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By Barry D. Lichter, Pierre Sommelet

High-temperature heat contents of InSb, GaSb, and AlSb were measured over the temperature range 400" to 1450°K using a diphenyl ether drop calorimeter. Smoothed ualues of the thermal properties, H$ - H:9s, have been derived and are tabulated at even temperature intervals. The heats of fusion of the three compounds were determined as, respectively, 5707 *100, 7780 * 100, and 9800 5 3011 cal per g-atorn at the determined melting points of 797" l°, 985" * , and 1330" * 5°K. The calculated entropies of fusion are, respectively, 7.16 0.12, 7.90 * 0.11, and 7.37 * 0.23 cal per deg per g-atotn. The heat capacities increase substantially on tnelting in contrast to the behauior of structurally related germanium and silicon. Deriations from the Kopp-Neumann rule are negative for solid compounds and positive for the liquid phases. Previously obsevrrd "post melting" in InSb is confirmed. The high-temperature thermal properties of 111-V compounds are presently not well-established, despite the technical importance of these semiconducting cbmpounds. Uncertainties in available heats of fusion and heat contents have seriously hampered thermo-chemical evaluations' and thermodynamic analyses of phase equilibria2"" in these systems. This paper reports results of high-temperature heat content investigations of InSb, GaSb, and AlSb measured in the range 400" to 1450°K employing a diphenyl ether drop calorimeter. Similar measurements for InAs and GaAs will be reported in a following publication.~ EXPERIMENTAL PROCEDURES Samples. High-purity samples of the compounds InSb and GaSb were supplied in the form of crushed crystal fragments by Dr. Carl Thurmond of the Bell Telephone Laboratories and in the form of single crystals by Dr. A. Strauss of the M.I.T. Lincoln Laboratory. Single-crystal samples of semiconductor-grade AlSb were supplied by Dr. W. P. Allred of the Bell and Howell Research Center. Chemical analyses indicated that all compounds were stoichiometric to *0.1 at. pct, which is within the experimental uncertainties of the analyses. Samples were crushed, weighed, and encapsulated in evacuated, thin-walled, fused silica capsules. The capsules were nearly identical in external shape, 2 cm by 2 cm diam, but varied in weight due to differences in wall thickness. One sample of AlSb was contained in a thin-walled, high-purity alumina cup encapsulated in silica and used for heat content determinations of liquid AlSb. The capsule materials showed no visual evidence of reaction with any of the compounds. The sample and capsule weights are given in Table I. Calorimeter. A Bunsen-type calorimeter, similar in design to a previously described instrument6 but employing diphenyl ether (C6H5)'0 as the calorimetric substance, was used for measurements of heat contents above 300.0°K, the melting point of diphenyl ether. Heat input to the calorimeter caused isothermal melting of diphenyl ether, and the resulting increase in volume was measured by displacement of mercury from the calorimeter into a 200 cm horizontal, calibrated capillary, 1.25 * 0.01 mm diam, or into a weighed beaker. The advantages of diphenyl ether over water have been previously pointed out7 and include: i) an increase by a factor of 3.5 in sensitivity as measured by the ratio of the volume change to the enthalpy change on fusion, ii) the smaller required extrapolation from the melting point to the standard temperature of 298.17"K, and iii) the positive volume change on fusion of diphenyl ether in contrast to the contraction which occurs on fusion of ice. Diphenyl ether was purified by fractional crystallization to 99.95 mol pct as determined from the melting point depression with fraction crystallized. During assembly of the calorimeter, the ether was repeatedly outgassed under high vacuum to remove dissolved air. The calorimeter receiving vessel consisted of an 8-in.-long by 1:-in.-diam copper tube with twelve horizontal 3-in.-diam radiator "fins" for dissipating heat to the surrounding mantle of diphenyl ether. Before forming the mantle the chamber surrounding the receiving vessel contained 3300 cu cm of liquid diphenyl ether above 250 cu cm of mercury which was

Jan 1, 1970

NEW MEMBERS The following list comprises the names of those persons who became members during the period Apr. 10, 1916 to May 10, 1916. ALLEN, WILLIAM R.... Pres., Boston and Montana Development Co., Butte, Mont. BARKER, EDGAR EARL, Min. Engr. Mine Supt., Chile Exploration Co., Chuquicamata, Chile, S. Amer. BAYLESS, JOHN Z., Met. Engr Alaska Gastineau Min. Co., Thane, Alaska. BLACKWOOD, ARTHUR E., Mgr., Sullivan Machinery Co., 30 Church St., New York, N. Y. BREYER, FRANK G., Chief Testing Dept., The New Jersey Zinc Co., (of Pa.), Palmerton Pa. CARPENTER, JAY A., Mill Supt... . West End Cons. Mining Co., Tonopah, Nev. CORLESS, GEORGE BRADFORD, Geol., Missouri Bureau of Geology and Mines, Joplin, Mo.

Jan 6, 1916

By R. H. Sweetser

The Committee on Evaluation of Coal for Blast-furnace Coke reports progress in the working out of the problem of evaluation. There has been no full meeting of the Committee but there have been several conferences with two or more of the members present, and the different members have expressed themselves freely on the five points that have been under consideration since the meeting of the Committee in New York on Feb. 16, 1932. The need of a method of coal evaluation, not only of coking coals but all other kinds, is obvious. Under NRA it becomes imperative that coals of the same size from the same seam be priced according to their variations in quality, especially in reference to cleanliness in respect to freedom from extraneous ash-forming materials. In looking over the correspondence that has passed between members of our Committee, it is evident that much of the confusion and misunderstanding would disappear if we could realize that practically all of the variations in value of coal from the same seam of coal are due to variations in the amounts of extraneous materials that are contained in the coal as it passes over the scales for shipment. It is not now a question with our committee as to the differentials in value, or in prices, between different kinds of coking coals or between noncoking and coking coals; our present problem is to arrive at the method for determining the scale of values of the coal from a certain coal seam according to the increase or decrease of extraneous ash and moisture from a predetermined base line adopted for that particular coal. The five points mentioned above are the same as discussed at the meeting in February, 1932, except that the temperature for determining the moisture content has been changed from 212" F. to 221" F., at the suggestion of Dr. A. C. Fieldner. The points are: 1. It is proposed that the coal industry adopt as a base line for evaluating all coals the analysis of the coal as it passes over the neighing device that determines the tonnage of coal bought and sold. 2. It is proposed that the Committee on Evaluation of Coal for Blast-furnace Coke approve the adoption of the base line for Pittsburgh seam coal presented by F. A. Jordan at the annual meeting of A.I.M.E.

Jan 1, 1934

By W. S. Ayres

By Thomas C. Baker

The Fresnillo unit of the Mexican Corporation, S. A., is situated at the old historic mining town of Fresnillo, Zacatecas, Mexico, 33 miles north of the city of Zacatecas and 750 miles south of El Paso, Tex. It is connected with the Mexican Central Railroad by a broad-gage spur 5.5 miles long, belonging to the company. Fresnillo is surrounded by a broad semi-arid valley on the Mexican plateau at an elevation of 7300 ft. The monotony of the valley is broken by a number of low hills. Near the town of Fresnillo is the " Cerro de Proano," an elliptic-shaped hill of gentle slope, rising out of the plain to a height of 325 ft.; the base has a major axis of 4500ft. and a minor axis of 3000 ft. In this hill is the silver-bearing mineralized zone, which comprises past and present mining operations. (In this paper money values are expressed throughout in American currency and the dry short ton of 2000 lb. is used.) The discovery of ore at Fresnillo is credited to the Spaniards, soon after the conquest of Mexico. There are, however, no authentic records to show the amount of work done by them. In 1832, the State of Zacatecas took possession of the property and operated it. Evidently the rich ore above the horizon of the plain had been fairly well exhausted, as an old record states that thirty shafts were used for unwatering, requiring 300 men and 1500 animals. The cost of pumping alone amounted to $150,000 a year. In spite of the fact that cheap convict labor was used, mining costs were reported as $20 and treatment charges as $20 per ton. In 1835, the state was obliged to seek foreign capital, and a company formed in London secured a controlling interest in the property. This new organization sank two shafts, one 11 by 19 ft. and the other 10 by 15 ft., to unwater the mines and extract ore. Large Cornish pumps were purchased in England and hauled overland from Vera Cruz; engines also were installed to operate the arrastres (grinding mills) in the patio process of ore treatment. Substantial buildings were erected and operations were conducted on a large scale, for that period. The patio, the largest in Mexico, was 1150 ft. square. The costs for 1850 were:

Jan 1, 1925

By S. Norton, S. LeFevre

In the West, capitalists have expended many millions of dollars developing the low-grade porphyry ores of copper. Half a dozen of these great enterprises have proved to be wonderful commercial successes. They have demanded improved crushing and concentrating machinery and consequently it has been developed. Many improved methods, cheap power, superior business organization, all these have contributed to this success, but the main feature is the handling of the material in enormous quantities, on a manufacturing scale. The mining chance of "striking it rich" has been eliminated by the manufacturing certainty of handling large quantities of material of known value, which while of relatively low grade, is available in large tonnages, assuring a supply for many years' run of the mill. Then the returns on the money invested are sure. The concentration of low-grade magnetic iron ores, separating the magnetite crystals from the gangue by the use of magnets, is a field of work in which the lessons taught by the development of the porphyry coppers can be studied to advantage. Large-scale operations, and the liberal expenditure of enough money at the start to insure the most economical operations, are the means of securing the desired results. The problem is to utilize millions of tons, and we may safely say billions of tons, of now worthless iron-bearing rock and to produce from it 10,000,000 to 20,000,000 tons per year of high-grade ore carrying 60 per cent. iron or higher; to take the lean material as found in nature, varying widely in iron content, and bring it up to a uniform standard of shipping ore. At present these ores are mined carrying from 25 to 50 per cent, iron, and the shipping product is brought up to 60 or 65 per cent. Fe. If future economies of operation make it possible to extend this process so that 15 per cent. iron in the crude ore can be treated as a commercial success, the additional tonnage available will be enormous. A 15 per cent. Fe crude ore raised to 60 per cent. Fe concentrate with 5 per cent.

Jan 1, 1917

No. 576.-Graduate mining engineer, married, 32 years of age. Have had 10 years' experience in mining from position of mucker to that of general superintendent. For past four years have been in Copper River District of Alaska as mining engineer, and superintendent of gold and copper mines. Desire position in U. S. Best of reference. No. 577.-Member, technical, age 27, married. Open for engagement. Past year in war mineral field work, operation and production. Ten years thorough experience in both subordinate and executive positions, gold, silver and copper in the U. S., Mexico and South America. Devel-

Jan 5, 1919

By Lawrence Henderson

TO increase tonnage in the early days of coal mining it was necessary only to hire more men. The job now is to increase the tons per man, but other troubles arise because this has been accomplished. With the introduction of continuous miners, newer and faster loading machines, and faster belt conveyors the safety engineer has been faced with new difficulties. Use of larger equipment created roof control problems, which were thoroughly studied by the safety engineers of various companies. With the assistance of the U. S. Bureau of Mines, safety engineers in Alabama conducted roof bolting experiments wherever they appeared to be applicable. Accident records before and after the method was adopted showed results more than justifying the efforts and funds expended. The larger mining companies responded enthusiastically to the program because roof bolting not only prevented accidents but also increased production efficiency, in many cases rep- resenting the margin between profit and loss. In Alabama today there are miles of roof supported by bolts.

Jan 8, 1957

Although copper production established a new record, lead and zinc registered gains, and iron production held steady, the mixed trend in metallic and nonmetallic mining and generally lower prices in 1961 resulted in a net decline in the total value of domestic mineral production. According to preliminary estimates from the U.S. Bureau of Mines, the value of metals produced in this country during the year was approximately $1.9 billion, a decrease of $117 million from 1960; the value of nonmetallics was about $3.7 billion, a $14 million decrease. The following report of mining and mineral developments during 1961 is based on USBM and industry sources. Aluminum Output Dips from 1960 Record Government reports indicate that the domestic primary aluminum industry produced approximately 1,880,000 tons, equivalent to 77% of this nation's capacity. This production is about 6% below the 1960 record output of 2,014,498 tons. Shipments of primary metal ingot slightly exceeded the quantity produced.

Jan 2, 1962

John Eliot Allen has been made acting head, dept. of geology, New Mexico Institute of Mining and Technology, Socorro, N. Mex. He had been associate professor of geology. Robert B. Anderson has accepted a position with the U. S. Steel Co., Gary, W. Va., as assistant to the superintendent, No. 2 mine. [ ] Donald L. Archibald has joined the sales dept. of the Ellicott Machine Corp., Baltimore. He formerly had been associated with the Joy Mfg. Co., St. Louis. J. C. Boswell has been appointed manager of the Fairbanks dept., United Smelting Refining & Mining Co. J. B. Metcalfe has been appointed assistant to the president. G. Howard LeFevre was elected vice-president and general manager of metal sales and R. N. Hunt, vice-president and chief geologist was elected a director. R. B. Earling, vice-president and general manager of Alaskan operations, has retired but. will con¬tinue to serve on the board of directors. J. D. Crawford has been appointed general manager of Alaskan operations.

Jan 1, 1952

Discussion of the paper of F. C. NEWTON, presented at the New York meeting, Feb-ruary, 1915, and printed in Bulletin No. 9S, February, 1915, pp. 473 to 477. H. 0. HOFMAN, Boston, Mass.-The results of these large-scale experiments, which were carried on at Perth Amboy, show that there are many differences between theoretical conceptions and their applications to work on a large scale. The author has given reasons why the results of bringing a desilverizing kettle to the high melting point of the zinc-silver alloy, Zn3Ag2, melting at 665° C., are not satisfactory. In all probability the alloy is dissolved in the lead; it may also be decomposed by the lead; the practical result is that this high temperature does not work. It remains now for the laboratory man to carry on systematic experiments

Jan 5, 1915

By J. R. Wylie, L. C. Huntley

Drilling for oil in the eastern producing states was fairly active during the first part of 1931, although less so than in 1930. With low prices development declined during the year, until the low prices of the summer resulted in an almost complete shut-down of drilling. This coincided with the action of the Conservation Board of the Pennsylvania Crude Oil Producers Assn, in limiting pipe line runs to 50 per cent of the 1930 normal for the Bradford district and upper country, and to 70 per cent for the balance of the region. Not only was new drilling halted but in many cases oil-producing properties were shut in. In November crude prices were partly restored, and all oil offered was being taken except in the Bradford district which was restricted to 80 per cent of the 1930 normal. During the latter part of the year drilling was being resumed on a moderate scale, and new production indicated a resumption of the proration order. The interest in gas development which has been under way for several years, maintained its supremacy over the search for oil in 1931. New reserves of importance were developed during the year in the Western Kentucky Coal Basin, in the Eastern Kentucky shale gas territory, in Stark County, Ohio, as well as the Oriskany sand development in northern Pennsylvania and central New York. A gas line was completed to the Eastern Seaboard serving Washington and Baltimore, and other lines were under construction designed to serve portions of the territory not hitherto supplied with natural gas. The low price of fuel oil at seaboard is understood to be the deterrent factor against further extension of natural gas lines to these markets at present. The development of these new reserves, as well as those developed by intensive drilling in old areas, resulted in the building up of large potential gas production and a lowering of rates paid to the producer. This, coupled with the country-wide tendency to lower the consumer rates of all public utilities, resulted in a general threat to reopen rate cases before various state commissions. Oil Development The past year was marked only by the almost complete shut-down of new development, reaching its low point during the summer, with its

Jan 1, 1932

By N. J. Grant, B. C. Giessen, U. Wolff

With the aid of the splat-cooling technique of rapid quenching, metastable alloy phases based on antimony ad bismuth have been prepared. At room temperature, simple cubic phases were found in the Sb + Au, 56 + Yd, and Sb + Ni systems. Another phase was retained in the Au-Bi system at -190°C; in this systent, a microcrystalline phase and a rhombohedrally distorted phase were also observed. The crystal chemistry of these phases is discussed in terms of their valence electron concentration range. A remarkable five-step Phase sequence was found upon heating and equilibration of certain metastable Au-Bi alloys. USING the splat- cooling technique of rapid quenching from the liquid,' a large number of metastable intermediate alloy phases have been prepared in recent years. Thus, Hume-Rothery phases of the hexagonal type based on the valence electron concentration have been produced in systems where they are missing in equilibrium, e.g., Ag-Ge 1 or AU-Sb. 3 In a comprehensive study of metastable alloys based on tin, simple hexagonal metastable y phases were found, raising the total of stable and metastable y phases from 3 to 13. 4 In the In-Bi system, five new metastable intermediate phases were retained.' In most cases, the new metastable phases have some crystal chemical characteristics in common: a) They have rather simple, elementlike structures with few atoms per unit cell, e.g., y phase,4'5 or the metastable primitive cubic phases in the Ag-Te and and Au-Te systems.= b) Their structures are often related to those of the terminal phases, or to elements that are straddled in their position in the periodic table by the constituent elements; this is the case for metastable ß (In-Bi) with the structure of white ß Sn,' or metastable a (Cd-sn). 4 c) They seem to represent the crystal structures appropriate to certain average group number (AGN) ranges in which no or few single-phase structures exist in equilibrium. These average group number ranges can probably be equated in the case of many elements of the Ba(Zn)-Bs(As) groups with the averaged valence electron concentration. In the present work, the splat-cooling technique has been applied to the alloys of antimony and bismuth. In equilibrium, neither element forms intermediate alloy phases with other B elements from groups Bl(Cu) to B4(Si) that contain more than 66.7 at. pct of Sb or Bi, respectively, e.g., AUSb 2. 7 Thus, antimony- or bismuth-rich phases, which might be closely related to antimony or bismuth, and which would reflect struc- tural changes occurring on alloying with small amounts of addition elements, do not exist. Also, the terminal solubility of antimony and bismuth for all B metals is very small. It was therefore of interest to investigate the influence of enforced, nonequilibrium solid solution of addition elements in antimony and bismuth on their crystal structures. It was found that additions of group B 2-B4 metals act distinctly differently than additions of group T 10 and B1 metals. The latter set of additives will be treated here. EXPERIMENTAL TECHNIQUES Alloy preparation and splat-quenching followed closely the procedures described in Refs. 1, 4, and 5; they consisted of the preparation of master alloys from high-purity starting materials (99.99+ pct) and blast-atomizing of 20-mg quantities onto copper sheets. The resulting approximately 1 to 5 u thick foils were investigated by X-ray diffraction. The cooling rates obtained are of the order of 107 to 10 8 C per set,'" causing solidification to proceed at a rat; of approximately 100 cm per sec.' Powder patterns of the resulting fine-crystalline materials were taken with filtered CuK, radiation. For antimony alloys the substrates were held at room temperature and for bismuth alloys at -190°C both during splat foil deposition and X-ray investigation. Annealing treatments at several

Jan 1, 1969

The papers discussed in the following pages were presented during two sessions of the Geophysics Education Committee of the Mineral Industry Education Division on Feb. 17 and 18, 1941. At the first meeting, to consider the "Influence of Geophysics upon Geology Curricula," this Committee was joined by the Geophysics and Mining Geology Committees of the A.I.M.E., the Society of Economic Geologists, representatives of the American Geophysical Union, and delegates from the Committees on College Curricula and on Applications of Geology of the American Association of Petroleum Geologists. Quentin D. Singewald and Sherwin F. Kelly presided. At the ensuing session, especially emphasizing the integration of geology, physics and chemistry for the solution of earth problems, the joint participants with the Geophysics Education Committee were the Geophysics Committee, and representatives of the American Geophysical Union and of the Committee on College Curricula of the American Association of Petroleum Geologists. Richard M. Field and W. R. Chedsey presided. In the following summary of the discussion at the two meetings, written discussion submitted subsequently is not differentiated from that offered orally at the session. A provisional report of the Geophysics Education Committee was presented at the second session, and some of the following discussion refers to it. This report has not been printed (it is anticipated that a more comprehensive, final one will be rendered at the 1942 annual meeting). A few mimeographed copies of this provisional report were made. Dr. W. P. Haynes presented some notes prepared by Dr. F. H. Lahee, Chairman of the American Association of Petroleum Geologists' Committee on College Curricula. This Com- mittee's inquiries reveal the general opinion that a four-year academic preparation is inadequate, five or six being advisable. The fundamentals, mathematics, physics, chemistry, and English composition, should be stressed in the first three years, with specialization in the last two or three years. Some companies provide an apprenticeship period, and themselves give additional training. During academic years more attention needs to be given to engineering training, to field mapping, and in geology to stratigraphy and sedimentation. The amount of mere memory work should be cut, and men trained to observe and reason. Dr. Lahee emphasized the need of more adequate preparation in English composition, because of the inability of many graduates to compose acceptable reports. Sherwin F. Kelly pointed out that much time in university training, which ought to be devoted to technical subjects, was taken .up with English courses. He emphasized that it is the part of the universities to demand of the high schools that the students they send to the university be properly trained to speak and write English. Prof. W. T. Thom protested against the crowding of high-school material into already overcrowded college curricula. C. E. Dobbin, chairman of the Committee on Applications of Geology of the American Association of Petroleum Geologists, described briefly the work of his committee in publicizing geology, and said that it found a widespread popular interest in the subject but a lack of appreciation of its importance. He recommended that attempts to coordinate the works of geologists and geophysicists be expanded somewhat toward the further developing and encouraging of a "species of geopolitician" capable of assisting the progress of geology and geophysics by more vigorous advertising of

Jan 1, 1946

The papers discussed in the following pages were presented during two sessions of the Geophysics Education Committee of the Mineral Industry Education Division on Feb. 17 and 18, 1941. At the first meeting, to consider the "Influence of Geophysics upon Geology Curricula," this Committee was joined by the Geophysics and Mining Geology Committees of the A.I.M.E., the Society of Economic Geologists, representatives of the American Geophysical Union, and delegates from the Committees on College Curricula and on Applications of Geology of the American Association of Petroleum Geologists. Quentin D. Singewald and Sherwin F. Kelly presided. At the ensuing session, especially emphasizing the integration of geology, physics and chemistry for the solution of earth problems, the joint participants with the Geophysics Education Committee were the Geophysics Committee, and representatives of the American Geophysical Union and of the Committee on College Curricula of the American Association of Petroleum Geologists. Richard M. Field and W. R. Chedsey presided. In the following summary of the discussion at the two meetings, written discussion submitted subsequently is not differentiated from that offered orally at the session. A provisional report of the Geophysics Education Committee was presented at the second session, and some of the following discussion refers to it. This report has not been printed (it is anticipated that a more comprehensive, final one will be rendered at the 1942 annual meeting). A few mimeographed copies of this provisional report were made. Dr. W. P. Haynes presented some notes prepared by Dr. F. H. Lahee, Chairman of the American Association of Petroleum Geologists' Committee on College Curricula. This Com- mittee's inquiries reveal the general opinion that a four-year academic preparation is inadequate, five or six being advisable. The fundamentals, mathematics, physics, chemistry, and English composition, should be stressed in the first three years, with specialization in the last two or three years. Some companies provide an apprenticeship period, and themselves give additional training. During academic years more attention needs to be given to engineering training, to field mapping, and in geology to stratigraphy and sedimentation. The amount of mere memory work should be cut, and men trained to observe and reason. Dr. Lahee emphasized the need of more adequate preparation in English composition, because of the inability of many graduates to compose acceptable reports. Sherwin F. Kelly pointed out that much time in university training, which ought to be devoted to technical subjects, was taken .up with English courses. He emphasized that it is the part of the universities to demand of the high schools that the students they send to the university be properly trained to speak and write English. Prof. W. T. Thom protested against the crowding of high-school material into already overcrowded college curricula. C. E. Dobbin, chairman of the Committee on Applications of Geology of the American Association of Petroleum Geologists, described briefly the work of his committee in publicizing geology, and said that it found a widespread popular interest in the subject but a lack of appreciation of its importance. He recommended that attempts to coordinate the works of geologists and geophysicists be expanded somewhat toward the further developing and encouraging of a "species of geopolitician" capable of assisting the progress of geology and geophysics by more vigorous advertising of

Jan 1, 1946

By James Cudworth

THE Birmingham district of Alabama has utilized the slag from its blast furnaces consistently since the earliest development of the slag industry. Today there are producers of slag cement who started business in 1900, and who have, under a progressive policy, expanded the number of their products to meet present demands. There are producers of slag aggregates and other crushed slag products who have been successful for periods of over thirty years. There are at the present two companies, Cheney Lime and Cement Co. and the Southern Cement Co., manu-facturing puzzolan cement; three companies, Birmingham Slag Co., Woodstock Slag Co., and Swann Chemical Co., making slag aggregates and by-products; one company, Tennessee Coal, Iron and Railway Co., a subsidiary of the U. S. Steel Corporation, producing ground open-hearth basic slag for soil conditioning. Two companies, the Sloss Sheffield Steel and Iron Co. and the Woodstock Slag Co., make slag concrete in ready-mix plants and one company, the Superock Company, manufactures fine and coarse slag aggregates under a new granulation process. No Portland cement is made with slag as an ingredient, because dolomite is used so extensively as a blast-furnace flux that the magnesium content of the slag is excessive.

Jan 1, 1937

By Freeman Bishop

This year the metal mining industry is in for some difficult decisions as the nation struggles to control inflationary pressures resulting from higher production costs and a money-squeeze policy. Re- clouding these problems will be campaign oratory as Congress seeks reelection. Charges will be hurled back and forth between a Republican White House and a Democratic Congress. Inflation and Vietnam will be the big one. Hut pollution i. coming on strong. President Nixon has formed a new Council on Environmental Quality although he already had named a similar unit within his Cabinet six months ago. Both are charged with bringing 1.0 bear all of the Federal Government's talents on the focal points of antipollution measures The biggest task will be to find out how many different "units" are currently mixed up in these efforts.

Jan 1, 1970

By John Chipman

THE equilibrium between titanium in liquid iron and titanium oxides has been studied by Hadley and Derge.' They have shown that a minimum occurs in the oxygen content of the metal between 0.1 and 1.0 pct Ti, but its exact level was not fixed. The oxide phase in this minimum range was principally TiO, containing some iron oxide. On the other hand, for concentrations above 5 pct Ti the oxide phase was TiO and the oxygen content of the metal increased rapidly with increasing titanium content. From their observations and the free energy of Ti0 and TiOz reported by Kelley and ah,' it is possible to derive approximate values for the activity coefficients of titanium and oxygen in liquid iron-titanium alloys and the conditions for equilibrium in steel deoxidation. Neglecting possible departures from the stoichio-metric composition, the condition of equilibrium with Ti0 may be expressed as follows: TiO= Ti_ + C) log K = log NTl + log [% O] + log yTi + log fQ Here as a matter of convenience the titanium concentration is expressed in mol fraction while that of oxygen is in weight percent. The activity coefficients are yTi and fo. The value of log fo approaches zero as the concentration of titanium approaches zero, while that of log yTi approaches a limiting value of In Fig. 1 the sum of log NTi + log [% 0] is plotted for mol fractions of titanium between 0.05 and 0.50. The smooth extrapolation gives a value of —4.15 which corresponds to log K — log y:i . We therefore have the equation: According to the data of Kelley and Mah,' the free energy of formation of Ti0 at 1900°K is -82,400 cal. The free energy of solution of half a mol of oxygen in iron, taking 1 pct 0 as the standard state, is -29,300 cal. From these we write: From these equations the activity coefficient of titanium at infinite dilution in iron is found to have a value of 0.011 or log y°. = -1.96. This is only an approximate value but is certainly better than the estimated 0.05 in Basic Open Hearth Steelmaking To obtain approximate values for the activity coefficient at intermediate concentrations, it is as- sumed that log yTi(l is constant and equal to -1.96. This corresponds to a value of E;: = 3 In yTi/aNTi = 9.0 which is not unreasonable We now have the value for the activity of titanium and the percentage of oxygen in equilibrium with TiO. It is therefore a simple matter to calculate the activity coefficient of oxygen which is shown in Fig. 2. The effect of titanium is rather large, being comparable to that of vanadium, but not so large as has been reported for aluminum. The slope of the line at low concentrations corresponds to E: = aln yo/ aNTi=-0.37. At concentrations below 1 pct Ti the deoxidation constant and oxygen content for equilibrium with TiO, can be calculated from the foregoing data and the free energy of formation of TiO,, which according to Kelley and Mah is -144,600 cal at 1900°K. The free energy of solution of oxygen has been given; that of Ti to form a dilute solution with 1 pct Ti as the standard state is RT ln (0.5585 y:i/47.9) = -34,800 cal. From these data we find (for concentrations in wt pct): TiO, = Ti + 2 -0; hFTgO0= + 51,200 cal log if =-5.89 The interaction coefficients, concentrations being expressed as wt pct, are e;: = alogfTi/a[% Ti] = +0.048 and e:' = a logfo,/a[ojTi] = -0.187. The calculation gives the following results which, in view of the impurity of the oxide phase, must be regarded as approximate:

Jan 1, 1961

By George W. Maynard Maynard

IN this paper I desire to embody the results of some personal observations of the working of the Siemens direct process as I witnessed it for a part of three days at the works of the Siemens-Anderson Company, in Pittsburgh. This preliminary investigation was to have been followed up by one extending over a considerable period of time, and would have embraced analytical and physical tests. Circumstances over which I had no control, resulting in the temporary suspension of work, have postponed the presentation of a complete paper. If the opportunity is afforded me, I purpose doing this at a future meeting of the Institute. To those interested in the development of the process, reference is made to the papers of Dr. Siemens in the Journal of the Iron and Steel Institute for the years 1873 and 1877, and to the paper of our late lamented brother, Holley, in the 8th volume of the Transactions of our own Institute. Dr. Siemens, in the introduction to his paper "On the Manufacture of Iron and Steel by Direct Process," read before the Iron and Steel Institute in September, 1877, says: " In mixing comparatively rich iron ore in powder with about 25 per cent. of its weight of pounded coal, and in exposing this mixture for some hours to the heat of a common stove or of a smith's fire, metallic iron is formed, which, on being heated to the welding-point on the same smith's hearth, may be forged into a horseshoe of excellent quality. The admixture with the ore of some fluxing materials, such as lime or clay, will, in most cases, be of advantage to rid the iron of adherent slag." This is the keynote of the Siemens direct process. Dr. Siemens says further: "If we regard the production of wrought iron from an abstract point of view, we perceive that we have to accomplish two things, viz., the deoxidation of the ore, and the fusion of the earthy matter .mixed with it; and if we calculate the amount of carbon necessary to accomplish this end, we shall find that in using, say, hematite ore, consisting of peroxide of iron with from 10 to 15 per cent. of silica, we shall require barely 40 per cent. of carbonaceous matter per ton of iron contained in the' ore to effect its reduction, and also the fusion of the slag."

Jan 1, 1882

By G. W. Maynard

In this paper I desire to embody the results of some personal observations of the working of the Siemens direct process as I witnessed it for a part of three days at the works of the Siemens-Anderson Company, in Pittsburgh. This preliminary investigation was to have been followed up by one extending over a considerable period of time, and would have embraced analytical and physical tests. Circumstances over which I had no control, resulting in the temporay suspension of work, have postponed the presentation of a complete paper. If the opportunity is afforded me, I purpose doing this at a future meeting of the Institute. To those interested in the development of the process, reference is made to the papers of Dr. Siemens in the Journal of the Iron and Steel Institute for the years 1873 and 1877, and to the paper of our late lamented brother, Holley, in the 8th volume of the Transactions of our owu Institute. Dr. Siemens, in the introduction to his paper "On the Manufacture of Iron and Steel by Direct Process," read before the Iron and Steel Institute in september, 1877, says: " In mixing comparatively rich iron ore in powder with about 25 per cent. of its weight of pounded coal, and in exposing this mixture for some hours to the heat of a common stove or of a smith's fire, metallic iron is formed, which, on being heated to the welding-point on the same smith's hearth, may be forged into a horseshoe of excellent quality. The admixture with the ore of some fluxiug materials, such as lime or clay, will, in most cases, be of advantage to rid the iron of adherent slog." This is the keynote of the Siemens direct process. Dr. Siemens says further: " If we regard the production of wrought iron from an abstract point of view, we perceive that we have to accomplish two things, viz., the deoxidation of the ore, arid the fusion of the earthy matter mixed with it; and if we calculate the amount of carbon necessary to accomplish this end, weshall rind that in using, say, hematite ore, consisting of peroxide of iron with from 10 to 15 per cent. of silica, we shall require barely 40 per cent. of carbonsceous matter per ton of iron contained in the ore to effect its reduction, and also the fusion of the slag."

Jan 1, 1882