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By A. Beeby Thompson

FOR more than 2500 years, natural gas issues in the Surakhany district of the Apsheron peninsula were the object of pilgrimages by fire worshippers and Hindoos from Burma and India. Even as late as 1890, Hindoo priests conducted ceremonies in a temple at Surakhany, which probably replaced a more ancient one; but later, the visits of the pilgrims were prohibited in order to check the spread of Asiatic diseases in that region. For centuries, limited supplies of oil have been abstracted from shallow excavations in the Caspian oil belt and dispatched into the interior of Asia and elsewhere for medicinal and industrial purposes. Statistics show a yield of 37,400 bbl. in 1863, but only since 1869 has there been serious development; in that year the yield was 203,000 bbl. At that time, hand digging was supplanted by drilling, and the enormous wells that resulted from tapping sources hitherto beyond the reach of operators completely demoralized the industry for a time, owing to inadequate outlets for the products. The early activities in this area were greatly hindered by annoying taxation, monopolies, imperial land grants, etc., but when these were revoked or adjusted, in 1877, the industry sprang into prominence and, between 1898 and 1901, the Baku fields produced practically one-half of the world's supply of oil. Within a few miles of Baku lie the two richest oil fields in the world; viz., the Balakhany-Saboontchy-Romany and the Bibi-Eibat, the latter constituting almost a suburb of the city. For many years the gasoline obtained in the refineries of the Baku area was burned in pits, being considered an undesirable product, and until 1870 the residue also was destroyed, its value as a fuel not being recognized. Kerosene was the main product sought by the refiners. It was shipped across the Caspian Sea and up the Volga to the industrial centers of Russia. Only on the completion of the Baku-Batoum railway did the Baku oil fields secure

Jan 8, 1920

Page The Cobaltchromium Binary System (paper by A. R. Elsea, A. B. \Yesterman, and G. K. Manning, Met. Tech. June, 1948, Mechanism of Precipitation in a Permanent Magnet Alloy (paper by A. H. Geisler and J. B. Newkirk, Met. Tech. Aug. 1948, Tp 2444)................................................................................................. 300 Some Effects of Applied Stresses on Precipitation Phenomena (~aper by W. L. Finlay and W. R. Hibbard, Jr., Met. Tech. Sept. 1948, Tp 2470)....................................................................................... 301 Diffusion of Carbon in Austenite with a Discontinuity in Composition (paper by L. S. Darken, Met. Tech. Sept. 1948, TP 2443) 304 An Electron Diffraction Study of Oxide Films Formed on Nickelchromium Alloys (paper by J. W. Hickman and E. A. Gul- bramen, Met. Tech. June 1948, Tp 2372)..................................................................... 305 An Electron Diffraction Study of Oxide Films Formed on Copper-nickel Alloys at Elevated Temperatures (paper by J. W. Hickman and E. A. Gulbransen, Met. Tech. June 1948, TP 2391)................................................ 307 Decarburization of Chrome Nickel Alloys by Their Surface Oxides in High Vacua and at Elevated Temperatures (paper by E. A. Gulbransen, W. S. Wysong, and K. Andrew, Met. Tech. Sept. 1948, TP 2438)................................ 307 Fractographic Study of Cast Molybdenum (paper by C. A. Zapffe, F. K. Landgraf and C. 0. Worden, Met. Tech. Aug. 1948, TP 2421)................................................................................................. 308 Effect of Composition on Grain Growth in Aluminum-magnesium Solid Solutions (paper by L. J. Demer and P. A. Beck. Met. Tech. June 1948, TP 2374)............................................................................. 309 Effect of a Dispersed Phase on Grain Growth in Al-Mn Alloys (paper by P. A. Beck, M. L. Holzworth and P. Sperry, Met. Tech. Sept. 1948, TP 2475)................................................................................. 310 Statistical Rate Theory of Metals—Mechanism of Flow and Application to Tensile Properties (paper by J. W. Fredrickson and H. Eyring, Met. Tech. Aug. 1948, TP 2423)............................................................... 315 Nucleation of Slip Bands (paper by J. G. Leschen, R. P. Carreker, and J. H. Hollomon, Met. Tech. Sept. 1948, TP 2476) and.. 318 Transient Plastic Deformation (paper by R. P. Carreker, J. G. Leschen, and J. D. Lubahn, Met. Tech. Sept. 1948, TP 2477).. 318 Plastic Deformation of Large Grained Copper Specimens (paper by W. R. Hibbard, Jr., Met. Tech. Sept. 1948, TP 2469). ... 323 Plastic Flow in Anisotropic Sheet Steel (paper by L. R. Jackson, K. F. Smith, and W. T. Lankford, Met. Tech. Aug. 1948, TP 2440)................................................................................................. 323 The Effect of Thermal-mechanical History on the Strain Hardening of Metals (paper by J. E. Dorn, A. Goldberg, and T. E. Tietz, Met. Tech. Sept. l948, TP 2445)....................................................................... 325 The Room and Elevated Temperature Properties of Some Sand Cast Magnesium-base Alloys Containing Zinc (paper by T. E. Leontis, Met. Tech. June 1948, TP 2371)..............................................................., 327 The Low Temperature Properties of Tin and Tin-lead Alloys (paper by H. S. Kalish and F. J. Dunkerley, Met. Tech. Sept. 1948, TP 2442)............................................................................................335 Thermal and Electrical Properties of Ductile Titanium (paper by E. S. Greiner and W. C. Ellis, Met. Tech. Sept. 1948, TP 2466).................................................................................................... 335 Property Changes during Aging (paper by A. H. Geisler, Met. Tech. Aug. 1948, TP 2436)............................... 337 Factors Affecting the Tensile Notch Sensitivity of Magnesium Alloy Extrusions (paper by I. Cornet, Met. Tech. Aug. 1948, TP 2419)................................................................................................. 338 Effect of Grain Size on Tensile Strength, Elongation and Endurance Limit of Deep Drawing Brass (paper by H. L. Walker and W. J. Craig, Met. Tech. Sept. 1948, TP 2478)............................................................. 339 A Copper-base Alloy Containing Iron as a High-strength, Highconductivity Wire Material (paper by W. Hodge, R. I. Jaffee, J. G. Dunleavy, and H. R. Ogden, Met. Tech. Aug. 1948, TP 2422).............................................. 340 A High Strength-High Conductivity Copper-silver Alloy Wire (paper by W. Hodge, R. I. Jaffee, J. G. Dunleavy, and H. R. Ogden, Mel. Tech. June 1948, TP 2366)...................................................................... 340 The Effect of Chronlium on the Ma Point (paper by J. B. Bassett and E. S. Rowland, Met. Tech. Aug. 1948, TP 2417.... 341 The Kappa Eutectoid Transformation in the Copper-silicon System (paper by W. R. Hibbard, Jr., G. H. Eichelman, Jr., and W. P. Saunders, Met. Tech. Sept. 1948, TP 2441).............................................................. 343 Stabilization of the Ausknite-martensite Transformation (paper by W. R. Harris, Jr. and M. Cohen, Met. Tech. Sept. 1948, TP 2446)................................................................................................ 344 Secondary Hardening of Tempered Martensitic Alloy Steel (paper by W. Crafts and J. L. Lamont. Mel. Tech. Sept. 194,8, TP 2439)................................................................................................. 345

Jan 1, 1950

By R. J. Cowan

IN the art of cementation a controversy has been going on for years as to whether solid or gaseous carbon is the active agent in carburizing steel. More recently opinion has crystallized into a compromise to the effect that carburizing is a gaseous cementation of steel in the presence of solid carbon. The importance of this theory has a particular bearing upon the work to be described. In the art of carburizing, use is commonly made of such words as "catalytic," "atomic," "nascent" and "activated;" in an attempt to describe the process. These words are used indiscriminately. For, instance, the gas is said to be "catalytic" and carbon to be "nascent," or vice versa. In using these expressions, investigators are confirming the acceptance in their minds of the active conditions of both gas and carbon in the cementation process.

Jan 1, 1931

Jan 1, 1888

By H. P. Croft

[ ] Professor Hibbard's paper presents a very interesting theory concerning the influence of texture on the tendency of brass tube to stress-corrosion crack. I should like to present the result of some work done in 1941 which may throw further light on the subject. In the first place, in regard to his review of the influences of grain boundaries, we not only confirmed the findings which he quoted, but also were unable to crack single crystals of beta brass in the standard mercurous nitrate test in 50 hr under loads up to 18,500 psi. Samples containing two or more crystals of beta brass always cracked at grain boundaries and generally followed the same pattern as for alpha brass, although cracking occurred sooner than in alpha brass under the same conditions. Such a specimen is shown in Fig 4. Second, at the possible risk of repetition, we should like to call attention to the reported role of grain size as influencing the tendency to stress-corrosion crack. This phenomenon, originally mentioned by Dr. Allan Morris in the Transactions, AIME, 1931, is illustrated in Fig 5, showing the effect of variations in grain size on the tendency of drawn brass wires to crack under load in the mercurous nitrate solution. This was taken from my work published in Proceedings A.S.T.M. 41, (1941), 905.

Jan 1, 1948

By Alfred H. Bell, George V. Cohee

Illinois produced 146,788,000 bbl. of oil in 1940, or nearly 11.0 per cent of the total for the United States, and ranked fourth among the oil-producing states. Its production was only slightly less than that of Oklahoma, which produced 11.5 per cent of the national total. Illinois' production in 1940 represents an increase of 55 per cent over the previous year, when it amounted to 94,912,000 barrels. The development of the Devonian limestone in the Salem and Centralia fields is largely responsible for the increase in production during 1940 Production from the Devonian limestone in these two fields was estimated to be 36,698,000 bbl., or 25 per cent of the state's total production (Table I). The increase in production during June, when the state's daily average production attained a peak of 518,200 bbl. for the week ending June 29, was due to the Devonian production at Centralia (Fig. I). The initial production of the best Devonian wells in the Centralia field was as high as 12,000 bbl. in 24 hr. Daily average production in IIIinois for 1940 was 400,000 bbl. of oil, but actually daily production fluctuated widely during the year. At the beginning of 1940 daily production was approximately 330,000 bbl. During the first hali of the year it in-creased irregularly to the peak in June mentioned above and as the prolific Devonian producing areas were drilled up, the state's daily production declined rapidly during July and continued to decline, although more slowly, until the end of the year, when the daily production was approximately 325,000 bbl. The daily average production per well in the new fields at the end of the year was approximately 40 bbl. (Fig. I). Oil from the Devonian was also produced in the Bartelso field, Clinton County, the Sandoval field, Marion County, and the Irvington field, Washington County, bringing the estimated total production from the Devonian limestone to about 26 per cent of the state's total production, The remainder was obtained largely from the Mississippian system. About 2 per cent of the total was from Pennsylvanian and Ordovician strata. The decline in the Devonian limestone production has been so rapid that the 1941 output from this system will probably be only a small fraction of that of 1940 unless large new reserves are discovered. The "Trenton" (Ordovician) limestone has been tested in two wells in the Centralia field and both were small oil producers at a depth of about 4000 it. The "Trenton" also was found productive in the Salem field at a depth of 4500 ft. (Table 5). The initial production of the discovery well, which was completed shortly after the end of the year, was 130 bbl. on pump. Other wells drilled early in 1941 had initial productions averaging 172 barrels. The outlook for 1941 is for a continuation of drilling activity in Illinois, but at a declining rate (Fig. I, upper curve). The most active area at the end of 1940 was in the deep basin area in Wabash, Edwards, White, and Hamilton Counties.

Jan 1, 1941

By Alfred H. Bell, George V. Cohee

Illinois produced 146,788,000 bbl. of oil in 1940, or nearly 11.0 per cent of the total for the United States, and ranked fourth among the oil-producing states. Its production was only slightly less than that of Oklahoma, which produced 11.5 per cent of the national total. Illinois' production in 1940 represents an increase of 55 per cent over the previous year, when it amounted to 94,912,000 barrels. The development of the Devonian limestone in the Salem and Centralia fields is largely responsible for the increase in production during 1940 Production from the Devonian limestone in these two fields was estimated to be 36,698,000 bbl., or 25 per cent of the state's total production (Table I). The increase in production during June, when the state's daily average production attained a peak of 518,200 bbl. for the week ending June 29, was due to the Devonian production at Centralia (Fig. I). The initial production of the best Devonian wells in the Centralia field was as high as 12,000 bbl. in 24 hr. Daily average production in IIIinois for 1940 was 400,000 bbl. of oil, but actually daily production fluctuated widely during the year. At the beginning of 1940 daily production was approximately 330,000 bbl. During the first hali of the year it in-creased irregularly to the peak in June mentioned above and as the prolific Devonian producing areas were drilled up, the state's daily production declined rapidly during July and continued to decline, although more slowly, until the end of the year, when the daily production was approximately 325,000 bbl. The daily average production per well in the new fields at the end of the year was approximately 40 bbl. (Fig. I). Oil from the Devonian was also produced in the Bartelso field, Clinton County, the Sandoval field, Marion County, and the Irvington field, Washington County, bringing the estimated total production from the Devonian limestone to about 26 per cent of the state's total production, The remainder was obtained largely from the Mississippian system. About 2 per cent of the total was from Pennsylvanian and Ordovician strata. The decline in the Devonian limestone production has been so rapid that the 1941 output from this system will probably be only a small fraction of that of 1940 unless large new reserves are discovered. The "Trenton" (Ordovician) limestone has been tested in two wells in the Centralia field and both were small oil producers at a depth of about 4000 it. The "Trenton" also was found productive in the Salem field at a depth of 4500 ft. (Table 5). The initial production of the discovery well, which was completed shortly after the end of the year, was 130 bbl. on pump. Other wells drilled early in 1941 had initial productions averaging 172 barrels. The outlook for 1941 is for a continuation of drilling activity in Illinois, but at a declining rate (Fig. I, upper curve). The most active area at the end of 1940 was in the deep basin area in Wabash, Edwards, White, and Hamilton Counties.

Jan 1, 1941

By Charles A. Kliche

INTRODUCTION The Northern Great Plains Coal Province which occupies approximately 36.6 ha contains about one-half of the nation's total coal resources. About one million ha are underlain by coal that is considered to be mineable from the surface. The topography of the province is predominately plains, rolling hills, and some badland areas characterized by breaks or sharply eroded hills. Elevations range from about 1500 m above sea level on the west to about 600 m above sea level on the eastern boundary. The average slope of the ground is approximately 2 m per km. Streams in the province drain generally easterly and southeasterly (1). In the United States, the Northern Great Plains Province lies within the states of North Dakota, South Dakota, Montana, Wyoming, Nebraska, and Colorado. The coal within the province is located almost entirely in the states of North Dakota, Montana, and Wyoming. Although it is relatively low rank, the coal within the province encompasses a large portion of the total remaining U. S. reserves. The U. S. Geological Survey estimates the total remaining coal resources of the United States to be 2.6 trillion mt within 1000 m of the surface, and 2.9 trillion tons within 1830 m of the surface. Of this total, only about 177 billion mt are classified as reserves meaning that they are (1) known in location, quantity and quality from geologic evidence supported by engineering measurements, and (2) economically recoverable based on currently available technologies and current market value (2).

Jan 1, 1983

By G. L. Fisher, R. Maddin

The rate of self-diffusion in silver single crystals during torsional strain was measured over a wide range of tenperatures and strain rates. The torsional strain was applied in a cyclic manner by reversing the divection of twist aftev a certain fraction of the total strain was reached. Surface roughening was substantially reduced in cyclically strained specimens compared with those strained entirely in one direction. Diffusion coefficients were determined using a special sectioning technique whereby slices could be removed parallel to the surface of a strained torsion specimen. The accuracy of the technique was first determined using roughened specinzens statically diffused to various penetration depths. Simultaneous strain-diffusion experiments were then performed over the temperature range 550' to 800 using strain rates of lo-' to 2.2 x 10' sec-'. The increase in silver self-diffusivity during torsional plastic strain was small. In only one case was the enhancement greater than twice the static value of the diffusion coefficzent. The enhancements increased slightly with decreasing tenzperature and increased with increasing strain rate. A dislocation pipe mechanism of enhancement was found to explain the present results satisfactorily. The magnitude of the enhancements and the tenzperatures at which they were observed suggests that a steady-state dislocation density of 10' to 109 dislocations cm-2 existed during the high-tempevature deformation. The diffusion coefficient in an fcc metal can be increased by 1) an excess concentration of point defects and 2) the rapid movement of diffusing atoms along grain boundaries and dislocations. Plastic deformation may be responsible for enhancements by both of these mechanisms. The results of simultaneous strain-diffusion experiments have caused a controversy over the magnitude of the effect of strain upon diffusion. Experiments reporting large enhancements have been criticized for the manner in which the diffusion coefficient was measured. Several of these experiments have been contradicted by other results obtained in a similar manner. No enhancement was reported by two investigators''' who performed their experiments at high temperatures where strain is expected to have little effect upon diffusion. A recent theoretical analysis3 indicates that strain enhancement by a vacancy mechanism will be small and exist only at low temperatures and rapid strain rates. It is doubtful whether any experiment has yet proven that strain enhancements can occur by an excess vacancy mechanism. In the present research, experiments were performed at extremes of temperature and strain rate in an attempt to measure enhancement of diffusion by strain. Self-diffusion of silver during torsional deformation was chosen since two separate investigations4j5 indicate that at least a small enhancement exists under these conditions. An accurate method of determining the diffusion coefficient, mechanical sectioning, was employed after a technique was devised to apply it to the roughened surface of a strained torsion specimen. First, the accuracy of the technique was determined for different penetrations (2fi). Then diffusion experiments were performed at temperatures between 550" and 800°C at strain rates of 10"" to 10"" per sec. I) EXPERIMENTAL PROCEDURE Preparation of Specimens. The experimental procedure detailing the growth of crystals, their treatment, and the annealing techniques during straining are contained in earlier publications.496 The dimensions and orientations of the torsion specimens are shown in Figs. 1 and 2. licatiin of Torsional Strain. The torsion procedure was changed from that used previously. The specimens were strained in cycles to reduce the gross distortion and surface roughening inherent in twisting to high strains in one direction. For all strains above 0.30, the total surface strain was obtained as follows: the specimen was twisted to 0.10 strain in a clockwise direction; the direction was reversed; the backlash in the torsion apparatus was taken up; and the specimen was twisted in a counterclockwise direction through the initial starting point to 0.20 surface shear strain in the opposite direction. The strain reversal took no more than 1 min to accomplish. The total accumulated surface shear strain was arbitrarily taken as the sum of the 0.10 strain in the clockwise direction plus 0.20 in the counterclockwise direction. Although cyclic torsional strain was beneficial, surface roughening and specimen distortion were not entirely eliminated. The variation in the diameter at various points on the specimen was often much greater than the depth of the diffusion zone. Since serious errors might result if specimens were sectioned in the usual manner, a technique of lathe sectioning was devised to allow sections to be taken parallel to planes of equal concentration.

Jan 1, 1967

By William J. Priestley

Much time has been devoted, by metallurgists, to the study of steel after solidification and remarkable strides have been made in the heat treatment of steel, but less knowledge is available of the thermophysical activity of the constituents of steel prior to solidification in the mold. It is known that certain elements added to steel produce marked changes in physical properties, also that other elements added to steel produce similar changes, but we have only meager knowledge as 'to. how these elements combine in steel under different conditions of solidification. It is not sufficient to know, from chemical analysis, that a certain element is present in steel. We should know how this element is in combination with the other elements and whether the combination is such as will give the greatest physical properties. Certain elements go into solid solution with the iron, while others segregate to the grain boundaries and combine with the impurities collected there. Until it is known where an alloy produces the most beneficial effect and a means is determined for controlling its physical location by altering solidification conditions, or otherwise, we will not obtain the maximum value from our alloys. When molten steel freezes, it forms a heterogeneous mass of various crystalline constituents; and as the transformation of steel from a liquid state to the solid crystallized state is a critical step, involving as great a transfer of heat as any other operation in the making of finished steel, a variation in the rate of this heat transfer will have much to do with the arrangement of the various constituents in the solid state. The object of this paper is to show some of the effects on steel caused by variations in the rate of cooling in the ingot mold, particularly as to ingotism, segregation, dendrites, and intergranular material.

Jan 1, 1924

Jan 1, 1883

By P. D. I. Honeyman, P. A. Faust

At the Miami plant of the International Smelting Co., Inspiration, Ariz., there are four reverberatory furnaces, all 120 ft. long. At present only one of these furnaces is in operation. It is operated as a wet-charge furnace, the charge being distributed for about 65 ft. down the furnace length. Usually this charge contains about 12 per cent moisture and runs 25 per cent sulfur, of which there is eliminated in the furnace from 25 to 30 per cent. The furnace is oil-fired, the fuel being burned in a battery of Cananea-type, low-pressure burners. The flame is kept short and conditions so adjusted as to obtain complete combustion within the furnace. The average furnace draft, taken through the verb arch, amounts to only 0.02 in. of H2O. Draft is purposely kept low to cut down infiltration through the flues and boiler settings, and control dampers are regulated to maintain this uniform condition throughout the charging as well as the smelting period. Hot gases discharge from the furnace uptake through a common header flue to the waste-heat boilers. The general layout and dimensions of the plant are shown in Fig. 1. Four Stirling boilers, two of class M-26 (713 hp.) and two class M-31 (850 hp.), serve the furnace. Three usually are sufficient to take care of normal operation, the fourth boiler being used as a spare when necessary. The distribution of hot gases to the various boilers is regulated by the dampers in the boiler exit flues. Normally the boilers closest to the furnace uptake would evaporate more water than do those farther away, but dampers are regulated so as to distribute fairly well the load between the several boilers. Steam from the waste-heat plant is delivered to the adjoining power house of the Inspiration company, where it is used both in the Nordberg blowing engines and for electrical generation. Steam pressures and temperatures recorded are those in the main power-plant header and are thus inclusive of all losses in about 500 ft. of 10-in. line. Steam for smelter heating and auxiliary use is taken from the main waste-heat header, is reduced to 125 lb. and distributed through separate lines. Boiler feed water is supplied by the power plant and consists of returned condensate, augmented to a large extent by make-up water

Jan 1, 1934

By H. Rush Spedden, A. M. Gaudin

IN the belief that a critical study of its operating problems might be a sound investment, the Cuban American Manganese Corporation initiated an ore-treatment research in cooperation with the Massachusetts Institute of Technology. One of the early objectives of this research naturally became the relationship of the microscopy of the Cuban ores of the Corporation to their flotation treatment. The operations in Cuba have already been described by F. S. Norcross, Jr.7 and the laboratory study of manganese oxide flotation goes back a number of years .4 Broadly speaking, the difficulties encountered in the flotation of manganese ores are that the consumption of reagents is extremely high, the concentrate contains more silica than is desirable and the tailing losses are relatively high. An appreciable betterment on any of these scores would achieve a definite betterment in costs, quantity of minable ores, and quality of product. The microscope study discussed in this paper was made on samples from the Quinto mine, from the Ponupo mine, and from mill products at various stages of passage of the ore through the mill. The writers have had access to Company records and in particular to the petro¬graphic studies made on thin sections of ore by the late Professors R. J. Colony and Philip Krieger, of Columbia University. They acknowledge their debt to both of these men for the help derived from the reports. Manganese oxides are black, friable, smudging. It is, therefore, very difficult to judge operations by inspection. The mineralogy of manganese compounds seems to be confused, and the authors believe that many more minerals have been described than actually exist. Much of this difficulty is due to the prevalence of the structural conditions that will be discussed further in this paper; namely, the porosity and the friability of the ores, and the extremely intimate association of minute manganiferous mineral crystals with impurities of various sorts. By all odds the most important manganese mineral in Cuba is the one that in this paper is called "psilomelane." The name "psilomelane" has been used in so many different ways that the choice of it for this ore may not be approved by all. However, it seems to be the best under the circumstances. This mineral accounts for about 97 per cent of the manganese in the ores of the Quinto and Ponupo mines and in the mill feed. The remaining odd 3 per cent consists mostly of pyrolusite together with minor amounts of other manganese oxide minerals. DESCRIPTION OF PSILOMELANE Aggregate Structure In grains or lumps, psilomelane has a characteristic fibrous appearance and seems

Jan 1, 1942

By R. B. Mears, G. F. Sagar, R. H. Brown

There are well recognized procedures for determining the various tensile, fatigue, and other mechanical properties of the common structural materials. This makes it possible for engineers to design structures of various materials which have adequate initial strength to stand the stresses to which they are subjected in service. There is also considerable general information about protective measures suitable for protecting the usual structural materials from the effects of ordinary environments. However, often insufficient quantitative information is available on the combined effects of stress and corrosion to permit the designer satisfactorily to appraise the structure from the stress-corrosion standpoint. This situation is further complicated by the fact that the stresses causing stress¬corrosion failures are usually not the design stresses but rather the residual forming and assembly stresses which are generally of unknown magnitudes. Thus, tests which will rapidly evaluate the susceptibility of materials to stress-cor¬rosion failures are extremely useful. Of particular value are tests which can be applied to built-up structures as well as to simple specimens, since, as mentioned above, residual stresses often are caused by fabricating procedures and assembly operations. The present paper contains

Jan 1, 1945

By David R. Mitchell

Many of the difficult operating problems of the preparation of coal for market, of sampling coal shipments and in the utilization of coal are caused by segregation in the coal mass. Segregation may be of two kinds: i.e., "size segregation," in which particles of the same size in a mass of coal containing a range of sizes collect together and "density segregation," in which particles of the same density or specific gravity in a mass of particles of varying density gather together. Mechanics of Segregation Size segregation cannot take place with closely sized coal. As the size range increases, the tendency for size segregation increases. Similarly, cleaned coal with particles of approximately the same specific gravity have very little tendency for density segregation. The wider the density range of particles and the more particles of different density, the greater the chances are for density segregation. The following discussion deals primarily with coal of a wide size range as screenings and of wide density differences as uncleaned or run-of-mine screenings. If a mass of coal containing particles of a wide size range is subject to the stream action of a moving current of water, the small particles are transported farther than the coarser. Particles of different density in a stream of moving water are subject to the laws of classification, the heavier settling out first. The familiar sluice box of the gold miner and the action of rivers and other streams in classifying material according to

Jan 1, 1938

By David R. Mitchell

Many of the difficult operating problems of the preparation of coal for market, of sampling coal shipments and in the utilization of coal are caused by segregation in the coal mass. Segregation may be of two kinds: i.e., "size segregation," in which particles of the same size in a mass of coal containing a range of sizes collect together and "density segregation," in which particles of the same density or specific gravity in a mass of particles of varying density gather together. Mechanics of Segregation Size segregation cannot take place with closely sized coal. As the size range increases, the tendency for size segregation increases. Similarly, cleaned coal with particles of approximately the same specific gravity have very little tendency for density segregation. The wider the density range of particles and the more particles of different density, the greater the chances are for density segregation. The following discussion deals primarily with coal of a wide size range as screenings and of wide density differences as uncleaned or run-of-mine screenings. If a mass of coal containing particles of a wide size range is subject to the stream action of a moving current of water, the small particles are transported farther than the coarser. Particles of different density in a stream of moving water are subject to the laws of classification, the heavier settling out first. The familiar sluice box of the gold miner and the action of rivers and other streams in classifying material according to

Jan 1, 1938

||Abad, Leopoldo F., Min Engr, Div of Mines, Bureau of Science Manila, P I '23 Abadilla, Quirico A, Geol, Lago Pet Corp Box 172, Maracaibo, Venezuela '20 ||Abbey, Robert Graham, The W W Sly Mfg Co Train Ave, Cleveland, Ohio '21 Abbott, A. N., Mines Supt, Mazapil Copper Co, Ltd Concepcion del Oro, Mexico '23 Abbott, Clarence E., Mgr, Mines & Quarries, Tenn Coal, Iron & R R Co, 1242 Brown Marx Bldg, Birmingham, Ala. '04 Abbott, Louis Benjamin, Chief Engr , Consolidation Coal Co , Elkhorn Div Jenkins, Ky. '16 Abbott, Robert R., Met Engr , Peerless Motor Car Co Cleveland, Ohio '12 ||Abbott, Wells Osborn, Ray Consolidated Copper Co Hayden, Ariz. '23 Abeel, George H, Jr., Cons Min Engr 4612 West 17th St , Los Angeles, Cal '18 Abel, Albert E., Asst to Pres, Valley Mould & Iron Corp Sharpsville, Pa. '19 Abernathy, George Elmer, Prof of Geol & Min , Kansas State Teachers College, Pittsburg, Kans. '20 Abey, Hiroshi, Min & Met Engr, Min & Met Dept, The Higher Technical School, Osaka, Japan. '17 ||d'Ablaing, Philip R, Chem , Anaconda Copper Min Co Great Falls, Mont '25 Aborn, Robert H , Research Assoc., Mass Inst of Tech Cambridge, Mass '19 Abouchar, Sylvain Sley, Min. Engi & Geol , care of S H Sekaly, 13 Rue El Nimr, Cairo, Egypt '17

Jan 1, 1923

By M. C. Chang, J. Dasher

The Crucible mine in Pennsylvania, operating on Pittsburgh seam coal, is rated at 5000 tpd. The washing plant, built in 1943, is rated at about 400 tph, using hydroseparator boxes to wash the coarse coal (4 x 5/16 in.) and hydrotator units for the fine coal (5/16 x 0). It is generally acknowledged that gravity concentration equipment cannot be used efficiently to bene-ficiate coal finer than about 65 mesh. Before the present flotation circuit was installed, Crucible recovered its fine coal slurry, predominantly —24 mesh material, by passing it through a battery of five 14-in. and one hundred and ten 3-in. Hey1 & Patterson cyclones in parallel with a 75-ft Dorr thickener. About two thirds went to the cyclones and one third to the thickener. Underflows from cyclones and thickener were filtered, respectively, in one 12-disk Eimco and two 4-disk Oliver filters fitted with stainless steel cloth. The resulting cakes were added to the coarse metallurgical coal. The filtrates, overflow from the 3-in. cyclones, and thickener overflow were recycled to the coarse coal plant. The three major problems encountered in this system became acute when the mine switched from track-mounted machinery to the more economical off-track equipment. The quality and uniformity of product declined, too much slime accumulated in the circuit, and waste pond disposal became highly impracticable. Lowering of Quality and Uniformity: Since the filter cake was not beneficiated in any way, addition of this material, which contained about 18 pct ash. would certainly lower the quality of metallurgical coal. Difficulties of handling the high-ash, high-moisture cake were compounded by the lack of adequate blending facilities at the mine, making it impossible to maintain uniform feed for the coke ovens. For a two-month test period, to verify the source of trouble, all filter cake was excluded from the metallurgical coal. The excluded filter cake was stocked in the yard. Slime Buildup: The moisture retained in the coarse coal products and the filter cake provided daily the only means of slime bleed from the circuit. As this bleed was not enough to offset the incoming fines in the raw coal feed, there was excessive buildup of slimes. To operate at all, it was necessary to purge the system each weekend by pumping all the solids from the thickener to a waste pond. The slimes built up during the week progressively increased the apparent viscosity and density of the circulating plant water, so that hydroseparators and hydrotator units had to be constantly adjusted. Uniformity, yield, and quality of the metallurgical coal suffered in consequence, and the filter cake ash and moisture contents increased from Monday to Friday. Limited Waste Disposal: Location of the plant does not permit unlimited waste pond area. Maintenance of a waste pond for the purpose of emptying the thickener during weekends became a costly burden that could not be tolerated. HOW THE PROBLEMS WERE SOLVED The flowsheet (Fig. 1) chosen to overcome these difficulties is considered the one most economical to install and operate. In a preliminary change made before the flotation circuit was installed, the cyclones and thickener were first operated in series, the overflow from the 3-in. cyclones, after flocculation, being discharged into the thickener and the thick-

Jan 1, 1960

By H. E. Rorschach

Oil-field activities in Oklahoma made 1936 the best year since 1930. Approximately 2800 wells were completed, an increase of about 20 per cent over 1935. Purchasers' reports filed with the Corporation Commission showed a total of 200,240,252 bbl. of oil purchased from leases in 1936. The assembly of a complete table of the oil fields of the state was not achieved, as many of the early records of operators and pipe-line companies are not complete, and data for the older fields will perhaps never be fully tabulated. Table 1 includes all of the new fields and most of the important fields of the State of Oklahoma. The outstanding developments of the year were: the discovery of rich Wilcox-sand production in the Moore pool; the spectacular drilling campaign in the Capitol or Mansion extension in the Oklahoma City pool; the surprising extension of the Olympic pool and the Hunton lime zone in the Fitts pool; and the failure to find more Ordovician production in southern Oklahoma. Wildcat discoveries, which were on a par with 1935, resulted in the discovery of such promising pools as Billings-Wilcox, North Bethel, North Earlsboro and North Lucien. The Fitts-Upper Simpson, Edmond, Jesse, Keokuk Falls and South Burbank pools underwent considerable development. Fitts Pool.—The Fitts area in Pontotoc County was greatly extended during the year and was the leader in drilling activity in the state. The producing limits were pushed to the east and north and the development of the Hunton lime horizon was outstanding. In the Upper Simpson zone 162 wells were completed; 137 in the Hunton lime zone and 26 in the Wilcox zone. The Oil Creek zone, a sand body below the Wilcox member, was discovered by the Magnolia-Statler No. 3 well located in the 1/4. 1/4 of sec. 28-2N.-7E. Moore Pool.—The Moore pool, in Cleveland County, which was opened in 1935 by the Sinclair Prairie-Franklin Community No. 1 well, surprised the oil industry when the Sinclair Prairie-Marvel No. 1 well, on Apr. 1, 1936, discovered a rich body of Wilcox sand below the distillate

Jan 1, 1937

By R. U. Jackson

Belt conveying is a method of transportation that requires proper servicing and maintenance if completely economical results are to be obtained from the system. With a trucking system, it is common practice to deliver the trucks to a servicing station each day or at the end of each shift. With railroad transportation there is a similar procedure. Sufficient credit is seldom given to this periodic inspection and maintenance procedure, yet it is the key to the successful operation of trucking and rail haulage systems. How about the belt conveyor transportation system? Here is a system that requires no operator for each individual unit. It requires only a main switch and an adequate sequence interlocking system, and the system is so simple to operate that maintenance is considered as only a casual requirement-nothing is done about it until after trouble has developed.

Jan 1, 1956