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By C. Özgen Karacan

Longwall mining is an underground mining method during which a mechanical shearer progressively mines a large block of coal, called a panel, in an extensive area. During this operation the roof of the coal seam is supported only temporarily with hydraulic supports that protect the workers and the equipment on the coal face. As the coal is extracted, the supports automatically advance and the roof strata cave behind the supports. Caving results in fracturing and relaxation of the overlying strata, which is called "gob." Due its highly fractured nature, gob contains many flow paths for gas migration. Thus, if the overlying strata contain gassy sandstones or sandstone channels, gas shales or thinner coal seams which are not suitable for mining, then the mining-induced changes can cause unexpected or uncontrolled gas migration into the underground workplace. Vertical gob gas ventholes (GGV) are drilled into each longwall panel to capture the methane within the overlying fractured strata before it enters the work environment. Thus, it is important, first to understand the properties of the gas reservoir created by mining disturbances and, second, to optimize the well parameters and placement accordingly. In this paper, the production rate-pressure behaviors of six GGVs drilled over three adjacent panels were analyzed by using conventional multi-rate drawdown analysis techniques. The analyses were performed for infinite acting and pseudo-steady state flow models, which may be applicable during panel mining (DM) and after mining (AM) production periods of GGVs. These phases were analyzed separately since the reservoir properties, due to dynamic subsidence, boundary conditions and gas capacity of the gob reservoir may change between these two stages. The results suggest that conventional well test analysis techniques can be applicable to highly complex gob reservoirs and GGVs to determine parameters such as skin, permeability, radius of investigation, flow efficiency and damage ratio. The insights obtained from well test analyses can be used for a better understanding of the gob and for designing more effective gob gas venthole systems.

Jan 1, 2009

By Halagowder Devaraj, Mostafa Sheykhnazari, Veer P. Bhavanandan

"A sensitive colorimetric assay for detecting mucins and glycoproteins rich in 0-glycosidically linked saccharides is reported. The method combines the susceptibility of N-acetylgalactosamine terminating 0-glyco idically linked saccharides to P-elimination with the Morgan-Elson reaction for N-acetylhexosamines with free reducing ends. All mucin and mucin-type glycoproteins but none of the serum-type glycoproteins tested resulted in characteristic color production. All mucins tested gave linear responses in the range 5 to 200 ""g and the assay was also adapted to the microscale involving the use of 96-well microtiter plates. The microassay in which the volumes of samples and reagents are scaled down 2.5-fold was particularly useful in monitoring of mucins, in the presence of other glycoconjugates, in large numbers of samples obtained during fractionation procedures. Cesium chloride, cesium bromide, potassium thiocyanate, and various detergents do not interfere with the colorimetric determination. Guanidine hydrochloride, cesium triftuoroacetate, and B-mercap- . toethanol decreased color by 30 to 45%; however, the interference was not serious to prevent the use of the method for detection of mucins in their presence. The use of the method for the specific detection of mucin during fractionation by gel filtration and density gradient centrifugation of cystic fibrosis sputum samples is demonstrated. Mucins are an important class of biomacromolecules whose structure-function relationship is poorly understood (1,2). The investigations of mucins are hampered by difficulties in purifying these very large size molecules which appear to avidly bind other components of the mucus (3,4). One of the problems during purification is the specific detection of mucins. For example, during the various purification steps, the fractions containing mucins are typically detected by assaying for neutral sugars (hexoses) (5,6), for sialic acids (7), or for periodate oxidizable saccharide units (8). However, these methods are not entirely satisfactory because neutral sugars, sialic acids, and periodate-oxidizable saccharides are also components of other glycoconjugates. In addition, the neutral sugar and sialic acid measurements are also subject to interference from high levels of proteins and nucleic acids."

Jan 1, 1990

By L. Mark Irwin, R. A. Marsyla

The objective of this laboratory investigation was to develop a mattesmelting process for the recovery of copper from industrial smelter dusts . Experimentation was conducted on three samples of Cottrell precipitator dust from a northern Michigan smelter with variations in the following conditions : Temperature , charge composition , pelletization , and moisture content . Based on chemical analyses of the furnace slags , poorest recovery of copper was effected in smelting dry charges regardless of composition . Some improvement was noted with uniformly moistened charges and still more with pelletized (but dry) mixes , but best results were obtained from smelting moist , self - fluxing pellets . Under favorable conditions , experiments yielded furnace slags with an average copper content of only 0.15 percent , which is well below that of industrial copper reverberatory slags .

Jan 1, 1963

By P. M. Ambrose

This report describes an accident, which took place in the Chemical Corrosion Laboratory at the College Park, Md., Station of the Federal Bureau of Mines. The accident occurred while Walter L. Acherman, chemist, was performing a routine manipulation during a corrosion experiment involving commercially pure titanium and red-fuming nitric acid. There was a sudden and very violent reaction, and a large quantity of acid was thrown in the face and over the body of Acherman, causing serious injury. L. B. Golden, chief of the Chemical Corrosion Section, was exposed to nitric acid fumes during the ensuing rescue and first-aid operations and died on January 25, 1954. According to the medical report, the direct cause of Mr. Golden's death was pulmonary edema and confluent bronchopneumonia; the contributary cause, was inhalation of fumes from red fuming nitric acid. The following employees of the College Park Station contributed to this report by supplying information on the accident and assisted in the rescue operation: L. B. Golden, chief, Chemical Corrosion Section; T. E. Green, chemist; Robert Warf field, chemist; L. A. DeVivo, laboratory mechanic; D. W. Chalkley, laboratory mechanic; E. H. Neagle, laboratory welder; and R. L. Heath, laboratory general mechanic.

Jan 1, 1955

By Christopher Mark, Anthony T. Iannacchione

Falls of ground continue to be one of the most serious causes of injury to U.S. miners. Of the 256 fatal injuries that occurred in mining between 1996 and 1998, 52 (20%) were caused by falls of ground (Table I). Falls of ground affect some sectors of the mining industry more severely than others. For instance, nearly 40% of the 98 coal mine fatalities between 1996 and 1998 were caused by falls of ground. Underground miners are at much greater risk than surface miners. Nearly half (45 out of 101) of underground mine fatalities were attributed to roof, rib and face falls, while less than 5% of the 155 surface fatalities were caused by falls of highwalls or slopes. Sources of Data All of the injury data examined in this study were derived from MSHA’s Fatal Investigation Reports (www.msha.gov)and the MSHA accident database. Because falls of ground often result in serious injury, MSHA Fatal Alert Bulletins and Fatal Investigation Reports provide a useful snapshot of ground control issues in the mining industry. MSHA requires that mines file a report on every reportable accident that occurs, containing information on the accident’s location, severity, classification, activity, and nature of injury, etc. A short narrative is generally included as well. Accident reports can be searched by many of the above fields. From 1996 to 1998, miners suffered a total of 55,096 injuries, which ranged in severity from death (degree 1) to injuries with no days away from work nor restricted duty (degree 6). Six percent of the total injuries were from falls of ground, including machine accidents where caving rock was coded as the source. As the data in Table II indicate, 98% of all non-fatal fall of ground injuries occurred in underground mines, with underground coal mines accounting for 83% of the total. Table II also shows the distribution non-fatal fall of ground injuries by severity and commodity. The injuries are classified into Lost Time Injuries that resulted in permanent disability (degree 2) or days off work (degrees 3-4), and Injuries Without Lost Time that resulted in no more than restricted duty (degree 5-6). Overall, groundfall injuries appear to be more serious than other types of mining injuries. 65% of all ground fall injuries resulted in lost time compared to 54% of all types of mining injuries.

By R. V. Higgins

Many contributions to methods of forecasting the performance of waterfloods of a five-spot pattern have been made by investigators. In most of these forecasting methods, a previously selected sweep efficiency is used, and other simplifying assumptions are employed to obtain the objective. In this paper the calculated oil recoveries from several five-spot single- and multiple-layer stratified reservoirs were made with a minimum of assumptions, and because of the techniques used, no previously selected sweep efficiency was required. As a result, the accuracy of the forecast is increased. Permeability curves and continuously changing saturation gradients are used in every section of the pattern. By means of a potentiometric model, the flood pattern is divided into channels, the centers of which are the streamlines. The channels are divided into cells. As flood water enters, the permeability and saturation of each cell change with time. In this study the production from multiple-sand layers of different absolute permeability but with the same relative permeability-saturation relations are combined. The results are shown for a single- and 10-layer reservoir with a permeability variation of 0.60. The oil rate, water-oil ratio, and recovery are shown as functions of time for a 2- and 20-centipoise oil starting in primary phase and after fill-up.

Jan 1, 1962

By Andrew M. Leszcykowski

The Bureau of Mines (Bureau) conducted mineral investigations of the Payette Crest-South Fork area in west central Idaho near McCall, Idaho, in 1989. There are no known producing mines or mineral production from the area. Forty-seven samples were taken (stream sediment, rock. and placer); no identified mineral resources were delineated.

Jan 1, 1991

By S. M. Shelton, W. A. Calhoun

"INTRODUCTION Discovery and development of a southwestern Arkansas quicksilver district are recent history. In July 1930 4/, a specimen was discovered near the Little Missouri River in sec. 1, T. 7S. R. 26 W., which was identified as cinnabar. In the summer of 1931, Leo Yount began prospecting for cinnabar near the Little Missouri River. In the fall of that year he operated a small three-tube retort near the present Parker Hill mines and produced several flasks of quicksilver. Yount optioned a considerable block of ground containing the best showings in the Little Missouri River area, and on February 19, 1932, he and W. C. McBride, Inc., of St. Louis, Mo., formed the Southwestern Quicksilver Co., which was the largest producer in the district until operations ceased in September 1934.The Southwestern Quicksilver Co. installed a rotary furnace on Parker Hill in April 1932, which treated ore from the three principal mines Gap Ridge, Parker Hill, and Parnell Hill. In 1934 production was entirely from the Gap Ridge and Parker Hill mines. Nothing was done at Parnell Hill except a little small-scale work on a share basis.Mercury Producers, Inc., later took an option on the holdings of the Southwestern Quicksilver Co. and in June 1935 began operations. The company produced considerable quicksilver before the lease and option were surrendered in the summer of 1936. Most of the work of Mercury Producers, Inc., was on Parnell Hill, but some work was done on Parker Hill and at the Bell prospect on ground not controlled by the Southwestern Quicksilver Co."

Mar 1, 1942

By Henry J. Kellner, Michael J. Brnich

This U.S. Bureau of Mines report addresses issues involved in using a limited number of training apparatus to give hands-on self-contained self-rescuer (SCSR) training to a succession of miners, and provides guidance regarding methods for minimizing the spread of infectious diseases. Procedures used for preventing the spread of infectious organisms in dentistry, cardiopulmonary resuscitation (CPR) training, and scuba training are examined. The sanitizing methods of three organizations that require individuals to insert the mouthpiece as part of the SCSR donning sequence are discussed. It was found that each of these organizations was able to render their mouthpiece assemblies microbe free simply and inexpensively.

Jan 1, 1989

By L. L. Oden

The Bureau of Mines has studied a number of processes to remove Cu from molten steel scrap with the objective of determining if any of the laboratory methods studied warranted in depth research investigations. Experimental approaches included oxidizing Cu from steel containing other metals that form stable mixed oxides with Cu (AI, Cr, Fe, Mn, Mo, and V), injecting the same metals as oxides to simplify the mechanism of complex oxide formation, partitioning Cu into alkali or alkaline earth silicate slags or oxide-moderated sulfides, and coremoving Cu and S by injecting active compounds of Ca and Mg. The most promising tests, producing nearly 0.3 pct Cu in the slag, used Ar injection of K20-moderated Na2S-FeS below the surface of molten steel containing about 0.6 pct Cu and protected by a CaO-SiOz slag; however, in depth research investigations currently are not felt to be warranted.

Jan 1, 1987

By Ad. Breyre

[Internal-combustion engines have been used in Belgian mines for a long tine. As early as 1899, the use of these engines underground was considered, but the general policy was to prohibit such an application unless ministorial permission was granted' in special instances. At that time only gasoline engines were available, and a few of these were installed as stationary engines, although in general they were replaced later by electric or compressed-air motors. However, the number of gasoline locomotives continued to increase. Regulations governing the use of these locomotives soon were formulated and as early as 1920, when a now set of regulations was promulgated, the use of gasoline locomotives in mines could be authorized by the Provincial Inspection Department and no longer depended on obtaining a ministerial decision. Since 1931 this authorization may be given by the Chief Inspector of Mines, Director of the Mining District. Since 1920, safe practices have boon incorporated in the regulations.]

Jan 1, 1940

By John W. Sweeney

Shales and clays from Illinois were sampled, tested, and evaluated to determine feasibility of producing lightweight aggregate by rotary-kiln methods. Sampling procedures and the 1 ,,,y of the Pennsylvanian shale units are discussed. Chemical, X-ray spectrographic and X-ray petrographic analyses were run on the samples to determine if a correlation existed between chemical mineralogic composition and expansion. Preliminary expansion testing was conducted in a muffle furnace. Rotary-kiln tests were conducted in a 16- inch by 14-foot rotary kiln. The weight of the aggregate ranged from 27 to 59 pounds per cubic foot. Concrete cubes employing the aggregate were tested to determine the qualities of the concrete. Compressive strength of the concrete using the 7-bag of cement cement per cubic yard mix, after autoclave curing for 6 hours, ranged from 2,950 to 6,750 psi. No correlation was found between the chemical, X-ray spectrographic, and X-ray and petrographic analyses and expansion, Sixteen samples made suitable lightweight aggregates in the laboratory rotary kiln. The expansion temperature range of eight of the samples was extremely narrow, and difficulties would probably be encountered in processing these materials commercially.

Jan 1, 1965

By Ad. Breyre

Internal-combustion engines have been used in Belgian mines for a long time. As early as 1899, the use of these engines underground was considered, but the general policy was to prohibit such an application unless ministorial permission was granted in special instances. At that time only gasoline engines were available, and a few of these were installed as stationary engines, although in general they wore replaced later by electric or compressed air motors. However, the number of gasoline locomotives continued to increase. Regulations governing; the use of these locomotives seen were formulated and as early as 1920, when a new set of regulations was promulgated, these of gasoline locomotives in mines could be authorized by the Provincial Inspection Department and no longer depended on obtaining a ministerial decision. Since 1931 this authorization may be given by the Chief Inspector of Mines, Director of the Mining District. Since 1920, safe practices have been incorporated in the regulations.

Jan 1, 1940

By O. C. Blade

This report on the properties of aviation gasolines and aviation jet fuels produced in the United States during 1956 was made under a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. Analytical data are presented for 120 samples of aviation gasoline and for 38 samples of aviation jet fuel. The analyses were made on samples typical of the manufacturers' 1956 production in their laboratories and the results submitted to the Bureau of Mines for compilation. The products of 20 manufacturers of aviation gasolines and of 17 producers of aviation jet fuels are represented.

Jan 1, 1957

By J. W. Town

Recrystallization studies on chrome-bearing spinel materials were made by the Bureau of Mines to determine the effects of certain fluxing agents and cooling rates on the chromium-to-iron ratio of recrystallized spinel. Statistically designed and evaluated tests showed that the ratio of chromium to iron in naturally occurring chrome spinel could be increased from 1.5 to 1 to over 7 to 1 and that the ratio of chromium to iron in the chrome-spinel in a stain-less steel slag could be raised to over 18 to 1. Silica, magnesia, and lime had significant positive effects, while alumina had a significant negative effect. Cooling rates of 200 C per hour in a programmed spiral globar electric furnace were satisfactory for growing crystals of recoverable size.

Jan 1, 1967

By G. M. Kintz

In safety work a study of past accidents is of value in determining means of reducing future accidents of the same character. This is particularly true with reference to coal-mine explosions. Data from publications of the United States Bureau of Mines and from published reports of the State inspector of coal mines of Colorado are presented in this circular in the belief that they will be of value to operators by indicating methods of preventing future coal-mine explosions. The tables included are complete only with regard to major disasters. The Bureau of Mines considers as a major disaster one in which five 'or more men are killed. However, this circular also includes a considerable number of minor disasters, Various explosions in the coal mines of Colorado from 1883 to 1932, inclusive, are listed with information available as to their probable cause, number of men killed and measures which, if they had been in use at that time, might have prevented them. John McNeil, first Colorado State coal-mine inspector, on page 43 of his first report for the period ended July 31, 1884, made the following recommendations for the prevention of explosions in the coal industry: True causes could be traced either to insufficient ventilation, carelessness and lack of rigid discipline in carrying on energetic ventilation and other precautions needed to be enforced in a mine giving off explosive gases. *** When any quantity of fine coal dust is observed in an entry, air course, or room it should be made damp and be removed from the mine, and thus beep every place as free from dust as possible. *** A system of bratticing close up to the face of each and every place in the mine from crosscut last made (whether gas should just then show its presence or not) which should not be more than 50 or 75 feet according to the nature of the mine.

Jan 1, 1933

By Wm. W. Odell

In distributing natural and mixed gas, the industry is each year confronted with the problem of manufacturing gas in increasing amounts as the supply of natural gas becomes more nearly exhausted. The manufactured gas is now used in mixtures with the still available natural product, and will subsequently be used straight as a substitute gas. The gases that might be considered, and are producible by tried and developed processes, include water gas, carbureted water gas, and coal gas. Singularly, these gases can be used in this manner in ordinary appliances only when proportional amounts of them in the mixtures do not vary beyond rather definite limits, unless burner adjustments are made. The limits are defined by the specific gravity, content of inerts, and burning properties of the respective gases. Anticipating a future standard for city gas lower than that of natural gas during the period when considerable natural gas is available, there is justification for considering the possibility of re-forming natural gas and making a product that has substantially the same properties as other gases which can readily be generated. This report gives the results obtained during a series of tests made under a cooperative agreement by the U. S. Bureau of Mines with the Ohio Fuel Gas Co., re-forming natural gas at Toledo, Ohio, in full-scale operation in a water-gas generator having a grate area of 25.1 square feet. ACKNOWLEDGMENTS The Ohio Fuel Gas Co. constructed a special water-gas generator for the tests and provided men and the necessary funds for its operation. Appreciation is expressed for the general spirit of helpful cooperation which was evidenced in the activities of all those who took part in the work. Particular acknowledgment is made of the assistance rendered by C. W. Wallace, manager, and by C. F. Cramer, superintendent, and A. Upp, foreman of the plant.

Jan 1, 1929

By L. E. Schultze

As part of the Bureau of Mines research program on recovering alumina from domestic resources, methods for extracting iron from aluminum sulfate solutions (obtained by leaching kaolinitic clay with dilute sulfuric ,acid) were investigated. In countercurrent extraction experiments at a l-gal/hr flow rate of aluminum sulfate leach liquor, the iron concentration 'was decreased from 1.4 g/l to 0.01 g/l after four stages of using a primary amine extractant. The iron-loaded amine solution was regenerated in five stages using 3[N] sulfuric acid or in four stages using 6[N] sulfuric acid. The aluminum sulfate solution obtained was suitable for the preparation of alumina meeting cell-grade standards of less than 0.01 pct iron.

Jan 1, 1979

By John P. Powell

A comprehensive study of the effects of hydraulically fracturing water-flood wells in Oklahoma has been made by the Federal Bureau of Mines. This report presents results of that study and an analysis of some of the factors governing the results of fracture treatment on waterflood properties. Originally, hydraulic fracturing was used to stimulate oil production from old wells producing by primary methods, and its application to water-flooding was regarded with skepticism by most producers. However, since 1953 the number of fracture treatments of both oil and input wells in waterfloods has increased steadily. Hydraulic-fracture treatments in waterfloods have generally been successful in stimulating production from oil wells and increasing the rate of injection into input wells. Hydraulic fracturing has enabled several producers to turn probable failures into economically successful projects.

Jan 1, 1961

By William H. Pomroy

Fire on surface mining equipment is a serious hazard to life and property. The Bureau of Mines, through a program of contract and in-house research, has developed and in-mine demonstrated reasonably priced, reliable automatic fire protection systems to deal with this problem. This report reviews the development and subsequent testing of systems for haulage trucks, front end loaders, coal augers, dozers, drills, and shovels. A variety of fire sensors, extinguishing agents, and control systems arc discussed in the context of mine equipment designs and operating environments

Jan 1, 1980