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By W. M. Mobley

The coal industry in Alabama, centered in Birmingham, has pioneered coal-bene-ficiation practice in the United States. The nature of the coal seams and mining methods employed have necessitated use of equipment and methods best adapted to the local conditions. Although all of the 30 or more coal seams now being mined in the state receive beneficiation, only the three most important producers of coking coals, the Pratt, Mary Lee and Black Creek, are discussed in detail. Nature of the seams, washability characteristics and equipment used are given as examples of the extent of work and progress in this field. The coal seams in Alabama are relatively thin and pitching, making mining difficult and expensive. Most of them are characterized by thin partings of rock or shale in the seam itself, as well as laminations of bone and rash. Mechanical mining methods have increased the occlusions from roof and floor to such an extent that nearly all the coal mined in the state must receive some treatment before it can be put on the market. During the year ending Sept. 30, 1943,' 18,129,792 tons of coal were mined in the state and 14,364,177 tons, or 79.2 per cent, received treatment. Excluding from the total the 1,223,014 tons produced by small wagon mines and the hand-picked lump coal, the amount re- ceiving beneficiation would be more than 90.00 per cent. This is, by far, greater than in any other coal-producing state. The earliest record of coal beneficiation in Alabama was the installation in 1890 of an experimental Lurig washer by Alexander Cunningham, for the Sloss Iron and Steel Co. at its blast furnace in Birmingham.2 In 1894 the Jeffrey Manufacturing Co. introduced the English Robinson washer, a combination of a hydraulic classifier and centrifugal machine. Erskine Ramsay, who has contributed so much to the coal industry, saw its possibilities as well as its mechanical defects and soon had his inventive mind at work. He added a sludge tank of his own design, and many Robinson-Ramsay washers were installed in Alabama and other states. The Stewart jig appeared in 1900, followed by the Montgomery jig in 1910 and both have found extensive use. Increased interest in this field led to new designs, such as the American, Elmore, Burke and Faust. The first Baum-type Norton jig was operated in 1930 and within the last five years six large installations of this type have been made by the McNally-Pitts-burg, Jeffrey and Link-Belt Companies. Wet-washing tables were introduced in 1922 but not extensively used until recently. The two most popular types are the Deister-Overstrom and Deister Plat-O. The coal-cleaning equipment used in Alabama has been relatively simple, yet efficient, but as the amount of impurities in the raw coal has been increased by mechanical mining and labor costs have become higher, much interest has been shown in sand cones, froth flotation and

Jan 1, 1947

By J. S. Marsh

JOSEPH PRIESTLEY prepared oxygen on Aug. 1, 1774, and noted with great surprise "that a candle burned in this air with a remarkable brilliant flame." On Aug. 2, 1774, some ironmaker possibly began to wonder if this substance could be used to increase his rate of production; at any rate, there is no disputing the fact that the notion of using oxygen for steelmaking in concentrations greater than that available in great abundance-as air-has been in existence for years. Action was delayed by the lack of enough oxygen at a cost within reach of the steelmaker. Within the last several years enough has been available to permit large-scale tests of its use for both combustion, with which this paper is concerned, and for decarburization. The literature is now enormous and easily available; it is sufficient here to cite three items of historic- importance in that all are about 25 years old and in that all are remarkably consistent as far as they go, with what is known today.1,2,3 SIGNIFICANCE OF HIGH-TEMPERATURE HEAT The principal 'function of the open-hearth furnace is to supply sufficient, high-temperature heat to melt the charge and then to increase its temperature to a range suitable for tapping, ordinarily in the neighborhood of 2900°F. That heat is required to make steel everybody; however, there seems to be some confusion now and then about the significance of high-temperature heat. Transfer of energy-and heat is energy is always from a point of higher potential to a point of lower potential and, other things being equal, the greater the potential difference, the greater is the rate of transfer of energy. In the open hearth the flame, of course, is the high-potential source. Perhaps the most satisfactory approach is through the notion of theoretical flame temperature; which is the ratio of heat input to the heat content of the combustion products,* the former is composed mainly of heat of combustion of the fuel plus sensible heat of the fuel plus sensible heat of the combustion air. Thus, flame temperature can be increased by increasing the value of the numerator, by decreasing the value of the denominator, or both. The first method is as old as the open-hearth process and, of course, makes use of preheated air; its possibilities have been by no means exhausted. The second method can be put into effect only by changing the composition of the combustion air, since the combustion of a given quantity of fuel produces a definite quantity of product, and since the denominator includes the non-reactive fraction of the air, principally nitrogen. In other words, the denominator consists of the volume of exit gas multiplied by its heat capacity and that volume consists of carbon l is understood by dioxide and water vapor as reaction

Jan 1, 1948

By John M. Kelly

New Mexico produced 31,913,816 bbl. of oil in 1942, the lowest annual production since 1936, and dropped one place to rank eighth among oil-producing states. This production decreased 7,838,052 bbl., or 19.71 per cent, from the 1941 figure is the result of transportation difficulties caused by the dislocation of tanker sailings to east coast ports. The average per-well allowable in New Mexico on Jan. I, 1942, was 43 bbl. and at the end of the year was 38 bbl. Allocations as set by the New Mexico Oil Conservation Commission followed the recommendations of the Petroleum Administrator for War. After setting the daily outlet, however, the average daily pipe-line runs were 87,545 bbl.—11.06 per cent short of these allocations. Production for Lea County was 26,812,949 bbl., Eddy County 4,624,578 bbl., northwestern New Mexico 473,609 bbl., Chaves County 2,680 barrels. Drilling activity for New Mexico in 1942 was approximately 84 per cent of that in 1941 with 339 completions. Of these completions 254 were oil wells, II gas wells, and 74 dry holes. Proven fields accounted for 55 of the dry holes and 19 were wildcats. Three new oil fields and one new gas field were discovered as the result of wildcat drilling. Extensions were made to one oil field and one gas field. By the close of the year, the New Mexico Oil Conservation Commission had designated 59 areas as proven for oil and/or gas. Southeastern New Mexico Lea County Monument was again the largest producing field in the state, with 5,729,336 bbl.; Eunice was next, with 5,217,965; Vacuum produced 3,295,624 and Hobbs 2,973,488. The Hobbs field has the largest accumulated production, which at the close of 1942 totaled 100,381,417 bbl. The 100-million-barrel mark for Hobbs focused attention on the fact that this is the first field in the state to attain this figure, and also that, as Hobbs has been under continuous proration since July 1930, or approximately the entire life of the field, this 100-million-barrel recovery was obtained with 86 per cent of the wells in the pool still flowing and having a drop in bottom-hole pressure of only 3.5 Ib. per million barrels recovered. Hobbs stands out as perhaps the best regulated major oil field in the world. Two new oil fields were discovered in Lca County, the most inlportant being the area designated as East Lusk, consisting of the south 4 tiers of Sections in T. 19 S., R. 32 E. The discovery well was drilled in the SW. SW. 1/4 of sec. 21, T. 19 S., R. 32 E., by Culbertson and Irwin, Inc., and others. It was completed at a total depth of 2751 ft. in the Seven Rivers formation of Permian age. The initial potential of the well was 237 bbl. per day on pump. The oil produced has a gravity of 24.10 A.P.I., with sulphur content of 0.9 per cent. This oil has an asphaltic base and because

Jan 1, 1943

By W. O. Philbrook, A. E. El-Mehairy

The reduction by hydrogen of individual particles of dense hematite implanted in beds of inert spheres is controlled by single-particle kinetics. No evidence of reagent starvation was found down to low flow rates established by pressure gradients as low as 0.01 in. H2O per- in. of depth in beds of spheres as small as 3/16 in. diam. The optimum size for most rapid reduction of beds of homogeneous ores results from the effect on reducing potential of the gas of competing factors of supply and consumption. A recent publication1 presented the results of a study of the rate of reduction of iron ore in a fixed bed by hydrogen introduced at constant pressure differential. Under these conditions the reagent flow rate varied directly with the bed permeability, which was a function of particle size and shape and bed voidage, and inversely with the temperature-dependent viscosity of the gas. The present note adds data from supplementary experiments designed to reveal whether or not any partial reagent starvation arising from a flow-dependent transport resistance in the gas phase might have been operative. Kinetic studies were made of the reduction of individual spheres of iron oxide inserted into beds of inert spheres, so that the reagent flow rate and aerodynamic conditions were again determined by bed characteristics and temperature. The experimental techniques and apparatus were similar to those previously described.' The synthetic iron ore spheres were wet-rolled by hand from powdered, reagent-grade* Fe2O3 and subsequently dried and then fired in air at 1250°C. The indurated pellets has almost no porosity as indicated by their specific gravity of 5.10. The beds were made of dense alumina spheres, closely sized to the same dimension as the iron oxide spheres, in the following diameters: 3/16, 1/4, 5/16, and 3/8 in. Each bed was hand-packed of particles of a single size to a controlled voidage of 0.32 and depth of 3 in. within a capsule having an internal diameter at least 10 times the particle diameter. A few weighed iron oxide spheres were individually planted in the central plane of the bed of inert spheres at points away from the wall. Reduction was carried out at atmospheric pressure by purified hydrogen at 670°, 800°, and 985°c. The reagent was supplied at precisely controlled pressure differentials of 0.01, 0.02, and 0.03 in. of water per in. of bed depth. This gave a range of flow rates similar to that used in the study of beds of ore and comparable with blast-furnace practice in terms of mols of reducing gas per hr per sq ft of cross-section. Viscous flow prevailed in all beds under the experimental conditions of this study. The reduced particles were checked for loss in weight and then sectioned for metallographic examination. Occasional particles were found to have contained minute internal cracks that interfered with the concentricity of the reduction interfaces, and data for such particles were rejected. An experimental rate constant for the reduction of the imbedded Fe2O3 spheres was calculated on the assumption that the rate was proportional to the metal-oxide interface area by an equation that has been found by McKewan2 to describe the reduction of single spheres

Jan 1, 1962

By Clarence E. Sims, George A. Moore

INTRODUCTION IN previous publications of the writers4-7 it has been shown that vacuum extraction of steel can be carried as close to quantitative completion as desired provided the steel is in the austenitic state and sufficient time is allowed. For precise work, the method claims preference because the equipment for holding and heating the sample can be made simple, and because crucibles, boats, and other unnecessary materials can be eliminated and the blanks thus made very small. It is well known that the evolution rate of hydrogen is smaller just above the transformation than immediately below, as would be expected from the increase in solubility when passing into the gamma state. Many attempts have been made to obtain analyses by extraction just below the transition, using times of approximately 2 hr. While it is true that the rate of evolution drops nearly to zero under these conditions, it has repeatedly been shown that the process is incomplete since on raising the temperature into the austenitic range, evolution will be resumed, usually after a considerable induction period. The low-temperature evolution process appears to be useful in some cases for comparative tests where the residual error may be more or less constant between samples. For general use, however, there is no guarantee that the error caused by incomplete extraction is constant; hence, the more laborious but more reliable high-temperature process must be used. At high temperature, an original flash evolution, similar to that at lower temperature, is first observed. After not more than an hour, the flash subsides and evolution settles down to a regular first-order reaction rate for which the half-life* is usually of the order of a few hours for the 5/8-in. diam cylinder at 1050°C. The regular evolution may be followed for whatever period appears justified, after which the residual gas may be estimated as equal to that which was evolved in the last observed half-life period. Tests have shown that the composition of the evolved gas does not vary greatly during the progress of evolution; therefore the residual gas may safely be taken to have the same composition as the portion col-

Jan 1, 1948

By C. A. Hartnagel

The production of petroleum in New York state in 1942 amounted to 5,410,000 bbl. This represents an increase over each of the four preceding years, and, with the exception of 1937, is the largest production since the peak of over six million barrels in 1882, shortly after the discovery of oil in Allegany County. The oil industry in New York is virtually stabilized and there has been little or no exploration for new sources of supply in recent years. The boundaries of the present fields were established more than 30 years ago and since then no additional reserves have been found. Deep drilling for natural gas during the past 10 years both within and without the oil fields has failed to find oil in quantity below the present producing sands of Devonian age. Oil Since 1882, the New York fields have produced approximately 140 million barrels of oil. Of this amount, 65 million was produced up to the year 1919 by ordinary pumping methods; that is, without flooding by water or the use of other secondary-recovery methods. In the year 1919, when a law was passed making the use of water-flooding methods legal, the oil production, of the state amounted to only 851,000 bbl. In the 23 years since 1919, there have been produced in the state 75 million barrels, or 10 million more than in the previous 37 years, which included the period of flush production. Price.—On March 26, the price of crude oil was raised from $2.75 to $3.00 per barrel, hut this increase had little or no effect on the number of wells drilled. In the Allegany field, which accounts for three fourths of the state's oil production, 1259 wells were completed in 1942, 7 less than in 1941. The smaller number of wells drilled was not only due to the shortage of labor but also was caused by the fact that in water-flooding territory a definite program for drilling wells is followed, and the flush period of an oil well is not usually reached in time to profit by any given price increase. Daily Production.—All of the oil wells in New York state, some 21,000 in number, are small producers. The average daily oil production is 7/10 bbl. per well. Under good flooding conditions, a maximum production of 5 to 8 bbl, a day is reached about one year after the flood begins to act on the well. In 5 years the daily production usually is less than one barrel. Although most of the oil in New York is produced by flooding, an estimated 2500 old wells produce without flooding. Some of these produce as little as 1/20 bbl. a day and are pumped only at intervals. The small producing Wells are mostly on lands leased to the larger oil companies and later will be included in a flooding program. At present, they are pumped only because the owners of the land insist on the royalty. Government Aid Needed.—Because of its good lubricating qualities, New York oil is one of those for which there is an insistent and growing demand, but even at its present price of $3.00 per barrel, many of the operators are producing at a loss.

Jan 1, 1943

By H. C. George

THE Wisconsin. Zinc District, or the Upper Mississippi Lead and Zinc District as it is often called, lies in the southwestern corner of Wisconsin, in, Grant, Iowa and Lafayette Counties, and it includes adjoining parts of Illinois and Iowa. The district is about 70 miles long, north and south, and about 40 miles wide, east and west. It lies wholly within what is geologically known as the non-glaciated area of the Upper Mississippi Valley. HISTORY OF THE DISTRICT The district was first opened up as a lead producer in 1822. From this time until 1860, about 205,000 tons of cog lead (galena) and washed lead (galena) was produced from shallow crevices and openings. From 1860 to 1900, about 74,500 tons was produced, and since that time, from 5000 to 7000 tons has been produced annually. Since-1900, most of the lead concentrate produced has been as a byproduct of the zinc mines. The first zinc ores were mined about 1862. These were the carbonate ores, locally known as " drybone." Very little zinc blende was mined in the district, previous to 1875. The zinc blende ores mined from 1875 to 1900 were mostly of the high-grade, hand-cobbed, sheet-ore class, which usually contained from 45 to 60 per cent. metallic zinc. Such nines as the "Sallie Waters," ? Quinlin," "Lead Mine," "Benton Blende" and "Ida Blende," located near Benton, Wis., were mines which produced ores of this type, during this period. The mines located at Highland, the "Coker Mine" located at Livingston, Wis., and the "Opencut Mine" located at Shullsburg, Wis., were mines that were heavy zinc carbonate producers, previous to 1900.

Jan 12, 1917

By B. R. Coil, C. A. Ross

NEW demands for underground power in the Miami mine of the Miami Copper Co., Miami, Ariz. has brought about expansion of the distribution system for both ac and dc power. Progress in mining equipment and the normal changes in the mine were responsible for this increased demand. Early power requirements were for pumping and haulage. A 440 v ac power line down No. 5 shaft took care of a small pumping load and shaft station lighting, 275 v dc power was generated by motor generator sets on the surface, with a churn drill hole from surface to the 570 haulage level serving as a cableway. Electric lights were installed where power was available, and thus were confined to the haulage level and shaft stations. All industrial power in the Miami area is 25-cycle, which dates back to the hydroelectric generator installation at Roosevelt Dam in 1908-10. The Problem The main haulage level was moved to the 720 level and later, to the 1000 level, requiring a longer feeder line with the resultant voltage drop. Also, as mining progressed to the east, the churn drill hole for the power cable would have been subjected to subsidence cracks. The first extension in the use of electricity was in electric blasting. About 1935 the mine went to electric blasting, using the dc haulage current. Bringing electric current to the working levels of the mine for blasting greatly expanded the use of electric lights. Lights were used in tool rooms, powder and cap magazines, stairways, and other semi-permanent installations. Like all mines, Miami Copper began to study and experiment with mechanical mucking and transportation of ore by slushers, shakers, and belts during the late 1930's and early 1940's. At the beginning of the program, power was supplied from the haulage level 275 v dc system. Later it became necessary to run a cable, carrying 440 v ac power, down the No. 7 ventilation shaft. The increased use of power came about gradually, and many new problems were added, not the least being the introduction of switch boards and power cables into the working areas of the mine, where drifts and crosscuts take weight, and require repairs. The 25-cycle current presented special problems, in that 25-cycle transformers are twice as large and about 2V2 times as heavy as 60-cycle transformers of the same power output. The 25-cycle transformers were considered too large for installation in the mining areas. In 1947 the distribution system was revised and standards were adopted, governed by the following

Jan 1, 1952

By J. W. Craig, H. L. Walker

Industry has for many years recognized the dependence of certain mechanical and physical properties. as well as workability, upon grain size variations in brass. Although the dependence of properties upon grain size has been recognized there are not many instances where a planned program of testing has been conducted and where the only intentional variable has been grain size. In particular the literature is limited with respect to the effect of grain size on the endurance limit, though there are many industrial applications where the brasses are subjected to cycles of repetitive stresses. Literature A number of the physical and mechanical properties of a given brass sheet, in the annealed condition, will depend upon: (I) The ready-to-finish grain size before final rolling, (2) the percentage deformation by cold working, and (3) the time and temperature of annealing. The first and second variables affect the recrystallized grain size, and the third variable affects the coalesced grain size. Gibbsl has shown the effect of two different ready-to-finish grain sizes upon the tensile strength and hardness of deep drawing brass strip after a definite amount of cold rolling. The smaller the ready-to-finish grain size, the higher the tensile strength and hardness, but with lowered ductility, Gibbs also demonstrated, for a given time and temperature of anneal, that the tensile strength, hardness, and elastic limit are higher for the smaller ready-to-finish grain size, but the elongation is lowered. Townsend and Greena112 have reported data which show that cold working increases the tensile strength, hardness, and load carrying ability of deep drawing brass sheet under reversed stress. Greenall and Gohn3 have reported data which show that the smaller grain sizes have higher tensile strength and hardness properties, and the data also show that increased cold working increases the tensile strength and hardness properties of deep drawing brass sheet. Kommers4 has reported data for tests of brass of known ready-to-finish grain size, a specific amount of cold reduction, and annealed at different temperatures above and below the recrystallization temperature. Kommers' results indicate that annealing below the recrystallization temperature does not change the tensile strength and hardness properties, but the endurance limit may be increased from 22,000 to 28,000 psi. The increased endurance limit is explained as resulting from the reduction of internal stresses by a stress-relief anneal. Burghoff5 and associates have reported data on creep tests, over

Jan 1, 1949

By A. C. Wallace

THE development of the natural resources of any district of any magnitude, inevitably gives rise to many problems off title, usually due to the greatly enhanced value of the land. The development of the mining industry in the Quapaw Agency has been no exception to this general rule. Our problems, how-ever, have not been many or particularly serious. The Quapaws were allotted and patents issued by the United States Government in 1895. These patents contained a restriction against alienation for a pe-riod of twenty-five years. The effect of the restric-tion was to prevent the Indian from selling, leasing, or in any way encumbering his land. The Govern-ment, in a paternalistic spirit, sought to teach the Indian thrift and industry and to insure him a place of residence. This is evidenced by the first Leasing Act passed by Congress, which permitted only incom-petents and those physically disabled to lease their land for either agricultural or mining purposes. The able-bodied Indian was denied the right to lease. It soon became apparent to the Government, how-ever, that this was a mistaken policy, and in 1897 a General Leasing Act was passed by Congress and it was under this act that the mining industry in the Quapaw Agency was developed. The act, reads as follows: "That the allottees of land within the limits of the Qua- paw Agency, Indian Territory, are hereby authorized to lease their lands, or any part thereof, for a term not ex-ceeding three years, for farming or grazing purposes, or ten years for mining or business purposes. And said al-lottees and their lessees and tenants shall have the right to employ such assistants, laborers, and help from time to time as they may deem necessary: Provided, That when-ever it shall be made to appear to the Secretary of the Interior that, by reason of age or disability, any such allottee cannot improve or manage his allotment properly and with benefit to himself, the same may be leased, in the discretion of the Secretary, upon such terms and conditions as shall be prescribed by him. All acts and parts of acts inconsistent with this are hereby repealed." It was the interpretation of this Act that gave rise to our first serious problems. It will be noted that the Act says that "allottees of land" within the limits of the Quapaw Agency are authorized to lease their land. Thus, the first question was presented by the use of the term "allottee," and the question was as to whether or not Congress intended to limit the Quapaw Indian to the leasing of his own allotment or did Congress mean that the term "allottee" was synonym-ous with "Indian" and intend to give the Indian a right to lease both his allotment and his inherited land and was an Indian without an allotment an "allottee" even though he was a member of the Qua-paw tribe and the owner of the Quapaw land by in-heritance, and not being an allottee, could he lease his inherited Quapaw land under the authority granted in this Act?

Jan 5, 1928

By C. L. T. Edwards

In the preparation of this paper, the author has drawn upon experience with the operation of a blast furnace on Ioo per cent scrap burden, which he believes was the first operation of its kind in the country. It is the writer's further belief that much of the controversy attending discussions of this subject may be obviated by the presentation of a group of facts that should be known by blast-furnace men and open-hearth men alike. The following question has been raised: "Is iron made with scrap in the blastfurnace charge as good iron as that made without scrap—made with straight ore?" This question may he answered in part by the fact that the open-hearth men of the Bethlehem Steel Co. who used pig iron from a blast furnace that operated on Ioo per cent steel scrap found no difficulty in the processing of such iron other than that to be expected from the known analysis. Operation with ioo PeR Cent Steel Scrap During World War I, there was accumulated at the Bethlehem plant of the Bethlehem Steel Co. some 22,000 tons of alloy-steel turnings and borings. This scrap material was highly corroded and, like alloy-steel turnings of that period, were as a drug on the market. There was also a small tonnage of scale, rich in valuable metal. If this scrap could be worked up into pig iron, it would become readily available for use in the open hearth. In order that the pig iron should contain the maximum percentage of nickel, permission was obtained from the Management to try a Ioo per cent scrap operation. Accordingly, a blast furnace was swung over on July 25, 1919; the percentage of steel scrap increased more or less irregularly until July 29, when Ioo per cent steel turnings were charged. Except for occasional charges of nickel scale as an "cxtra," the operation continued uninterruptedly until Aug. 27, when the furnace was swung back to the regular ore—ore and scrap—operation. During this period, the furnace production ranged from a low of 568.60 tons to a maximum of 766.07 tons. At the swing-over from Ioo per cent scrap to the regular burden, the charge I hung up rather severely. While the latter condition has nothing to do with the object of the paper, a brief discussion of the experience will appear later because of the interest it may have for blast-furnace operators. In Table I, results of the first and last days of the ore charge are shown, July 25 and July 29. The last column shows a summary for the period of maximum scrap ' charge. The furnace employed had a hearth 16 ft. o in., bosh 22 ft. o in., stock line 15 ft. 6 in., bell 11 ft. 6 in., batter in., bosh angle 73' 27' and a Balrer-Neuman top, with gas-engine blowers. Analyses Range of material charged Gravel: SiO2, 64.40 to 70.54 per cent; A1203, 3.52 to 4.58; CaO, 7.27 to 9.49; MgO, 5.09 to 6.14; FeO, 1.67 to 3.34, ignition loss, 9.50 to 13.83. I

Jan 1, 1942

By D. A. Dukelow, G. Derge

THE Fe0-Mn0-Si0, system has many properties of fundamental interest besides its occurrence in steel-making. The system is the simplest ternary complication of the FeO-SiO, binary whose electrochemical properties have been explored. Therefore, knowledge of the conformance of Fe0-MnO-SiO, melts to Faraday&apos;s laws, as investigated by current efficiency measurements, would be of particular value in interpreting the observed variations of electrical conductivity, while at the same time furthering understanding of this type of molten oxides. Pertinent to the present study are conductivity data of FeO-SiO, and Fe0-Mn0-SiO2, and current efficiency data of FeO-SiO,. Concerning conductivity measurements, Inouye, Tomlinson, and chipman&apos; studied the specific conductivity, a, of molten wüstite as a function of temperature and oxide addition. Liquid FeO in equilibrium with an iron crucible was found to have a o whose magnitude and positive temperature coefficient were undeniably semiconductor in nature (o1400°C = 269 ohm-1cm-&apos;). Additions at 1400°C of 5 mole pct MnO decreased o to 227 while a similar addition of SiO2, dropped o to 125. Additional SiO2 produced an exponential decline of o. It was reasoned that because wüstite is known to be oxygen excess and since there is no pronounced change in oFeO upon melting, that UFeO(L)is p-type semiconduction. Björling2 gives o data for the ternary FeO-MnO-SiO, using fayalite, 2 FeO-SiO,, as the base substance. Upon addition of tephroite, 2 MnO-SiO, he noted a small decrease in o. Taking his data for 1400°C with one-half of the fayalite replaced by tephroite, o shows a decrease of some 40 pct relative to o for fayalite, i.e., 5 ohm-&apos; cm-&apos; to 3. In line with this observation, Mori and Matsushita3 reported that substituting MnO for FeO in the silicate de- creased o slightly except at high SiO, contents where the decrease was somewhat larger. Investigating the ionic nature of FeO-SiO2 melts, Simnad, Derge, and George4, found the anode current efficiency, C,, as calculated from iron anode weight loss, was temperature invariant and in general increased with SiO2 concentration. The authors suggested the possible presence of electronic conduction to explain why C+ < 100 pct. Fig. 4 includes their results as curve (b). EXPERIMENTAL METHOD Apparatus—Fig. 1 is a schematic section of the electrolysis cell used in all the current efficiency runs. The melt was contained in an iron crucible that rested on an alundum ring. A centered silica tube came within 1 in. of the surface of the melt and initially served as a thermocouple well and then as the guide for the anode.

Jan 1, 1961

By Alfonso Rizo-Patrón, A. M. Gaudin

Previous studies of activation in flotation have directed attention to the action of the activator on the mineral to be floated rather than to the relationship of the activator to the collector. The latter phase of the problem, however, seems to have definite scientific, if not also practical, interest. In the investigation reported in this paper, experiments were carried out, largely with quartz as subject, barium as activator, and oleate as collector. The results obtained indicate that a I: I ratio of collector ion to activator ion gives optimum results, and that a 2:1 ratio almost fails to achieve activation and flotation. Yet, a 2:I ratio would have been expected on stoichiometric grounds, had the coating been a normal salt of the activator ion with the collector ion, since barium is a divalent cation and oleate a monovalent anion. To interpret and rationalize the observations, considerations of the crystal chemistry of quartz are helpful. The point of view to which these considerations lead may be of general applicability to systems involving suspensions of solids in liquids; they confirm that an adsorbed coating is inescapable. Apparatus and Supplies The experimental work consisted in barium-ion abstraction tests, hydrogen-ion and hydroxyl-ion abstraction tests, flotation tests, and determinations of the surface of the crushed quartz. The flotation machine was built according to the design of D. W. McGlashan.* It consists of a drill press in which the bit has been replaced by a stainless-steel impellor surrounding a stainless-steel sta-tor, as in the Fagergren laboratory machine. The air intake is controlled by a valve, and the cell consists of a beaker. The quartz was obtained from vein quartz stored in large chunks. It was first crushed to 20 mesh, then sized on a 28-mesh screen. The 20 to 28-mesh size alone was retained for use. This size was freed of coarse iron by passage through a Ball-Norton magnetic separator, bleached with boiling hydrochloric acid to remove residual abraded iron, washed with distilled water until the washings were thoroughly free of ferrous, ferric, and excess hydrogen ion, and stored in covered Pyrex beakers under water until used. The barium was used as barium chloride, Baker&apos;s analyzed C. P. The oleate was used as sodium oleate. It was prepared from sodium hydroxide, Baker&apos;s analyzed C. P., and oleic acid purified by R. R. de Arellano3 in the laboratories at the Massachusetts Institute of Technology. The purification procedure was elaborated from the recent $researches of Brown and Shinowara.2 It consisted in: (I) saponification of olive oil with potassium

Jan 1, 1943

By Walter Fuchs

IT is now generally conceded that coal is the product of deposition and transformation of debris of forests and swamps.29 Ample data are available to illustrate the metamorphosis of biochemical substances through biological action; other data show the progressive regional metamorphism existing in coal beds ;25 and numerous examples of change effected by intrusion of igneous dikes into coal deposits have been established.23 However, often the relative importance of the biological and the geological factor in determining the character of the various natural coals is a debatable question. Since both biological and geological factors are ever present in nature, the problem, at first glance, would appear to resemble certain probability problems: specifically the simultaneous toss of two coins, with the biological factor as heads and the geological as tails. The probability is 2 : I for the combined effect of both factors, as compared to the exclusive effect of either one, if the a priori probability is the same for each factor. This condition can be analyzed by a thermodynamic treatment of data, which may be obtained from a consideration of pertinent biological, chemical, geophysical and geological facts. SYNOPSIS OF BIOLOGICAL AND CHEMICAL FACTS The biosphere is not sterile; i.e., microorganisms are always present. Microorganisms have been established in the ocean deep, under the ice of the polar regions, in the sand of the deserts, and in swamps far below the surface. The various biological media may be acid, neutral, or alkaline, and they may or may not be readily accessible to air. Microorganisms are encountered almost everywhere, except where the temperature is not within the range tolerable by microbial life. Of course, with changing conditions, the type of microorganisms will change. All chemical products of life-proteins, fats, carbohydrates, lignins, waxes, resins may serve as a habitat of microorganisms. In the decomposition of a medium. some microorganisms macerate organic matter mechanically and remove certain constituents for their own nutrition; others decompose a large part of the organic matter but may leave certain constituents undecomposed. Some attack only certain specific ingredients of the organic matter. All of them build up cell substance. The nitrogen content of the medium largely determines the degree of decomposition. Below 1.7 per cent nitrogen, growth of microorganisms and hence decomposition of organic material is retarded; consequently organic material will accumulate.17, 32 Such accumulations of organic material may give coal eventually. Coals differ in type and rank. The nature of the original vegetation and the conditions attending the transformation of the accumulated debris determine the type of coal such as bright, splint, cannel, and algal or boghead coals. Chemical analysis of representative samples of a given type of

Jan 1, 1941

By E. W. Hough, G. L. Stegemeier

Empirical equations for surface tension of propane and normal butane as functions of reduced temperature are obtained from experimental data. Another correlation relating surface tension to enthalpy of vaporization is given for these two compounds. In addition, new paracbor numbers are calculated for the normal paraffin hydrocarbons. These numbers are utilized for the calculation of interfacial tension of two-component systems as functions of pressure and temperature, using a modified form of Weinaug-Katz equation. The experimental data for two binary systems are approximated by the correlation. From these results it is found that the interfacial tension in the high-pressure region remains extremely low at large pressure decrements below the critical pressure. Thus, it appears that condensate systems may have flow characteristics almost like single-phase conditions even though the pressure is within the two-phase region. Experimental data have shown that interfacial tension divided by density difference approaches zero as the critical pressure is approached. A calculation of wetting-phase saturations indicates that the saturation gradient at the two-phase contact becomes increasingly abrupt as the critical pressure is approached. DISCUSSION Prediction of the surface and interfacial tension of the light hydrocarbons and of two-component hydrocarbon mixtures at various temperatures and pressures may be made if other physical properties are known. Extensive experimental work on single-component and binary systemsl is the basis for the correlations outlined in this paper. Interfacial tension is defined as the specific surface-free energy between two phases of unlike fractional composition, while surface tension is defined as the specific surface-free energy between two phase:; of the same fractional composition. The usual definitions relating interfacial tension to a liquid-liquid interface and surface tension to a gas-liquid interface are not clearly defined when the critical region is included, and there is no sharp distinction between a gas and a liquid phase. Interfacial tension is probably the most important single force that makes one-half to one-third of the total oil actually in place in a reservoir rock unrecoverable by conventional gas-drive or waterflood methods. A rough estimate of this figure for the United States is 100 billion bbl. Interfacial tension presently is used by petroleum engineers in the estimation of saturation gradients at the gas-oil contact and at the oil-water contact. The data in this paper should prove useful for estimates of reserves involving gas-oil contacts. Relative permeability undoubtedly is influenced by interfacial tension, for sufficiently small values. These data should be useful in determining how small the values are In addition, these data should eventually add to our fundamental knowledge of surfaces. At the critical point, all surface excesses approach zero and the thickness becomes very large. SINGLE-COMPONENT SYSTEMS It has been observed1 that the following relationships are good approximations to the physical properties of propane and n-butane.

By H. G. Dwyer

CONSIDERATION for future expansion influenced the design of the new smelter at Chuquicamata. The section of the smelter now going into operation, while large, represents only little more than half of the ultimate plant. Equipment for the direct smelting of raw concentrates has been arranged in the conventional manner although needless details have been eliminated wherever possible while mechanical and electrical features not usually found in copper smelters have been incorporated. Access is afforded to all equipment but platforms and walkways have been held to a minimum. The poling and other platforms in the converter aisle, normally subjected to battering by ladles and other heavy equipment in transit, are of concrete construction with steel grid armor embedded in the exposed surfaces. Noticeably absent are the many platforms formerly required for the handling of converter flux since this material is charged to the converters through the side walls of the converter uptake hoods. Clear space with ample headroom is provided under each converter and converter puncher&apos;s platform to permit clean-up by small bulldozers. Remote controls have been introduced at many points. Electrical control rooms and control centers have been conveniently located. An electrical tunnel with cross tunnels and escapeways is situated under the entire length of the converter aisle for power feed lines. Skull breaking facilities are in a separate building near the smelter. A silica-slurry building with brick storage area is adjacent to the smelter building so that elevator service is available to both buildings. A smelter office, a change house and lunchroom are provided in convenient locations. Units of the smelter as presently constructed are shown in the plan and table on page 1194. The ultimate smelter will house 7 reverberatory furnaces, 14 waste-heat boilers, 9 Peirce Smith converters, 4 casting furnaces serving 2 casting wheels, and one holding furnace serving a straightline casting machine. Additional crane requirements in the converter aisle will necessitate the installation of special hoisting equipment in space already provided in a raised section of the roof over the casting end of the aisle. Thus a complete crane may be lifted high enough above the crane rails to permit the passing of another crane underneath thereby giving all cranes full use of repair facilities already installed. For the collection of gases, 2 dust chambers, each with separate stacks, will collect converter gases and 2 balloon flues with separate stacks will collect reverberatory furnace gases. Extensions necessary to complete the ultimate plant will be possible with little interruption to normal operations since the future converters and reverberatory furnaces will be added at the east end while additional casting facilities will be added at the west end of the present plant. The future units may be added singly or all at one time depending on requirements.

Jan 1, 1952

By Alfred Brooks

THE only oil produced in Alaska in 1923 was obtained from a dozen small wells, one of which was drilled during the year on the single patented tract of petroleum land in Alaska, in the Katalla field. These wells are owned by the Chilkat Oil Co., which finds a ready local market for its product in the form of gasoline produced in its own refinery. The search for oil has been continued, but except in the Cold Bay field there has been no drilling in new fields during the year. Drilling was in progress during 1923 at Pearl Dome, 18 miles from the coast. Here the Associated Oil Co. sank two wells, about 500 and 950 ft. deep, but suspended drilling in June. The Standard Oil Co., drilling on the same structure, reached a depth of 300 ft. by August and is reported to have reached about 700 ft. by November. The company began the, installation of a second drill in August. George C. Martin, who hastily examined the Chignik region, south of the Cold Bay field, reports that what is known of the geology near Chignik is not favorable to the presence of petroleum. Kirtley Mather, who made a geologic survey of the northern part of the Alaska Peninsula, reports that some of the structures and the formations are favorable to the presence of oil. A small seepage has long been known in the region near the mouth of Douglas River, which flows into Cook Inlet. Sidney Paige last summer made an examination .of the oil seepages which have long been known near Cape Simpson, 50 miles southeast of Point Barrow, the northernmost point of Alaska. He reports that there are two very large seepages emanating from small ridges about a mile apart and several miles from the coast. These are marked by flowing petroleum, and cover many acres. There is a very large accumulation of petroleum residue at these seepages. The surface exposures consist of clay shales with hard thin partings of calcareous shale which lie nearly horizontal, and are probably, of Jurassic age. Mr. Paige and his two sub-parties explored a large area inland from the Arctic coast between Cape Beaufort on the south and Point Barrow and Cape Simpson on the north. He himself ascended the Meade River for 150 miles. These surveys indicate a wide distribution of what is believed to be the formation from which the Cape Simpson seepages emerge, which is probably of Jurassic age. These rocks near the north Arctic coast are little disturbed, but are increasingly folded to the south, toward the mountains. No other seepages have been found, but what is known of the geology is not unfavorable to an oil field. This entire region lies in Naval Petroleum Reserve No. 4, and it was examined by the Geological Survey at the request and expense of the Department of the Navy.

Jan 3, 1924

By J. H. Henderson, J. Naar

The displacement of a wetting fluid from a porous medium by a non-wetting fluid (drainage) is now reasonably well understood. A complete explanation has yet to be found for the analogous case of a wetting fluid being spontaneously imbibed and the non-wetting phase displaced (imbibition). During the displacement of oil or gas by water in a water-wet sand, the porous medium ordinarily imbibes water. The amount of oil recovered, the cost of recovery and the production history seem then to be controlled mainly by pore geometry. The influence of pore geometry is reflected in drainage and imbibition capillary-pressure curves and relative permeability curves. Relative permeability curves for a particular consolidated sand show that at any given saturation the permeability to oil during imbibition is smaller than during drainage. &apos; Low imbibition permeabilities suggest that the non-wetting phase, oil or gas, is gradually trapped by the advancing water. This paper describes a mathematical image (model) of consolidated porous rock based on the concept of the trapping of the non-wetting phase during the imbibition process. The following items have been derived from the model. 1. A direct relation between the relative permeability characteristics during imbibition and those observed during drainage. 2. A theoretical limit for the fractional amount of oil or gas recoverable by imbibition. 3. An expression for the resistivity index which can be used in connection with the formula for wetting-phase relative permeability to check the consistency of the model. 4. The Iimits of flow performance for a given rock dictated by complete wetting by either oil or water. 5. The factors controlling oil recovery by imbibition in the presence of free gas. The complexity of a porous medium is such that drastic simplifications must be introduced to obtain a model amenable to mathematical treatment. Many parameters have been introduced by others in Iprogressing" from the parallel-capillary model to the randomly interconnected capillary models independently proposed by Wyllie and Gardner3 and Marshall4. To these a further complication must be added since an imbibition model must trap part of the non-wetting phase during imbibition of the wetting phase. Like so many of the previously introduced complications, this fluid-block was introduced to make the model performance fit the observed imbibition flow behavior. THE IMBIBITION MODEL ASSUMPTIONS The following assumptions are common to many two-phase models previously described. 1. The wetting characteristics of the medium are clearly defined. 2. When two fluids co-exist in the medium, the wetting phase will fill the smaller pores and the non-wetting fluid the bigger ones. 3. The pores have a circular cross section. 4. Apparent pore radii are related to the capillary pressure (drainage) by

By M. C. Lavine, H. C. Gatos, R. S. Mroczkowski

The structure of GaAs-Ge heterojunctions prepared by a back-melting process was studied by X-rav diffraction, melallographic, and electron-micro-analyzer techniques. The boundary region between the GaAs and the germanium was found to consist of a four-layered band. A discontinuity between the two inner bands was brought about by solidification occurring simultaneously from the GaAs and the germanium side. The junction material OH either side of the central discotinuity was found to have grown as a single Crystal with the orientation of the parent substrate. It was found essential to determine the GaAs-Ge phase diagram. This was accomplished by a series of alloys containing 0 to 40 wt pet GaAs. Over this range the diagram is a simple eutectic with the eutectic point at 74 wt pet Ge and 845 C. The limiting- solubility of Coils in germanium was found to bc less than 5 wt pet. The Kossel divergent-beam X-ray technique was used to study orientation relationships across the boundary lager. A great deal of effort has been recently expended on the electrical properties of heterojunctions. Little attention, however, has been given to the metallurgical variables which may be of importance in the formation of the junctions. The present work was undertaken to investigate some of the more pertinent metallurgical aspects of interface-alloyed GaAs-Ge heterojunctions. Such parameters as solidification processes, composition gradients, orientation effects, and the accommodation of crystal structures have been the objects of study in this program. EXPERIMENTAL PROCEDURES Phase Diagram. The phase diagram of the GaAs-Ge pseudobinary system was determined by means of cooling curves. A Bridgeman furnace was employed with the center section maintained at 1200°C and the upper section at 800°C. Melts varying from 0 to 40 at. pct in GaAs content were used. Each charge was incapsulated under a two-thirds atmosphere of argon in a carbon-coated quartz tube. Five min in the furnace hot zone provided rapid melting and homogenization. The capsule was then removed to the cooler portion of the furnace. Cooling times were of the order of 3 min. The resulting homogeneous microstructure indicated that equilibrium conditions were obtained by this procedure. Formation of Heterojunctions. Rectangular parallelepiped single-crystal samples were cut with the large faces of either the (l00), (110), or (111) orientation. The remaining four surfaces were also cut to specific orientations to permit accurate relative orientation of the GaAs-Ge pairs. The

Jan 1, 1965

By J. B. Newkirk

Results of a Debye-Scherrer X-ray investigation are given which show that the order-disorder transformation is a first-order or heterogeneous reaction in Cu-AU alloys with compositions near CuAu. Evidence was found for conventional tie-line segregation across a usual type of two-phase field separating the ordered and disordered fields in the Cu-Au equilibrium phase diagram. The horizontal and vertical widths of the two-phase fields are about 3 atomic pct and 20°C, respectively, at 43 and 54 atomic pct Au. No evidence for the existence of an ordered structure based on a stoichiometric composition of Cu3Au2 could be found. ALTHOUGH the modern theories relating the de-Agree of order of binary alloys to temperature and composition have met with considerable success, the nature of the transformation from the disordered state to the ordered state and vice versa has never been well understood. It has been assumed by some&apos; that this is a second-order transformation, that is, a homogeneous change of state. Others2 hold that the transformation is first-order and that the effects characteristic of heterogeneous phase transformation apply. Since this subject is discussed in detail in a recent paper,&apos; the arguments will not be repeated here. The present paper summarizes an experiment which was designed to distinguish between these two viewpoints for the case of Cu-Au alloys near the composition CuAu. The Cu-Au system is an important one because it furnishes prototype alloys, the behavior of which has formed the basis of much of the present-day order-disorder theory. It has recently been shown- hat in alloys near Cu3Au there is a temperature range within which the ordered and disordered states coexist in equilibrium and are distinguishable as separate phases. Therefore, the transformation must be first-order for these alloys. A similar demonstration for alloys near CuAu, however, has been lacking. Experimental Method Essentially the experiment consisted of equilibrating Cu-Au samples at various temperatures, quenching them in water to retain the high temperature states, and then examining them at room temperature for the coexistence of the ordered and disordered structures. The thermal gradient method of heat treatment- as used because it was important that all temperatures over the transformation range should be represented in the test. Briefly, this method consisted of holding a wire of the desired composition, sealed under vacuum in Pyrex, in a known temperature gradient for a long enough time to allow each part of the wire to assume the crystal structure characteristic of the temperature at which it was held. The temperature gradient was produced by inserting into an ordinary wire-wound cylindrical laboratory furnace, an 18 in. length of 1/8 in. ID ceramic tube which was heavily wrapped with asbestos. The furnace power was controlled by a Tag-liabue Celectray controller and a chromel-alumel thermocouple with the junction located on the heating elements. During the equilibrating treatment the widest variation of temperature within the gradient tube was approximately 4°C at the highest temperature. The temperature at various places within the tube was determined, before inserting

Jan 1, 1954