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By Harrison Souder

UNDER the stimulus of steadily in- creasing 'demands of the steel industry at home, and with the supply of available ores from abroad appreciably diminished owing to vigorous rearmament campaigns in Europe, production of Eastern magnetite ores reached an all- time peak in 1937. Although the figures given in the accompanying table are partly estimated (actual figures were available for eleven months only), it appears that 1937 production was nearly 47 per cent higher than that of 1936.

Jan 1, 1938

By O. B. Hopkins

As prefatory to the body of this paper, a few general statements will be made (1) in regard to the history and importance of the asbestos, (2) as to the principal sources of the raw material, and (3) as to the types and modes of the occurrence of asbestos.

Jan 1, 1915

By William H. Mount

St. Joe Minerals Corp. has a long operating history of utilizing rubber-tired, trackless mining equipment in its Southeast Missouri Lead Belt underground mines. The company's first completely trackless mine, Hayden Creek, was opened in 1952, employing rubber-tired drill jumbos, electric shuttle cars, and articulated diesel trucks. The trucks were comprised of a conventional scraper tractor unit matched with a rear-dump rock wagon. These machines featured the first true earthmover tires to be used underground by St. Joe. The articulated truck concept proved to be very successful, and constitutes an increasing portion of the underground haulage today. St. Joe's second completely trackless mine, the Indian Creek property, was opened in 1954; conventional 9.1-t (10-st) rear dumps were used for haulage. Main haul roads were designed to be wide and fairly level to accommodate speeds of 32-40 km/h (20-25 mph).

Jan 4, 1976

More than 400 members and guests registered for the 146th General Meeting of the Institute held in Mexico City Nov. 9 to 15, inclusive. Of these, 250 came by special train or automobile from 24 states of the Union, and the others were resident in Mexico. Mexican Government officials, headed by Manuel Santillan, Sub- secretary of the Department of National Economy, acting in. behalf of the President of the Republic, and including the Secretary of Foreign Relations and the Governor of the Federal District, were most hospitable in their official welcome and provided splendid entertainment of various kinds. A reception was tendered by Hon. Josephus Daniels at the U. S. Embassy. Among other hosts were officials of a number of large operating companies, including M. H. Kuryla, of the Real del Monte company; Jules Lacaud, of the CompaiLia Minera de Chontalpan; and Harry Wright, of the Consolidated Steel company.

Jan 1, 1937

By W. Rutledge

As is well known, the Sydney coal-field comprises an area of about 200 square miles, being about 32 miles from the month of Big Bras d' Or, on the northwest, to Mira Bay on the southeast, by about 6 miles in width. The whole of this area is underlain by

Jan 1, 1886

By Earl A. Gulbransen, Kenneth F. Andrew

DRY oxidation of zirconium has been studied by several groups.'" The present work extends our early study1 to the high-temperature studies of Cubicciotti2 and Belle and Mallett.8 ulbransen and Andrew1 showed that the parabolic rate law fitted the 2-hr experiments between 200" and 425°C after an initial deviation. An energy of activation of 18,200 cal per mol was calculated. Cubicciotti,' in a study between 593" and 880°C, showed that the parabolic rate law fitted the data and an energy of activation of 32,000 cal per mol was calculated. In contrast to these studies on sheet specimens, Belle and Mallett3 studied the oxidation reaction on rod specimens and found a cubic rate law to fit the data.

Jan 1, 1958

By A. J. M. Ross, R. G. Wayland

The Homestake mine is situated in Whitewood mining district, in the northern Black Hills of South Dakota, in the city of Lead, Lawrence County. The entire property, comprising 557 lode claims with a total area of 3343 acres, is held under United States Patent. The older claims were 300 by 1500 ft. under local regulations, the newer ones 600 by 1500 ft. The Homestake was discovered April 9, 1876, by Moses and Fred Manuel, and Jake Harney, who were drawn into the northern hills, from the Custer placer district, by news of the discovery of rich placer deposits in Deadwood Gulch. They located a number of additional lode claims and, in a short time, the whole country was covered with locations. The Manuel brothers built an arrastre the following winter and took out $5000. The next year the Homestake lode was sold to Senator George Hearst and associates, who organized the Homestake Mining Co. Other companies were formed to exploit other groups of claims and at one time fivc companies were operating on this deposit, the Father DeSmet, the Dead-wood-Terra, the Caledonia, the Highland, and the Homestake Mining Co. These companies, however, have been merged into the Homestake Mining Company. The first stamp mill, known as the "Eighty Mill," commenced operation on July 12, 1878, and production has been nearly continuous since that time. Geology The orebodies of the Homestake are found in an intensely folded and altered bed of dolomitic limestone occurring in a series of ancient rocks believed to be of Archean age, belonging to the Keewatin series. The Keewatin series is estimated to be 20,000 ft. thick and is made up essentially of quartz mica schists, garnet schists, quartzites, slates, and some green schists, probably derived from basic igneous rocks. The dolomitic limestone bed has a thickness of 40 to 60 ft. The great width of ore, as much as 400 ft. in some of the stopes, is due to the folding, wherein the bed is repeated. In other cases the bed is stretched and pinched out. Dikes of Tertiary rhyolite cut across the country and, in places, sills overlie the

Jan 1, 1925

By O. D. Sherby

In 1938, Kanter' revealed that the steady-state creep rate of low-carbon iron alloys could be correlated by an activation energy expression, where the activation energy for creep, Qc, was found equal to about 90.0 kcal per mole for most of the alloys investigated. He suggested that creep at high temperatures might be controlled by some sort of solid self-diffusion process since the value of Qc was about equal to the known value for self-diffusion, Qd. Correlations were not further attempted along these lines until many years later, when new evidence2-8 was presented suggesting that Qc = Qd for many metals. This equality now appears to be established for ten metals (Al, Pb, Ni, Mg, Cd, In, a Fe, y Fe, Cu, and Au). This experimental fact prompted several investigators to postulate various mechanisms of dislocation motion which would yield an activation energy for creep equal to that for self-diffusion.7-9 Possibly the most accepted theory is that based on dislocation climb7 where a dislocation is envisioned to surmount a barrier by an atom-vacancy exchange process, thereby "climbing" from one slip plane to another. Such a model would suggest that the steady-state creep rate, i, should be directly proportional to the rate of self-diffusion, D, for a given creep stress. In order to more clearly reveal the relationship between creep and diffusion, and to eventually determine the correct model, it would be desirable to obtain data showing correlations between i and D, rather than with a comparison of the temperature coefficients, Q. It has been known for some time that the self-diffusivity of iron atoms is greatly decreased when body-centered-cubic (a) iron transforms to face-centered-cubic (y) iron. This has been ascribed to the more close-packed structure of y iron. The diffusivity ratio at the transition temperature is Da/Dy =350. Correlations of creep data for a and y iron5 reveal that the creep rates under a given stress at the transition temperature differ by about the same ratio (ea/ey 2 200). It would be difficult to reconcile these results on any other basis than that the diffusivity of atoms probably controls creep of iron in some very direct way. No other published data on other allotropic metals appear currently available for further checking such a possible correlation between i and D. Thallium transforms from a hexagonal close-packed (a) structure to a body-centered-cubic (ß) structure at 230°C (503°K) and the self-diffusivities of the two structures have been determined by shirn.10 His results are plotted in Fig. 1 where it will be noted that Dß/Da = 25 at the transition temperature. It would appear desirable, therefore, to determine the creep rates of polycrystalline a and ß thallium at the transition temperature, as well as determine

Jan 1, 1959

By Ionel I. Gardescu

Natural gas influences the movement of oil through reservoir rock by affecting the physical properties of the oil and the pressure within the reservoir. The presence of gas bubbles changes the laws of flow and the distribution of forces. The problem of flow of oil and gas through a porous rock is complex, and most authors, in order to analyze their problems, have found it necessary to make or accept certain generalized assumptions. Some of these assumptions, particularly the ones dealing with capillary phenomena and moleculnr forces, have not received sufficient attention and by lack of understanding have often been misinterpreted. Herold1 has called attention to the resistance offered by gas bubbles in capillary spaces and has drawn some interesting conclusions with regard to the action of natural gas in a reservoir rock. He has duplicated an experiment of the French physicist Jamin, has interpreted his findings in terms of molar mechanics, and, from experimental observations, has made a number of assumptions which he later applies in discussing problems of natural flow and recovery of oil. The Jamin action is an assumption because it lacks a physical proof and has never been determined quantitatively. Tickel12 attempts to develop a formula expressing the work performed by a distorted bubble. H. A. Wilson, in the recent publication of the American Petroleum Institute on the function of natural gas, discusses the phenomenon in terms of classical physics. Both contributions are incomplete and offer no experimental data. This paper includes a study of the static condition of equilibrium of gas and liquid bubbles confined to capillary spaces. In order to avoid any possible confusion, it is proposed to restrict the term "Jamin action"

Jan 1, 1930

By Cyril Smith

ALTHOUGH alloys of copper and silicon were examined several years ago,1 and their excellent mechanical properties were shown, it was not until C: B. Jacobs2 introduced manganese in small quantities to the alloys that they became of commercial importance. A few years ago The American Brass. Company took over the patents and commenced to manufacture the alloy under the name "Everdur." The present study of the constitution of the ternary system was undertaken in order to reach a fuller understanding of the behavior of the alloy. REVIEW OF PREVIOUS WORK ON, THE BINARY SYSTEMS There have been no papers published dealing with the constitution of the ternary system, although some tests of the mechanical properties have been described,3 which indicate that there is a change insolubility with temperature.

Jan 1, 1930

By H. L. Talbot, A. J. Hall, R. S. Young

A METHOD for the chemical differentiation of oxidized cobalt from sulphide cobalt in complex mine and concentrator products is of considerable interest to a number of mining companies throughout the world. At Rhokana Corporation, in Northern Rhodesia, for instance, cobalt is found chiefly in the sulphide form, as carrollite, but a cobalt oxide mineral also occurs irregularly underground, and relatively small quantities in the mill feed from time to time are difficult to detect it visually at the concentrator. The oxide cobalt is not amenable to the sulphide flotation process used at Rhokana and nearly all of it passes into the tailing. The occasional. period when high tailing losses occur with no appreciable change in the cobalt content of the mill feed has naturally been disturbing to the concentrator staff, who had no means of determining whether an influx of cobalt oxide ore or laxity on the part of the mill flotation operators were responsible for these results. A procedure for determining oxidized copper minerals, based on their solubility in dilute sulphuric acid saturated with SO2, has been used for many years in the copper industry. In the presence of cuprite the procedure fails, but otherwise it gives results quite satisfactory for control purposes. Empirical methods for determining oxidized forms of zinc and lead have been proposed, but they are generally unsatisfactory except in isolated cases of a very simple ore. No published procedure for determining oxidized forms of cobalt or similar elements has come to the authors' notice. EXPERIMENTAL PROCEDURE There are obviously two alternatives in attacking a problem of this nature. One is to employ a solvent for oxide cobalt that will not dissolve cobalt sulphide. The other is, to find a substance capable of oxidizing the cobalt sulphide to sulphate, which of course is water-soluble and can then be leached from the water-insoluble oxide cobalt. A representative sample of Rhokana cobalt oxide ore was secured, ground to minus 200-mesh, and carefully rolled to furnish a standard sample for this work. The analysis of this material gave the following percentages: Co, 0.55; Cu, 1.64; Fe, 2.98; S, 0.08; SiO2, 41.42; A1203, 11.20; CaO, 13.82; MgO, 3.80. As a source of cobalt sulphide a similar large sample of carrollite was prepared, analyzing Co, 23.36 per cent; Cu, 27.32; and S, 31.13. This sample of course was not pure carrollite, but was the best obtainable in quantities sufficient for a standard intended for considerable work. It was a pure sulphide sample, microscopic examination showing only carrollite, a little bornite, and gangue, with no visible sign of oxidized ore present. A wide variety of reagents were used in an effort to selectively dissolve oxide cobalt or to oxidize sulphide cobalt to

Jan 1, 1946

By Henry Mulryan

THE largest and purest known deposit of diatomite is being actively mined and processed 3 ½ miles south of Lompoc, Santa Barbara County, Calif., by the Johns-Manville Products Corporation. The workings FIG. 1.-LOCATION OF DIATOMITE DEPOSIT AT LOMPOC. cover 4000 acres, the depth of economically recoverable diatomite being 1000 ft. (Fig. 1). Lompoc, a community of 2500 population, is situated in the Santa Ynez River Valley 10 miles inland from the Pacific Ocean. It is 44 miles

Jan 1, 1936

ALASKA Established November 19, 1947 Regular meetings fourth Monday of each month except June, July, and August Theodore A Loftus, Chairman John C Boswell, Vice-Chairman Patrick H O'Neill, Secretary-Treasurer Box 1034, Fairbanks, Alaska District Vice-Chairmen Robert L Thorne, Juneau, Alaska Alfred J Lomen, Jr , Nome, Alaska Donald G. Wilcox, Anchorage, Alaska

Jan 1, 1952

By Erwin S. Sperry

It is a tradition in the brass industry that bismuth is ail injurious element in brass, even more deleterious than antimony; but such a belief has lacked verification. The occasional presence of bismuth in commercial copper (although less frequent than was formerly supposed) led the author to investigate this tradition. The f'ollowing experiments mere conducted in the same man-

Jan 1, 1899

Jan 1, 1951

By R. D. Leitch, W. P. Yant, R. R. Sayers

In 1924, the United States Public Health Service was requested to undertake a special study of stream pollution. The Public Health Service asked the United States Bureau of Mines to take up the study because the training and experience of the personnel of the former was considered not to be as well suited to this type of investigation as that of the Bureau of Mines. Under H. Foster Bain, then Director of the Bureau, field investigations were begun in the spring of 1925. Along with mine-drainage wastes, the problem of gas-house and coke-oven waste was investigated in the laboratory and a method of treatment by sodium hydrate and benzol was found to be promising. The idea was obtained by A. C. Fieldner, chief engineer of the Bureau Experiment Stations, on a trip to Germany in 1924. He saw a practical application of the process, but obtained no information as to definite chemical or mechanical processes. Because of the then pending American patent applications by the German firm, we made no attempt to develop our findings further. Shortly afterward, a similar method of treatment was developed in the United States,' and since that time we have devoted our attention entirely to mine drainage. This paper is a presentation of some general facts and information gathered during the past five years on coal-mine drainage. Scope of Work There was such a diversity of opinion at the time this work was begun, on the whole subject and apparently so little accurately known, that it was decided to undertake a basic study from which first, certain definite information might be evident, and second, what might be considered

Jan 1, 1931

By Simon H. Ash

The coal-mining districts of Washington are mainly west of the Cascade Mountains; Fig. 1. The mines are on the foot hills of the slope, the lignite fields of Lewis and Thurston counties extending into the valleys west of the mountains. An exception is the Roslyn field, a small but important area on the eastern slope. If western Washington is divided into three areas from north to south, the bituminous coal fields and most of the active operations will be found largely in the middle area. The southern portion contains lignites over a large area. In the northern portion, mining is practically restricted to one mine, the Bellingham, which is working a subbituminous coal seam near the city of Bellingham. The degree of alteration that the coal of a particular field has undergone may be gaged roughly by the position of the field with reference to the Cascade Mountains. The lignites of Tenino, Tono, Mendota, and Castle Rock, on the railway line connecting Seattle and Portland, occur in a region of low relief, in which the Eocene coal measures have suffered only minor disturbances. Subbituminous coals occur in the foot hills, as at Renton, Newcastle, and Bellingham. Coalg high in fixed carbon are found nearer the mountains, where the measures have been sharply tilted and folded, as at Black Diamond and Carbonado. The two typical anthracite fields are located still higher, in the rugged mountains where outcrops appear both in deep gorges and on ridges at elevations approaching 5000 ft. At Carbonado is found the only semianthracitc seam worked on a commercial basis. The occurrence of this seam in a region of bituminous coal is due to the nearness of an igneous sill, which has changed its character from bituminous to semianthracite. Purpose of Paper On account of the various faults and dips and the varying nature of the wall rock, many difficulties are encountered in mining and winning the coal. The paper gives some of the methods used in mining and, in some detail, the conditions that affect the efficiency of these methods.

Jan 1, 1925

By Russell W. Dayton

THE metallurgical polarization microscope has been utilized in several researches in the last few years, thus attaining a fair degree of prominence, but little has been written in a manner suitable to a metallurgist concerning the theory of this instrument. In this investigation the theory was carefully studied, and the results are presented here in a detailed manner, yet as simply as possible. The theory - is discussed with particular reference to the three chief functions of the instrument: (1) determination of anisotropy; (2) effect of strain; and (3) identification of inclusions. Each of these is investigated experimentally, with especial attention to the mechanism of producing any effect. Where possible, the discussion is supplemented by photomicrographs. The instrument used had numerous defects as a polarization microscope; these and their remedies are discussed. In the microscopic study of transparent mineral sections (chalcography) the use of polarized light has aided tremendously in the identification of a mineral. The determination of strain in transparent substances (photoelasticity) by the use of polarized light has lately become a commercial process, used in testing finished glass articles. The success of the use of polarized light with opaque materials has not been so great. The magnitude of the effects obtained is much less than that of the corresponding effects with transparent materials, and the mechanical difficulties are much greater. Königsberger, (1)‡ in 1909, was the first to apply polarized light to the microscopic study of

Jan 1, 1935

By F. S. McNicholas

In the first big blast at Climax, a "loop back" (three-wire system) was used (Fig, I), with the idea of securing a wiring system that would give to all series the same amount of current. Single-phase, 60-cycle, 13,800-volt power was furnished to the blasting transformers, each of which has a rated capacity of 600 amp. at 480 volts. Two blasting leads were taken from these transformers, giving a blasting current of single phase, 60 cycle, 480 volts, with an instantaneous capacity of more than 600 amp. The blasting switch was on the secondary leads from the transformers, to avoid lag in energizing them.

Jan 1, 1940

By F. S. McNicholas

In the first big blast at Climax, a "loop back" (three-wire system) was used (Fig, I), with the idea of securing a wiring system that would give to all series the same amount of current. Single-phase, 60-cycle, 13,800-volt power was furnished to the blasting transformers, each of which has a rated capacity of 600 amp. at 480 volts. Two blasting leads were taken from these transformers, giving a blasting current of single phase, 60 cycle, 480 volts, with an instantaneous capacity of more than 600 amp. The blasting switch was on the secondary leads from the transformers, to avoid lag in energizing them.

Jan 1, 1940