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By R. R. May

A preliminary examination of the Houston strip-coal mine, situated on the Alaska Railroad at milepost 175 (61 rail miles north of Anchorage, Alaska) and a review of all available information resulting from early coal exploration activities in the area resulted in plans to investigate the coal-bearing formations at depth by means of diamond core drilling to indicate the existence of additional reserves of coal in close proximity to railroad transportation, where it would be quickly available to meet rapidly expanding military and civilian fuel requirements. From the date of mobilization of equipment, August 28, 1951, until date of suspension, August 18, 1952, 2,010 feet of diamond drilling was completed. Ten definable coal beds were cut, of which 2 appear to be persistent and minable over an area of approximately 1/2 square mile. Within this area the 2 minable beds contain approximately 5,000,000 tons of coal in place. Of the remaining beds, at least two others may be minable to the eastward near their projected outcrops; however, these and deeper beds (at least in the vicinity of the drill holes) lie beneath a zone of pressurized gas and brackish water. From a practical standpoint, continued development and utilization of the coal in this vicinity will depend on the operators' ingenuity in developing cheap mining methods and on diligent prospecting for strippable coal under the comparatively light glacial cover.

Jan 1, 1957

By R. S. Conti

This U.S. Bureau of Mines (USBM) report discusses the results of research conducted in the USBM experimental mine at its Lake Lynn Laboratory to determine the alarm times of smoke and carbon monoxide (CO) sensors, and a point type heat sensor (PTIIS) to slowly developing coal-conveyor belt fires. The tests were conducted at air velocities of 0.44 and 0.97 m/s, The data clearly indicate that smoke sensors provide earlier warning of fire than 10 ppm CO sensors, and that 10 ppm CO sensors provide earlier warning than PTHS, A success rate of 1.0 (indicating detection of every test fire) was obtained for both smoke and C8 sensors. For the PTHS, the success rate was 0.57 at the lower air velocity, decreasing to 0 at the higher air velocity, Data are also presented showing the sequence of fire events and detection events at the two air velocities as a function of time. Results show that early detection and warning of underground mine fires will improve the probability of miners' escape.

Jan 1, 2010

By ALICE V. Petar

Like many gem materials, amber has a colorful history which may be traced through the writings of the ancients and the ornamental relics discovered from time to time. Like few gem materials, however, it is distinctly useful in products whose value has no connection with the gem industry. Long prized for its beauty, amber was fashioned into articles of jewelry and ornaments to please the fancy of ancient rulers and to find a place among treasured pos- sessions in their tombs; it has been used by adherents of various creeds for rosaries and other religious symbols; and although still sold for these pur- poses it also lends itself to such commercial purposes as raw material for varnish. Amber is only on the border-line of the mineral kingdom; actually it is of vegetable origin, having been formed as resin from trees of the conifer family that existed during the Tertiary period. It is the hardest of the fos- sil gums. The United States produces no amber, although a few occurrences are known. Most of the world's supply comes from East Prussia, where it is ob- tained from both land and sea. For many years pieces of amber were gathered from the Baltic by fishermen and deep-sea divers; and although about 10 per- cent of the Prussian amber is still recovered from the sea, most of the out- put is mined from open pits on the Samland Peninsula.

Jun 1, 1934

By D. D. Fischer

Recovery and separation of molybdenum and rhenium from a process solution was accomplished by a technique developed by the Federal Bureau of Mines involving a combined solvent extraction and activated carbon adsorption procedure. The processing sequence required treatment of the solution with S02 to reduce the chlorate ion and adjust the pR prior to solvent extraction of molybdenum and rhenium with a tertiary amine. Molybdenum and rhenium were stripped from the organic phase with an NH40H solution, and the strip solution was then passed through activated carbon to preferentially adsorb the rhenium. After washing entrained molybdenum from the column with a brine solution, rhenium was eluted with an MeOH-H20 mixture. The activated carbon was regenerated with water. Molybdenum was recovered as (NH4)6Mo7024 by evaporating the column effluent. Rhenium in the column eluate was reextracted with a tertiary amine, stripped from the organic phase with dilute NH40H, and recovered as NH4Re04 by evaporating the strip solution. The final (NR4)Re04 product contained < 80 ppm impurities. Sodium sulfate was crystallized from the first solvent-extraction raffinate by lowering the solution temperature to 0° C. Precious metals contained in the original process solution were adsorbed onto the activated carbon.

Jan 1, 1975

By Eugene T. Sheridan

The annual survey of the fuel-briquet industry by the Bureau of Mines, United States Department of the Interior, revealed that 21 fuel-briquet plants in 11 States were in operation and reported production in 1956. The demand for fuel briquets in the United States has gradually declined since 1948, and the number of operating plants has decreased from 36 to 21. Also, the annual productive capacity of the industry has decreased, although not a proportionate amount because most of the plants that were abandoned were small and in most instances had a designed capacity of less than 25,000 tons per year. In 1956 the 21 active plants had an annual capacity of 3.7 million tons (table 2), which was only 20 percent less than the total capacity of the 36 plants in 1948. This indicates that most of the larger plants have remained active, even though operating at reduced rates, and the average capacity of the industry has increased from 130,000 tons per plant in 1948 to 177,000 tons in 1956. Since 1948 operating rates have decreased from 67 percent to 41 percent of annual capacity.

Jan 1, 1958

By E. C. Tarpley, H. M. Cooper, R. F. Abernethy

The standard method of employing preliminary air-drying to determine the moisture in coal has been criticized with respect to the loss of heating value from excessive air-drying. By this method, the coal is air-dried at approximately 10-15° above room temperature with the loss in weight being less than 0.1 percent per hour, and then the residual moisture at 105°C is determined. The total moisture is calculated from these two values.

Feb 1, 1948

By N. S. Dalal, X. Shi, V. Vallyathan

"Electron spin resonance (ESR) and cytotoxicity measurements were made on newly fractured silica to examine specifically the role of the fractured-induced, siliconbased radicals (Si· and SiO·), and silica-generated hydroxyl (·OH) radicals in the mechanism of the cell membrane damage by silica. The concentration of the Si· and SiO· radicals was controlled through decay processes, thermal annealing, and boiling, while that of the ·OH radicals was varied by using catalase, superoxide dismutase, KMnO4, Ha2seO3, ascorbic acid, and metal ions, and monitored via ESR spectroscopy. The dust's cytotozicity potential was evaluated by measuring the silica-induced hemolysis and also by determining lipid peroxidation (using linoleic acid). Prom the comparison of hemolysis and ESR results it is deduced that the radicals play little· or no role in the silica-induced hemolysis. However, the lipid peroxidation data indicate that the radicals might be involved in the initiation of an oxidative chain reaction leading to the macrophage membrane damage through lipid peroxidation. INTRODUCTIONThe biochemical mechanism of Quartz-related pneumoconiosis is still not fully understood. It is believed, nevertheless, that one event of primary importance is the perturbation of cell membranes by the dust particles (Allison et al., 1966; Allison and Harrow, 1971; Bateman et al., 1982; Parazzi, et al., 1968; Reiser and Last, 1979; Shi et al., 1989; Summerton et al., 1977). The ensuing cell-membrane damage unleashes certain lytic enzymes resulting in additional cell injury and eventual fibrosis (Nolan et al., 1981; Summerton et al., 1977). Thus considerable effort is currently being made towards the understanding of the processes by which quartz particles disrupt the membrane of a red blood cell (RBC) or a pulmonary alveolar macrophage (PAM). A simple but important method of evaluating the membrane damage potential of a dust is the hemolysis test (Harington et al., 1971). Even though this test is used routinely for screening dusts for their cytotoxicity potential, the biochemical mechanism underlying the cell lysis by many dusts, including quartz, is still controversial (Kilroe-Smith, 1974; Singh and Rahman, 1987), and this provided us the impetus for the present undertaking."

Jan 1, 1989

By R. E. Heithecker, Van A. Mills

"Crude oils are capable of dissolving quantities of gas under pressure. This fact has been known for some time, but questions have arisen as to the effects of gas in solution upon the characteristics of the oil. Previous investigations4 show that gas in solution in an oil affects the viscosity and surface tension of the oil, but the effects on the volume and A. P. I. gravity of the oil have not been known. The results given in this report show that there is a decided change both in volume and in the A. P. I. gravity of the oil due to the solution of the gas in the oil under pressure. As gas is dissolved, the volume of the oil and the A. P. I. gravity increase. The converse of this phenomenon is also true: if the gas is released from a saturated oil, there is a shrinkage in volume and a decrease in A.P.I. gravity due to the release of gas from solution. However, various oils show marked tendencies to retain a portion of the dissolved gas upon releasing the pressure to that of the atmosphere. This retained gas has an appreciable effect on the volume and A. P. I. gravity of the oil because the oil does not resume its initial volume or gravity while it retains dissolved gas. In a sense the oil has been ""freshened"" and will not return to its original or weathered volume until it loses some of the lighter fractions. Wiggins5 has shown that a fresh oil decreases both in volume and in gravity because of the weathering of the lighter fractions while the oil is standing in storage tanks.This paper includes data attained during the determination of volume and gravity correction factors to be applied in the oil recovery investigations of the Bureau of Mines. Three oils having a wide range in gravity were used in determining the correction factors. These oils were from the Bartlesville-Dewey field, Oklahoma, the Seminole field, Oklahoma, and the Inglewood field, California. The same gas that was used in the oil recovery experiments was used throughout this investigation. Determinations were made of the volume and A.P.I. gravity increases resulting from the gas going into solution at 200, 400, 600, 800, and 1,000 pounds pressure; also the increases in the volume and gravity of the oil due to retained gas were determined after the dissolved gas was liberated from solution by releasing the pressure to that of the atmosphere.Samples of residual and liberated gas were taken throughout the investigation in order to study the selective absorption and selective retention by the oil of the various constituents of the gas. The analyses of these gas samples showed that there was selective absorption and selective retention of the constituents of the gas. The tests on Inglewood crude gave the most pronounced example of selective absorption and selective retention of the gas.All of the tests were conducted at a constant temperature of 709F."

Oct 1, 1928

By John Nagy

Experience and research have shown that an effective way to reduce structural damage from explosions is to provide adequate pressure-relief vents in the walls of equipment and buildings within which explosions might occur. In general, free or unrestricted openings represent the most efficient type of vent. However, in many manufacturing operations it is impractical to use free vents, and it becomes necessary to cover the openings with diaphragms or blow-out disks, hinged panels, or other devices, in order to give protection against weather changes, to prevent the efflux of dusts or vapors from equipment during normal operations, or for other reasons. A few data on the pressure-relieving capacities of hinged panels and a paper diaphragm were published in Bureau of Mines Report of Investigations 3924, which covered the first phase of the dust-explosion venting study made by the Bureau. The present report describes recent experiments that were made to determine the relative effectiveness of an unrestricted vent and 22 types of closures, including various paper, cloth, and metal-foil diaphragms, hinged doors or panels, and several kinds of scored and unscored glass panes. The tests showed that many of the vent closures were effective in releasing the explosions rapidly during their incipient stage, so that the development of destructive pressures was prevented. Vents of this type should prove useful in safeguarding industrial equipment from severe explosion damage. The experiments disclosed that the venting capacities of the diaphragms are approximately inversely proportional to their static bursting strengths.

Jan 1, 1950

By R. F. Abernethy

A modified Unterzaucher method was applied to the direct determination of oxygen in coal. Coal samples were pyrolyzed in a nitrogen atmosphere, and the gaseous oxygen compounds liberated were converted to carbon monoxide by a platinized-carbon catalyst at 9000 C. After passing over heated copper and through a tube containing soda-asbestos and magnesium perchlorate, the purified carbon monoxide was oxidized to carbon dioxide by iodine pentoxide--liberating an equivalent amount of iodine. The iodine was titrated with 0.02 ~ sodium thiosulfate; in a few tests the weight of carbon dioxide produced was determined. Direct oxygen determinations of coal included organic oxygen from the coal substance, plus a small quantity of inorganic oxygen derived principally from carbonate minerals and from combined water of silicates in the mineral matter. The influence of mineral matter on the direct oxygen determination was investigated by testing (1) untreated coal, (2) demineralized coal from which most of the mineral matter except pyrite was removed by treatment with hydrofluoric and hydrochloric acids, and (3) coal samples treated with dilute hydrochloric acid.

Jan 1, 1966

By Manuel Gomez

The Bureau of Mines used data from 31 core samples to develop prediction equations for evaluating chemical and carbonization properties of six seam units in a lignite deposit approximately 2 miles wide and 8 miles long in the Wilcox Formation of central Texas. Statistical response surfaces, based on core analyses, were computed for 14 parameters indicative of lignite quality. These computed surfaces, and their mathematical equations, can be used to predict values of the selected properties of the lignite seams at any desired surface coordinate position between core hole locations. The wide range of application shown by this study indicates that the methods of statistical regression analysis may be useful to evaluate large deposits of lignite or higher rank coal.

Jan 1, 1969

By W. W. Cutler

An oil-field drilling campaign is used in this paper to signify the spacing of the wells to be drilled as well as the drilling program, which is interpreted as the number of wells drilled in a unit of time, This has an important bearing upon the time of receiving income, as well as upon the amount of revenue obtained In periods of low prices for oil, such as the present, the margin of profit is at the best very small, and the correct determination of the drilling campaign may be the deciding factor between incurring financial loss or gain during the depressed period. General policy of the operator. Drilling should be planned by the field engineer to conform with the general policy of the operator. This policy may be one of conservation daring the early life of the property, but as mentioned later, this may result in a smaller ultimate recovery it often occurs that the market price of oil does not warrant rapid development, or it may be desirable to hold in reserve a supply of oil for a refinery. The policy may be to recover all of the oil as quickly as possible, or it may be to maintain a constant and sustained production. In any case, the operator should, outline as far as possible a definite policy, and should understand the principles underlying the recovery of oil, the influence of rapidity of drilling and effects of spacing, in order that he may obtain the oil as required with the least expenditure.

Jan 1, 1921

By Oliver Bowles

Chalk is defined as a noncrystalline, soft, friable, fine-grained, light-colored type of limestone. It consists essentially of calcareous shells of minute organisms known as "foraminifera," although skeletal remains of molluscs, corals, and sponges are also present. Flint balls which are found so commonly in the chalk cliffs of Europe are regarded as segregations of the remains of certain organisms, such as radiolarians and sponges, that secrete siliceous shells or spicules. The famous chalk beds of northwestern Europe are of Upper Cretaceous age, a geological period that was particularly favorable for the develop- ment and multiplication of foraminifera. The distinguishing physical characteristics of true chalk never have been fully defined; probably its noncrystalline and colloidal properties are most important. The properties of chalk, whiting, and whiting substitutes are not well understood, and much re- search is necessary before definite reasons may be ascribed for the behavior of these materials under various conditions of use. The Bureau of Mines has undertaken a detailed study of chalk and similar materials to determine their exact properties and to establish a basis for classifying formations loosely designated as chalk occurring in various parts of the United States, but the results of this study will not be available for some months. Whiting is a pulverized, purified, and carefully sized chalk. Whiting substitutes consist of finely ground limestone or dolomite, ground marble (marble flour), white marl, and chemically precipitated calcium carbonate.

Jul 1, 1931

By John E. Shelton

Flotation tests were conducted on two samples of copper-nickel-bearing ore from the Harriman area near Rockport, Maine. The samples were taken by Roland F. Beers, Inc., for tests in cooperation with the Federal Bureau of Mines. One sample, analyzing 0.38 percent copper and 0.71 percent nickel, was essentially a disseminated pyrrhotite in hypersthene. Pentlandite, chalcopyrite, pyrite, and millerite were intimately associated with the pyrrhotite. Locked series flotation tests on this sample showed that 87.4 and 73.4 percent of the copper and nickel, respectively, could be recovered in a bulk concentrate that analyzed 3.47 percent copper and 5.34 percent nickel. The copper-and nickel-bearing minerals were collected with sulfhydric collectors in an alkaline circuit. Cleaning the concentrate three times with the addition of pH regulators was sufficient to attain the previously stated grades. The second sample had analyses of 0.31 percent copper and 0.85 percent nickel; talc and hypersthene were the main gangue minerals. Bulk sulfide flotation, made while depressing the talc, resulted in a concentrate that analyzed 2.33 percent copper and 4.70 percent nickel at recoveries of 70.0 and 54.4 percent, respectively. Flotation of the talc followed by bulk sulfide flotation resulted in a nickel content greater than 5 percent. A locked-series test showed that 60.7 percent of the copper and 73.7 percent of the nickel could be recovered at grades of 1.29 and 4.85 percent, respectively.

Jan 1, 1961

By A. T. Harris

Ground quartzite, known in the industry as amorphous silica, is produced from a quartzite deposit near Honey Brook, Pa., by George F. Pettinos, Inc., of Bala-Cynwyd, Pa. The quartzite is mined by the open pit method and processed in a mill at the mine. The operation regularly produces five standard grades of sand and one grade of crushed stone; however, the company accepts special orders and will produce material to meet the customer&apos;s specifications. Beneficiation (chiefly crushing and screening) is controlled by laboratory screen tests on samples taken during preparation of the sand. The chief uses of the sand are for foundry operations, furnace lining, concrete aggregate, and Other specialized uses. The quartzite in this deposit is of uniform composition and does not require control by chemical analysis. However, for special purposes, analysis will be furnished.

Jan 1, 1965

By A. T. Harris

Ground quartzite, known in the industry as amorphous silica, is produced from a quartzite deposit near Honey Brook, Pa., by George F. Pettinos, Inc., of Bala-Cynwyd, Pa. The quartzite is mined by the open pit method and processed in a mill at the mine. The operation regularly produces five standard grades of sand and one grade of crushed stone; however, the company accepts special orders and will produce material to meet the customer&apos;s specifications. Beneficiation (chiefly crushing and screening) is controlled by laboratory screen tests on samples taken during preparation of the sand. The chief uses of the sand are for foundry operations, furnace lining, concrete aggregate, and other specialized uses. The quartzite in this deposit is of uniform composition and does not require control by chemical analysis. However, for special purposes, analysis will be furnished.

Jan 1, 1965

By Frank L. Hess

In the first cart of that little space of time that we have designated as the nineteenth century, chemistry had reached a wonderful stride. Viewed from the present heights attained by the efforts of innumerable chemists with perfected apparatus, mire reagents, air under pressure, water, gas, and electricity conducted to the desk, and. numberless other helps, it seems marvelous that chemists of that day obtained such results. In 1820, about half of the elements had. been discovered; of these discoveries, Swedes had made 15 or more, about once-third of the elements then known and nearly half of those discovered after 1700.

Jan 1, 1939

By E. P. Youngman

The basic mining law of French Morocco is the Edict of 1914, "Danir of Jamary 19, 1914, for the Regulation of Mineral Prospecting and Exploitation in the Zone of the French Protectorate of the Cherifien Empire," which, as the preamble states, was promulgated at the instance of the Director General of Public Works, in consideration of the fact that mines constitute one of the sources of wealth of the Empire. According to a consular report, dated May 18, 1923, by Bradford, men- tioned above, the mining industry of that country, aside from the exploitation of the extensive phosphate deposits, can scarcely be said to exist, but the potential field for mining is promising. However, no large-scale exploitation of the mineral wealth of French Morocco can be hoped for until there is complete pacification of large areas that are still in an unsubdued state or until adequate transportation facilities, scientific prospecting, and large investments of cap- ital are assured. An edict in 1920 (Dahir of January 27, 1920) modified the law mentioned above by declaring the prospecting for and the exploitation of phosphates to be exclusively reserved to the Government. The Dahir o. August 7, 1920, announced the creation of the Cherifien Phosphate Office (Office. Cherifien des Phosphates), a State monopoly charged with the exploration, management, and exploitation of the phosphates of Morocco.

May 1, 1930

By T. A. Sullivan

The use of sulfur combined with either sand or waste copper tailings was investigated by the Bureau of Mines as a substitute for a good graded aggregate in asphalt paving materials. The research was part of a utilization program to develop meaningful uses for a projected oversupply of sulfur. Many sections of the country lack good aggregate for paving but do have available sources of sands and sulfur. The development of paving mixtures of desert sands or tailings with sulfur and asphalt was accomplished in the laboratory and tested by laying small paving test sections. Three types of material were studied for use with the sulfur and asphalt. They were (1) a concrete sand similar in gradation to river or beach sands, (2) desert blow sand, and (3) waste copper tailings. Desert blow sand and waste copper tailings are much finer than concrete sand. Mix designs were established for the three types of materials, sulfur, and asphalt used in the paving materials. The best mix designs were as follows, in weight-percent: 80.5 concrete sand, 13.5 sulfur, and 6 asphalt; and 77 either blow sand or tailings, 17 sulfur, and 6 asphalt. Small-scale testing showed that these mixtures were suitable paving materials but would require specialized equipment for transporting and laying. The chemical modification of sulfur to obtain properties that would allow placement of these materials with normal asphalt paving equipment was studied. Results indicate that reacting sulfur with dicyclopentadiene before adding it to the paving mixture was effective in modifying the sand-sulfur-asphalt paving so it could be placed and rolled with conventional equipment.

Jan 1, 1975

By R. R. Brown

The Bureau of Mines undertook a limited feasibility study to determine the practicality of removing copper from automobile scrap by thermal treatment. Test specimens, prepared by wrapping bare and insulated copper wire around small steel coupons, were heated at 600° to 1,150° C in various atmospheres for different lengths of time under both static and dynamic conditions. The tests indicated that adequate removal of copper cannot be effected by thermal treatment of scrap above the melting point of copper. Tests showed that copper present in scrap as insulated wire is embrittled by thermal treatment at 800° to 900° C if the insulation contains lead, and that the embrittled copper is almost completely removed by a mechanical action such as tumbling. Also chemical pretreatment of specimens to effect embrittlement of copper and the magnetic separation of oxide scale were studied. Tests showed that bare copper can be embrittled by depositing waterglass (Na, Si409) on copper prior to thermal treatment.

Jan 1, 1968