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University of Alabama-University, Alabama, Mining and Metallurgical Society, James W Stewart University of Alaska-College, Alaska, Mining Society of the University of Alaska, Jack R Hoskins University of Arizona-Tucson, Arizona, Miners Society, A E Gorum Birmingham-Southern College-Birmingham, Alabama, Pick and Hammer Club, Daniel D Arden University of British Columbia-Vancouver, British Columbia, G M Dawson Club, A Gunning University of California-Berkeley, California, Mineral Technology Association, Bernard York Carnegie Institute of Technology-Pittsburgh, Pennsylvania, The Metals Club, Gerhard Derge Case Institute of Technology-Cleveland, Ohio, Case Metallurgical Engineering Society, Robert F Hehemann City College of New York-New York, New York, CCNY Student Chapter AIME, Daniel T O'Connell

Jan 1, 1955

(The following list contains the names of those members of the Institute of whose connection with military service. we have only recently become acquainted; it also includes the names of a few who have recently been promoted or transferred. A complete list was published in the Year Book, issued as a supplement of the Bulletin for March, 1918.) ADAMS, HENRY, Major, Assistant to Department Engineer, North-eastern Dept. ALINE, P. A., Co. C, 316th Supply Trains. * Low-cost cottage construction in America; a study based on the housing collection in the Harvard Social Museum, by Winthrop A. Hamlin. Cambridge, Mass., Harvard University, 1917. (Publications of the Department of Social Ethics, No. 7.) 30 pp., 4 charts. Illus.

Jan 5, 1918

By R. K. Agarwal

Transforming from a mere novelty field of science to a well-recognized branch of engineering, the scientific discipline of rock mechanics continues to mature. The past decade has witnessed an unprecedented in- fusion of scientific research approach into mine design. In the preceding year alone, there were six national and international congresses which also indicated the increased interest, in rock mechanics and participation by scientific personnel with diversified backgrounds. It may be presumptuous to conclude that the time, effort and money spent thus far on procedures for mine structure design have necessarily resulted in the evolvement of design techniques; but certainly the prospects of evolving such techniques art: more promising at present than ever before.

Jan 1, 1970

Quarrying and crushing 500 tons of limestone plus burning some 240 tons of limestone per day are the two initial phases in the production of borax, soda ash, sodium sulfate and related chemicals at Stauffer Chemical Co.'s plant in Westend, Calif. These processing steps have been upgraded in recent years by the installation of new primary and secondary crushers, an 8 x 340-ft rotary kiln plus kiln feed, control and cooling components-all designed and manufactured by Traylor Engineering and Manufacturing Division of Fuller Co. As a result of this new equipment, a new product- quicklime-has been added to the West End product family and considerable reductions have been realized in fuel and manpower costs.

Jan 1, 1965

By Douglas M. Smith

Silver-gold ratios were studied at the Tayoltita epithermal vein deposit using channel sample, channel sample line, stope, ore body, and vein sample populations. The ratios are highly variable among individual channel samples (25:1 to greater than 500: 1) with both high and low values randomly distributed within ore bodies and veins. Whole vein ratios for the 14 most important ore producing structures range from 44: 1 to 105:1, and show zonal distribution relative to two small granitic stocks, low values closest to the intrusives. The zoned nature of the deposit suggests that the stocks, apophyses of an underlying batholith of late Eocene age, were the heat engines which powered the hydrothermal system responsible for ore deposition.

Jan 1, 1980

By Richard Akerman

At the International Sessions of the Iron and Steel Institute of Great Britain, the American Institute of Mining Engineers and the Verein Deutscher EisenhUttenleute, held in Allegheny City, Pa., in October, 1890, Sir James Kitson, then President of the Iron and Steel Institute, presented an account by Sir Henry Bessemer of the origin of the process which bears his name.? The paper graplhically told how, after the first successes immediately following the first reports given at Cheltenham of the new process, there rapidly succceded such obstacles and difficulties in its practical application, that the whole matter was nearly abandoned in 1858. Suddenly, however, the situation changed, so that at length it became possible

Jan 1, 1894

By W. A. Forbes

by the combustion of this gas as it reached the air was a familiar sight in the days when open-top furnaces were in vogue. As blast-furnace practice progressed, however, involving the use of hot blast and the development of power from the gas, blast-furnace construction was modified to conserve this gas for heating hot-blast stoves, raising steam under boilers, and various miscellaneous purposes. When the use of blast-furnace gas was extended to the driving of gas engines, the necessity for thoroughly cleaning the gas became apparent., and soon the advantages of also properly cleaning the gas for use in stoves and udder boilers became more fully recognized.

Jan 10, 1913

By AIME AIME

THE sixteenth annual meeting of the Woman's Aux¬iliary, A. I. M. E., was held Tuesday morning, Feb. 16, at the Engineering Societies Building. The meeting was well attended, there being 99 registered from the metropolitan area and 78 from the sections throughout the United States. Mrs. Sharpless, the secretary, read the minutes of the annual meeting held a year ago, after which Mrs. Bassett, the president, gave her address of welcome. Mrs. Bassett said in part: "I would like, at this time, to welcome you all to this, our sixteenth annual meeting, and to express my appreciation to all the national officers and members of the board of directors for their loyal support and for the excellent work done by the chairmen of sections and their members. It is with much pleasure that I look back upon my visits with the sections in Washington, Arizona, Northern and Southern California, Chicago, Colorado, Western Pennsylvania and Utah before I assumed the office of president. During the last year I have much enjoyed meeting with the sections in Boston, Washington and New York. It is our duty to see that the achievement for 1932 be equal to that of the year that has just passed."

Jan 1, 1932

By John Nunes, Frank R. Larson

Temperature-dependent functions of various ten-sile flour stress and fracture parameters were investigated on iron and low composition alloys of Fe-C, Fe-Cr, Fe-Mn, and Fe-Ni. Data were obtained over a range of test temperatures from 200" to -196"C at an initial strain rate of 0.01 min". It was found that the strain-hardening exponent, n, for the Fe-Ni alloys increased significantly at very low testing temperatures with increased alloy addition. Also, the stress and strain at fracture followed a predictable transitional type of behavior. The flour stress-temperature dependence was evaluated employing the relation: M where it is shown that composition can strongly influence the constant M. An empirical formula describing this effect is as follows: M = MI (equivalent at. pct Ni)-'" Some preliminay, tests were run on several commercial steels to test the generality of this relationship. One of the phenomenological explanations of the ductile-to-brittle transition encountered in bcc metals is based upon the difference in the temperature dependence of the flow and fracture stresses.' It states simply that the fracture stress is relatively insensitive to temperature and that the yield or flow stress rises rapidly with decreasing temperature so that, when the flow stress reaches the fracture stress, brittle fracture occurs without appreciable plastic deformation. This behavior is illustrated schematically in Fig. 1 where the ductile-to-brittle transition is shown to occur at two possible temperatures. The lowest temperature, TB, represents essentially completely brittle behavior while the higher temperature, TN, represents "notch" brittle behavior. Support for this theory is obtained when it is observed that fcc metals, which do not commonly have a ductile-to-brittle transition, also do not commonly exhibit any strong temperature de- pendence of the yield stress. This relationship of yield or flow stress behavior with the ductile-to-brittle transition has been generally observed for most metals representative of these two crystallo-graphic structures. One exception to this generalization appears in the case of tantalum where no apparent ductile-to-brittle transition has been observed. However, this may simply be an indication that this type of behavior is not directly related to the flow stress and that some other mechanism such as twinning must also be operative. A comparison of the typical temperature dependence of the yield stress of some representative metals is shown in Fig. 2. In the study of the temperature dependence of the strength of metallic materials, considerable ef-

Jan 1, 1963

By AIME AIME

WILBER JUDSON is one of that fairly large group of mining engineers that graduated at an Eastern college, worked his way up in various jobs in the West and in the Latin-American countries, and finally came to New York as an administrative officer of a large mining company. Since coming to New York he has been a loyal friend and counselor of the A.I.M.E., and is now serving a second term as one of its Directors, his first term covering the period 1935-1938. Mr. Judson was born in the capital city of Michigan on July 26, 1880. Probably it was his roving spirit rather than professorial urging that was responsible for the fact that four colleges were responsible for his education: Northwestern, University of Michigan, Harvard (S.B., 1901), and the Michigan College of Mines (graduate study). In his first ten years of professional work he might have been found serving as mine foreman at Catamarca in the Argentine, as superintendent of the Inter Ocean mine at Sunshine, Colo.. as foreman for the Cerro Prieto, Magdalena, Sonora, as superintendent of the Hudson Iron Co. in New York, or as manager of the Dolores mine in Chihuahua for the Mines Co. of America, or in Spain, or in Panama.

Jan 1, 1942

As it is the plan of the War Department to return 400,000 soldiers a month during the next four months, Colonel Arthur Woods, Special Assistant Secretary f War, has requested the Engineering Societies to assist the Government by soliciting their members to advise the respective societies, at the earliest possible moment, f any place where companies can employ returned soldiers. This request applies not only to the professional men who are returning but also to the miners, mechanics and other skilled labor among the enlisted men. Army discipline has not only made these men think more quickly but also more willing and obedient workers. The whole training has been conducive to regular habits and clean living steadying these men and fitting them to meet emergencies more quickly and has instilled more loyalty to their superiors and to their jobs. Further, the military instruction they have received has increased the men's powers f concentration. The War Department cannot too strongly bring before the employers of skilled labor the fact that the employment f discharged soldiers will be advantageous to the employer and economically beneficial to the country. The following is a list of the vocations of the men who are now returning:

Jan 6, 1919

By Clarence M. Haight

The general practice in drill sharpening shops, of which descriptions have been written, is about as follows: The bit is heated to 1600" to 1900°F. Then when forged to the proper shape and size in the sharpening machine, the steel is allowed to cool; it is then passed to a hardening furnace where only the end is heated to about 1450" F., and then quenched in cold water, brine, or in brine with oil on top.

Jan 1, 1922

By John V. Beall

Many months ago, the ME staff began thinking about what to put on the February cover of the Centennial Commemorative issue. We have considered photographs of mines, equipment, symbolic artwork and various collages. Our theme is "the next 100 years in mining" and the cover ideally should convey a related message or idea. All of us are convinced that there are many exciting technical changes that will be coming. But even so, we decided that, in our opinion, the engineer is the most vital factor. For this reason we chose to put a man on the cover of this issue. At first it was going to be the face of a man with whom each member could conceivably identify himself. It was one of the Bobs on our staff (we have four) who came up with the thought that since it's the future we are talking about, we should have a young man's or a student's face. Of course we firmed up our idea at the ninth hour, and it was too late to canvass the mining schools. However, by a stroke of luck, we were rapping with a group of University of Arizona students on the terrace of the Pioneer Hotel on December 7, 1970, and met Dave Bolles.

Jan 1, 1971

The useful minerals can be subdivided into two large groups. One comprises those which are mined because of their chemical composition. They represent the natural resources of certain materials or of energy (coal). The second group is used not because of their chemical composition but because of certain physical properties or combinations of physical properties. A large number of minerals are mined because of their hardness, their electrical and thermal properties, their color or plasticity. There has been increasing recognition of the value of mineral synthesis during the past 30 years. This is illustrated by the development of improved aircraft spark plugs and chemical porcelain about the time of the first World War. During World War II the impact of crystal chemistry upon ceramics became most pronounced. New ceramic bodies were tailor-made, such as those designed with a high dielectric constant and low power loss, for use in high-voltage, high-frequency communication. In the field of refractories special materials were needed for unusual heat-resisting service in jet and rocket engines, and in the processing of fissionable materials. The synthesis of natural minerals in the laboratory has long been of aid to geologists and mineralogists in their study of the origin of minerals and physico-chemical conditions under which certain minerals were

Jan 1, 1950

By Atmaram H. Soni

A statistical study of machinability led the writer to examine existing data in regard to a thermal conductivity-mechanical properties relationship. Various functional relationships were proposed and the multiple correlation determined by statistical methods discussed in detail in the 1iterature.4 The relationship having the greatest engineering and statistical significance is discussed below. The data for cast and wrought aluminum alloys''2 have been compiled and analyzed separately. The results of these analyses are presented in Table I. The empirical equations for estimating the thermal conductivity (cal sec-' cm-I °C) are: for cast aluminum alloys K = 0.584 -0.00984/ -0.00263 Hb [1] and for wrought aluminum alloys K = 0.604 -0.00424l- 0.00170 Hb [2] where 1 and Hb are the percentage elongation and Brinell hardness number. Results of a similar analysis pertaining to stainless steel3 are also given in Table I. This empirical equation for estimating thermal conductivity (Btu per sq ft per hr per °F per in.) is K = 216.19- 1.716l - 0.0997 Hb [3] The relationship between electrical resistivity and mechanical properties was also examined for aluminum alloys using the same statistical method. These results are listed in Table II. While the situation of exact multiple correlation

Jan 1, 1965

By David Baker

In a paper presented to the American Institute of Mining Engineers, September, 1904, entitled uImprovements in the Mechanical Charging of the Modern Blast-Furnace,"' I showed the great fault of mechanical charging-devices to be that the materials charged by the dumping of the skip were separated, the coarse materials having high velocity, and the fine, low— thus giving paths of low resistance through the stock in the furnace, which resulted in unequal distribution of the furnace-gases, unequal reduction, slips, scaffolds, irregular cutting of the inwall, "of" iron, and increased fuel-consumption. I showed how this could be prevented by rotary distribution, through which the irregular distribution in one layer charged is compensated by charging the subsequent layers from succeesively varied positions of the charger, and becomes practically eliminated when the angle between two successive positions is a little more or less than an even fraction of a full circle. Of all the devices then on the market, the nearest approach to the ideal arrangement was found in the Brown distributor, a full description of which was given. The one defect pointed out, however, was the difficulty of maintaining so much mechanism on the top of a blast-furnace. Since the presentation of that paper, I have designed a very

Jan 1, 1907

MR. CHARLES F. RAND, President, BUTTE, MONT., APR. 29, 1913. American Institute of Mining Engineers. Dear Sir: In conversation here with Mr. Sales, who is much interested in the work of the Committee on Mining Geology, he made a suggestion which you may be interested to hear. He, and many of us, are interested in papers along our lines of special activity, as they appear from time to time in the Institute Transactions, and often take these papers with us into the field. It appears that the work of special committees which are being formed is likely to result in a much greater number of available papers than the Institute has ever before been called upon to publish. This year's Transactions, for instance, have to be published in two volumes. Why would it not be a good plan, instead of printing heterogeneous volumes, to classify the papers into several volumes, under main headings such, for instance, as iron and steel, precious metal mining, and mining geology ? We would, in fact, be very glad to suggest this as a topic for discussion, if you think it wise, in response to the Secretary's letter of April 18. Very truly yours, J. W. FINCH.

Jan 5, 1913

By B. L. Thane

Within the past few years, the mining industry has taken a new impetus in all its branches. New mines are being opened every day, while old ones, which have been either working at a loss, or have been compelled to shut down, are now gradually being reopened and placed on a paying basis. This growth and new life is due, in a measure, to the discovery of new mining districts, but the most important cause of the progress is the wonderful advance that has been made in all branches of mine-engineering. By means of the important inventions and discoveries that have been made in mechanics, chemistry, and electricity, we are now able to work ores which, only a short time ago, would have been regarded as worthless. We find, for instance, the electrician eliminating two of our greatest difficulties, those of distance and superior elevation, while the mechanic has brought to the highest degree of perfection, not only ore-crushing and hoisting machinery, but all such devices as pertain to the mechanical handling of ores, and, at the same time, the metallurgist, with his combined chemical and mechanical skill, has helped us to extract the precious metals from the most refractory of ores. But when we turn to examine methods in actual use for

Jan 1, 1900

By J. M. W. Mackenzie

The rheological properties of aqueous solutions of several commercial flocculants were investigated using a rotating coaxial cylinder viscometer. Similarities between the pH-apparent viscosity relationship and the flocculating properties of the reagents are discussed here. Synthetic neutral polymers and polyelectrolytes are used extensively as flocculants in mining and chemical engineering operations. The action of these reagents has been interpreted as adsorption of the polymer flocculant to the mineral surface, followed by the formation of physical polymer bridges between the particles.4,5 A consequence of the bridging model is that the efficiency of a polymer flocculant depends on the degree with which the polymer is adsorbed to the mineral surface, and the extent to which the polymer molecule forms a bridge between colliding particles. The length of the polymer molecule and its orientation at the mineral surface are important in the bridging mechanism since the further the polymer segments can protrude from the mineral surface the greater the probability may be of these segments contacting another mineral particle. Linke and Booth7 have shown that, for a silica suspension, both the settling rate at a given polymer addition and the maximum settling rate obtainable increase with increasing molecular weight. The analysis of silberbergl0 has

Jan 1, 1964

By S. P. Burke

THE presence of gas in coal mines necessitates the use of costly ventila-tion arrangements and the use of expensive mining methods. On the other hand, the gas itself in many instances is of considerable intrinsic value, and its separate recovery might conceivably be a profitable under-taking. This paper is concerned with a study of the movement of gas in coal strata with the object of determining the laws governing gas move-ment and thus making at least a preliminary step toward the solution of the more practical problem of its control or recovery. Naturally, so important a subject has received much attention from scientists and engineers. In most cases, however, the studies have been concerned with the origin1?, the amount2, the composition3 and the method of retention4 of the gas in coal; or, from the more practical side, have been concerned with the phenomena and conditions associated with outbursts5 or explosions and their control. Numerous studies also have been made of the permeability of coal to gas6, of gas pressures measured in coal seams, etc. The authors are unaware, however, of any attempt to present a consistent or complete picture of the laws governing the movement of gas through the coal.

Jan 1, 1935