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By A. R. T. Denues

LIQUID-OXYGEN explosives commonly consist of a carbonaceous absorbent enclosed in a canvas wrapper and soaked with a liquid con-taining more than 90 mol per cent of oxygen. Investigation of these explosives in this country was initiated in 1917 by George S. Rice, then Chief Mining Engineer of the Bureau of Mines. The early development is summarized in two papers.1,2 Their characteristics, advantages and disadvantages were considered in a recent bulletin of the Bureau of Mines.3 Other publications of this Bureau4,5 treat the technology of these explosives and contain adequate references to pertinent literature. These investigations defined the properties of liquid-oxygen explosives and improved them greatly; however, an outstanding disadvantage is their high inflammability, a property of critical practical importance. These explosives as hitherto prepared are easily inflamed; the combustion resulting from an accidental ignition is particularly dangerous because of the ease with which it passes into detonation. For this reason the Bureau of Mines undertook a cooperative investigation, which has resulted in the development of fire-retardant treatment for the minimiza-tion or elimination of this hazard without materially impairing the explosive properties, including the ease of detonation. This presentation will offer a general description of the investigation and the outstanding results. Further phases will appear in subsequent short papers, and the entire investigation including the results of detailed experiments will be available in a forthcoming bulletin of the Bureau of Mines (Bull. 429). The effects produced by fire-retardant treatments of the carbonaceous absorbent and of the canvas wrappers were investigated separately, and the efficacy of combinations of these treatments with particular reference to the possibility of inflammation and to the development of detonation from inflammation was studied. The experimental explosive was pre-pared from a granular carbonaceous absorbent and the results described may be more or less unique for such a material. An extensive preliminary

Jan 1, 1940

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By W. P. Sykes

Seven years ago, Dr. S. L. Hoytl presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. Steps in Preparation While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows : 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By W. P. Sykes

SEVEN years ago, Dr. S. L. Hoyt1 presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. STEPS IN PREPARATION While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows: 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By C. A. Heiland

The new geophone described herein was developed by Charles H. Hull, instrumentmaker of the Colorado School of Mines, and the writer. The first geophone was invented during the war for the purpose of detecting enemy sapping or underground mining operations and for locating enemy artillery. It is based on the principle of the seismograph—a heavy lead mass suspended by one or two diaphragms, which are clamped to an air-tight case. When the ground vibrates during the transmission of sound waves, the case moves with it while the so-called steady mass remains practically motionless. Attached to the top of the casing is a hose leading to an earpiece shaped like a stethoscope. When the mass and the diaphragm move up and down in the case, the air is compressed and rarified in the inside; thus the vibration is communicated as sound wave to the human ear. The geophone combines a surprising simplicity of construction with an extreme sensitivity. Other listening instruments were developed during the war, adaptations of the telephone and the microphone—that is, instruments operating through the medium of electricity—of which the so-called seismicrophone, an adaptation of the carbon-granule microphone receiver, probably has found the greatest application, but such instruments apparently have not proved as useful as the simple geophone despite obvious advantages arising from the use of electricity. The carbon receivers were more subject to extraneous noises and to what is called "frying," and they did not offer the advantage possessed by the geophone; namely, the simultaneous use of two receivers, which makes it possible to determine the location of the source of sound. During the war, the U. S. Bureau of Mines made a study of the geophone and of the propagation of sound waves through rock. These studies have been continued, as the earlier results proved the possibility of using the geophone in various non-military ways, principally in mining, and the results of these studies have been published.'

Jan 1, 1932

By W. R. Hamilton

THE knowledge of the existence of petroleum in Southern California dates back to the days of the missions. The presence of asphaltum and semisolid bitumen was reported at Santa Barbara in 1792, but no serious attempt was made to develop oil until Professor Silliman's optimistic report in 1865 started California's first oil boom. Wells were drilled in many counties of the State, but the equipment was unsuitable and the drilling difficult and no production was obtained except in Ventura County. Even there the production was of little importance commercially, and not until the early '80s did it become sufficient to again attract attention. In 1888 the production for the State had reached a total of about 700,000 bbl. per year, practically all light oil produced in Ventura County, Pico Canyon, Los Angeles County and in the Puente Hills. The production of petroleum attained the dignity of an industry in 1895 when the Los Angeles City and Coalinga fields were discovered. The subsequent development has been remarkable, and in 20 years the production has increased from 1,000,000 to 100,000,000 bbl. per year. The refining industry has kept pace with the production of oil. The Pacific Coast Oil Co., the predecessor of the Standard Oil Co. of California, was the virtual pioneer refining company of the State, having built a refinery at Alameda about 1880. When purchased by the Standard, about 1902, it was dismantled and the refinery at Point Richmond was built. The Richmond refinery is now one of the largest in the world, having a capacity in excess of 60,000 bbl. per day. A small refinery was built by the Union Oil Co. at Santa Paula in the early days of the industry and later many asphalt refineries were in operation in Southern California. The Pacific Coast Oil Co. was then, as has been its successor, the Standard Oil Co. of California, the principal refiner and marketer of light products, the most valuable of which was kerosene.

Jan 6, 1916

By Ray Arms

This paper includes a brief classification of dry-cleaning devices, with a theoretical discussion of the principles involved. It outlines the methods of handling dust and screening difficulties at the McComas plant, as well as other plants that are being constructed and other dry-cleaning devices being developed. It describes the American Pneumatic Separator and discusses the sizing required, the effect of moisture in the raw coal, disposition of the middlings, and other aspects of the process. It gives s results of tests on various coals, and results of operation at Raton and McComas. DRY CLEANING, or pneumatic separation, is not, strictly speaking, a recent discovery. Among the archives of the Patent Office may be found many patents dating back as far as 1850 which cover early attempts to separate materials of varying specific gravity or of different shape by means of air. Hundreds of patents covering this art have been issued, which may be roughly classified into four general groups, as follows: 1. Stationary devices with pulsating air currents. The separating surface is usually riffled and air is supplied by bellows or compressors. This group' also includes air jigs, which have been used rather extensively. 2. Stationary devices with continuous air currents. These submitted the material to a continuous current of air, either horizontal or vertical. Chaff is blown from wheat by such a device. 3. Reciprocating or vibrating devices with pulsating air. A small group in which the pulsating air is supplied by bellows and some motion provided in the separating surface to move the stratified material to various discharge points. 4. Reciprocating or vibrating devices with continuous air supply. This is by far the most important group and all recent developments have been along this line. All of the above groups involve the stratification of material by air and include none of the dry methods that use other principles, such as coefficient of friction, magnetism, etc.

Jan 3, 1924

By J. A. Capp

For certain classes of electric railways a steel conductor is preferable to the oldcr atld more commonly used overhead trolley-wire. The third-rail presents a rather better appearance, because of the absence of an overhead structure; it is easily installed, cheaply maintai~ied, presents s large area for conducting and collecting the current, and is therefore particularly suitable for high speed and heavy service. With costs calculated on the basis of equal coilductirity in rail aud trollej-wire, the third-rail constrrictiol~ is cl~caper than thc overhead trolley. But the average interurban road will lise a trolley-wire of considerably less conductivity than would be obtained with the smallest size steel rail (about 60 lb. per pard) that mould ordinarily be used, and here the first clost of trolley construction would generally be less thau that of the third-rail. While no third-rail installation has jet bee11 in operation long enough to give figurcs of value, it ~vould appear that the cost of maintenance of the thirdrail construction should be less than that of the overhead trolley. This consideration, together with that of sightliness and adaptability (particularly in the case of terminals, yards and very heavy or high-speed service), will frequently off'set the higher cost of the third-rail construction and make it the preferable means of' conducting the current from thc generator to the car-motor. For the first third-rail installations, old track rails were used when obtainable, and these old rails were supple~rlented with new rails of standard T-section and composition. With the coming of the very heavy, high-speed service during the past few years, the resistance of these old and new standard T-rails was found to be so high that they mould not carry the high currents necessary without too great a drop in the line-potential. The rails would, therefore, have to be suppleme~~ted with addi-

Jan 1, 1904

By Kefton H. Teague

Olivine is a mineral containing a mixture of forsterite (Mg,SiO,) and fayalite (Fe,SiO,) in solid solution. The name "olivine" was first applied by Werner in 1790 (Hunter, 1941) because of the olive-green color of the mineral. Uses The principal use of olivine is in various foundry applications. Perhaps the largest tonnage is utilized as a special foundry sand for mold-making in brass, aluminum, and magnesium foundries (Schaller, 1957, 1958; Snyder, 1957). Olivine was first used as an industrial mineral in the early 1930s for a refractory material (Anon., 1970; Hunter, 1941). As a refractory raw material, olivine was first introduced in the United States as handcobbed, selected, shaped blocks of crude olivine. This use met with limited success. More recently, finely ground olivine blended with MgO and pressed into bricks, which are then fired, have found use in glass tank furnaces and open-hearth furnaces. Ramming or gunning mixes for basic furnace linings also utilize olivine. Olivine has been used in ladle linings with varied success. In Europe, substantial tonnages of olivine are utilized in refractory brick for night storage heaters (Anon., 1970). A limited amount of olivine has been used in the past as a fertilizer (magnesium source) and has been fused with rock phosphate to produce a magnesium phosphate as a plant food. The relatively high magnesia (MgO) content of olivine also attracted attention to it as a potential source of both magnesium compounds and as a source of metallic magnesium (Bengston, 1956; Hunter, 1941). Industries using olivine have not standardized specifications. Normally, producers supply a product which meets individual customer requirements. Such requirements involve type and amount of impurities, grain size of product, refractory characteristics, etc. Geology Olivine occurs commonly as accessories in basic igneous and basic metamorphic rocks. Economic deposits are of magmatic origin and are restricted to essentially the dunite variety of periodotite. Dunites are medium to coarse- grained crystalline rocks, generally reddish brown on weathered outcrop, and are composed primarily of olivine.

Jan 1, 1975

By Henry Gross

RECENTLY, areas of abnormal rock pressure have been drilled on the Gulf Coast of the United States. These pressures may be caused by the recent and pronounced raising of some of the structures without loss of the formation pressure that existed when the reservoir was developing and the producing sand much more deeply buried. It is possible also that a permeable fissure may connect a shallow accumulation of gas with the gas cap of a much deeper reservoir of oil, gas and water. The pressures are so great that dependence on blowout-prevention equipment alone is hazardous to life and property. Fortunately, wells with excessive casing-head pressures, such as the Stanolind Oates No. 1 of the South Houston field, an 8700-ft. gas well with 6000 lb. per sq. in., and the near-by Stanolind Candelari No. 1, and 8100-ft. gas well with 5000 lb. per sq. in., have not blown out and cratered. A case is on record of drill pipe in a, well in Harris County, Texas, (Oates No. 1) rotating for 8 hr. through blowout-prevention rants holding a back pressure of 2900 1b. per sq. in. at the casinghead after the mud was altered by salt-water intrusion. Such conditions warrant the use of extremely heavy muds having low viscosity, made from galena (PbS) or specially prepared mixtures of hematite (Fe203) and galena suspended by bentonite. In some Gulf Coast wells, sodium silicate mixed with concentrated brine is used to drill through heaving shale formations. Such a fluid inhibits heaving remarkably, but it is expensive and costs as much as $10 per barrel. Barite has been used to weight this mixture. However, this mineral too rapidly increased an already excessive viscosity and it was thought that galena might be better for weighting such drilling fluid. The operator was anxious to try the latter, but none was available in the district.

Jan 1, 1938

George B. CoRless, Chairman. Superintendent, Gulf Coast Division, Humble Oil & Refining Co., Houston, Texas. W. H. Geis, Associate Chairman. Geologist, Los Angeles, California. Benjamin C. Craft, Secretary-Treasurer. Associate Professor, Petroleum Enginecring, Louisiana State University, Baton Rouge, La. Executire Committee George B. Corless, Chairman. M. Albertson, Production Engineer, Shell Petroleum Corporation, Houston, Texas. D. R. Knowlton, General Production Superintendent, Phillips Petroleum Co., Bartlesville, Oklahoma. R. P. McLaughlin, General Manager, Dominguez Oil Fields Co., Los Angeles, California. Hallan N. Marsh, Production Engineer, General Petroleum Corporation of California, Los Angeles, California. Theron Wasson, Chief Geologist, The Pure Oil Co., Chicago, Illinois. Production Engineering M. L. Haider, Vice-chairman. Petroleum Engineer, Carter Oil Co., Tulsa, Oklahoma. Joseph Chalmers, DeBataafsche Pet. Maatschappij, The Hague, Netherlands. Emile HugUenin, Deputy State Oil and Gas Supervisor, Los Angeles, California. Carl E. Reistle, Jr., Petroleum Engineering Department, Humble Oil & Refining Co., Houston, Texas. Production J. TERry Duce, Vice-chairman. Geologist, The Texas Company, New York, N. Y. Basil B. Zavoico, Associate Vice-chairman. Geologist, The Chase National Bank, New York, N. Y. Engineering Research R. L. Huntington, Vice-chairman. Associate Professor, Petroleum Engineering, University of Oklahoma, Norman, Oklahoma. Economics Sidney A. SwensrUd, Vice-chairman. Assistant to the President, Standard Oil Co. (Ohio), Cleveland, Ohio. Refinery Engineering Walter Miller, Vice-chairman. Vice-president, Continental Oil Co., Ponca City, Oklahoma. 10

Jan 1, 1938

By Lucius W. Mayer

The iron-mines of the Ilsede Hutte Co. are at a town called Peine, about 20 miles east of the city of Hanover, on the railroad to Brunswick (Braunschweig). Hanover, the capital of the province, is a military city, of approximately 250,000 inhabitants, and Brunswick, 33 miles to the westward, has half this number. The mines here described are located in a hamlet called Bulten. The Ilsede Hutte Co. operates two mines, 1.5 miles apart, in this district, Gruber Bulten Adenstadt and Gruber Lengede Bodenstadt. It also operates an iron-mine north of Hanover, known as Eiserhaven, and one in the Harz mountains, the Georg Friedrich, at Grauhof. At Bulten a coarse conglomerate, a, Figs. 1 and 2, contains nodules of limonite, cemented together by calcium phosphate. The ore contains Fe, 25 to 45; Mn, 3 to 4; P, 0.6 to 1.4; '5, 0.02 to 0.09; and CaCO,, 40 per cent. Directly above the conglomerate is limestone, 6, followed by a mixture of clay and sand, c. Below the conglomerate is a hard clay floor, d. The ore-body, from 10 to 12 km. long, and from 3 to 4 km. wide, has a maximum thickness of 20 m. It dips approximately 10" S.E., and strikes K 45° E. Diamond-drill prospecting shows that the thickness diminishes to 1 m. as the end of the deposit is approached to the northward. At this point the deposit is 250 m. below the surface. In Fig. 2, the arrow, A, indicates the general direction of the work along the face, a, which is carried forward in a straight line for its entire length. At B, a train is approaching, which has come from the bench-track, shown at C, by a circuitous route, and is dumping the overburden behind the face, in the space left by the excavated rock. Formerly the work at this mine mas essentially open-cut, the deposit having a very strong outcrop. Figs. 1 and 2 show also

Jan 1, 1909

US 4,132,758-Leaching of copper sulfide ore using nitrogen dioxide as the oxidant A slurry of ore in sulfuric acid is contacted with a nitrogen dioxide-containing gas at a temperature below 11 5" C and a pressure of from atmospheric to 35 PSI, the slurry agitated, and the resulting nitric oxide from the slurry regenerated to nitrogen dioxide for reuse About 90% of the copper In the ore IS dissolved, and the leach solution is separated for further processing. This procedure is also useful for sulfide ores of silver, molybdenum, nickel, cobalt, and zinc T C Franklewicz and R E Lueders, assigned to Kennecott Copper Corp Jan 2, 1979 7 pp (423-27) Filed 1 1-30-77 (855,983) (Drawings below ) US 4,138,231-Wet-cleanlng of gases from the roasting of copper sulfide ore, zinc sulfide ore, pyrite, or arsenopyrite The gases are washed in dilute sulfuric acid circulating in a closed system, the wash water treated to remove arsenic, the washed gas condensed by cooling; and the condensate separated, purified of residual arsenic, and neutralized B G V Hedenas, J E Wiklund, T R H Johansson, and KA Melkersson, assigned to Boliden AB Feb 6, 1979 7 pp (55-71). Filed 3-30-77 (782,908) Priority Sweden, 4-9-76 (76/04,219) (Flow diagram at right ) US 4,148,862-In the acid-leaching of silicate-bearing calcined zinc sulfide ore, finely divided calcine is leached at elevated temperature with sulfuric acid, and additional calcine is added at an optimum rate to precipitate SI~ICIC acid in the same stage In an easily settling, readily filterable form Reactions take place at a silica concentration so low that the solution is not greatly oversaturated An anionic flocculant- may be added to the slurry immediately before the filtration step S. P Fugleberg and J T. I Poijarvi, assigned to Outokumpu Oy Apr. 10, 1979 4 pp (423-106). Filed 10-6-77 (840,041) Priority Finland, 10-8-76 (76/2880)

Jan 1, 1980

By A. R. T. Denues

LIQUID-OXYGEN explosives commonly consist of a carbonaceous absorbent enclosed in a canvas wrapper and soaked with a liquid containing more than 90 mol per cent of oxygen. Investigation of these explosives in this country was initiated in 1917 by George S. Rice, then Chief Mining Engineer of the Bureau of Mines. The early development is summarized in two papers.1,2 Their characteristics, advantages and disadvantages were considered in a recent bulletin of the Bureau of Mines.,3 Other publications of this Bureau4, 5 treat the technology of these explosives and contain adequate references to pertinent literature. These investigations defined the properties of liquid-oxygen explosives and improved them greatly; however, an outstanding disadvantage is their high inflammability, a property of critical practical importance. These explosives as hitherto prepared are easily inflamed; the combustion resulting from an accidental ignition is particularly dangerous because of the ease with which it passes into detonation. For this reason the Bureau of Mines undertook a cooperative investigation, which has resulted in the development of fire-retardant treatment for the minimization or elimination of this hazard without materially impairing the explosive properties, including the ease of detonation. This presentation will offer a general description of the investigation and the outstanding results. Further phases will appear in subsequent short papers, and the entire investigation including the results of detailed experiments will be available in a forthcoming bulletin of the Bureau of Mines (Bull. 429). The effects produced by fire-retardant treatments of the carbonaceous absorbent and of the canvas wrappers were investigated separately, and the efficacy of combinations of these treatments with particular reference to the possibility of inflammation and to the development of detonation from inflammation was studied. The experimental explosive was pre¬pared from a granular carbonaceous absorbent and. the results described maybe more or less unique for such a material. An extensive preliminary

Jan 1, 1940

Separates of all the Technical Publications published in 1930 are available at Institute headquarters. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found in the TRANSACTIONS. Copies of these papers have been mailed to those members of the Institute who are registered in Classes A-Mining Methods; B-Milling and Concentration; C-Iron and Steel Division; D-Non-ferrous Metallurgy; E-Institute of Metals Division; F-Coal Division; G-Petroleum Division; H-Non-metallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting, respectively. Other members may obtain copies by writing to the Secretary. Additional copies are sold at the rate of 1 cent per page; minimum charge, 25 cents. METAL MINING TECH¬ NICAL PUBLI- TITLE AUTHOR MEETING TRANS CATION VOLUME No. AND PAGE* 264-A.29. Quicksilver Industry in 1929. Im- L. H. Duschak San Francisco T30, 283, 312 provements in the Metallurgy of C. G. Maier and Oct., 1929 Quicksilver and Symposium on The others Present Status of the Quicksilver Industry (With Discussion) (37) 271-A.30 Observation on Ground Movement R. E. Palmer New York T30,168 and Subsidences at Rio Tinto Feb., 1930 Mines, Spain (20) 274-A.31 Development and Installation of the C. L. Berrien New York T30, 139, 166 Hawkesworth Detachable Bit (29) . Feb., 1930 276-A.32 Protective Measures Against Gas O. A. Glaeser New York T30, 129, 187 Hazards at United Verde Mine (11) Feb., 1930 287-A.33 Use and Cost of Compressed Air (12) R. S. Lewis New York Feb., 1930 314-A.34 Miami Copper Company Method of F. W. Maclennan New York T30, 39, 80 Mining Low-grade Orebody (44) Feb., 1930 319-A.35 How Human Beings Respond to W. J. McConnell New York Changing Atmospheric Conditions Feb., 1930 (9)

Jan 1, 1930

By David White

The submission of carefully prepared estimates of the oil reserves of the United States calls for no apology or explanation. In this country, petroleum is a rapidly wasting asset and an occasional appraisal of the amount remaining in the ground is a simple business procedure to safeguard the general welfare and the prosperity of the republic. The rumored danger of failure, in the near future, of the foreign supply on which we depend in constantly increasing amounts makes the immcdiatc review of our available reserves the more imperative. The Director of the U. S. Geological Survey, in March, 1921, requested the American Association of Petroleum Geologists to cooperate in the preparation of new estimates of the oil remaining in the graund. With the members of this cooperative committee, state geologists, regional geologists, oonsulting specialists, and geologists and engineers attached to many companies worked both independently and through subcommittees. The reports for districts, counties, fields, etc., after review by local or state committees, were discussed by the joint cooperative committee in conferences that, in some instances, were attended by the original compilers of estimates for the states or smaller areas. Finally the data were reviewed and the figures revised by the joint cooperative committee, so that the totals given in Table 1 represent the opinion of the committee, which was composed of F. W. DeWolf, W. E. Wrather, Roswell H. Johnsont Wallace A. Pratt, Alexander W. McCoy, Carl H. Beal, C. T. Lupton, G. C. Matson, K. C. Heald, W. T. Thom, Jr., A. E. Fath, Kirtley F. Mather, R. C. Moore, and David White, chairman. Oil geologists and engineers understand well the speculative nature and the chances of error that must attend estimates of the petroleum in the ground when they cover not merely prospective territory, but possible territory. Neither the character nor the magnitude of the factors of uncertainty is to be disguised. Further, the inevitable differences of opinion between geologists of equal rank and experience must also bc

Jan 1, 1923

By David White

The submission of carefully prepared estimates of the oil reserves of the United States calls for no apology or explanation. In this country, petroleum is a rapidly wasting asset and an occasional appraisal of the amount remaining in the ground is a simple business procedure to safeguard the general welfare and the prosperity of the republic. The rumored danger of failure, in the near future, of the foreign supply on which we depend in constantly increasing amounts makes the immcdiatc review of our available reserves the more imperative. The Director of the U. S. Geological Survey, in March, 1921, requested the American Association of Petroleum Geologists to cooperate in the preparation of new estimates of the oil remaining in the graund. With the members of this cooperative committee, state geologists, regional geologists, oonsulting specialists, and geologists and engineers attached to many companies worked both independently and through subcommittees. The reports for districts, counties, fields, etc., after review by local or state committees, were discussed by the joint cooperative committee in conferences that, in some instances, were attended by the original compilers of estimates for the states or smaller areas. Finally the data were reviewed and the figures revised by the joint cooperative committee, so that the totals given in Table 1 represent the opinion of the committee, which was composed of F. W. DeWolf, W. E. Wrather, Roswell H. Johnsont Wallace A. Pratt, Alexander W. McCoy, Carl H. Beal, C. T. Lupton, G. C. Matson, K. C. Heald, W. T. Thom, Jr., A. E. Fath, Kirtley F. Mather, R. C. Moore, and David White, chairman. Oil geologists and engineers understand well the speculative nature and the chances of error that must attend estimates of the petroleum in the ground when they cover not merely prospective territory, but possible territory. Neither the character nor the magnitude of the factors of uncertainty is to be disguised. Further, the inevitable differences of opinion between geologists of equal rank and experience must also bc

Jan 1, 1923

By W. L. McMorris

The Convertol process was first described in Germany by Muschenborn' in 1952. In the U. S. Fraser' reported this new process in 1953, and Brisse and McMorris" presented the results of a Convertol pilot plant at the Alpheus preparation plant in Gary, W. Va., illustrating the mechanics of the process by a series of sketches. The purpose of the present investigation was threefold: 1) to determine the relative effectiveness of various oils and hydrocarbons for recovering coal by the Convertol process, 2) to ascertain the behavior of coal pulps in this process under various operational conditions, and 3) to compare Convertol with flotation in the recovery of fine coals. APPARATUS, PROCEDURE, AND COAL SAMPLES In laboratory work with the Convertol process a Waring Blender equipped with a speed-regulating rheostat was used for wetting, conditioning, inversion, and retention of the coal pulp. A 5-in. International centrifuge was adapted to dewater the agglomerated clean coal product by installation of a 100-mesh screen inside the regular bronze basket of the centrifuge. Except where otherwise stated, the Convertol testing was performed by the following steps: 1) A 450 to 500-cc coal slurry, containing 24 pct by weight of solids, was agitated in the blender for 10 min at 100 rpm to insure complete wetting and mixing. 2) Eight percent by weight of oil was added to the coal slurry in the blender and agitated for 1 min at 11,000 rpm to result in the phase inversion or agglomeration of oil-coated coal particles. 3) The agglomerated coal slurry was poured onto a 100-mesh sieve and wet-screened for about 2 min to remove most of the ash and some of the water. 4) The material remaining on the screen was transferred into the centrifuge for final dewatering. 5) A portion of the clean coal was immediately weighed out for moisture determination, while the

Jan 1, 1960

By Bertrand Robinson

Epitomized, there have been no innovations recently in crushing, but in grinding the trend has been towards larger units under more automatic control with an increased use of autogenous grinding. Crushing Portability of primary crushers to "follow the face" reduces material handling costs. The top size of crusher feed still establishes the size of the crusher; the feed opening should be 1 1/2 times the size of the largest feed. The maximum size of crusher product is 1 ½ times the open scale setting of a jaw or gyratory crusher. Practice dictates use of scalping screens ahead of any type of crusher when the feed contains 25% or more of product size. If required capacity is under 600-700 tph economics favor a double toggle crusher or an impactor. For larger capacities the gyratory crusher is favored.

Jan 1, 1970

By James Terry Duce

Production of oil in Bahrein for the war years was as follows: YEAR BBL PER YEAR Prior to 1939 . . . . . . . . . . . . . . 22,287,055 1939 . . . . . . . . . . . . . . . . . . . . . . 7,588,554 1940 . . . . . . . . . . . . . . . . . . . . . . 7,073,919 1941 . . . . . . . . . . . . . . . . . . . . . . 6,794,157 1942 . . . . . . . . . . . . . . . . . . . . . . 6,240,627 1943 . . . . . . . . . . . . . . . . . . . . . . 6,571,609 1944 . . . . . . . . . . . . . . . . . . . . . . 6,713,795 1945 . . . . . . . . . . . . . . . . . . . . . . 7,308,938 Total to Jan. 1, 1946 . . . . . . . . 70,578,654

Jan 1, 1946