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Do not write until you have something to say. Think first; then write. In order to be understood, you must know what you wish to say. Clear writing is the consequence of clear thinking. Therefore consider your subject well before you begin to write; ruminate on it; marshal the salient facts in your mind; saturate yourself with the ideas you wish to express and with cognate ideas; then express yourself deliberately. If you are bubbling over with your subject the words will come, but you might as well expect to sail without a breeze as hope to give life to words without the living thought. Here I may advert to the fact that among the uneducated it is a common expectation to acquire the knack of writing without taking the trouble to study the art of literature. I overheard a woman in a suburban train remark to her neighbor: "I'd like to be able to write well without stopping to think about it". She was one of many that would like to do a thing well without the trouble of thinking; but it cannot be done in respect of anything to which thought is essential. The possession of a good voice does not justify a person in expecting to sing successfully to a large audience; before singing in public one has to master the technique of singing; one has to learn first how to breathe properly, how to enunciate, and many other things. The successful singer is an artist, not a megaphone. Most of us would regard a man or a woman without any training in the art of singing as a fool or an impostor if he or she were to give a public concert, yet we do not recognize the equal foolishness and imposture of persons that write books before they have studied the technique of writing. That is why so many books are unreadable, and why many books by clever men are difficult to read. They start to write books before

Jan 1, 1931

By AIME AIME

METALLIC corrosion, which results from the chemical affinity of different metals for non- metallic elements, should be considered from both the kinetic and static viewpoints. From the stand- point of statics the metals may be arranged in the order of their affinity for oxygen, chlorine or any other acid- forming element. They may also be arranged in the order of the magnitude of the heat of combination of their corresponding compounds. It is misleading to talk about some metals as "noble," because these relations are all relative; and the order varies for oxygen, chlorine or whatever the element may be. A third way to arrange the metals is by their solution pressures. These three methods indicate that one metal is better under one set of conditions, but not so good under other conditions. Considering the problem from the standpoint of kinetics, the thing which saves most metals is what may be called the sluggishness of reactions. Using organic substances as an example, we know they will all oxidize, but fortunately they do so rather slowly. An increase in temperature always means an increase in the reaction rate, and preventing corrosion at high temperatures is a greater problem than at low temperatures. A second consideration is to avoid all sub- stances which might provoke catalytic action, and as it is generally impossible to foresee what substances might do this, the thing is to avoid all substances other than the main constituents of the alloys. A third consideration is to avoid local electrolytic action, which again indicates the advisability of avoiding the contact of differing substances.

Jan 1, 1926

By K. P. Gupta, P. A. Beck, N. S. Rajan

By determining the a phase boundaries in the following ternary systems: V-Fe-Si (at 1175oC), V-Co-Si (at 1175°C), V-Ni-Si (at 1175oC), Cr-Mn-Si (at 1000°C), Cr-Co-Si (at 1175°C), Cr-Ni-Si (at 1175°C), V-Fe-A1 (at 1175°C) and Cr-Co-A1 (at 1175°C), it was found that Si exerts a stabilizing effect on these a phases, while A1 tends to destabilize them. Si atoms in solid solution occupy sites D in the a structure, The co/ao ratio increases with increasing Si-, Mn- or Fe-content. The volume of the unit cell decreases with increasing Si-content. THE stabilization of certain metal silicides (the Nowotny phases) by the addition of relatively small

Jan 1, 1961

ASIDE from the John Fritz Medal, in which the Institute participates through its representation on the John Fritz Medal Board, the Institute itself has five major awards to make annually for excellence in technical papers, as follows: The Robert W. Hunt Medal, The Hadfield Prize, The J. E. Johnson Jr., Award, The Lewisohn Platinum Prize to senior members, and the President's Prize to junior members. ROBERT W. HUNT MEDAL The partners of Robert W. Hunt established a fund which was presented to the Institute at a fitting ceremony on May 27, 1920, to establish an annual medal and a sum of money to be awarded under the following rules: 1. The award shall consist of two prizes; first of a gold medal, second of a sum of money; a certificate to accompany each prize. The money prize shall not be awarded to. a member over 40 years of age, but under unusual circumstances, both prizes may be allotted to one person provided that he is not over 40 years of age. In general it will be understood that the Committee shall award the money prize to the younger men, rather than the medal. 2. The awards shall be made not oftener than once a year to that person or persons contributing to the Institute the best original paper or papers on iron and steel. The scope of the term "iron and steel" shall be determined by the sub-committee considering the awards. In general, papers dealing with the practical side of the subject have preference over those dealing with the theoretical side in recognition of the fact that Captain Hunt's main contributions to the industry have been in the improvement of production and quality of material. 3. A sub-committee of three to five including the Chairman of the Iron and Steel Committee, shall be appointed by the iron and Steel Committee annually to adjudge the award subject to approval. 4. The awarding committee shall submit its report to the Iron and Steel Committee at its October Meeting, and the. award be certified to the Secretary of the Institute in time to permit the presentation to be made at the Annual Meeting of the Institute. 5. The recipient of the award shall be designated "The Hunt Medallist." SIR ROBERT HADFIELD PRIZE Sir Robert Hadfield has offered an Institute prize of $1000 for researches with regard to the different forms of combination of carbon in iron and steel. Until within a few weeks no paper has been submitted which could compete for this prize. If the paper in hand should not meet the requirements, the donor has suggested that the prize be transferred and offered for: (a) the determination of the hardness in metals in connection. with super-hardness, (b) in consideration of questions of fuel economy, (c) in consideration of questions of industrial development and labor. J. E. JOHNSON, JR. AWARD This award is made from the income of a fund of $3000 donated by Mrs. Margaret Hilles Johnson in memory of her husband, J. E. Johnson, Jr., who was a prominent engineer, author of two valuable volumes on iron blast-furnace construction and practise, vice-chairman of the Institute's Iron and Steel Committee, and a frequent contributor of papers to the Institute's TRANSACTIONS.

Jan 1, 1925

By Thomas C. Wilder

The concentration and activity of oxygen in liquid copper has been measured by the reversible galvanic cell: at 1100°and 1200°C for the concentration range of oxygen of 3 to 5600 ppm Measurements for approximately thirly alloys at each temperature indicate that the activity of oxygen roughly follows Henry's law, the activity coefficients of oxygen being 0.12 and 0.205 at 1100° and 1200°C, respectively. These results compare javorably with the results of seven other electrochemical and gaseous equilibrium studies on this system, the free energy of the solution reaction 1/2 O2 = O (7 at. pct in Cu, liq) being -18.10 * 0.30 kcal per gfw at 1200°C. Estimates of the standard molar free energy of formation of CupO(S) are also made. Praclicul consideration of this cell as an oxygen sensor for liquid metals is discussed briefly. SOLID mixed-oxide electrolytes which have a defect structure in the anion sublattice have recently become a very popular means by which the chemical potential of oxygen is measured at high temperatures. Since the pioneering work of Kiukkola and Wagner1 such electrolytes have been used in numerous cell studies for determining the thermodynamic properties of metallic oxides and oxy compounds, the partial pressure of oxygen in vacuum systems and other atmospheres, and the properties of oxygen dissolved in metals and alloys. The use of a solid electrolyte in a cell for a fast reliable method of oxygen determination in liquid metals would be a very important tool to the process metallurgist. In copper, for example, the oxygen content of the molten metal in the cathode furnace is a prime factor in determining the "set" or solidification profile of cast wire bars. In this investigation the activity of oxygen in liquid copper was measured by an electrochemical cell employing the electrolyte ZrO2 + 7 1/2 wt pct CaO. The cell used at 1100° and 1200°C was

Jan 1, 1967

By Michael Hoch, Daniel B. Butrymowicz

The isothermal section of the Ta-Ti-Zr-0 system at 1500°C was investigated using X-ray diffraction and rrzetallographic techniques. Up to 71.4 at, pct 0 the system contains nine four -phase regions. Zsopleths at 10, 20, 30, 40, 50, and 60 at. pct 0 were constructed. The purpose of this investigation was to determine the general shape of the quaternary equilibrium phase diagram of tantalum, titanium, zirconium, and oxygen at 1500°C. The system was truncated at 66.7 at. pct 0 on the Ti-0 and Zr-0 binaries and at 71.4 at. pct 0 on the Ta-0 binary. The Ti-Zr-0 system was investigated in this laboratory.' The binary systems of interest have been compiled and discussed by Hansen and Anderk, chmidt, Hayes, Roberson, and asche, and Hoch and athur.' EQUIPMENT The Same equipment as that for the study of the Nb(Cb)-Ti-Zr-0 system was used.' The X-ray dif- fraction patterns were analyzed with the help of the ASTM card set7 and NBS circulars.' MATERIALS The tantalum powder (99 pct pure), the titanium powder (99.6 pct pure), the tantalum pentoxide, and the zirconium dioxide used in this study were purchased from the Fairmont Chemical Co., Newark, N.J. The zirconium powder (99.4 pct pure) was obtained from the Charles Hardy Co., Inc., New York. Reagent-grade titanium dioxide was purchased from the Matheson Co., Inc., Norwood, Ohio. The oxides were dried in air at 700°C for 24 hr before use. Though the materials used were not "hyper-pure", the impurities present do not affect the results (lattice parameters, phase boundaries), within the experimental accuracy. PROCEDURE The samples were heated by induction in a vacuum furnace, and examined metallographically and by X-ray diffraction at room temperature. The procedure was the same as that in the Nb(Cb)-Ti-Zr-O work,' EXPERIMENTAL RESULTS AND DISCUSSION OF DATA A four-component system can be represented by a tetrahedron at a single temperature and pressure

Jan 1, 1964

By Henry Drinker

The Institute has lost a valued member by the death of Eckley B. Coxe, Jr. He bore the name of one who was largely instrumental in founding the Institute, and to whose support and guidance as active member, Vice-President, and President, the Institute owes. much. Eckley B. Coxe, Jr., was the nephew of the late Eckley B. Coxe. He held a large interest in the coal estates owned and developed by his family, and he was thus naturally led to take a continuing interest in mining matters, and for years and up to the time of his death was a full member of the Institute. He died at his residence, Drifton, Pa., on Sept. 20 last, aged 44. He was a member of the class of '93 of the University of Pennsylvania,. of which great institution he was a devoted alumnus. His educational and charitable activities were numerous, but his chief life-work and interest was in archeological investigation and research in Egypt, carried on through the Museum of the University of Pennsylvania of which Museum he was President. The discoveries made by the various expeditions financed and directed by him, and the notable publications issued by his direction and at his expense, chronicling the results, are among the most important researches ever made of buried Egypt. Mr. Coxe was a member of the International Historical Society and of many educational and charitable organizations. By his will, among other bequests, he left $500,000 to the Museum of the University of Pennsylvania and $100,000 to the University, the income of the latter fund to be applied to increasing the salaries of the professors of the Institution. He also left $100,000 to the Children's Hospital of Philadelphia, of which he was a manager, and in addition thereto $10,000 of which the income is to be applied in providing Christmas presents for .the child patients, and in providing an annual dinner for the patients and attendants of the hospital. He bequeathed $50,000 to Leonard Hall, an associate mission of the Episcopal Church, at South Bethlehem, Pa., $25,000 to the Epileptic Hospital and Colony Farm (Philadelphia) ; $50,000 to the Philadelphia Orthopaedic Hospital and Infirmary for Nervous Diseases; $15,000 to the United Charities of Hazleton, Pa., the income to be applied to the salaries of nurses; and $25,000 to the Mining and Mechanical Institute of the Anthracite Coal Region of Pennsylvania, founded by his uncle, Eckley B. Coxe, and of which Eckley B. Coxe, Jr., was an active trustee up to the time of his death. This Institute is known as one of the best preparatory schools for technical education in Pennsylvania, and is mainly devoted to extending an opportunity for education by day and night schools to the boys and young men of the Anthracite Region. Its principal is an alumnus of Lehigh University; it has an able local Board of Trustees, and an Advisory Board consisting of the Provost of the University of Pennsylvania, the President of Lafayette College, and the President of Lehigh University, all three of which institutions have established prize scholarships in the institute. Mr. Coxe carne of a distinguished ancestry, the record of which is fully given in the biographical notice of his uncle, Eckley B. Coxe, by Dr. R. W. Raymond, in Vol. XXV of the Transactions.`

Jan 12, 1916

By James Terry Duce

The symposium on production for the year 1941 contains few papers on the foreign situation. Rigid censorship prevails in various countries, as the question of the volume of petroleum supplies has become one of great strategic importance. This is even truer than in the last war, owing to greater mechanization of armies. It has always been the policy of officers in charge of the symposium to refrain from publishing information that might possibly injure national or private interests. At the close of the war we hope again to publish full and accurate records of production abroad. Excerpts from Circular to AutHORs In order to facilitate interpretation of the data in this chapter, we print the fol-lowing excerpts from the Circular to Authors. The field is the unit in this tabulation. In cases of fields extending across State boundaries, such as Rodessa, it is suggested that each State author treat the section of the field in his State as a unit, and by a footnote indicate that the field extends into an adjacent State. Each space in Table I may represent one of four possibilities; either it is not applicable to the particular field, or the proper entry is not determinable, or the proper entry may be determinable but is not determinable from data available to the author, or the proper entry is determinable. When spaces are not applicable, leave blank; in spaces where the proper entries are determinable but not de-terminable from data available to the author, please insert y; in spaces where the proper entries are determinable by the author, make such entries. y implies a hope that in some future year a definite figure will be available. The entry of a zero is a positive declaration, and an important declaration where it is in order. Inability to determine precisely the correct entry for a particular space should not lead the author to insert merely y. Contributions of great value may be made by the author in many cases where entries are not subject to precise determination. In such cases the author should use his good judgment and make the best entry possible under the circumstances. For many spaces the correct entries represent the opinion of the author (for example, "Area Proved") and in such cases the entry need not be hedged to such extent as when the quantities are definite yet can be ascertained only approximately by the author. In cases under definite headings but where figures are only approximate, the author may use x. It is thought that the nearest whole numbers are sufficiently accurate for our purposes except as to percentage of sulphur in oil. If an author desires to report any other figures to tenths, he may do so. The quantity of gas produced should include, where possible, gas sold or otherwise marketed, and gas blown into the air, burned as flares or otherwise wasted. Segregation of these figures would be interesting if the authors can make such segregation. In any event, the figures should represent as nearly as possible the total quantity of gas removed from the reservoir.. Under the columns on "Depth," the average depth to the top of the productive zones and to the bottom of the productive wells, when

Jan 1, 1942

By R. E. Cuthbertson

AN early appreciation by the management that Climax ore presented a challenging problem of economic concentration was responsible for the establishment, in June 1926, of an ore-testing department at the experimental plant of the Colorado School of Mines at Golden, some ninety miles from Climax. An engineering office was later organized in the same community for the design of all ore-treatment units erected at Climax during the period of rapid growth. Work of the ore-testing and design staffs was effectively co-ordinated under a common head. The primary reason for having the ore-testing and plant design departments in Golden, was to place these activities under the able supervision of A. J. Weinig, consultant for the Climax Molybdenum Co., and director of the experimental plant. A secondary consideration was the availability of excellent facilities for research in ore dressing in a highly favorable environment. Concentration of molybdenite by flotation from an ore of simple mineral composition does not appear, superficially, to present a serious problem in ore dressing but experience belies this apparent simplicity. The molybdenite content of average Climax ore is low and it is finely

Jan 1, 1946

By J. J. Lillie

Sublevel stoping was first developed in the Michigan iron mines many years ago. Since that time this method, and modifications with long hole drilling, have been used in a number of non-ferrous mines and have been described in various papers and articles. With a few exceptions, the operations where sublevel methods have been applied are producers of large daily tonnages from ore bodies of considerable size. In selecting mining methods for small properties or relatively small detached ore bodies, sublevel methods often have been overlooked. The method has been used successfully in relatively small operations at Copper Canyon, Nevada, and, more recently, in mining small ore bodies at Darwin, Calif. As a result of this experience, we believe that a review of the general procedure, the advantages noted, and the results obtained will be of interest to many operators of relatively small mines. General Description Briefly, sublevel stoping consists of, first, driving sublevel drifts at predetermined vertical intervals through the length of the stope block; second, breaking an initial mining slot across the stope; third, driving crosscut benches from each sublevel by slabbing into the slot; and, fourth, breaking the ground between benches. Applicability Since this is an open stope method, it requires wall rock that will stand over reasonable stope lengths without caving or excessive slabbing. Ore must be moderately firm but need not be hard. The method is best adapted to steep dipping, tabular or lenticular ore bodies but may be applied to ore bodies of almost any shape if their vertical extent is appreciable. It can be used with dips that are too flat for successful shrinkage stopes and can be modified for use with slushers on dips below about 40". Initial mining at the Copper Canyon operation consisted of sublevel stopes for the wider ore sections and shrinkage stopes for the narrow sections where ore widths averaged about 15 ft. After some experience and a study of comparative results on completed stope blocks, sublevels were substituted for shrinkage stopes even in the narrow ore widths. Practical stope lengths depend upon the character of the walls and the continuity of values within the ore body. Where blocks of low grade or waste are included in the stoping limits, these areas can readily be left as pillars for intermediate wall support and longer stope lengths may be planned. Raises can be spotted in narrow or low grade areas and stope lengths adjusted accordingly. Stoping Details To illustrate stoping details, assume that we have an ore shoot 15 to 30 ft wide and about 200 ft long, with walls that would stand over a stope length of 80 to 90 ft (Fig1). PRELIMINARY DEVELOPMENT Preliminary development for sublevel stoping would be simple. A service raise is driven at about the center of the block and stope limits planned to leave a pillar around this raise. Sublevel drifts driven each way from this central raise will outline the

Jan 1, 1950

By Craig R. Barrett, Oleg D. Sherby

The creep characteristics of four pure metals with widely Varying stacking-fault energies (silver, copper, nickel, and aluminum) were evaluated above 0.5Tm. Creep tests were performed under conditions of constant atomic diffusivity and constant stress over the elaslic modulus. The sleady-state creep rate, Es, was found to he a funclion of the THE most common empirical representation of the steady-state creep rate, Es, at high temperatures and intermediate stresses is of the form where a is the applied stress, E is an elastic constant, A and n are constants (n is typically stacking-fault energ, y, such that Es is proportional to y3,5. In addition, it was uncovered that the primary creep strain and the strain to fracture increased with increasing y, and that the ratio of initial to steady-state creep rate decreased with increasing y. about 5), Q is the activation energy for creep (usually equal to that for self-diffusion), and kT has its usual meaning. sherbyl and McLean and ale' have used this expression to correlate creep data for a number of pure metals. An interesting aspect of Eq. [I] is the absence of any dependence on the stacking-fault energy. While most creep data seem to obey the stress and temperature dependence predicted by Eq. [I], when data for several metals are put on a master plot they do not fall on a common line but form a band. The width of this band corresponds to a variation in Es of 102 to l03. sherbyl attempted to explain this band by assuming that a grain-size effect was present which led to the observed variation. On the other hand, Felt-

Jan 1, 1965

By B. B. Cox

The Iraq Petroleum Company, Ltd. continued its systematic exploration and exploitation of the Kirkuk field on a unitized basis. Pressures, gas-oil ratios, oil-water level and oil-gas level remained satisfactory. All wells were produced by flowing and more than two-thirds of the crude was stabilized. The only exports from Iraq during 1937 were from the Kirkuk field. Mosul Oilfields, Ltd., through its operating subsidiary, the British Oil Development Company, Ltd., inaugurated an exploratory program to find lighter oil than the heavy, black, sulphurous reserve proved in the Qaiyarah-Najmah-Jawan-Qasab field. Deeper drilling in this field found a small reserve of 17" to 19" A.P.I. black sulphurous oil in the Pilsner (Upper Cretaceous). Ten structures outside the proved field were tested or were under test at the end of the year. In spite of this intensive program no reserve of lighter oil was discovered. The reserve at Qaiyarah-Najmah-Jawan-Qasab averages 16" A.P.I. with 6+ per cent sulphur from the "continuous limestone" (Lower Miocene, Oligocene, Middle Eocene) and from the Pilsner (Upper Cretaceous). The Khanaqin Oil Company, Ltd., a subsidiary of the Anglo-Iranian Oil Company, Ltd., conducted the normal exploitation of its Naft Khaneh oil field and supplied the local Iraq market requirements. Slightly more than 31,600,000 bbl. of crude was produced in Iraq during 1937. The following table gives the total crude produced by the I.P.C. for export during the last four years. Year 42-gallon BarreL Increase over Preceding Year 1934 7,096,669 1935 27,014,904 19,918,235 1936 29,521,053 2,506,149 1937 31,171,476 1,650,423 " Converted at an average of 7.6 bbl. per ton. Published by permission of the Near East Development Corporation. Manuscript received at the office of the Institute March 11, 1938. * Geologist, Socony-Vacuum Oil Co., Inc., New York, N. Y.

Jan 1, 1938

By Charles Macdonald

WROUGHT-IRON eye-bars for bridges and roofs, designed upon what is known as the pin connection system, have been successfully manufactured in this country for some years. The most approved methods employed have been the hydraulic upsetting process, and by die-forging under a hammer. In upset eyes the fibre of the iron is necessarily much distorted ; and in bars of considerable size, this disturbance seriously impairs the strength of the connection. Mr. Collingwood, in discussing my paper on "Proportions of the Heads of Eye-bars," read before the American Society of Civil Engineers, Jan. 21st, 1874, submitted sketches of certain bars intended for the anchorage of the East River bridge, which had been exposed to the action of sulphuric acid a sufficient length of time to thoroughly cleanse the surfaces, and expose the condition of the fibre. These sketches are here reproduced for the purpose of illustrating the effect of this methpd of manufacture. In Figs. 1, 2, and 3, it will be observed that the fibres at A, and E, have been folded back upon themselves and otherwise twisted and disturbed, in a manner not calculated to inspire confidence in the integrity of the connection. To compensate for this defect, a large excess of metal is thrown into the eye; but a method of manufacture which involves such a necessity, even although it be the one giving the best results thus far, all things being considered, is far from being perfect.

Jan 1, 1879

By Charles Macdonald

Wrought-iron eye-bars for bridges and roofs, designed upon what is known as the pin connection system, have been successfully manufactured in this country for some years. The most approved methods employed have been the hydraulic upsetting process, and by die-forging under a hammer. In upset eyes the fibre of the iron is necessarily much distorted ; and in bars of considerable size, this disturbance seriously impairs the strength of the connection. Mr. Collingwood, in discussing my paper on "Proportions of the Heads of Eye-bars," read before the American Society of Civil Engineers, Jan. 21st, 1874, submitted sketches of certain bars intended for the anchorage of the East River bridge, which had been exposed to the action of sulphuric acid a sufficient length of time to thoroughly cleanse the surfaces, and expose the condition of the fibre. These sketches are here reproduced for the purpose of illustrating the effect of this method of manufacture. In Figs. 1, 2, and 3, it will be observed that the fibres at A, and E, have been folded back upon: themselves and otherwise twisted and disturbed, in a manner not calculated to inspire confidence in the integrity of the connection. To compensate for this defect, a large excess of metal is thrown into the eye; but a method of manufacture which involves such a necessity, even although it be the one giving the best results thus far, all things being considered, is far from being perfect.

Jan 1, 1879

By H. H. Podgurski, Hsun Hu

Large cryslals of high-purily iron (99.996+ pcl) cannot be obtained by the usual strain-ameal technique. Repealed phase transformation by thermal cycling prior to crilical deformation improves the capabilily of cryslal growith but fails to yield satisfactory crystals. Imperfect columnar crystals can be produced by the phase-transition method. The addition of a small amounl (0.005 wl pet) of nilrogen IT was reported'-4 that for metals of very high purity the usual procedures of the strain-anneal technique fail to produce large crystals. This was eliminates practically all the difficulties in crystal growth by the normal strain-anneal procedures. An actual example is presented, showing that most parts of a strip have been converted into a large crystal by this method. The addition of nitrogen, which can be removed from iron with less difficulty, is believed to be more desirable than carbon additions for the same purpose. thought to be due to the strong tendency for recovery in the high-purity metals: hence the critically strained matrix undergoes polygonization instead of recrystallization upon annealing for crystal growth. Talbot1,2 succeeded in overcoming this difficulty by adding 0.03 to 0.04 pct C to high-purity iron before critical deformation. followed by annealing in hydro-

Jan 1, 1965

By AIME

TITANIUM-RICH ilmenite deposits, situated in the Allard Lake area in Quebec some 400 miles down the St. Lawrence River from Quebec City and 28 miles north of Havre St. Pierre on the north shore of the Gulf of St. Lawrence, are undergoing an intensive development program by the joint efforts of the Kennecott Copper Corp. and The New Jersey Zinc Co. Easily accessible ore, amounting to about 125 million long tons and carrying from thirty to forty per cent titanium oxide, has been delimited. Plans are being made for construction of an electric smelter at Sorel, on the south bank of the St. Lawrence midway beween Montreal and Three Rivers, which will produce 650 long tons of high-grade titanium slag and 500 long tons of iron per day from 1500 long tons of ore. Occurrence of ilmenite ore in this area has been known since J. A. Retty reported his geological work in the lower Romaine River area for the Quebec Bureau of Mines in 1941. In this report Dr. Retty mentions the presence of anorthosite rocks, some of which were rich in ilmenite. Claims were staked by several interests but the small showings and complex metallurgy were too formidable for any organization not adequately equipped with capital, metallurgical knowhow, and market outlets. However, Kennecott became interested and through a newly formed Canadian subsidiary, Kennco Explorations Ltd., options were taken up under the direction of A. H. Robertson. An area of 300 square miles was traversed in the summers of 1945 and 1946. During 1946 and 1947 geophysical and diamond-drill prospecting disclosed a num-

Jan 1, 1948

By Walter Weeks

THE process of cooling air by allowing it to expand and do work in an engine is well known, but the theory of obtaining cold air by free expansion without the aid of an engine operating with cutoff has been little discussed. CASE I If compressed air is allowed to expand to the atmospheric pressure through an orifice in an air line that is supplied by a running compressor, no cooling results except the negligible one due to the Joule-Thompson effect, which will not be considered in this discussion. The effect of moisture will also be neglected.

Jan 1, 1937

By Rclssell Gibson, F. S. Turneaure

The tin deposit of Monserrat; Bolivia, consists of one major vein 1600 m in length. The ore is unusual because of the notable quantity of teallite, even though cassiterite is the principal tin mineral. The deposit, formed at shallow depth under a wide range in temperature, may be classed as xenothermal. Polished sections reveal a complex history of replacement, with low-temperature minerals deposited before high-temperature minerals.

Jan 1, 1950

By J. Chipman, G. G. Hatch

T. ROSENQVIST*—It is a pleasure to see the excellent way in which the experimental part of this work has been handled. There seems to be little doubt that the distribution data obtained corresponds most closely to thermodynamic equilibrium under the prevailing reducing conditions, namely equilibrium with graphite and one atmosphere CO pressure. The desulphurization curves in Fig 10 show the same general feature as the curves given by Holbrook and Joseph, but the distribution ratios are from 20 to 40 times greater—undoubtedly due to a closer approach to true equilibrium. In the theoretical discussion, the authors calculate a theoretical distribution (S) ration -jg-. which they find to be about 50 times greater than the experimental. The deviation is so great that the basis for their calculation needs a more thorough examination. The authors base their thermodynamic calculation on free energy expressions where diluted solutions of FeS and CaS are used as standard states. (The activity coefficient in diluted solutions is taken to equal unity.) Such a standard state will change when the nature of the solvent is changed. Taking the free energy of the reaction [FeS] ? (FeS), Eq 2, which is derived from the distribution of sulphur between an iron and a FeO-melt, it is very unlikely that the free energy of this reaction will be the same for a distribution between pig iron and a calcium silicate slag. Therefore a more fundamental basis for the thermodyuamic calculations seems needed, where all thermodynamic equations are referred to unambiguously defined standard states. The most natural standard states for CaO and CaS are the pure solid substances at the same temperature. As standard state for sulphur in iron, pure liquid FeS can be used. This rules out Eq 2 [FeS] ;=s (FeS) because ?F° = 0. The standard equation will then be: FeS, + CaO6 + Cgraph ?Fei + CaS8 + CO. vFo1773 = 25,000 cal It would be more universal and also simpler to refer the escaping tendency of sulphur in liquid iron to the corresponding H2S/H2 ratio which can readily be determined experimentally. As standard state a gas mixture H2S/H2 = 1/1 can be used. (This corresponds at the temperature of liquid iron closely to one atmosphere S2 vapor.) Thus the standard equation for the sulphur reaction can be formulated as follows: H2S0 + CaO3 + Cgraph ?H2o + CaS8 + COg The standard free energy of this reaction has been calculated from the best available data to AF°m3 = —35,000 cal. This gives for the equilibrium constant at 1500°C Now, the solubility of CaS in blast furnace slags has been determined by McCafferey and Oesterle* and corresponds at 1500°C to about 10 pet S (varying somewhat with the composition of the slag.) If the activity of CaS is assumed linear between 0-10 pet as curve 1, (see Fig 11), then acaO = 0.1 (S); (S) being wt. pet sulphur in the slag. For a diluted solution of sulphur in an iron melt saturated with carbon, the ratio H2S/H2 is, according to Kitchener, Bockris and Liberman,f about 0.01 [S], [S] being wt. pet sulphur in iron. Substituting these values in the expression for Kp we find The value 2.103 is only 4 times greater than the experimental coefficient found by Hatch and Chipman, but the value is very sensitive to a small error in AF°. A better agreement with the experimental distribution coefficient can be obtained if one assumes the activity of CaS to run like curve 2 (Fig 11). This (S) will give a lower theoretical W, value, a value which varies with (S) exactly as Hatch and Chipman learned. Such a shape of the activity curve, which corresponds to a positive deviation from Raoult's law, is actually to be expected from the fact that liquid silicate and sulphide phases usually show incomplete miscibility. A closer agreement between experimental and theoretical data can not be expected before we have more complete data for the individual activities of CaS and CaO in the slag. The activities acaS and Ocao referred to the solid phases as standard states, are exact defined quantities contrary to the somewhat undefined expression "free lime," and they are independent of any theory for the constitution of liquid slag. J. CHIPMAN (authors' reply)—The authors wish to thank Mr. Rosenqvist for his very interesting and useful thermodynamic addition. Curve 2 of his figure offers the needed basis for explaining the increase in the ratio (S)/[S] with increasing sulphur content. Attention is called to an error in the printed paper: Fig 2 and 3 are reversed. M. TENENBAUM*—In the figures showing the relationship between excess base and sulphur distribution (Fig 6, 7 and 9) the slope of the curve tapers off in the negative basicity range. Somewhat the same thing is observed with open hearth slags. In that case, the fact that some sulphur distribution between slag and metal is obtained with negative basicity is interpreted as indicating some dissociation of the lime silicate compounds whose existence in oxidizing basic slags has been used to explain various observed phenomena with regard to other slag-metal reactions. In the case of the blast furnace slags, the reduced slope of the sulphur distribution curve with decreasing excess base is attributed to the amphoteric effect of alumina. Has the possibility of other explanations been investigated ?

Jan 1, 1950

By E. H. Rose

IN a year of sober reflection and stocktaking after the mineral-squandering spree of World War II, the role that beneficiation of low-grade must henceforth play in American mineral industry has become unmistakable. From the volume of research and development progress in mineral engineering during 1946, mineral dressers evidently have ample resoluteness to meet the challenge. Perhaps ,the most conspicuous trend of the year was the renascence of interest in gravity concentrating methods and more serious effort than ever before to make them effective in finer size ranges down to 200 mesh. This has been forced by the problem in iron ores where the low value of the product will not support a high flotation reagent cost, however good flotation pilot plant results may have been and however well the acute problem of variable feed may be met. The race is on between rabbit flotation and tortoise gravity methods and a surprising amount of betting money is being laid on the tortoise which already is showing previously unsuspected talent for speed. Mostly, however, a wait-and-see attitude prevails during the present preliminary heats. As evidence of the latter, two magnetic plants are now on the boards for magnetic taconites on the eastern Mesabi to establish a reprieve against the time when nonmagnetic taconites must be addressed. Incidentally, these operations will force the blast-furnace issue on preparation of fine material since a minus-100-mesh grind is contemplated.

Jan 1, 1947