasonal variations in the earth resistance of ground mats, as illustrated by Table 12, reinforce the need for periodic

Jan 1, 1976

By Lloyd A. Morley, Alan M. Christman

General A review of the literature has revealed important areas which should be investigated during the field work. Of the utmost importance is the safety of mine personnel. Should a phase-to-ground fault occur on a shovel or other piece of equipment, current may return to the substation through the machine's contact surface with the mine floor, thereby raising the frame above ground potential and posing a shock hazard to anyone who touches the equipment. If the frame-to-earth resistance is very low, then no dangerous potentials will be developed, and a basis for elimination of the ground conductors from trailing cables could be postulated. However, should the contact resistance be high, then lethal voltages could be present on the machine frame. In this instance, low-resistance ground conductors in the trailing cable would be a necessity. Therefore, field tests should include measurements of the earth resistance of electrically operated portable or mobile mining equipment such as shovels, draglines, and drills. When the electrical distribution system is subject to lightning discharges, the grounding grid must safely carry to earth and dissipate enormous current surges. It is essential that the grounding grid have a low value of earth resistance, because any potential developed across the grounding grid as a result of current flow will appear on the frames of all machinery connected to the grid. Thus, an earth resistance

Jan 1, 1976

By R. J. Matetic, D. Elsworth

The objective of this U.S. Bureau of Mines hydrologic-subsidence investigation was to evaluate the effects of longwall mining on the local ground water regime through field monitoring and numerical modeling. Field data were obtained from multiple-position borehole extensometers (MPBX's) that were used to measure subsurface displacements. Survey monuments were installed to measure mining-induced surface deformations. Numerous drawdown and recovery tests were performed to characterize hydrologic properties of the overburden strata. Coreholes were drilled above the study area to determine lithologic and strength characteristics of the overburden strata using the rock samples collected. Electronic recorders were installed on all monitoring wells to continuously monitor ground water levels in coordination with mining of the longwall panels. A combined finite element model of the deformation of overlying strata, and it's influence on ground water flow was used to define the change in local and regional water budgets. The predicted effects of the postmining ground water system determined by the model correlated well with field data collected from the field site. Without an infiltration rate added to the model, a static decrease of 3.0 m (10 ft) in water level would occur due to mining of both longwall panels and if an infiltration rate was inputted in the model, no predicted long-term effects would occur to the ground water system.

Jan 1, 1995

Develop a safer, more effective, and more efficient method to control fires in abandoned coal mines and waste banks. Maintain the costs of this new method at less than or comparable to conventional AMI fire control methods. How It Works Cryogenic extinguishment of subsurface fires is a method of heat transfer. Bureau-designed injection equipment produces a pumpable slurry of liquid nitrogen and solid particles of carbon dioxide. Liquid or gaseous carbon dioxide from a pressurized tank flows to a bell-shaped nozzle where the change in pressure causes the carbon dioxide to form a granular snow. The solid carbon dioxide is mixed with liquid nitrogen. A jet pump is used to move the slurry through the delivery lines and into a simple injection probe. At injection, the nitrogen vaporizes and the carbon dioxide sublimes. This phase change produces a cold gas (-180° C) that, as it expands and moves in all directions, removes heat and also displaces oxygen. This combined process inhibits the combustion process and lowers the temperature below the reignition point. When the liquid nitrogen and solid carbon dioxide are converted to gases, the expanding gas acts like a piston, forcing warm air out of the porous bed, Although smoke and hot gases arc forced from the burning coal, generally there is no significant increase in the odor associated with burning coal.

Jan 1, 1992

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

The need for a large capacity, high speed computer is more apparent in the revised model than in the original one. Core storage requirements for data and model logic have at least tripled. This dictates the use of one of the large modern machines such as the IBM 360-370 series or the Univac 1108 and 1110, which handle the model without the need for extensive program overlay. Computer time is expensive on these machines, however, and comprehensive analysis has gone into optimizing computer execution time consistent with model information flow sensitivity. For example, revised locomotive tramming routines have been developed which will significantly cut execution time compared to the previous version. Transceiver Applications The computer coding for the model has been developed to enable program execution and testing using a remote terminal on a time sharing system. In fact, nearly all of the coding, debugging, testing and modifications have been performed from a terminal during develop¬ment. The gaming options described in the Model Input Section of this report have been designed so that they are easily changed by the user from any remote site. One restriction on remote applications which could arise, however, is where highly detailed output options are specified, resulting in a large amount of output records which could be handled more efficiently on a high speed printer.

Jan 1, 1974