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By George R. Mansfield

INTEREST in the reserves of phosphate rock in the United States and their proper conservation has recently been aroused by hearings held in different parts of the country by the "Joint Committee to investigate the adequacy and use of phosphate resources of the United States." This committee was appointed within a few days after a Presidential message to Congress on the same subject, dated May 20, 1938, and began to function almost immediately. Hearings were held in Washington, D. C., Pocatello, Ida., Wilson Dam, Ala., Knoxville, Tenn., and Lakeland, Fla. The resulting testimony, when published, comprised a volume of 1182 pages.1 At the earlier hearings held in Washington and Idaho the seeming disparity between the great reserves of the West and the smaller reserves in the East led to some suggestions as to the desirability of curtailing or even prohibiting the exportation of phosphate rock so that eastern producers, becoming alarmed, cooperated in making available for the use of the committee information hitherto closely guarded. This information has provided an opportunity for new studies by official agencies, for a restatement of the reserves of Florida and Tennessee, and for some modification of figures for the Western States. The writer, representing the Federal Geological Survey, was given free access to the Florida material and has prepared for publication a report,2 some features of which are summarized in this paper. The Tennessee material was studied by Dr. G. I. Whitlatch,3 of the Tennessee Division of Geology. Prof. J. Stewart Williams,4 of the Utah State Agricultural College at Logan, has published a recent study of the phosphate resources of Utah and the writer has given some further study to reserves of western phosphate from the viewpoint of including material of lower grade than that hitherto considered. Technologic advances in the phosphate industry must be credited with a large share in the expansion of reserves by making available for

Jan 1, 1940

By O’Brian. Daniel T.

Ore reserve determinations supporting property appraisals and economic analyses leading to investment decisions typically require many repetitive calculations. Computers have become well-accepted tools for accomplishing these computations, and are partly responsible for the development of new evaluation methods during the last decade. Excellent descriptions of manual ore reserve may be compared with current computer reserve methods1,2 in North America2 and South Africa3. A comparison indicates that computers are used in two cases: a) when a cost savings can be achieved by the simple conversion of a manual method to a computer processed equivalent, and b) when the quantity of data and ore reserve estimation purpose justifies adoption of a complex ore reserve computational method not feasible on a manual basis. Ore reserve computations essentially consist of using sample data and a mathematical method to arrive at an estimated geometry, tonnage, and grade for a mineral deposit. The mineral deposit is then subdivided, if necessary, into ore and waste components. This separation is based on economic factors which may be explicitly introduced in the computation or incorporated in a numerical cutoff grade4. Computer methods for accomplishing these tasks are presented in three papers. "The Use of Contour Surfaces as Predictive Models for Ore Values" discusses the requirements for a satisfactory value prediction model and the importance of considering auto -covariance. A weighted moving average method is described and compared to other mathematical surface development methods. In the second paper, "The Applications and Limitations of Computer Techniques in the Evaluation of Hypothermal Tin Lodes," particular problems encountered in estimating geometrically erratic economic deposits with a low valuable mineral content are documented. Economics and probabilistic concepts are introduced, allowing a comparison of risk and speculative value for a deposit. Economic considerations are integrated with ore estimation techniques in the third paper, "Method of Calculation of the Iron Ore Reserves in the Lorraine Deposit." The prediction model

Jan 1, 1969

By David Donoghue

THE. years 1901, 1910, and 1924 may be considered as the beginning of new eras in the history of the oil industry of the Gulf Coast of Texas and Louisiana. Spindletop, in 1901, with its enormous cap-rock production revealed the possibilities of the salt domes. The lateral sand development at Vinton, in 1910, renewed interest in the then known domes which were non-producing, or were producing from the cap rock or from sands above the cap rock. The discovery of three domes, Nash, Orchard and Long Point, in the year 1924, by means of the torsion balance and the seismograph, is the beginning of intensive explorations of the Gulf coastal plain by geophysical methods. Domes other than those mentioned have no doubt been found during the last few months of the year but tests have not been drilled to confirm the evidence of the instruments. DISCOVERY OF DOMES BY GEOPHYSICAL METHODS The Rycade Oil Corpn. operated the first torsion balance on the Gulf Coast in October, 1922, and the Roxana Petroleum Corpn. brought in one of these instruments and began work in December, 1922. The U. S. Coast and Geodetic Survey made some gravity observations at Damon Mound, in 1923, with a pendulum apparatus. In March, 1924, the Marland Oil Co. placed the first seismograph on the Gulf Coast and the Gulf Production Co. followed with one in May. In June, 1924, the Gulf Production Co. began operations with a torsion balance. The Atlantic Oil Producing Co., The Texas Co., and others have experimented with several types of instruments involving various principles. During the next few years, a great advance in geophysical methods may be expected, especially if one of the newly discovered domes should be productive. The first dome discovered was the Nash, in Fort Bend County, Tex., about 6 mi. east of Damon Mound. A slight elevation and two shallow wells containing sulfurous waters made the locality somewhat interesting from the standpoint of surface indications, and the torsion-balance measurements indicated the presence of a dome. On July 20, 1924, the Rycade Oil Corpn. No. 1 Wisdom encountered lime at a depth of 634 ft. and anhydrite at 639 ft. The hole was abandoned on Sept. 8, 1924, at 769 ft. in anhydrite. A cavity in the anhydrite caused much delay and the final abandonment of this test.

Jan 3, 1925

The official Institute reports for the year 1929 were distributed in pamphlet form at the Annual Meeting, February, 1930, and were later included in Section 2 of Mining and Metallurgy, June, 1930, and thus made available to the entire membership. Membership In its report the Admissions Committee set forth the changes in membership during 1929, as follows: Total membership, Jan. 1, 1928, 8582; elected and placed on rolls in 1929, including 59 reinstatements, 509; loss by resignations in 1929, 88; loss by death in 1929, 110; loss by suspension in 1929, 37; membership at end of year not including Student Associates, 8856. Distribution of membership: Honorary Members, 16; Members, 6590; Junior Members, 38; Associates, 1041; Junior Associates, 1033; Rocky Mountain, 138; total membership, Jan. 1, 1930, 8856; Student Associates, 150; total including student associates, 9006. Treasurer's Annual Report, Year of 1929 Statement of Receipts For the year ended December 31, 1929 Dues: Arrears............................................ $ 3,501.75 Current............................................ 97,257.12 New Members...................................... 5,721.50 Advance........................................... 1,970.79 $108,451.16 Initiation Fees.................................................. 7,436.00 Magazine Receipts: Advertising Gross Receipts........................... $40,610.81 Magazine Sales..................................... 3,799.84 44,410.65 Sale of Transactions Current........................... $ 2,985. 15 Sale of Special Editions Current........................ 5,147.82 Sale of Back Transactions and Special Editions........... 4,186.93 Sale of Year Book..................................... 65.50 Sale of Authors' Reprints.............................. 2,585.40 Sale of Pins and Fobs.................................. 14.73 Sale of Technical Publications.......................... 1,451.55 Sale of Bindings...................................... 3,949.13 20,376.21 Net Interest Received: On Bank Balance and Temporary Investments......... $ 2,595.04 On Lie Membership Fund........................... 3,223.43 On James Douglas Library Fund...................... 5,425.61 On General Reserve Fund............................ 2,015.58 13,259.66 Miscellaneous Receipts........................................... 335.80 Total Receipts................................................ $194,269.48

Jan 1, 1930

By Harvey Cline, Donald P. Ferriss

THE violent outgassing of commercial tungsten and other refractory metals when melted in an electron beam zone refining apparatus1"3 is dealt with experimentally by one or both of two approaches. One is to provide a suitable emission current control1,2 the other is to purify the metal in the solid state before melting.4 The first of these is usually sufficient, but the authors chose also to investigate the source of the troublesome gases and to devise means of solid-state purification. Some further insights into the use of tungsten as a structural material at temperatures near its melting point were also revealed in the course of the work. One may speculate on the causes of gas formation in tungsten at high temperature by inferences from the literature and an examination of the impurities in commercial wire. Davenport5 observed microporosity in both tungsten and molybdenum filaments heated to several hundred degrees below their melting points. Studying the function of oxygen in molybdenum welds, Perry, Spacil, and wulff8 attributed similar porosity to the disproportionation of Moo2 to molybdenum metal and Moo3. Tungsten dioxide also disproportionates7 above 2000oC to yield WO3 vapor at considerable pressure. Commercial tungsten contains some 5 to 20 wt ppm O and a similar concentration of carbon depending on the details and precautions of processing. Therefore, evolution of CO is also a strong possibility as a source of gas at high temperatures. Furthermore, even for activities in the order of 0.01, it may be calculated that the pressure of CO at 3000°C would be over 4000 psi, which is in excess of the tensile strength of tungsten at this temperature.9,10 Powder metallurgy tungsten contains some 0.02 pet Fe and 0.002 to 0.005 pet of the elements Ni, Si, Al, Ca, Mn, Mg, and Mo; at temperatures over 2800°c, therefore, these elements will exhibit appreciable vapor pressure, though small compared to that of WO3 and CO. Some of these impurities may react to form high-pressure monoxides such as SiO and A10. Finally, dissolved and occluded nitrogen is an ever-present source of high-pressure gas. Commercial Type 218, General Electric filament wires, 0.025 in. diam, were heated by resistance in 10 -4 mm of Hg and in argon or hydrogen at pressures from 50 µ to atmospheric. For temperature determinations in vacuo, the Jones - Langmuir8 current-temperature relationship was employed. For gaseous atmospheres, the burn-out temperature was assumed to be the same as in vacuo so that a small, constant correction could be made for temperatures below burn-out conditions (i.e., local heating to failure). Several dozen experiments may be summarized by pointing out some structural observations. At 3050oC in 1 atm of A, porosity is very evident after 30 min, as shown in Fig. 1. For the section in Fig. 2, failure occurred 200°C below the melting point and many voids have grown in the grain bound-

Jan 1, 1962

By D. W. Fuerstenau, G. D. Gumtz

Use of the discretized batch-grinding model for the simulation of locked-cycle grinding tests from batch-grinding data is illustrated. The simulated results were compared with actual locked-cycle experimental data for the dry grinding of dolomite. To illustrate the utility of this simulation method, a number of relationships between operating and performance parameters were generated, including relations between batch grinding and the Bond test, the production rate and the circulating load, and the production rate and the product size. A large amount of testing is done each year in the mineral industry for use with grinding unit cperations, and much of the experimental test data is obtained by the tedious locked-cycle testing procedure. In addition to being experimentally complex and requiring large amounts of sample, the very nature of the locked-cycle experiment yields results that cannot readily be interpreted. The attempts that have been made to model comminution systems during the last few years may provide a better and simpler way to obtain and analyze grinding test data; these models involve elements of both fitting to "model equations" and deterministic representations.1-1 The traditional engineering design techniques for comminution systems have relied mainly upon large amounts of industrial operating data that have been correlated with locked-cycle grinding data.',' Bond's empirical mill-design procedure involving locked cycle testing remains the most generally available method to this day. The purpose of the present paper is to show how much more useful data can be obtained from a simple batch-grinding experiment that provides information which subsequently can be utilized with population balance models of the grinding process to simulate locked-cycle behavior. These simulation results can, of course, be used in Bond's general design scheme. However, the combination of batch-grinding tests and the population balance model allows many more conditions to be considered than do single laboratory tests under specific locked-cycle conditions. The use of these simulation techniques for prediction of locked-cycle behavior represents one of the first practical applications for the simulation method in comminution.

Jan 1, 1971

By J. C. Bayles

Jan 1, 1886

ROBERT PEELE, New York, N. Y. (written discussion *).-This excellent paper is one of a number of recent detailed descriptions of the, methods and plant in use at prominent mines of the country. The publication of such papers cannot be too highly praised. In the past, the interchange of inside information has often been hampered by the disinclination of some mining companies to permit publication of details of their work. These companies apparently have not realized fully that free discussion is of mutual benefit; that members of mine staffs are aided in. keeping up to date, in improving old methods and devising new ones to meet changes in conditions, and, by a wholesome feeling of rivalry, are stimulated to introduce economies and do better work. In writing this paper, Messrs. Haight and Tillson have packed a large amount of information into a relatively small space, and the numerous illustrations, chiefly reductions of working drawings, are valuable. The authors are also to be commended for their highly detailed Table of Contents, which adds to the usefulness of the, subject matter. The method of mining at Franklin does not fall readily into any of the accepted classifications. It is a combination of shrinkage stoping and mining of the pillars by a modified top-slicing method. Attention may be called to the fact that, in the wider parts of the orebody, the stopes, 17 to 18 ft. (5.2 to 5.5 m.) wide are transverse; in the narrower parts, they are longitudinal, that is, in the direction of the' strike. This varia-tion is made necessary by the shape and character of the deposit, and distinguishes practice at Franklin from that in some of the western mines. The direction of the stops is changed from transverse to longitudinal when the orebody narrows sufficiently to make the length of a transverse stope approximately equal to its width. Some of the longitudinal stopes exceed 120 ft. (36 m.) in length, and when the hanging wall is bad, requiring prompt filling, three operations' proceed simul-taneously in the same stope, viz., ore is broken at one end, while drawing down goes on in the middle, and filling at the other end. Each transverse stope or chamber is begun by a crosscut from foot to hanging wall, which is afterward enlarged to the stone width and to a height of 12 or 15 ft. (3.7 or 4.6 m.). This preliminary work is done only once for each stope, because the stope is carried up far enough to continue stoping

Jan 1, 1918

Jan 1, 1934

By W. M. Dressel, A. Visnapuu

The Bureau of Mines, U.S. Department of the Interior, has upgraded high-iron domestic chromite concentrate to high-chromium concentrate by a laboratory carbonyl process. The chromite concentrate product has a chromium-to-iron ratio in excess of 3:l compared with the starting concentrate ratio of 1.6:1. The high-iron chromite was first reduced to convert the iron oxides to the metal, and then treated with carbon monoxide at elevated pressures and low temperatures to convert the metallic iron fraction to iron pentacarbonyl. Carbonylation was accelerated by the addition of hydrogen sulfide in small quantities. A constant flow of carbon monoxide swept the iron pentacarbonyl formed in the reactor out through a pressure-reducing valve. The mixture of carbon monoxide and iron pentacarbonyl at atmospheric pressure was then passed through a heated section to decompose the iron pentacarbonyl to carbon monoxide and iron, whereupon the latter plated out on the heated surface. Carbon monoxide pressure, temperature, and promoter trends for enhanced carbonylation are presented.

Jan 1, 1984

By Y. A. Rocher, J. E. Dorn, L. A. Shepard

Creep activation energies for single aluminum crystals favorably oriented for shear by (010) [101] glide were detemined over the temperature range from 78" to 900°K. Observations of slip bands on the specimen surface were made in conjunction with the investigation. From 78" to 780°K, the activation energies obtained in this imestigation agreed closely with those previously found for creep by (111) [101] slip. Between 78" and 140°K, the activation energy was identified with the Peierls process, while between 260°and 780°K the activation energy was close to that for cross-slip. The coarse wavy slip bands nominally parallel to the (010) plane observed above 260°K were attributed to fine cross-slip. From 800" to 900°K, unusually high apparent activation energies ranging from 28,000 to 54,000 cal per mole were obtained. These apparent activation energies were attributed to re crystallization. AS illustrated in Fig. 1, a recent investigation1 has shown that creep of aluminum single crystals by the (111) [i01] mechanism is controlled by three unique processes, each of which is characterized by a single activation energy which is independent of the applied stress and the creep strain. A comparison of the observed activation energies with theoretically calculated values permits a fairly clear identification of the three operative creep processes. Below 450°K, where the activation energy for creep is 3,400 cal per mole, the deformation is controlled by the Peierls process, the activation energy for creep agreeing well with that calculated by seeger2 for the energy required to nucleate the motion of a dislocation loop against the atomic forces of the lattice. Between 590° and 750°K, the observed activation energy for creep of about 28,000 cal per mole agrees well with the energy necessary to induce cross-slip. Seeger and schoeck3 estimate that the activation energy is about 24,000 cal per mole whereas Friedel4 recently calculated this activation energy to be 28,000 cal per mole. Above 800°K the activation energy of 35,500 cal per mole that was observed for creep agrees well with that estimated for self-diffusion in aluminum.= In this range the operative rate-controlling slip process has been clearly identified as that arising from the climb of edge dislocations. The objective of this investigation is to ascertain whether a single crystal of aluminum favorably oriented for simple shear in the [loll direction on the (010) plane might exhibit uniquely different activation energies for creep from those obtained previously for (111) [101] slip. Whereas the exis- tence of such unique activation energies would constitute incontrover table evidence for new mechanisms of slip, the absence of any new activation energies might suggest that slip of aluminum is confined to the (111) [loll mechanism. Several factors prompted the selection of the (010) [101] orientation for study. First, there are more reported observations of (010) [loll slip than of any other nonoctahe-dral mechanism.8-10Secondly, Chalmers and Martius1l have concluded from considerations of the energies of dislocations that (010) slip is the second most favored mechanism in face-centered-cubic metals. Finally, favorable orientations for simple shear by the (010) [loll mechanism provide the least favored orientation for slip by the (111) [101] mechanism. EXPE-RIMENTAL PRO-CEDURE The high-purity aluminum stock, specimen preparation, shear fixture, extensometry, and experimental technique used in this investigation were the same as those previously reported.' Single-crystal spheres grown from the melt of 99.995 pct pure Al* were _ *The high-purity aluminum used in this investigation was graciously given by the Aluminum Company of America. oriented, carefully machined into dumbbell-shaped shear specimens, annealed, and chemically polished. The finished specimen had a central reduced section 0.190 in. wide and 0.590 in. in diam and 1/4-in. grip sections at both sides, 0.690 in. in diameter. The specimen was oriented in the stainless steel grips of the shear fixture with the (010) plane perpendicular to the dumbbell axis and the [loll direction parallel to the stress axis within 2 deg. Creep activation energies were calculated in the previously described manner1 from determinations of the instantaneous change in shear strain rate produced by an abrupt 15 to 20 deg increase or decrease in test temperature. If is the instantaneous strain rate at strain y and temperature T1, and ?2 the instantaneous rate at y and T2,

Jan 1, 1960

By William C. Maurer

A survey of 25 novel drills has shown that spark drills have potential for drilling oil wells and blastholes at higher rates than rotary drills. Available laboratory and field data were extrapolated to drilling rates of 70 to 280 fph for full-scale spark drills. Most of the data used in these extrapolations were from small-scale laboratory tests at atmospheric pressure. Accurate extrapolation of the small-scale spark drill tests to full-scale field drills was complicated by the fact that the effect of fluid pressure in the well bore and the effect of spark size were not known. In order to answer these questions and to more accurately evaluate the potential of spark drills for drilling blastholes and oil wells economically, a high-voltage spark discharge system was assembled. This equipment produced powerful sparks (10,000 joules) equivalent to those that would be used on a 100-kw full-scale field drill. These sparks are 100 times more powerful than those previously used on spark drills, thus eliminating extrapolation of the spark size. In addition, a pressure chamber was modified to enable using these sparks to produce craters in rocks at fluid pressures up to 15,000 psi, thus eliminating extrapolation from atmospheric pressure to the high pressure existing in deep oil wells. These tests have provided considerable information for more accurately evaluating spark drills for oil-field drilling. MECHANISM AND THEORY OF SPARK DRILLING Spark-Drilling Mechanism When a high-voltage capacitor is discharged across two electrodes, the dissipated energy produces a high-temperature, high-pressure plasma for a few µsec. When these sparks are discharged in air, they undergo considerable expansion (Fig. 1) and produce low-pressure pulses (103-

Jan 1, 1970

By H. F. Yancey, M. R. Greer

At the annual meeting of this Institute held two years ago a new method1 of estimating the grindability of coal was described, based on experimental work carried on by the Bureau of Mines at its Northwest Experiment Station. Since that time, several organizations concerned with the testing or utilization of coal as pulverized fuel have adopted and used the method in determining the grindability of several hundred samples of coal. In addition, a series of comparative tests of this method and three others has been carried out in five laboratories under the auspices of Committee D-5 of the American Society for Testing Materials. As a result the Committee has recommended that the Bureau of Mines method, designated as the "ball-mill method," and the Hardgrove method2, previously advanced, be accepted as tentative standards3. Since the ball-mill method was originally developed and published, an opportunity has been presented to apply it to a larger number of coals and to study intensively some of the principles upon which the method is based. This paper presents a résumé of these further studies and includes a comparison with the Hardgrove-machine method. Trial runs were also made with another procedure recently proposed—the C.I.T. roll-test method4. Principles of Methods In the ball-mill method, the relative amounts of energy necessary to grind coals to the same fineness are determined by the number of revolutions of the mill required to reduce 80 per cent of the feed (500 grams of 10 to 200-mesh coal) fine enough to pass a 200-mesh screen. This is a

Jan 1, 1936

By H. F. Yancey, M. R. Greer

At the annual meeting of this Institute held two years ago a new method1 of estimating the grindability of coal was described, based on experimental work carried on by the Bureau of Mines at its Northwest Experiment Station. Since that time, several organizations concerned with the testing or utilization of coal as pulverized fuel have adopted and used the method in determining the grindability of several hundred samples of coal. In addition, a series of comparative tests of this method and three others has been carried out in five laboratories under the auspices of Committee D-5 of the American Society for Testing Materials. As a result the Committee has recommended that the Bureau of Mines method, designated as the "ball-mill method," and the Hardgrove method2, previously advanced, be accepted as tentative standards3. Since the ball-mill method was originally developed and published, an opportunity has been presented to apply it to a larger number of coals and to study intensively some of the principles upon which the method is based. This paper presents a résumé of these further studies and includes a comparison with the Hardgrove-machine method. Trial runs were also made with another procedure recently proposed—the C.I.T. roll-test method4. Principles of Methods In the ball-mill method, the relative amounts of energy necessary to grind coals to the same fineness are determined by the number of revolutions of the mill required to reduce 80 per cent of the feed (500 grams of 10 to 200-mesh coal) fine enough to pass a 200-mesh screen. This is a

Jan 1, 1936

By C. E. Cottrell, G. W. Preckshot, N. D. Delisle, D. L. Katz

Most crude oils contain asphaltic substances that may be naturally or artificially precipitated. In the Greeley field, California, this asphaltic bitumen is precipitated during the flow of the oil from the reservoir to the stock tank The mechanism of such precipitation is not well understood. This paper presents the progress that has been made by using the electron microscope as a new tool and by observing the effects of the streaming potential on the formation of bitumen particles. Crude oils at atmospheric pressure viewed in the electron microscope in very thin films under a vacuum showed no asphaltic particles. A technique of preparing slides of thin films by dilution of the oil with benzene and washing in petroleum ether was used at first, and these observations showed that the solvents caused the formation of the particles, varying from 0.01 to 0.2 micron in diameter. The electrical effects of fluids flowing through porous solid were studied, with emphasis on the formation of colloidal particles by the streaming potential. The streaming potential of crude oil flowing through sand was measured and was shown to be responsible for the formation of bitumen particles. These results bring out a new phenomenon, which may occur when crude oil flows through the porous oil reservoir. mechanisms. Asphalt has been the subject of widespread investigation but, owing to the complexity of the substances being considered, progress has been slow. Investigators working primarily with the asphaltic substances have treated the subject from the colloidal standpoint and have developed theories that picture the asphaltic particles as surrounded by adsorbed materia1s.14,15,17,24 The deasphaltization of lubricating oil by the use of solvents treats the subject primarily from the standpoint of liquid-liquid equilibria.'' A complete understanding of asphaltic substances would make possible the following of the material from its initial state in the crude oil through precipitation processes to the final plastic stage, the most common form of which is used in asphaltic pavements. Since these asphaltic particles are very small, it appears 'hat the electron microscope4 might be a useful tool in studying the precipitation processes. Specimens are examined by the electron microscope in a vacuum and as very thin films, requiring special techniques in preparation of samples. A brief description of the electron microscope and its operation will bring out the difficulties and advantages of its use for this problem. The first work was done with crude oils that had been diluted with solvents for the preparation of the film to be examined. Later a technique was developed by which the undiluted oil film could be made thin enough for direct examination. These two techniques show vastly different results Asphaltic particles have been precipitated from crude oils by a variety of

Jan 1, 1943

By G. W. Preckshot, C. E. Cottrell, D. L. Katz, N. D. Delisle

Most crude oils contain asphaltic substances that may be naturally or artificially precipitated. In the Greeley field, California, this asphaltic bitumen is precipitated during the flow of the oil from the reservoir to the stock tank The mechanism of such precipitation is not well understood. This paper presents the progress that has been made by using the electron microscope as a new tool and by observing the effects of the streaming potential on the formation of bitumen particles. Crude oils at atmospheric pressure viewed in the electron microscope in very thin films under a vacuum showed no asphaltic particles. A technique of preparing slides of thin films by dilution of the oil with benzene and washing in petroleum ether was used at first, and these observations showed that the solvents caused the formation of the particles, varying from 0.01 to 0.2 micron in diameter. The electrical effects of fluids flowing through porous solid were studied, with emphasis on the formation of colloidal particles by the streaming potential. The streaming potential of crude oil flowing through sand was measured and was shown to be responsible for the formation of bitumen particles. These results bring out a new phenomenon, which may occur when crude oil flows through the porous oil reservoir. mechanisms. Asphalt has been the subject of widespread investigation but, owing to the complexity of the substances being considered, progress has been slow. Investigators working primarily with the asphaltic substances have treated the subject from the colloidal standpoint and have developed theories that picture the asphaltic particles as surrounded by adsorbed materia1s.14,15,17,24 The deasphaltization of lubricating oil by the use of solvents treats the subject primarily from the standpoint of liquid-liquid equilibria.'' A complete understanding of asphaltic substances would make possible the following of the material from its initial state in the crude oil through precipitation processes to the final plastic stage, the most common form of which is used in asphaltic pavements. Since these asphaltic particles are very small, it appears 'hat the electron microscope4 might be a useful tool in studying the precipitation processes. Specimens are examined by the electron microscope in a vacuum and as very thin films, requiring special techniques in preparation of samples. A brief description of the electron microscope and its operation will bring out the difficulties and advantages of its use for this problem. The first work was done with crude oils that had been diluted with solvents for the preparation of the film to be examined. Later a technique was developed by which the undiluted oil film could be made thin enough for direct examination. These two techniques show vastly different results Asphaltic particles have been precipitated from crude oils by a variety of

Jan 1, 1943

(This list includes only those who have entered military service within the past month, or whose entry has only recently become known to us; it also includes a few names of those whose titles or assignments have been changed within the month. The last complete list was printed in Bulletin No. 131, November, 1917. A complete Honor List is maintained in the reception room at the office of the Institute.) BANKS, HAROLD P., 2d Lieutenant, Ammunition Train, 2d Division, U. S. A. BARKER, L. M., Co. B., 62d Infantry. BENHAM, W. M., Sergeant, Co. H, 158th Infantry. BOUDWIN, WALKER J., Co. C., 25th Engineers, Camp Devens, Ayer, Mass. BOWLES, MARTIN F., 2d Lieutenant, Co. B., 355th Infantry. BURG, ROBERT S., Instrument Sergeant, Headquarters Co., 340th Field Artillery, N. A. CHALMERS, JOHN W. P.; Signal Depot, Royal Engineers. CHETNEY, P. C., Corporal, 340th Field Artillery, Headquarters Co. CLARK,. WILL L., Federal Fuel Administrator for Arizona. COFFEY, George W., Lieutenant, Engineer Section, Officers' Reserve Corps.

Jan 1, 1918

By Julian Szekely

Through the simultaneous statement of Maxwell's equations. the turbulent Navier-Stokes equations and the differential thermal energy balance equation, a mathematical representation has been developed for heat transfer and fluid flow in electric arc furnaces. In broad outline the theoretical predictions appear to be consistent with experimental measurements. A discussion is presented of the general arc furnace control and optimization problem, together with the potential for the incorporation of the mathematical model given in the paper, into future control and optimization schemes. ELECTRIC ARC FURNACE STEELMAKING accounts for about 24% of the total steel produced in the U.S., consuming about 550kw-hr/ton of steel which amounts to about 1.4x1010 kw-hr annually. The percentage of steel produced by the electric arc furnace route has doubled since 1960 and is expected to increase further in the foreseeable future, particularly with the more extensive use of direct reduction technology. Table I shows, in terms of percentages, the principal items that contribute to the cost of running an electric arc furnace. It is seen that in addition to the fixed costs (labor, depreciation, taxes etc.) electrode costs and power consumption are the dominant inputs, and it follows that process changes that would ultimately reduce any of these cost components would have a significant impact on the efficiency of the operation. There are three main areas where progress in arc furnace design and operation must be directed in the next decade (Committee on Technology, 1981). 1. Increased furnace productivity 2. Reduction in processing cost 3. Improvement in the thermal efficiency of the furnace An estimate of the current operating efficiency of the electric arc furnaces may be obtained by comparing the theoretical minimum energy consumption per ton of steel with those achieved in operational practice. Theoretically 330-360 kw-hrs of electricity are required to melt one ton of cold scrap. For superheating, 8-12 kWh per 100°F are required. The actual energy requirements are given in Table II. It is seen that furnaces currently operate at 70-80% efficiency, with the major heat loss from the furnace resulting from the waste gases (Committee on Technology, 1981). While it is apparent that operational experience has produced a technology that is reasonably energy efficient this has been achieved in the almost complete absence of any detailed knowledge concerning the fundamental heat transfer mechanisms occuring in the furnace. The purpose of the present paper is to present a case for the usefulness of mathematical models in increasing the thermal efficiency of furnaces by investigating these heat transfer mechanisms and then combining this knowledge with existing electrode regulator mechanisms to produce truly efficient power cycles for melting and refining. In particular, existing mathematical models describing convection, radiation, and electro-magnetism in the furnace should be employed, and the development of optimization models which balance the cost of electrodes and energy against the thermal efficience of the furnace should be undertaken. Recent work in this laboratory (Szekely, McKelliget, 1981, 1982, 1983; Szekely, McKelliget, Choudhary, 1983) has made a useful start towards solving the problem of heat transfer within the electric arc furnace but the work still needs to be directly related to existing furnace power cycles and tested against plant scale measurements.

Jan 1, 1984

Institute of Metals - Iron and Steel - Mineral Industry - Industrial Minerals Year ?Division - Petroleum Division ? Division - Coal Division - Education Division -Division 1918 W M CORSE 1919 1920 W. H BASSETT 1921 1922 W B PRICE RALPH ARNOLD 1923 E DEGOLYER 1924 G K ELLIOTT 1925 F JULIUS FOHS 1926 PAUL D MERICA 1927 JOHN M LOvEJOY 1928 S SKOWRONSKI A W AMBROSE RALPH H SWEETSER

Jan 1, 1952

By R. J. Walter, W. T. Chandler

The Ch-H phase diagram was determined for by-drogen concentrations up to ChHo.9 at temperatures below 400°P'. The phase diagram includes a mis-cibility gap and a eutectoid transformation. A peri-tectoid transformation is postulated at the hydrogen-rich end of the diagram, Phase diagrams were determined for two levels oj purity, of the columbium. A single solid solution exists in the Cb-H system above 400°F. There has been considcrable disagreement among investigators concerning the system at temperatures below 400°F. Albrecht, Goode, and ~allett' proposed a miscibility gap containing two bcc phases with the two lattice parameters converging at about 140°C (285-F), and Brauer and ~erman' found a two-phase room-temperature region between 10 and 41 at. pct H. At sufficiently high hydrogen concentrations in the one-phase region, the hydrogen-rich phase was found to be face-centered orthorhombic. Wainwright, Cook, and Hopkills3 recently reported that the face centered orthorhombic hydride phase is derived from a unit cell which is slightly tetragonal with a small departure from 90 deg of the angle (y) opposite the r axis. The orthorhombic hydride phase was observed for hydrogen concentrations between 0.2 and 0.8 H/Cb atom ratio. Paxton and coworkers4 found that needlelike hydride plates formed in a hydrogen-charged columbium single crystal and suggested that this transformation possessed the characteristics of a diffusionless phase transformation. On the basis of room-temperature, X-ray diffraction data, komjathy' suggested that an order-disorder or martensitic transformation occurs. In the present study, the Cb-H system was investigated to resolve the discrepancies found in the literature for this system. PROCEDURE The columbium specimens were prepared from two heats of wrought 1/2-in.-diameter electron-beam melted columbium rod and from two columbium powders of -80 mesh size of different impurity contents. The columbium bar stock was pur chased from Urah Chmg Corp.; the 99 and 99.5 pct purity colulnbium powders were obtained from Fansteel Metallurgical Corp. and Kern Chemical Co.. respectively. The chemical analyses of the columbium bar and powders are listed in Table I. Hydrogen charging was performed by exposing the columbium specimens to hydrogen at 1 atm pressure at various temperatures. After exposure the specimens were quenched to prevent the hydrogen pickup which would take place if cooled in hydrogen, or the hydrogen loss that would occur if cooled in an inert gas. Adequate hydrogen purity was achieved by passing high-purity tank hydrogen (maximum 5 ppm total impurities) through an Engelhard catalytic Deoxo unit, magnesium per chlorate desiccant, and finally through activated charcoal at the temperature of boiling nitrogen. Activated charcoal at -321°F has been reported6 to remove impurities from hydrogen to a nondetectable level. A schematic representation of the heat-treating apparatus is shown in Fig. 1. A metal-sheathed thermocouple embedded in the colun~bium specimen was used to control the temperature during heat treatment and to pull the specimen boat into

Jan 1, 1965