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By C. H. Keplinger

WARTIME factors have strengthened the production engineering consciousness of the petroleum industry. The basic principles of sound oil-production technology have been accepted as the standard by the industry and the governmental co-ordinating agencies. Every effort is being made to furnish larger quantities of petroleum with a minimum expenditure of materials and under strict conservation practices. The sphere of influence of production engineering extends from fundamental reservoir control of withdrawal rates and reservoir pressures to bolstering production from stripper wells. Serious transportation difficulties in moving oil to the East Coast have stimulated secondary recovery operations in the Appalachian and East Central oil-producing states. Diminishing discovery of new oil reserves by exploration activities increases the importance of promoting efficient oil-producing methods and practices throughout all productive areas in the United Nations.

Jan 1, 1943

By Gerald, Sherman

INCREASED production and con¬sumption of all metals, indicate the progress of industry toward that condition formerly thought to be normal. With no market limitations on silver and gold the two new precious-metal mines, the Silver Queen (now the Golden Queen), in southern California, and the Sunshine, at Kellogg in northern Idaho have made progress toward a high routine production. The Golden Queen 300-ton mill is finished and ready. The Sunshine mill has been enlarged and production is now at the rate of 500 tons per day of high-grade silver ore. The Hecla Mining Co. is developing the Polaris vein, which should be the extension of the Sunshine to the east. Some rich ore is reported. The developments of the' East African Gold Fields, Ltd., in the Lupa gold field of Tanganyika Territory, have made good progress, but operation in an isolated locality is not rapid and a large plant will be required. There have been no other discoveries reported that can be compared with the three mentioned, but production has increased, with greater capacity in dredging equipment and underground mines more adequately prepared for production.

Jan 1, 1936

By J. L. Lytton, T. E. Tietz

UNALLOYED arc-cast molybdenum sheet is typically supplied in the cold-rolled and stress-relieved condition, hereinafter denoted CRSR. Such processing eliminates the yield-point phe-

Jan 1, 1964

By R. A. Wagstaff

MANY changes in equipment have had to be made to handle the flotation products at the blast furnace, and these changes have meant an expenditure of considerable money, which has not been compensated by an increase in smelting tonnage. To date, very few new lead mines have been developed, so that the help derived by the innovation of flotation has been directed to old producing properties, where the ratio of concentration is greater now than when gravity concentration was in effect. In some smelting plants there has been an abandonment of complete units due to the introduction of flotation. FLOTATION PRODUCTS DIFFICULT TO HANDLE The physical characteristics of the flotation product do not make for economic handling for lead blast-furnace work, either mechanically or metallurgically. The millman or miner do not know what trials and tribulations they have passed on to the smelterman. To the smelterman it is "the everchanging flotation," for little does he know what new reagent will be perfected tomorrow that may completely change the grade and physical characteristics of the product. Even the mining companies who have complete units of mining, milling and smelting have had a hard time to reconcile themselves to the fact that the unit cost per ton of ore smelted must go up with the increase of flotation product on the blast-furnace charge. The "smelterman's burden," for that is what flotation has been for the last few years, has not caused the smelter operator to lag or fall down, but has spurred him on with new zeal. The physical properties of the flotation products are as follows: (1) High moisture content; (2) mucky nature of product; (3) fineness of product, and (4) high metal content. NEW MECHANICAL DEVICES FOR HANDLING FURNACE PRODUCT These characteristics have caused the use of many new mechanical devices in smelting practice, for example: New transportation equipment, such as solid-bottom cars, is required; unloading equipment and sampling

Jan 1, 1928

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Jan 1, 1942

By H. L. Teichman, E. M. Sipprelle

ENACTMENT' of Public Law 290 by the 78th Congress authorized the U. S. Department of the Interior, Bureau of Mines, to conduct an experimental program to develop the technology for obtaining oil from oil shale. In adopting and later extending this legislation, the Congress recognized the impending necessity of supplementing ground petroleum reserves with synthetic fuels. Under the provisions of this legislation, the Bureau of Mines, among other things, was charged with the responsibility of developing mining techniques, methods, and equipment for mining the oil shales of the Green River formation of Colorado, Utah, and Wyoming. The oil shales of western Colorado are apparently richer, more accessible, and more amenable to exploitation than elsewhere in the Rocky Mountain region. The site chosen for the Bureau's Experimental mine is about 10 miles west of Rifle in northwestern Colorado. It is within a 1000-sq-mile area from which, it has been estimated, 300 billion barrels of shale oil could be produced from a 500-ft measure near the top of the formation. One hundred billion barrels of this amount could be produced from the Mahogany ledge, a 60 to 100-ft section near the bottom of the 500-ft measure. This ledge is considered to have economic importance at present. The Green River formation was laid down as sediment in the bottom of vast, shallow inland lakes during Eocene time. The deposit is flat-lying, and there are no faults, fissures, or local rolls. Oil shale is actually a strong, tough magnesium marlstone, which will stand unsupported over relatively wide spans. These and other natural physical characteristics favor mechanized, low-cost mining, which is essential for establishment of an oil-shale industry. It was realized from the outset that an extensive research program would be necessary to develop mining methods, equipment, and techniques for a mechanized, low-cost operation. The program was designed to include research. into all the productive phases of mining, such as drilling, blasting, loading, transportation, and maintenance of the mine structure. The methods, equipment, and techniques developed as a result of this research have established a production of 116 tons per man-shift total labor at a direct cost of $0,292 per ton. Another important phase of the research program that has received little publicity because of its theoretical nature is study of the roofstone behavior and determination of mine structure stresses. This paper purposes to discuss this phase of the research program. Preliminary studies of the physical properties of the Green River oil-shale formation were made in the Barodyramics Laboratory at Columbia University during the latter part of 1945 and the early part of 1946.* The purpose of these studies was to determine the maximum size of unsupported underground openings that would be commensurate with safety and still permit the use of large, efficient mining equipment. Also to be determined were the pillar support to extraction ratio and the shape, size, and spacing of supporting pillars. Selected samples of possible roofstones near the top of the Mahogany ledge, as well as representative samples of different rock types found within the ledge, were obtained from the Bureau's oil-shale mine for these studies. The maximum safe unsupported roof span calculated from this work was 200 ft. Using a safety factor of four, it was theoretically determined that openings 60 ft wide could be advanced under a roofstone at the top of the Mahogany ledge. To support the overburden, 60-ft-sq pillars would be left in a checkerboard pattern. From visual observations made of core samples through the selected roofstone at the oil-shale mine, it was determined that the roofstone was actually a plate 6 to 8 ft thick. Because the calculations were theoretical and allowance had to be made for unknown cracks and fractures in the formation, openings 50 ft wide and pillars 60 ft sq were originally contemplated in the Bureau's Experimental mine. This would be the minimum allowable width that would permit use of large underground mining equipment. For lower mining costs and greater efficiency larger openings were desirable. Different but analogous approaches were made to the problem at the Bureau of Mines Applied Physics

Jan 1, 1951

By H. L. Teichman, E. M. Sipprelle

ENACTMENT' of Public Law 290 by the 78th Congress authorized the U. S. Department of the Interior, Bureau of Mines, to conduct an experimental program to develop the technology for obtaining oil from oil shale. In adopting and later extending this legislation, the Congress recognized the impending necessity of supplementing ground petroleum reserves with synthetic fuels. Under the provisions of this legislation, the Bureau of Mines, among other things, was charged with the responsibility of developing mining techniques, methods, and equipment for mining the oil shales of the Green River formation of Colorado, Utah, and Wyoming. The oil shales of western Colorado are apparently richer, more accessible, and more amenable to exploitation than elsewhere in the Rocky Mountain region. The site chosen for the Bureau's Experimental mine is about 10 miles west of Rifle in northwestern Colorado. It is within a 1000-sq-mile area from which, it has been estimated, 300 billion barrels of shale oil could be produced from a 500-ft measure near the top of the formation. One hundred billion barrels of this amount could be produced from the Mahogany ledge, a 60 to 100-ft section near the bottom of the 500-ft measure. This ledge is considered to have economic importance at present. The Green River formation was laid down as sediment in the bottom of vast, shallow inland lakes during Eocene time. The deposit is flat-lying, and there are no faults, fissures, or local rolls. Oil shale is actually a strong, tough magnesium marlstone, which will stand unsupported over relatively wide spans. These and other natural physical characteristics favor mechanized, low-cost mining, which is essential for establishment of an oil-shale industry. It was realized from the outset that an extensive research program would be necessary to develop mining methods, equipment, and techniques for a mechanized, low-cost operation. The program was designed to include research. into all the productive phases of mining, such as drilling, blasting, loading, transportation, and maintenance of the mine structure. The methods, equipment, and techniques developed as a result of this research have established a production of 116 tons per man-shift total labor at a direct cost of $0,292 per ton. Another important phase of the research program that has received little publicity because of its theoretical nature is study of the roofstone behavior and determination of mine structure stresses. This paper purposes to discuss this phase of the research program. Preliminary studies of the physical properties of the Green River oil-shale formation were made in the Barodyramics Laboratory at Columbia University during the latter part of 1945 and the early part of 1946.* The purpose of these studies was to determine the maximum size of unsupported underground openings that would be commensurate with safety and still permit the use of large, efficient mining equipment. Also to be determined were the pillar support to extraction ratio and the shape, size, and spacing of supporting pillars. Selected samples of possible roofstones near the top of the Mahogany ledge, as well as representative samples of different rock types found within the ledge, were obtained from the Bureau's oil-shale mine for these studies. The maximum safe unsupported roof span calculated from this work was 200 ft. Using a safety factor of four, it was theoretically determined that openings 60 ft wide could be advanced under a roofstone at the top of the Mahogany ledge. To support the overburden, 60-ft-sq pillars would be left in a checkerboard pattern. From visual observations made of core samples through the selected roofstone at the oil-shale mine, it was determined that the roofstone was actually a plate 6 to 8 ft thick. Because the calculations were theoretical and allowance had to be made for unknown cracks and fractures in the formation, openings 50 ft wide and pillars 60 ft sq were originally contemplated in the Bureau's Experimental mine. This would be the minimum allowable width that would permit use of large underground mining equipment. For lower mining costs and greater efficiency larger openings were desirable. Different but analogous approaches were made to the problem at the Bureau of Mines Applied Physics

Jan 1, 1951

By AIME AIME

CORROSION of tanks, pipes and other equipment in the oil fields is becoming worse as the production of high- sulfur crudes in the Texas panhandle and west Texas areas increases. It has been estimated that .in certain fields of that State one tank out of every five has to be replaced every year because of the high sulfur content of the crude. One suggested method for combating tank corrosion is the use of .materials which have a high resistance to the corrosive action of hydrogen sulfide and high-sulfur crudes; aluminum is one of these materials. As a result, the United

Jan 1, 1929

By Mark W. Springett

The sampling of precious metal deposits entails inherent problems due to the low mineral abundances, high mineral specific gravities, skewed grade distributions and wide ranges of mineral particle sizes. Sampling practices and precautions are discussed with particular attention to each of the tripartite stages of sampling - sample acquisition, sample preparation and sample assaying. Practical examples of approaches to the sampling problem are given and some examples of significant sources of error are provided from gold and silver deposits in North America.

Jan 1, 1984

By J. W. Halley

Copper has frequently been recommended as an alloying element for steel and the precipitation-hardening of steels containing from 1 to 2 per cent copper has been studied by a number of investigators. The straight copper steels, however, have not been used extensively and little advantage has been taken of the precipitation-hardening of complex steels containing appreciable amounts of copper. It is difficult to produce a satisfactory surface on the straight copper steels and undoubtedly this has discouraged their use. During recent years a number of steels containing enough copper to make them susceptible to precipitation-hardening have been put on the market. These steels belong to the group usually referred to as "low-alloy high-tensile " steels. They were designed for use in the " hot-rolled" condition; transportation equipment and large structures that cannot be readily heat-treated have been their chief application. Little emphasis has been placed on the possibility of strengthening those containing substantial amounts of copper by precipitation-hardening. The present investigation was undertaken to determine the precipitation-hardening characteristic of one of the "low-alloy steels." Previous Work The first complete study of the effect of time and temperature on the precipitation-hardening of plain copper steels was made by Nehll in 1930. At about the same time Bucholtz and Koster2 studied copper-chromium steels but did not determine the relation between time and temperature to produce maximum hardening. Later, Smith and Palmer3 determined the rate of hardening at various temperatures for two I per cent copper steels containing different amounts of carbon. Their tests indicated that the higher carbon content decreased the rate of hardening. They made tests on many steels containing other alloying elements in addition to copper, but did not determine the time-temperature relationship for maximum hardening for any of the complex steels. Norton,4 in studying the limit of solid solubility of copper in iron, determined the time for maximum hardening of a 2.06 per cent Cu iron

Jan 1, 1940

By J. W. Halley

Copper has frequently been recommended as an alloying element for steel and the precipitation-hardening of steels containing from 1 to 2 per cent copper has been studied by a number of investigators. The straight copper steels, however, have not been used extensively and little advantage has been taken of the precipitation-hardening of complex steels containing appreciable amounts of copper. It is difficult to produce a satisfactory surface on the straight copper steels and undoubtedly this has discouraged their use. During recent years a number of steels containing enough copper to make them susceptible to precipitation-hardening have been put on the market. These steels belong to the group usually referred to as "low-alloy high-tensile " steels. They were designed for use in the " hot-rolled" condition; transportation equipment and large structures that cannot be readily heat-treated have been their chief application. Little emphasis has been placed on the possibility of strengthening those containing substantial amounts of copper by precipitation-hardening. The present investigation was undertaken to determine the precipitation-hardening characteristic of one of the "low-alloy steels." Previous Work The first complete study of the effect of time and temperature on the precipitation-hardening of plain copper steels was made by Nehll in 1930. At about the same time Bucholtz and Koster2 studied copper-chromium steels but did not determine the relation between time and temperature to produce maximum hardening. Later, Smith and Palmer3 determined the rate of hardening at various temperatures for two I per cent copper steels containing different amounts of carbon. Their tests indicated that the higher carbon content decreased the rate of hardening. They made tests on many steels containing other alloying elements in addition to copper, but did not determine the time-temperature relationship for maximum hardening for any of the complex steels. Norton,4 in studying the limit of solid solubility of copper in iron, determined the time for maximum hardening of a 2.06 per cent Cu iron

Jan 1, 1940

By Ellis Clark

The greater portion of the brown ore in the vicinity of Easton, along the north slope of the Lehigh Mountain or Durham range of hills, is obtained from mines instead of from open cuts or quarries, as is the case in the ore-beds in the western part of Northampton County, in Lehigh County, and in Berks County. The reasons for this method of procedure are various, and the principal causes of the shaft and regular mine system of working being adopted instead of the open air cuts, are: First, the large amount of stripping that would be necessary, as the richer and more valuable portions of the ore do not appear to be found as near the surface as those in other portions of the Kittatinny valley; second, the occurrence of the ore in regular beds, interstratified with the clay, and, to a less extent, in pockets or erratic deposits, as is the case in the mines of Lehigh County; and third, on account of many of the mines being situated at the immediate base of the Lehigh Mountain, where the surface water would be in such large quantities as to be with difficulty handled, and where the subsequent caving in of the sides of the open cut would be almost certain to expose the gneiss rock, which is water-bearing, the large quantities of water coming from which would probably drown out the ore-bed. Shafts, and a regular system of gangways and mining are therefore required by the configuration of the surface, the depth of the deposits and their geological structure. The ordinary size of the shafts is about four feet square, but where an extensive plant of pumping machinery is required the size may be increased to eight feet by six, with two compartments for the hoisting and pump-shaft respectively. A man-way, consisting of ladders with rests at intervals of twenty or thirty feet, is comprised in the pump-shaft, the wire rope being used for purposes of ascent and descent only in exceptional cases, on account of accidents which

Jan 1, 1879

Jan 1, 1924

By D. Ott

Results of a research project on investment or lost wax casting will be presented. The project was concerned with various aspects of the process as they are typical for the production of jewellery from gold alloys. During these investigations testing methods for investment quality as well as for casting quality and the various process parameters were developed and charateristic defects as they occur in practice were traced back to their origin in the process. Investigated were various static casting and centrifugal casting methods in different atmospheres as well as vacuum casting in devices of different design. It was shown that independent of the method a close control of the many process parameters interfering with each other is essential for a quality casting.

Jan 1, 1984

FOR two days preceding the Colorado Mining Association annual meeting, officers representing all interests of the lead and zinc producers hammered away at remedies for the ills of the industry behind closed doors at the University Club in Denver. For once in the stormy history of the industry, large and small producers alike came to agreement with an automatic sliding scale stabilization import tax. The proposal set forth in full on the following page, is not new being merely an amplification of the tariff arrangement whereby tariffs are imposed when the price drops below ceiling. Its advocates claim that it is simple, automatic, and flexible. It will give stability to the industry without subsidies and since no government bureaus will be required to administer it, there will be no cost to the taxpayer.

Jan 3, 1953

By Tkeoclore Marvi

IT is singular that an industry quite the antithesis of flying should record tremendous strides in the utilization of aviation through- out the entire depression period, .while in the same years private interests lagged and airplatie manufacturing plants closed to such an extent that he purchase of new planes of certain types was practically impossible. Though receiving little notice from aviation publications and national associations, this use of the airplane progressed by sheer merit. It saved money, conserved energies, and made minutes in the air the equal of weeks on foot or water. The advent of aviation into mining and petroleum operations dates back many years, yet it \vas not until the depression that this new facility of the mineral industry was put on its proper economic basis. There, by its possibilities for saving effort, time, and money, it takes its place equally with other great technical advances in nietl

Jan 1, 1934

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Jan 1, 1942

By R. S. Dean

True careful work of Gross and Zimmerley1 has established the fact that the energy actually used in grinding is proportional to the new sur-face produced. This confirmation of Rittinger's law was made by crush-ing quartz in a frictionless drop-weight machine and determining the surface of the quartz by its rate of solution in hydrofluoric acid. The details of this procedure have been described adequately elsewhere and need not be repeated here. The resultant data furnish the only available basis for comparing accurately the efficiency of grinding machines. This method is so cumbersome experimentally that it has been little used. As an alternative all sorts of approximations have been proposed. The best of these is complete size analysis by sieving and elutria-tion. Such procedure is very lengthy and difficult to carry out accurately. Furthermore, any sizing method becomes very inaccurate for determining surface with very fine sizes where the ratio of surface to volume becomes very large. To avoid the lengthy and difficult technique of elutriation it has been proposed to estimate the size distribution below 200 mesh from various probability formulas. Such a procedure is at best an engi-neering approximation; at worst it is a mere guess. Some time ago Dr. V. H. Gottschalk2 found that the coercive forces of magnetite powders were directly proportional to the surface area, regard-less of size distribution. It was at once apparent that this furnished a method for determining grinding efficiency quickly and accurately. The only requirement was a single determination of the relation between the work input of the Gross-Zimmerley drop-weight machine and the coercive force of the resultant crushed magnetite.

Jan 1, 1936

By M. B. Bever, J. E. Reynolds

IN several alloys of iron, copper, and lithium as well as in some pure metals, martensite formed on cooling reverts to the parent phase upon heating to a temperature below the equilibrium temperature at which the parent phase becomes stable.' These martensitic transformations, therefore, are thermally reversible, although appreciable hysteresis may be involved. The martensitic reaction has long been

Jan 1, 1953

By Charles R. Fettke

The Bradford and Richburg oil fields are the only pools where artificially conducted water drives on an extensive scale have been economically successful. Field practice has progressed from the original accidental or intentional circle flood, through the line flood development plan, to the intensive complete development plan, which is the most-recent and generally considered to be the most successful. Of the intensive development plan the five-spot arrangement of wells is the one that has been used most extensively. A further development associated with the latter method is the application of additional hydraulic pressure to that of the hydrostatic head of the column of water in the intake well. In conjunction with this method is the practice of delayed drilling of the oil wells until the water from the intake wells has entered even the less permeable portions of the sand and developed a "bank" of oil at which time all oil wells are drilled as nearly simultaneously as possible. The five-spot pressurc flood with delayed drilling gives more rapid return on investment than any other method. The seven-spot and nine-spot patterns are rarely used. No chemicals, such as sodium carbonate and other so-called flooding agents, are being added to the water at present since the field tests carried on in 1926 gave no positive results. All air and gas drives have been discontinued.

Jan 1, 1930