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By K. G. Davis

Dilute alloys of silzer in tilz haz been solidzjzed a1 controlled rules, in lzorizontal tubes 2 mrz and 0.5 rn in diam. Radioactive; tracer techniques we?-e used to study solute distvihutions along llze specimens and irmpurity substructures, as functions of the conditions growth. The results have heen mzalyzed using Burton, Prim, and Slichter's tnodel for the solute disty-ihution in the liquid ahead of an advancing solid-liquid interface. DECANTING techniques have been used to establish criteria for the formation of impurity substructure during solidification in several alloy systems An analysis equating the appearance of impurity substructure with the incidence of constitutional supercooling was developed,= in which diffusion was assumed to be the predominant mode of solute mixing in the liquid. Substitution of experimental data into the equations derived from the diffusion analysis gave reasonable values for solute diffusivity in the liquid. However, in these investigations solidification rates of 10 cm per hr and over were used, to minimize the effect of natural conection, whereas for crystals of high perfection lower solidification rates are needed, usually between 1 and 5 cm per hr. A knowledge of the conditions under which impurity substructures will be formed at low growth rates, and the degree of segregation to be expected, is therefore of interest. In the present investigation, radioactive-tracer techniques have been used to study the effect of growth rate, initial solute concentration, and size of specimen on the formation of substructure in uni- directionally solidified rods of dilute silver in tin alloys, over a range of growth rate between 0.5 and 10 cm per hr. Criteria for the formation of substructure were established by auto radiography. This was believed preferable to the decanting technique, for the relationship of the structure on a decanted interface with that of the freezing interface is not clear, since a layer of liquid is left on the surface following decanting.' The effect of substructure on the distribution of solute along the rods was also investigated. EXPERIMENTAL The procedure for sample preparation has been described in detail by einber. Alloys were prepared from tin of 99.999 pct purity and silver of 99.99 pct purity. A"', an emitter of both y and 0 radiation, was used as tracer. Samples of the alloys were drawn up into silica tubes with inside diameters 0.5 or 2 mm, remelted in a horizontal furnace, and solidified at controlled rates. A few centimeters of the samples were left unmelted for a measure of the initial concentration. Total sample length was approximately 20 cm. The temperature gradient in the furnace was kept constant at 36°C per cm in the region corresponding to the melting point for tin. To find how well this corresponded to the actual temperature gradient in the melt, a thermocouple of 38-gage wire was electrically insulated with a thin layer of Sauereisen cement and placed within one of the 2-mm-diam tubes, which was then filled with tin. The maximum diameter of the coated wire was 0.5 mm, the bead of the thermocouple junction being no larger than the diameter of the wire. A plot of temperature vs distance traveled by the furnace is given in Fig. 1 for a rate of furnace travel of 1 cm per hr. The temperature gradient in the liquid

Jan 1, 1967

By S. J. Rothman, L. T. Lloyd

S. J. Rothman and L. T. Lloyd (Argonne National Laboratory)— Hagel's paperz0 discusses the question of the mechanism for self-diffusion in bcc transition metals. Recent work21"23 has led us to agree with him in reabandoning the ring mechanism in favor of a defect mechanism, most likely vacancies. On the other hand, we think that Hagel's attempt to group together all self-diffusion in bcc transition metals is wrong. We prefer the scheme of Peart, Graham, and omlin," who separate them into two groups. One group contains the anomalously behaved metals P titanium,', y uranium, and perhaps zirconim.' The other group contains a iron," this alloy was held at 1800°C for 2 hr before quenching, its structure was all a. B. C. Giessen, I. Rump, and N. J. Grant (Authors' reply)—We very much appreciate the discussion by Deardorff and Kato regarding the a to /3 transformation temperature of hafnium. In the W-Hf program, as well as in a current study of the system Cr-Hf, standard precautions were exercised against contamination, including vacua of less than 10"5 mm Hg and a weight control check of all specimens to insure an impurity rise of less than 100 ppm. Following receipt of the above discussion, a revision was made in the annealing process. Arc-cast specimens were etched with a 10 pct HF-90 pct HNO solution until 1 mm of surface, including a possible oxide film, was removed. Annealing was done in a hafnium container which provided a long diffusion path for gaseous contaminants. Finally, the heat treating time was shortened. Structural changes were noted to occur quite slowly. A 99.5 at. pct Hf alloy showed 70 pct /3 after 30 min at 1700°C and was 100 pct /3 after 10 min at 1715°C. After 24 hr at 1740C, the alloy was found to be 10 pct/3. This change is due to contamination; it was estimated that it corresponds to an increase of 60°C in the transformation temperature over a 24 hr period. The corresponding change in 30 rnin would be slight. Using the same hafnium as in the above publication, and three new alloys at 98, 99, and 99.5 at. pct Hf, the transformation temperature was indicated to be 1715" 15°C. Since this hafnium contained 4.4 at. pct Zr, a correction of 40 5C, based on an assumed approximately linear transformation temperature curve, must be made for pure hafnium. This yields a value of 1755 20°C in good agreement with Deardorff and Kato's value. Because the slope of the boundary is small, this permits a good extrapolation, and we regard the W-Hf alloys as well suited to check the Hf transformation temperature. niobirn,'' and molybdenum,22 whose activation energies correlate with the melting temperature and whose Do values follow Zener's predictions.28 We have no quarrel with Hagel's placing chromium into the second group; we disagree with his interpreting our data to make uranium fit into that group. Hagel considers that the measurements of self-diffusion in uranium below about 950°C represent combined volume and grain boundary diffusion. This contention is based on the curvature of the penetration plot for our 891°C run,4 which also has a nearly straight line plot of log c vs x. Hagel has extrapolated these characteristics to our 803.5C run and fitted his Arrhenius plot for self-diffusion in y uranium to our four highest temperature points only. We think this is wrong for the following reasons.

Jan 1, 1963

By G. Y. Chin, A. R. Von Neida

The relationship between crystalline texture and magnetic anisotropy in a Co-10 pct Fe alloy has been investigated by means of X-ray pole .figures, hysteresis-loop tracings, and magnetic-torque measurements. The cold-rolled texture of a sample after 95 pct thickness reduction is of the "brass-type", that is, (110)[112/. At 500°C the cold-rolled material recrystallizes fo a (311)[112] orientation, plus a minor (210) [001] component. This texture persists up to 1400°C, at which point it is replaced by a secondary recrystallization texture, (111)[112]. Magnetic-torque measurements show that the easy axis of magnetization lies along the transverse direction in the cold-rolled material and changes to the rolling direction after primary recrystallization. This change is also reflected in the hysteresis characteristic; whereas the B-H loop along the rolling direction is nonsqunre with a low value of residual induction (750 vs 19,000 gauss at saturation) for the cold-rolled material, the annealed sample exhibits a very square loop with a large value of residual induction (16,000 gauss). Theoretical torque curves calculated from the texture data on the basis of magnetocystalline anisotropy energy compare favorably with the observed torque curves. Values of the crystal anisotropy constant, K1, obbained from these comparisons are in good quantitative agreement with single-crystal data. Furthermore, both the torque amplitude of the poly crystalline material and the magnitude of K1 obtained with a single crystal show an identical temperature dependence over the range from —195° 10 +220°C. It is thus conclzided that the magnetocrystalline anisotrpopy erlergy is chiefly I-esponsible. for the nzagnetic allisotropy of textured Co-10 pct Fe alloy. THE results of a study on the relationship between crystalline texture and magnetic anisotropy of an alloy containing 90 pct Co and 10 pct Fe by weight are reported in this paper. The alloy has an fcc structure: a saturation magnetization of about 19,000 gauss,2 and a nearly zero value of magnetoatriction.3 puzey4 has reported a large crystalline anisotropy constant of -7.4 X 105 ergs per cu cm, indicating the (111) directions as the easy axes of magnetization. Hence, texture variations resulting from cold work and annealing are expected to introduce a magnetic anisotropy in the polycrystalline material through the alignment of these (111) easy directions. In the present study, magnetic anisotropy of both rolled and annealed strips was determined by magnetic-torque measurements and hysteresis-loop tracings The results were correlated quantitatively with calculations based on texture data obtained by the X-ray pole-figure technique. It is established that the magnetocrystalline anisotropy energy is indeed chiefly responsible for the magnetic anisotropy of textured Co-10 pct Fe alloy. EXPERIMENTAL Material Preparation. The alloy nominally contained 90 pct Co, 9.5 pct Fe, and 0.5 pct Mn by weight, the chief impurities being nickel, carbon, and silicon (less than 0.5 pct total). The cast ingot was rolled to strips 10 mils thick and slit to 1 in. in width. After strand annealing at 900°C in a hydrogen atmosphere, these strips were further cold-rolled to various thicknesses down to 0.25 mil (97.5 pct reduction), with samples collected for study of the development of texture and magnetic anisotropy as a function of thickness reduction. subsequently, samples cold-rolled from 100 mils to 0.25 mil were obtained, thus extending the thickness reduction range to 99.75 pct. In addition, 0.5-mil samples cold-rolled from 10 mils were selected

Jan 1, 1965

By AIME AIME

AMERICAN participation in the World Engineering Congress in Japan will be generous. Nearly seventy papers have been prepared and for- warded for printing and the A. I. M. E. is well represented in the list. At our San Francisco meeting four of these will be briefly reviewed by the authors for the benefit of those who are unable to go on to Tokyo. They constitute a group dealing with the present economic status as seen by engineers of the world's iron, coal, petroleum and non-ferrous metals. Messrs. Leith, Smith and Tryon, Requa, and Probert have written papers that constitute a notable series. Messrs. Jeffries, Sweetser and Kinney, and other Institute members have written papers dealing more closely with technologic progress. The latest list of delegates and members is printed below, names of A. I. M. E. members being set in italics.

Jan 1, 1929

By A. Aly Selim

A computer model was developed to calculate the fragmentation cost for in situ leaching operations as a function of the blast design and deposit parameters. The model is based on blasting an ore zone only or an ore zone plus overburden by either a coyote blast or a vertical blasthole system. The model calculates the blast design parameters and the fragmentation cost based either on a user input powder factor value or on a powder factor calculated by the model as a function of the overburden height and the ore zone thickness. Examples of blast design parameters calculated by the model are the number and spacing of blastholes for a vertical blasthole system and the number and spacing of crosscuts for a coyote system. The model also calculates the total amount of explosives, the detonating cord length, and the number of primers. The cost of blasthole drilling can be calculated by the model based either on purchasing and operating a drill or on a user input value of the contracted cost of drilling. Application of the model to an example ore deposit showed that the vertical blasthole systems were more economical than the coyote system when there was no overburden and the deposit had an average ore thickness less than 45 meters. With no overburden and ore thickness greater than 45 meters, the vertical blasthole system was either more or less expensive than the coyote system depending on the number of levels used in the coyote system. With overburden, the coyote system was less expensive than the vertical blasthole system for blasting either the ore only or the ore plus the overburden. A coyote blast will usually produce larger particle sizes than a vertical blasthole system. Larger particle sizes can result in lower copper recoveries so that a less expensive coyote blast may not improve the overall economics of an in situ leaching operation. Blasting the ore zone only was generally less expensive than blasting the ore plus the overburden by either blasting system. Also, for the example considered, the coyote system costs were less sensitive to changes in overburden thickness and powder factor while the vertical blasthole system costs were less sensitive to changes in ore thickness.

Jan 1, 1977

The income of the Institute is derived mainly from dues, advertising in MINING AND METALLURGY and sale of publications. These sources are fortunately supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion con- stituting endowments for especial purpose?s. Aside from the medal funds the principal endowments are the James Douglas Fund for support of the Library, the Rocky Mountain Fund and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes. It is allocated by the Board of Directors upon recommendation of standing committees in each case. An active effort is being made to increase the endowments of the Institute, it being felt that unusual opportunities exist for research and public and professional service through the organization.

Jan 1, 1937

President Howe: It is, of course, not easy to discuss off-hand the paper which Mr. Becker has presented with so much lucidity. I will only make one remark, which is outside of the line of his argument, and concerns merely a passing allusion in his paper. Mr. Becker speaks of the fact that glass breaks with a flat or conchoidal fracture, and that steel shows a rough or " cupped " surface of frac-

Jan 1, 1895

Ahrenholz, Herman William, Jr., Student, Lehigh Univ Bethlehem, Pa. '35 Allen, Carl A., Student, Colorado School of Mines Golden, Colo. '35 Allen, Paul W., Student, Mass. Inst. of Tech Cambridge, Mass. '35 Allen, R. M., Jr., Student, Virginia Polytechnic Inst., "G" Co Blacasburg, Va. '35 Amberger, K. H., Student, Michigan College of Min. & Tech Houghton, Mich. '35 Andersen, Burton Lee, Student, School of Mines, Univ. of Washington Seattle, Wash. '35 Anderson, Joseph S., Student, Univ. of Texas El Paso, Tex. '35 Anderson, R. C., Student, Univ. of Washington Seattle, Wash. '35 Ansel, Gerhard 627 Clyde St., Pittsburgh, Pa. '34 Anutta, Frederick P., Student, Michigan College of Min. & Tech Houghton, Mich. '35 Apsouri, Constantin N., Graduate Student, Univ. of Arizona Tucson, Ariz. '35 Arakelian, Haig Mark, Student, Mass. Inst. of Tech Cambridge, Mass. '34 Archer, George K 1420 Court Pl., Denver, Colo. '34 Argall, George O., Jr., K. E. House Golden, Colo. '35 Argiielles, Alfredo, Student, Univ. of Texas El Paso, Tex. '35 Atwater, Ralph, Student, South Dakota School of Mines Rapid City, S. D. '35 Austin, Robert B., Miner, Page Mine, Federal Min. & Smelt. CoSpokane, Wash. '34

Jan 1, 1934

By A. O. HAYES

SYSTEMATIC methods of ore-finding are looked to the more as increasing production requires greater supplies of raw materials. Unrelenting search for new sources of supply is necessary, and all the skill of science must be displayed both in methods of discovering and recovering the minerals necessary to the demands of present-day life. To this end most national governments have some sort of a geo- logical survey and there is a growing understanding of the desirability for cooperation between federal and state or provincial organizations and also financial assistance, from state and private universities, mining companies, railroads and manufacturers. Such surveys are now being directed by well trained geologists selected from federal, state and university departments. Large-scale maps are being prepared and better geo- logical interpretation made, more thorough chemical and physical examinations are being made and original search is fostered, with the result that successful prospecting is better directed, new mining regions are more likely to be discovered, and the life of. old camps lengthened.

Jan 1, 1931

By V. J. Decarlo, J. J. Gilman

POLISHING pure zinc differs somewhat from polishing less reactive metals. The problem is not that of finding a suitable reagent, but rather of producing the polish in such a way that the surface remains polished after it is removed from the polishing bath. In other words., the anodic film that is vital to the polishing mechanism' must be tightly adherent and nonporous. It is usually desirable that it be thin. Polishing solutions consist of proper proportions of an acid and a strong oxidizing agent. In electro-polishing, the external circuit acts as the oxidizing agent. The proportions are critical because the essential surface film must be maintained at approximately constant thickness during the polishing process. In the case of zinc, chiefly two oxidizing agents, chromic and nitric acids, have been used. The simplest polishing reagent is concentrated nitric acid. However, it has certain disadvantages. It tends to pit: an excessive amount of heat is evolved during polishing; and the oxide film that it produces is not very stable, so that the polished sur-

Jan 1, 1957

By Jack Fox

On May 16, 17 and 18, 1871, the first meeting of the AIME was held in Wilkes-Barre, Pa. It was then that the objectives of the American Institute of Mining Engineers were set up. The first ones were to enable the Members of AIME, "comprising Mining Engineers and other persons interested in mining and metallurgy, to meet together at fixed periods for the purpose of reading papers upon and discussing subjects which have for their aim the economical production of the useful minerals and metals, and the safety and welfare of those employed in these industries, and to circulate among its members, by means of its publications the in- formation thus obtained." Now, 100 years later, the American Institute of Mining Engineers, which has now grown to be the American Institute of Mining, Metallurgical, and Petroleum Engineers, is still pursuing those objectives. Dues in 1871 were fixed at $10 per year. Now1 100 years later, the dues have risen to $20 per year. But in pursuing the objectives of the Institute, the services to members have vastly increased, as have the general costs of doing business-even "non- profit" business like ours.

Jan 1, 1971

By ROBERT R. RICHARDS

My. first paper, read at the Cobalt Meeting of the Institute,1 July, 1907, dealt with the behavior of a small Wilfley table when concentrating galena from quartz, the table being fed with natural products, with sized products; and with classified products. Since galena, having a specific gravity of 7.5, is among the heaviest minerals ordinarily concentrated by Wilfley table, it was desirable that a similar set of tests upon a mineral of, lighter weight should be made. Chalcopyrite, of a specific gravity of 4, would have been the best mineral for this purpose, on account of its great importance as an economic mineral, but in carrying out the test, however, I was obliged to content myself with a cupriferous pyrite, the specific gravity of which was 4.68 and the contents in copper 8.80 per cent. Through the kindness of Mr. H. 0. Cummins, this material was obtained from Shasta, Cal.,in very pure, clean, homogeneous condition. It was broken by rolls to 2 mm. in size, taking care to make a minimum of slimes. The quartz used to mix with it was pure, white, New England quartz, broken in the same way to the same size. In studying the accompanying tables, it should be borne in mind that the material concentrated was of low copper-content, and in many cases the quantity fed to the machine was 1 kg: or less.. As a consequence of the smallness of the 'quantity treated it was very difficult to adjust the table and get it in condition to do its best work before the feed became exhausted, and for this reason many results were obtained which appear irregular.

Sep 1, 1908

By A. A. Dor

Of the numerous methods that have been tested or considered for the beneficiation of low-grade iron ores, this article deals only with proven flowsheets that are adopted in plants in operation or which have been reliably pilot-plant tested. Several recommended layouts are described and discussed. They illustrate recent trends and embody improvements and new features that have resulted from the experience acquired in the operation of the plants already in service. They have been developed, in the last few years, in the course of designing several iron ore beneficiation plants of various types and sizes. Some of the design features in the layouts which are submitted represent, in some respects, personal views and may not meet the full approval of others in this field. It is hoped that this presentation will provide an opportunity for constructive discussion of the problems involved and of suitable solutions.

Jan 6, 1962

By J. Hall Carpenter, James E. Lawver

Shortly after the passage of the Taconite Amendment in Minnesota, several mining companies announced their intention to build new magnetite taconite plants and another announced its intention to augment present facilities. It is clear that Minnesota will enjoy an expanding magnetite taconite industry, but despite the fact that the reserves are large, eventually they will have to be supplemented by oxidized deposits. Furthermore, not all producers have magnetite taconite reserves. Due to the extensive oxidation of most of the western part of the Mesabi Range, there are no large blocks of unaltered magnetite taconite that lend themselves to open pit operations. Unless a commercial process can be developed to concentrate the oxidized, or so- called "nonmagnetic", taconite and semi-taconite, the existing mines operating in the western part of the range will be forced to shut down when the direct shipping, wash and gravity ores are depleted, or are no longer salable, because of their poor quality compared to high-grade pellets. KNOWN PROCESSES COSTLY The enormous reserves of the oxidized iron- bearing formation have offered a tantalizing challenge to metallurgists for many years. In fact, several processes for concentrating certain types of oxidized ore have been successful at both laboratory and pilot plant level, but to date no process for concentrating semitaconite or oxidized taconite has reached commercial fruition. Magnetic roasting, followed by low-intensity magnetic separation1, has shown considerable promise because the high iron recovery makes the ratio of concentration of many of the oxidized ores more favorable than that of magnetite taconite. However, the capital and operating costs are high and, in many cases, a high- grade concentrate cannot be made without resorting to flotation of the magnetic concentrate. Hence, most research groups are investigating alternate methods of concentration with the hopes of reducing the cost.

Jan 9, 1965

A SELF-RESPECTING miner doesn't wash the cuttin's off his hard hat until he quits his job but, on the other hand, he keeps his lamp clean and a "spot" focus on the work at hand; the former habit is a matter of pride and the latter serves for efficient operation. During 1949, the mining engineer got all the "wet raises" for the problem of cutting costs to meet the drop of metal prices and keeping research work up to schedule when strikes tied up his work were his headaches. We note, not without admiration, that he hasn't washed the muck off his hat in token of surrender but, on the contrary, his light shines bright on the job to be done as can be seen in the following pages. Few people have any conception of how much ore and rock have to be mined and how much sorting it takes to cull a pound of copper from a 1 % ore body. These people would be even more startled to picture the problems faced by the engineer in mining and extracting, profitably, .2 oz of gold from a ton of ore as is done at some of our lode mines. Strikers have sometimes kept our researchers from their pilot plants and research laboratories, but the end of the year shows progress in making ore out of taconite and ferruginous sandstone, with a pilot plant in operation at Aurora, Minn., and plans for one near Birmingham. Unfortunately, it looks as though the mining engineer will have to make John Doe secure in mineral resources in spite of himself. Coal for steel, power, and to warm our homes is still economically possible, in spite of Mr. Lewis, through development of mechanized tools for mining. During the year, the use of continuous mining machines has extended, transport systems are being adopted to keep the ore flowing from the face to the tune of 40 tons per man-shift. Experiments in the gasification of coal are going forward in several places and may eventually extend our fuel reserves by the addition of coal seams now too lean for mining. Liquid fuel from coal, oil shale, or natural gas will become economic when oil consumption exceeds our supply; but, at less than 30 cents a ton direct cost for mining oil shale, the engineer is almost making it competitive under present market conditions. In this age of specialists, the mining engineer is still holding his own as a broad-gauge man. As a matter of fact, he is emerging from a stage of semispecialization as a coal, nonmetallics, or metal mining man to the realization that, with mechanization, mining is fundamentally materials handling whether it is fluorspar, coal, or copper ore. From the coal business come rubber-tired mechanical loaders to the iron mines of Birmingham. Shuttle cars are also finding application in the lead mines of the Tri-State. Open-pit methods are universal. Belt conveyors, trucks, Diesels, and mobile, jumbomounted drills are finding application in all types of mining. In preparation, such methods as flotation,- heavy density, electrical, and centrifugal are finding application in coal, nonmetallics, and metals. These concepts have been recognized by the mining engineer who has kept himself informed and has been quick to seize a method, machine, or a process from another operation and, with ingenuity, applied it to his problems. This, our Annual Review issue, is written by mining engineers. In gathering these separate articles under one cover for publication, we think of it as a trrbute to the tireless energy and skill of these men. They get little of the publicity accorded physicists, medical men, labor leaders, or company executives, but they supply raw materials without which industry would die.

Jan 1, 1950

All branches of our profession may look back 'with pride upon the patriotic service rendered by engineers during the war. That war has been won. The mortal danger which it threatened has been averted. But the effects of the torture inflicted by it still remain, a fever in the blood of the body politic. Fever begets delirium and, unless its course be checked, has a tendency to produce convulsions. The only safe course is to take immediate steps to allay the fever. The seat of the present trouble is industrialism; as production is at the foundation of civilization, a diseased condition there carries pain and consequent unrest into every member of the organism. Who shall supply the cure? Quack doctors, nostrums in hand, rush forward from all directions promising to perform miracles. But sane men know that no miracles, though invoked by star gazers of purest intention, will prevent or accelerate the orderly operations of the laws of nature and of human life. Delirium must be controlled by the firm, gentle hand of intelligent, sympathetic authority. Fever must be allayed first by removal of all poisons from the system, then by consistent ministration of cooling, quieting restoratives, then by simple, wholesome nourishment. Nature will, under such treatment, supply the permanent cure.

Jan 12, 1919

By P. E. Hopkins

Introduction and History IN speaking of the economic geology of southeastern Ontario, W. G. Miller and C. W. Knight' say that "there occurs in southeastern Ontario a variety of minerals and rocks of economic value, probably as great as in any district of like size on the North American continent. Some of these deposits, including marble and trap, are inexhaustible. Others, including talc and iron pyrites, have proved to be of considerable economic importance. From time to time, during the last 50 years, the following minerals and rocks have been mined or quarried with varying success: gold, iron pyrites, zinc blende, copper pyrites, galena, mispickel, magnetite, hematite, talc, actinolite, mica, marble, ophicalcite, feldspar; fluorite, apatite, corundum, graphite and sodalite. All of the economic materials, with the exception of fluorite, appear to be of pre-Cambrian age. The fluorite veins penetrate the Ordovician, Black River, limestone." Accompanying that report was an article by the writer on the Queensboro Pyrite Area which includes one of the two working pyrite properties in southeastern Ontario. In the present paper will be given a brief description' of all the known pyrite deposits in the area which may at some time possess an economic value, with fuller descriptions of the two working mines-The Canadian Sulphur Ore Co.'s mine near Queensboro, and the Nichols Chemical Co.'s property at Sulphide. The earliest mining of iron pyrites in Ontario was done in 1868 on the Billings property near Brockville. The mines were closed down in 1879 under the assumption that they were exhausted. Many other

Jan 8, 1916

Jan 1, 1925

By L. VOGELSTEIN

OUTSTANDING among the year's events in copper has been the reimposition of an import duty of 4r. per pound in this country which became effective June 21. In consequence of this action by Congress, the Ottawa Empire conference recommended a duty of 2d. per pound equivalent at normal rate of exchange to our 4c. duty, on all copper originating outside of the Empire. Lip to the middle of this year only Russia and Japan had a closed market; the import duty on copper in Russia is 30 per cent ad valoremm and in Japan about 2c. Russia's consumption has always been in excess of production and she has imported from 2(1,000 to 40,000 ton, of copper per annum. Japan, with a production of 6,000 to 7,000 tons per month, has absorbed, in normal times, its production, but during recent: sears has exported varyiug quantities in 1929. 2,200 ton-: in 1930, 2,700 tons, and in 1931. 3,600 ton-. Aside from the-e two countries, the international market has heretofore been free. It and when the British Empire duty become, effective the world's markets will be divided into four unit: 1. Russia and Japan, 2. United States. 3. British Empire. 4. Rest of the world. The world's production at present is rennin it the rate of 930.000 tons per annum. This year's production will be over 1,000,000 tons because the several curtailment did not become effective until the second quarter. consumption will be slightly in excess. Deducting from 30,000 tons Russia's and Japan's production of 121.000 tons, 806,000 tons is left divided a, follows:

Jan 1, 1932

By W. A. Eardley

FIFTEEN years ago the world's deepest oil well penetrated the earth about 7300 ft. That depth has now been more than doubled. Why has such deep drilling become necessary and how has it become possible? Three factors have had an important bearing: (1) Depletion of shallow zones, making it necessary to search for deeper producing measures. (2) The perfection of prospecting methods, which have been success- fully used to locate favorable buried structures, many at great depth. (3) Improvement in the quality of steels used for drilling.

Jan 1, 1940