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By Thomas M. Plouf

Getting optimal performance from flotation cells can, in many cases, be critical to a project's economic viability. Simple testing procedures can sound early warning signals as well as maintain optimum recoveries from the flotation cycle. The materials required for a simple testing laboratory include: (1) pH meter or pH paper, (2) bottles of reagents used in plant flotation, (3) stop watch, (4) calibrated eye droppers. (5) laboratory flotation machine (1000-g tank, open impeller), (6) froth collection pans, (7) magnifying glass, (8) sizing screen sufficient to retain 10% of the flotation feed coarse fraction, (9) sizing screen for the size particles at which desliming of the plant flotation feed is to take place, and (10) a set of screens covering the complete range of feed particle size.

Jan 4, 1978

By Stuart Croasdale

NOT long ago I was called upon to conduct some experiments on the treatment of ores from the New Cornelia copper mine, Ajo mountains, Arizona, for the Calumet & Arizona Copper Co. The problem was a very interesting one and contained some unusual features. Incidental with this problem was the utilization of a large amount of low-grade pyrite in the Bisbee mines of the company, provided this could be accomplished by any feasible method. The New Cornelia mine is situated 45 miles south of Gila Bend, the nearest railroad point, on the Southern Pacific Railroad. It is about 160 miles, almost due west, from Tucson. This section is one of the most arid in the United States. The normal annual precipitation, as given by the United States Weather Bureau covering a period from 1870 to 1901, is 3 to 5 in. During June and July, 1913, the records kept by the company gave the following results. These are all I have available, but they show the enormous evaporation that can be expected, which may be a factor in leaching operations on a large scale.

Jan 8, 1914

By H. L. Hartman

The past 15 years have seen rapid advances in the metallurgy of materials for drill machinery and bits, but rock drilling itself continues to be largely an art. Jet piercing, roller bit rotary drilling, and rotary percussion are all promising new techniques, but the percussion rock drill, still used for 90 pct of the blastholes in U. S. hard-rock mining, has undergone no major modification since pneumatic machines were first used successfully in the 1860's. This singular lack of progress stems directly from ignorance of the nature of impact failure of rock and the fundamentals of rock penetration in general. For nearly three-quarters of a century, mining engineers did not know what went on at the bottom of a drillhole. More and more, in recent years, investigators in the field have come to realize that to understand percussion drilling they must study the basic action of percussion bits penetrating rock—not the per- formances of commercial rock drills, with their many attendant variables that cannot be isolated or controlled. Using a vertical drop tester, the writer investigated the sequence of rock failure under the impact. of a simple, chisel-shaped bit when changes were made, singly, in significant variables. Results of this and other research are reported here. BASIC CONCEPTS The formation of a crater in rock under the impact blow of a bit can be observed experimentally. Directly beneath the edge of the bit the rock is crushed into fine powder; toward the sides of the crater it chips out into relatively large fragments. An explanation of these phenomena has been offered by Drilling Research Inc. on the basis of work sponsored by this organization at Battelle Memorial Institute (Ref. 1,1954, Summary, pp. 9-18). High-speed photography and force waveforms obtained from strain gages mounted on the bit near the cutting edges recorded the sequence of events in crater formation with a die-shaped or blunt, wedgc-

Jan 1, 1960

By J. K. Stanley

Iron-cobalt alloys in the range of 35-50 pct cobalt are of interest in the electrical industry because they possess the highest magnetic saturation of any magnetic material known. l1,2The magnetic saturation induction of the 35 pct alloy is 24,200 gausses, compared to 21,600 for pure iron (Fig I). This difference is significant in electrical apparatus, whcre weight or space is at a premium. Saturation values higher than that for iron can be attained up to about 70 pct CO hut economics restrict the use to as low a cobalt content as possible without sacrifice of saturation. Fig 2 shows the iron-cobalt equilibrium diagram. Up to the present time, two factors have retarded the use of iron-cobalt alloys in the electrical industry for magnetic purposes.? One is the high cost of cobalt ($I.50 per pound) and the other ig the inherent brittleness of the binary iron-cobalt alloys. Straight iron-cobalt alloys up to 25 pct cobalt are ductile and easy to process to thin sheet or strip by conventional methods of hot and cold rolling, but the alloys containing higher percentages of cobalt, including those for which the saturation magnetization is a maximum (35 to 40 pct), are increasingly brittle with increasing cobalt, at least up to 50 pct, and are consequently difficult to process, either hot or cold. Work by White and Rah13 indicated that iron-cobalt alloys could be made ductile by alloying with vanadium, and after quenching the alloys (vanadium up to about 4 pct) were found to he colt1 rollable to very thin gauges. With this as a background, we resumed our work on these alloys with the objective of developing methods for economical commercial production of wide strip. For this purpose we have concentrated on the 35 pct alloy in order to obtain the highest possible saturation value. Experiments were carried out on many alloy additions to the iron-cobalt alloys and on the response of these compositions to heat treatments. This work finally culminated in a commercially producible iron-cobalt alloy which has been named Hiperco.* Materials StudIEd and Procedur' Binary alloys of iron and cobalt in the range of 35 pct cobalt are difficult to hot work (by forging or rolling) without such additions as C, Mn, Si, V, Cr, Mo, W Or perhaps others. Another beneficial effect of such additions is that they increase to a greater or less extent the strangely low electrical resistivity of these alloys about 10 microohms per cm3

Jan 1, 1948

By J. K. Stanley

Iron-cobalt alloys in the range of 35-50 pct cobalt are of interest in the electrical industry because they possess the highest magnetic saturation of any magnetic material known. l1,2The magnetic saturation induction of the 35 pct alloy is 24,200 gausses, compared to 21,600 for pure iron (Fig I). This difference is significant in electrical apparatus, whcre weight or space is at a premium. Saturation values higher than that for iron can be attained up to about 70 pct CO hut economics restrict the use to as low a cobalt content as possible without sacrifice of saturation. Fig 2 shows the iron-cobalt equilibrium diagram. Up to the present time, two factors have retarded the use of iron-cobalt alloys in the electrical industry for magnetic purposes.? One is the high cost of cobalt ($I.50 per pound) and the other ig the inherent brittleness of the binary iron-cobalt alloys. Straight iron-cobalt alloys up to 25 pct cobalt are ductile and easy to process to thin sheet or strip by conventional methods of hot and cold rolling, but the alloys containing higher percentages of cobalt, including those for which the saturation magnetization is a maximum (35 to 40 pct), are increasingly brittle with increasing cobalt, at least up to 50 pct, and are consequently difficult to process, either hot or cold. Work by White and Rah13 indicated that iron-cobalt alloys could be made ductile by alloying with vanadium, and after quenching the alloys (vanadium up to about 4 pct) were found to he colt1 rollable to very thin gauges. With this as a background, we resumed our work on these alloys with the objective of developing methods for economical commercial production of wide strip. For this purpose we have concentrated on the 35 pct alloy in order to obtain the highest possible saturation value. Experiments were carried out on many alloy additions to the iron-cobalt alloys and on the response of these compositions to heat treatments. This work finally culminated in a commercially producible iron-cobalt alloy which has been named Hiperco.* Materials StudIEd and Procedur' Binary alloys of iron and cobalt in the range of 35 pct cobalt are difficult to hot work (by forging or rolling) without such additions as C, Mn, Si, V, Cr, Mo, W Or perhaps others. Another beneficial effect of such additions is that they increase to a greater or less extent the strangely low electrical resistivity of these alloys about 10 microohms per cm3

Jan 1, 1948

By E. V. Kleber, V. F. Novy, R. C. Vickery

The constitutional diagram for the gadolinium-cobalt system has been determined. Seven intermetallic compounds have been found at compositions corresponding to the follwing gadolinium-cobalt ratios: 3:1, 1:1, 2:3, 1:2, 1:3, 1:4, 1:5. The GdCor compound has a congruent melting point above 1600°C. whereas the remaining compounds melt incongruently. Eutectics exist at 16 wt pct Co and 84 wt pct Co, with melting points of 620° and 1260°C, respectively. PREVIOUS papers'" have recorded constitutional data for systems of gadolinium with iron and nickel. This paper presents data obtained on alloys of gadolinium with the remaining 3d transition element-cobalt. voge13 found that cerium forms, with cobalt, the intermetallic compounds; Ce3Co, CeCo, CeCo2, CeCo3, CeCo4, and CeCo5 Other workers4-' found the 1:2 compound in this series to exist in a C-15 (face-centered cubic) structure and the 1:5 compound to exist in a hexagonal crystal system. Comparison of earlier data with that now reported will be made subsequently. EXPERIMENTAL Methods of alloy preparation, annealing procedures, and experimental techniques have been previously reported.' The cobalt content of alloy specimens was determined volumetrically. RESULTS Microstructure—The alloy containing 10.5 wt pct Co corresponds closely to the composition of the first intermetallic compound Gd3CO. In Fig. 1 the microstructure is essentially single phase composed of Gd3Co which formed peritectically. The globular areas are remnants of the peritectic reaction which did not quite go to completion. A eutectic occurs between Gd3Co and the next higher compound GdCO, which is followed by a series of peritectic compounds. Fig. 2, an arc-cast alloy containing 20.2 wt pct Co, shows large primary crystals of GdCo etching either white or black (depending on crystallographic orientation), embedded in the eutectic. Similarly, in Fig. 3 at 31.2 wt pct Co, a compound, probably GdCo3, has separated from the melt. Subsequent peritectic reactions were almost completely by-passed as the alloy cooled, the residual liquid freezing as a fine eutectic. In the 47.5 wt pct Co alloy, Fig. 4, the high melting point compound, GdCO4, has solidified as massive, white-etching grains, which reacted with the liquid to form GdCo3 as the second phase. The microstructure of an arc-melted alloy containing 60.5 pct Co is complex, Fig. 5, and presents some difficulty in interpretation. The grey etching matrix is probably primary GdCO4. The dappled phase represents grains of GdCO5 which have separated from the melt on cooling. The discrete spots in this phase are eutectic liquid. Small light etching crystallites are probably GdCO5 formed by the incomplete high-temperature peritectic reaction. GdCO4 is retained in arc-melted specimens containing 70.5 wt pct Co, Fig. 6. White areas of this compound are held in a matrix of GdCO5 the appearance of which is mottled slightly by inclusions of the second eutectic in this system. The development of the spheroidized eutectic at high cobalt contents is depicted in Fig. 7 (80.3 wt pct Co) in which the white massive crystals are GdCO5 compound. Further development of this eutectic is seen in Fig. 8, the primary white phase here being pure cobalt. Thermal Studies—Differential thermal analyses and melting point determinations have yielded the data shown in Fig. 10. The high gadolinium eutectic, indicated by microscopy, was confirmed at about 16 wt pct Co, melting at 620°C . A eutectic also occurs at about 84 wt pct Co melting at about 1260°C. The thermal arrests at 8803 960°, 1060; and 1210°C,

Jan 1, 1962

By W. W. Mason

The US began exporting coal in the late 1800s, at first in very small quantities to Canada and, beginning in 1897 and 1898, to the east coast of South America. Shipments to European countries began on a very limited basis in 1902 and these shipments increased gradually until World War I when shipments overseas increased from 7.3 Mt/a to 20 Mt/a. After the war exports dropped as fast as they had increased and, with the exception of exports to Canada, remained at very low levels until just after World War II when the US again emerged as a major coal exporter. World War II left the coal industries of Europe in ruin. As the US was the only country able to supply large quantities of coal at reasonable prices needed for reconstruction of the European economy, the US coal exports overseas expanded rapidly to 38.6 Mt in 1947. Additionally, we shipped 23.8 Mt of coal to Canada in that year for a total export of 62.3 Mt. Unfortunately, that level was not reached again until 1957 when exports reached an all-time high of 69.3 Mt - a high that has not been reached since. Over the years the level of US coal exports has fluctuated fairly widely. Approximately 80-90% of all US coal exports are high quality metallurgical grade coal so our exports level depends directly on world-wide economic conditions and world steel production levels.

Jan 1, 1982

By C. W. Pollock

THAT a distressing explosion of some magnitude did not take place in the Berry No. 3 mine of the Ford Collieries Co. recently was solely because no source of ignition was present when the stage was set for such an occurrence. The mines of this company, which are in West Deer Township, Allegheny' County, Pa., have been operating in the double or thick Freeport seam since 1.909. During this entire period they have been classed as gaseous by the Pennsylvania Department of Mines, and some gas has been encountered from time to time almost entirely however in development work in the vicinity of clay veins or wants-and never to my knowledge on gobs or in rib work.

Jan 1, 1935

By Ashok K. Sinha

During the course of an in~*estigation into the occurrence of ordered AB3 structures, the following new phases have been found —CrRh3 (AuCu3 type), CrCo3 (MgCd3 type), HfCo4 (Ths Mn23 type), and WPt, MoPh type). The composition of the TiPt3-x phase (TiNi, type) is close to Ti23Pl77. The alloy chenzistry of transition rnetal AB3 structures is rezliewed in the light of electron concentration correlations of hex-agonality recently obtained for quasi-binary alloys. The relatizte colurne contraction in the AB3 structures increases with increasing difference in volume of the conzponents. A family of ordered close-packed layered structures is formed by stacking identical layers of composition AB, in various sequences, such that the coordination is twelvefold throughout and there are no A-A contacts. Previous work' on quasi-binary AB3 alloys has led to the conclusion that the stacking sequence of the AB, structures changes with increasing radius ratio RA/RB from a purely cubic, through different mixtures of hexagonal and cubic stacking to a purely hexagonal stacking. However. for binary AB3 alloys, a correlation between the type of the crystal structure and the position of the components in the various volumns of the periodic table has been noted.2-5 It has been noted6 that this correlation appears to hold even though the radius ratio RA/RB may vary over a considerable range with the location of the components in the three long periods. Another study7" of several quasi-binary systems led to the conclusion that an increase in hexagonality of the stacking is associated with increase in the electron concentration e/a. as defined by the average per atom of the total number of electrons outside the inert gas shells. In apparent conflict with this conclusion, it is known that seven binary alloy structures isotypic with TiNi3 which is 50 pct hexagonal occur at a higher electron concentration (e/n = 8.5) than that (e/a = 8.25) for the 100 pct hexagonal MgCd3 type structure present in seven binary AB3 alloys. Table 111. In the present work, an investigation into the occurrence of binary AB3 structures in transition metal alloys was made, and a survey of binary AB3 structures is presented. EXPERIMENTAL The starting materials were pure metals of 99.9 wt pct purity. The alloys were arc-melted under partial pressure of argon and annealed in sealed silica capsules lined with molybdenum foil under argon at- mosphere. The total weight loss upon melting and subsequent annealing was always less than 1 pct and hence the alloys will be referred to by their intended (unanalyzed) compositions. Wherever the constitution permitted. the alloys were given a homogenizing treatment at 1200°C (3 days) prior to annealing. Unless otherwise stated all alloys were annealed at 900°C for 1 week and water-quenched. Sometimes the final annealing treatment was carried out on powders to accelerate the attainment of equilibrium. X-ray powder patterns were taken using a Guinier-de Wolff focusing camera (CuK, radiation) or an asymmetrical focusing camera (Co or CrK, radiation). For lattice parameter determination. internal silicon standards were employed. The intensity calculations were made using a Fortran IV program written by Jeitschko and parthe.9 RESULTS Twenty AB3 and three AB4 alloys were investigated. Table I lists the crystallographic data on some of the intermediate phases encountered in the present work. Table II contains the X-ray data for HfCo, (Th,,Mn,, type). The positional parameter, x. was assumed to be 0.378. the value for Th6Mnn2310 The X-ray pattern of ZrCo, was very similar to that of HfCo, and the previous structure determination of ZrCo, by Kuzma el al." was confirmed. Ordering in the alloy CrCo could be ascertained by the presence of only one weak super lattice line (101). the others being too weak presumably owing to the small difference in the scattering powers of chromium and cobalt. This line was observed in the X-ray pattern of powder from the massive sample annealed at 830°C (7 days) after the powder had been reannealed at 600°C (24 hr). The diffraction pattern of the powder similarly reannealed at 830°C (24 hr) contained only the lines due to a mixture of hcp and fcc Co(Crj solid solutions. Therefore, it appears reasonable to assume that O2 and/or N2 contamination which would be less likely to occur during the 600°C anneal was not responsible for the observed weak reflection. Also. this reflection cannot be identified with any of the strong lines of the neighboring s phase which is present in the Co-Cr system at higher chromium contents. The composition corresponding to the TiNi3 structure observed by Raman et al.12 in the two-phase alloy Ti,zt,, has been established in the present work as being between There was satisfactory agreement for the low-angle lines (up to d = 1.997A) between the observed diffraction pattern of TiCua and that calculated assuming the ZrAu, structure. as recently proposed by Pfeifer-et a1.I3 However. some of the superlattice lines. e.g., at d = 1.937 and 1.919A. predicted by the ZrAu, structure were not actually observed eve? though neighboring lines. at d = 1.947 and 1.986A. of comparable calculated intensity were present. The ZrAu

Jan 1, 1970

By Robert G. Woolery, S. Ramachandran, James A. Weber, Donald J. Hansen

Union Carbide began looking seriously at heap leaching in 1971. At that time some 1.6 million tons of mineral averaging 0.40 kg U3O8 /t) (0.80 lb U3O8) were stockpiled at various sites around the Gas Hills, Wyoming, uranium facility. Several alternatives for economically exploiting these reserves were considered and heap leaching seemed the most attractive. At the time, Western Nuclear Inc. was operating a heap leaching project nearby in which the low-grade ore was leached with sulfuric acid, the product liquor treated in an on site solvent extraction circuit, and the stripped product liquor re-acidified and recycled. The operators were most generous in allowing us to visit their site and in answering our questions. They were also helpful in discussing the problems associated with heap leaching. Their experience confirmed our belief that it was possible to operate a heap leach profitably on material too low grade for conventional milling. Based largely on what we had learned from Western Nuclear's experience, we undertook a program involving a laboratory study to determine the characteristics of the mineral stockpiles, as related to heap leaching, and to conduct a pilot heap leach adjoining our Gas Hill mill. Basically the pilot heap construction and leach procedure were similar to those described in the literature l, 2 with certain modifications to permit detailed monitoring of the operation. In May 1972, the decision was made to construct a test heap. The UCC plant at Gas Hills, Wyoming was selected as the most appropriate site for the following reasons: (1) The necessary equipment for heap construction was readily available. (2) Stockpiles of mineral from the various mining sites were on hand: (3) Construction of the heap could be made on an abandoned tailings pile minimizing problems associated with environmental approval. (4) Proximity of the mill would allow product streams to be absorbed into existing circuits. (5) Necessary utilities were available. (6) Tailings water from the existing circuit could be used for leaching. A program for the pilot heap leach was developed with the following primary objectives. (1) To confirm the data obtained in bench-scale tests particularly on uranium recovery, acid usage, and ore permeability. (2) To evaluate plastic liners used for base preparation. (3) To investigate heap configuration variables. (4) To determine heap leach amenability of the different mineral sources. (5) To establish the economics of heap leaching low-grade ores.

Jan 1, 1979

By Frank F. Aplan

INTRODUCTION Coal is a solid, combustible mineral substance resulting from the degradation and alteration of vegetable matter largely in the absence of air. In this natural process of coalification, some non-combustible mineral matter is always associated with the combustible material. Coal preparation or cleaning is the process of removing this inert mineral matter from the coal. Preparation is highly successful in removing the large fragments of inert material, but is not very effective in removing the fine inorganic mineral matter intimately associated with the coal. Of the 600 million tons of coal produced in the United States every year, approximately one-half is produced by coal cleaning methods (1). The bulk of this tonnage is cleaned by coarse or intermediate gravity preparation methods (5 inches to 28 mesh, Tyler). Fine cleaning, say, -28 mesh, is done by shaking tables, washing cyclones, and flotation, or, until recently, the fines were either incorporated into the clean coal or simply discarded--not infrequently, the latter. In 1972, only 13 million tons of raw coal were cleaned by flotation in the United States, and from this 8.4 million tons of clean coal were produced (1). The percentage of clean coal produced by flotation in Europe (England, West Germany, Poland, U.S.S.R., etc.) is substantially higher. However, coal flotation has grown rapidly in the United States from only a few plants in 1950 to 31 in 1960 (2) and 66 in 1970 (1). Virtually all new preparation plants incorporate flotation into their basic flowsheet. The essential difference between ore and coal flotation is that for ores the entire tonnage is ground to flotation size, whereas for coal

Jan 1, 1976

By JAMES QATLEY

THE atmosphere, which plays such an important part in the manufacture of iron and steel, is the most variable element involved in its several processes; and particularly is this true of the blast-furnace process, which consumes air in large quantities. At no time since the blast-furnace became an important and widely used apparatus-even when it was operated in the most crude manner-have the variations in composition of the raw materials used been as frequent and as great as the variations in humility of the atmosphere. Important, improvements have been made in the blast furnace and its accessories, such as the hot-blast stoves, the increase in size and change in the shape of the furnace, more efficient blowing engines, the increased protection given to the bosh walls, and the careful preparation of' the raw material, all of which have exerted a pronounced influence on the furnace-operations from a metallurgical standpoint. But during the past eight years little advance has been made in this direction; the fuel-consumption has not diminished, nor has there been any material increase in production. Within that period, however, there has been witnessed the greatest development in appliances for the economical handling of material. So complete has been the work in this direction, that, except in isolated cases, in this country at least., a further extension does not hold out much promise of a satisfactory return on the investment required. It seemed that, with the exception of the gas-engine, we had about reached the limit, for like a strong wall, the atmosphere, with its humility as variable to-clay as when first blown into a primitive blast-furnace, appeared to stand as a Barrier to

Jan 1, 1905

Aaby, Alton O , (S'47) Univ of Minnesota, Mimeapolis, Minn Aaby, Waldo S , (S?48) Univ of Minnesota, Minneapolis Minn Aalde, Kaare, (S'48) Univ of Nevada, Reno, Nev Aaring, Floyd D , (S'48) Univ of Oklahoma, Nor man, Oka Aaronson, Hubert I , (S'47) Carnegie Inst of Technology, Pittsburgh, Pa Abbott, Peyton Osborn, (S'46) 1502 Westover, Austin 21, Texas Abel, Malcolm D , (S'47) Univ of Texas, Austin, Texas Aberg, Richard S , (S'47) Univ of Minnesota, Minneipolis, Minn Abrahamson, Guy C , (S'43) 420 W Dennis St , Wilmington, Calif Abrahao, Benjamin, (S'46) Escola Politeenica da Unnersidade, de Sin Piulo, Braizil Achter, Meyer R , (S'46) Carnegie Inst of Tech , Pittsburgh, Pa

Jan 1, 1952

By Jay A. Carpenter

IN six years the construction of Hoover Dam and the power plants probably will have reached the operating stage and this vast new source of power will then be continuously available for industry. The height of the darn will be 580 ft. and the average annual flow of the Colorado River is calculated at approximately 24,000 cu.ft. per sec. If this full head and average flow can be maintained the year round, about one million horsepower will be generated. The U. S. Reclamation engineers, taking into consideration the probable range in flow and head, have set the figure for power contracts at 660,000 firm horsepower, which can be assured at all times of the year. During the months of heavy run-off of water from the Colorado River Basin the power plants should be able to generate the full 1,000,000 hp. capacity of the power plants, so there will be 340,000 excess or secondary horsepower. The cost of firm power at the switchboard will be close to 2.15 mills per kw.-hr., equal to $14.05 per hp.-yr., and the cost of the secondary or off-peak power will be close to 0.8 mills per kw.-hr., or $5.22 per hp.-yr. In no place in the country can such cheap power be obtained today. The electrochemical industry is in a state of flux because the power costs from its old sources have increased so much (to $30 per hp.-yr. at Niagara) that the industries have had to seek new sources, so they have gone to Canada and Norway and built new plants.

Jan 1, 1932

By Edgar Marburg, William R. Webster

The desirability of bringing about greater uniformity in specifications governing iron and steel is generally recognized, and has found expression within recent years, in the efforts of numerous technical societies in that direction. When the International Association for Testing Materials was organized at Zurich in 1895, a committee was appointed, charged as follows: " On the basis of existing specifications, to seek methods and means for the introduction of international specifications for testing and inspecting iron and steel of all kinds." The American representation on this international committee consisted originally of five, and now of eight members. In view of the magnitude and importance of the subject, the Executive Committee of the American Section of the International Association for Testing Materials, since incorporated as the American Society for Testing Materials, appointed a committee of 34 members, including the American members of the above-named international committee, to frame standard American specifications for iron and steel. This committee reported on specifications for (1) Structural Steel for ridges and Ships; (2) Structural Steel for Buildings; (3) Open-Hearth Boiler-Plate and Rivet-Steel; (4) Steel Rails; (5) Steel Splice-Bars; (6) Steel Axles; (7) Steel Tires; (8) Steel Forgings; (9) Steel Castings ; (10) Wrought-Iron. These specifications were designed to be fairly representa-tive of the best current American practice, and were adopted by letter-ballot of the Society in August, 1901. The leading engineering societies have participated at various times in the discussion of these specifications and have lent valuable assistance through the appointment of special committees on like, or closely related, subjects. The American Society of Civil Engineers discussed the spec-

Jan 1, 1905

Executive SIDNEY J. JENNINGS, Chairman GEORGE D. BARRON J. E. JOHNSON, JR. EDWIN LUDLOW ROBERT M. RAYMOND Membership KARL EILERS, Chairman LEWIS W. FRANCIS J. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR L. WALKER Finance GEORGE D. BARRON, Chairman CHARLES F. RAND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY,1 Chairman ALEX C. HUMPHREYS2 GEORGE C. STONE2 J. H. JANEWAY4 BRADLEY STOUGHTON1

Jan 3, 1918

By E. DeGolyer

(San Franciso Meeting, September, 1915) I. INTRODUCTION THE Furbero oil field lies in the Gulf coastal plain of Mexico between the important ports of Tampico and Vera Cruz and about one-third of the distance between the two points from the latter (Lat. 20° 22' N., 97° 30' W. Gren.). It is in the State of Vera Cruz, about 14 miles west by south of the village of Papantla in the canton of the same name, and is the most southern of the developed oil fields of the Tampico-Tuxpam region being a distance of 50 miles south by east from the Potrero del Llano field and 42 miles in the sane direction from the Alamo field. The field has been developed by the Oil Fields of Mexico Co. and is in the midst of a large block of lands owned or leased by then. Communication is through the port of Tuxpam with which it is connected by a narrow-gauge railway and 6-in. pipe line some 52 miles in length. This field is of more than ordinary interest since it represents a type of oil deposit hitherto unknown. So far as I am aware, no other commercially valuable deposit of oil is known to occur under conditions of accumulation similar to those found here. The igneous nature of the so-called `sand' encountered in drilling was not recognized until a number of wells had been drilled; and it was not until recently. that the geological relations of the sill or laccolith, which gives rise to the accumulation of oil, were known and the so-called `anticline' was known to be, in part at least, the result of igneous intrusion. Geological surveys in this general region were made in 1900-1901 by W. H. Dalton and in 1907-1909 by P. C. A. Stewart, F. W. Moon, Leonard V. Dalton, and Dr. Max Muhlberg. More recent surveys have been made, however; under the direction of the author, by E. L. Ickes, B. C. Belt, B. Hartley, and Harve Loon-us. Notes of the earlier examinations were not available with the exception of the report by Dr. Muhlberg who apparently first recognized the true nature of the Furbero intrusion. This paper is indebted to his work and that. of the more recent surveys for much of the detail regarding stratigraphy and to Messrs. Percy Furber and Arthur C. Payne, President and General manager of the Oil Fields of Mexico Co. for permission to publish, and for much of the in-

Jan 9, 1915

By Oliver Bowles

AMONG mining men as well as in the popular mind the conviction has held sway that mining is pre-eminently a western industry. True it is that gold, silver, copper and other metals have made the States of California, Colorado, Montana, Utah. Nevada and Arizona famous. The prominence attained by these States as mineral producers is, however, not measured alone by the money value of the products of their mines. While the metals are without doubt indispensable in industry, the glamour of the precious metals, and the lure of copper, lead and zinc have given to their ore deposits a sentimental interest that often quite out-weighs their commercial importance. Today a great group of more commonplace minerals are finding a place in commerce and industry rivaling that of the metals, but there is little sentiment attached to them, and,. therefore, they attain relatively little publicity. This is the great group of the non-metallic minerals, exclusive of fuels and oils, including stone, sand and gravel, cement, lime, gypsum, asbestos, mica, phos-phate rock and many others. Almost unnoticed they have grown in production to almost unbelievable pro-portions. The estimated value of metal production for 1925 is given as $1,380,000,000, of the non-metals (ex-cluding fuels) $1,294,000,000. The non-metallic industries are not new, many of them date back almost to pre-historic times; but, as the greatest of them (on a tonnage basis) provides raw materials for the construction industries, it required the activities of the present age of construction to bring about their enormous development. Many of them enter manufacturing as well as con-struction. Non-metallic minerals constitute the back-bone of our great chemical industries. While construction and manufacture reach to all parts of the country their widest development has been in the great industrial centers of the eastern Seaboard and the middle West. Consequently the raw materials of mineral origin required for these great industries have attained a remarkable growth in the eastern half of the- United States. In compiling figures of mineral production for 1924, for which more complete data are available than for later years, the surprising fact is brought to light that the non-metallic mineral produc-tion alone of some of the eastern and middle-western States exceeds by a substantial margin the total min-eral production of some of the western States that have been classed as essentially mining States. Thus the non-metallic mineral production, exclusive of coal and petroleum, of the State of Ohio, was approximately $150,000,000; of Pennsylvania $175,000,000; and of New York $107,000,000. For the same year, 1924, the total mineral production of Utah was $84,357,000; of Montana $70,632,000; of Colorado $61,488,000; and of Nevada only $26,226,000. Even Minnesota, with its enormous iron ore production, reached only $107,845,-000, or a sum about equivalent to the non-metallic min-eral production of the State of New York.

Jan 8, 1927

By T. A. Read, H. K. Birnbaum

STRESS-induced twin boundary motion in the AuCd ß'phase (52.5 at. pct Au 47.5 at. pct Cd having an orthorhombic structure (space group D h)' was discussed for the case of transformation twins.' Mechanical twinning, i.e., introduction of new twin orientations by the applied stress was sometimes observed in the ß' phase which contained two transformation twin orientations. (See Ref. 2 for experimental details.) The transformation twins terminated at the mechanical twin boundary; the two initial orientations having been twinned to the new orientation as shown in Fig. l. In a "hard" tensile instrument, formation of each mechanical twin was accompanied by a sharp drop in load (and an audible click) resulting in a typical serrated load-extension curve. The mechanical twins increased in width and additional twins were nucleated as the load increased until the entire specimen was occupied by the mechanical twin orientation. A restoring force2 caused the mechanical twin and transformation twin boundaries to return towards their initial configuration on releasing the load. In a stabilized specimen* the total strain introduced by mechanical twinning was recovered on releasing the applied stress. Initial and final microstructures were identical. After decreasing gradually to a critical width, mechanical twins suddenly disappeared accompanied by audible clicks and sharp increases in load (measured at a constant rate of crosshead motion in a "hard" machine). Mechanical twins could be stabilized in any position by maintaining the applied load for a sufficient time, indicating a decrease in restoring force with time similar to that observed for transformation twins.' Orientation relationships for mechanical and transformation twins were determined and are shown in Fig. 2. The mechanical twin, T3, was twin related to transformation twin, T,, by reflection in (1ll), and twin related to transformation twin, T2, by reflection in (111)T, . T, was related to T, by reflection in(ll1)T1 . The "average" mechanical twin composition plane lay several degrees from (1ll), . In every specimen which mechanically twinned, orientation T3 was most highly favored by the applied stress, i.e., it was the twin orientation which provided the greatest change in length compatible with the direction of applied stress

Jan 1, 1961

LINN BRADLEY, H.' D. EGBERT and W. W. STRONG (communication to the Secretary*).--In the discussion of the paper, a request was made for a further explanation of the curves given on Chart I. In preparing the curves given on this chart, a typical blast-furnace top gas having the following composition by weight was assumed: Per Cent. C02 21.00 CO 24.00 Hz 0.25 CH4 0:25 N2 54.50 For any given top-gas temperature, Curves A, B, C, D, and E indicate in British thermal units the sensible heat lost in cooling the top gas to 60° F. by wet-cleaning methods. Top-gas temperatures are plotted as abscissae, sensible heats above 60° F. in British thermal units are plotted as ordinates, and separate curves are drawn for top gases carrying various amounts of moisture. For any given stove exit-gas temperature, curves A1,-B1, C1, D1, and E1, indicate in British thermal units the sensible heat carried out of the stoves by the moisture which is left in the top gas when it is dry-cleaned and enters the stoves hot. This moisture is removed when the gases are wet-cleaned and the sensible heat which it carries out of the stoves is therefore saved. As before, separate curves are drawn for top gases carrying various amounts of moisture. The curves in Fig. 1, therefore, indicate graphically how much more sensible heat is conserved by cleaning the top gases by the dry-hot method than is conserved by cleaning the top. gases by a cold-wet method and thus removing the greater part of the moisture carried by them. They also show of how little moment it is from a heat conservation standpoint whether or not the moisture carried by the top gases is removed before they enter the stoves. That wet cleaning secures the removal of this moisture and is thus to be recommended from a heat conservation standpoint is an argument often advanced by advocates of wet cleaning. The curves of Fig. 1 show how fallacious such an argument is.

Jan 6, 1917