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By AIME AIME

EVERYONE enjoyed the coal meeting and found it profitable. At least your correspondent did, and those to whom he talked. Close to a hundred were there. The Coronado proved an excellent headquarters hotel, though it is two miles or more from the business district of St. Louis; its Crystal Room was suitable for the technical sessions; its Lounge adequate for registration and informal chats; its Club Caprice made an artistic setting for the informal banquet; and its Coal Hole in the basement presumably served other needs-unfortunately we passed up an invitation to find out, and never got another. To be sure, the first day of the meeting (Monday, Oct. 28) was a drizzly one, but that only served to keep people inside where they belonged. Believe it or not, the first technical session was only five minutes late in getting tinder way, with H. N. Eavenson's words of welcome. M. M. Leighton then took over the conduct of the meeting, and invited Eugene McAuliffe to read his paper on how much coal the railroads are likely to use in the future. E. G. Bailey then presented some written discussion; among other things he wondered about the success of stokers on locomotives, and whether or not the burning of coal in locomotives could not he made a cleaner operation. Mr. McAuliffe pointed out that railroads are built to haul coal rather than to burn it. Maximum firebox efficiency is often subordinated to the traffic situation. Powdered-coal firing has not been a success because of limited firebox space. Stokers have resulted in economies indirectly, because large locomotives cannot he hand-fired and stokers thus make them possible. Nowadays it is not so important to do away with smoke, cinders, and soot, because most trains are sealed up and air-conditioned.

Jan 1, 1935

Jan 1, 1969

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

By J. W. JESSUH

TO certain people the name of Northern Rhodesia brings only a vague recollection of a distant country somewhere in Africa; to others, it means a big game territory and the opportunity for excellent shooting; to some, a land of sunshine and peace; but to mining men the name signifies the land where the latest discoveries of copper ore are astonishing the mining world and bid fair, in a few years, to make Northern Rhodesia one of the largest copper- producing countries. There is a fascination about this part of the globe that is somewhat similar to southern California, and at the same time there is that feeling of mystery peculiar to a tropical climate. Perhaps it is the isolation, the fear of wild animals, or the influence of an undefinable something which cannot be expressed.

Jan 1, 1931

By Charles A. Stetefeldt

This treatise is the sequel of a paper on "Russell's Improved Process for the Lixiviation of Silver-ores," etc., read at the Chicago meeting, in May, 1884, and published in the Transactions, vol. xiii., page 47. The facts it presents are principally compiled from Mr. Russell's notes on his practical experience gained in various places where the Russell process has been introduced. For a complete understanding of this paper a perusal of my former one is desirable, as can be seen from the frequent references here made to it. All silver-ores that do not carry a large percentage of lead or copper can be treated by Russell's process with success and economy. I do not mean to create the impression that from ores containing considerable quantities of lead and copper a high percentage of the silver cannot be extracted by this process. Such ores, however, will, in many localities, be reduced to better advantage by smelting. In case lead-bearing silver-ores are suitable for concentration, it may be profitable to concentrate the ore by Krom's dry system, obtaining a smelting-product high in lead, and to lixiviate the tailings and the dust. This plan has been adopted in a mill recently erected in Cortez District, Nevada. The dry system of concentration deserves the preference because it delivers the tailings and the dust in a condition ready for chloridizing-roasting. In wet concentration the drying of the tail ings would be expensive, and there would be a considerable loss of silver in slimes. Oxidized ores, containing silver chloride and lead minerals, may be lixiviated after crushing, and the tailings may be concentrated for lead. In this case wet concentration would be most suitable. This has been done at the Old Telegraph Mine, Utah. I would give, however, the preference to dry concentration in all cases which, of course, requires that concentration should precede lixiviation. The Russell process is also adapted to the treatment of tailings resulting from ores which have been worked either by the old

Jan 1, 1887

By Fred K. Stieler

The largest updraft sinter machine built has a roasting area of 132 sq.m. Sinter machines with an area of over 200 sq.m. are under consideration. These large machines require new techniques with regard to drive thrust and sealing mechanism. To optimize the results of sinter plants, the charge preparation systems and the return fines circuits were improved. Special crushers were developed for crushing return sinter of up to 800 ºC to a size of minus 6 mm. Strand cooling of Pb-sinter was investigated. Different methods for plant ventilation were compared. New processes, which might replace sintering in the future, are in the stage of large - scale testing.

Jan 1, 1977

THE first session was held in the small hall of the Academy of Music, on Tuesday evening, February 18th, 1879. The proceedings were opened by the reading, by President Eckley B. Coxe, of the following Address : SECONDARY TECHNICAL EDUCATION. Technical education is a subject to which both the American Institute of Mining Engineers and the American Society of Civil Engineers have of late years given much attention, and deservedly so. We all remember the admirable address of our former President, Mr. Holley, at the Washington meeting, upon this subject, and the very interesting reunion of the two societies in Philadelphia for its discussion. The problem to the solution of which the meeting devoted its attention was, "Shall the practical education of the engineer in the mine, in the rolling-mill, in the workshop, or in the field, precede, be contemporaneous with, or follow his theoretical studies in the technical school ?" I do not propose to add anything to what was so admirably said by so many of our leading engineers on that occasion ; but I shall ask your attention to another question in technical education, which seems to me equally worthy of our consideration, and which, I am sorry to say, has as yet attracted but little attention in this country. It is, "Shall the apprentices (I call them so for the want of a better general name), who are growing up and learning their trades in and around our mines and works, and from whose ranks the master mechanics and foremen of the future must be taken-shall they be provided with some means of obtaining as much theoretical training as may be necessary to enable them properly to understand the various processes and operations that they may be called upon to superintend, and not be obliged to pick up, as best they may, here a little and there a little truth mingled with much error?" In the former case, those who have the ability and industry to avail themselves of the advantages that should be offered to them would fit themselves to become real foremen, men who would understand and appreciate the true engineer and his methods. Of late years the young men of this country who have wished to enter our profession have had great facilities offered to them for so doing ; there have been undoubtedly great improvements in the methods of instruction; and although I am very far from imagining that no further progress can be made, or is demanded, yet I feel sure that

Jan 1, 1879

By Howard Martens, Pol Duwez

XPERIMENTS were performed on a Cr-Fc alloy Econtaining 44.7 pet Cr in order to determine the heat evolved during the transformation of the a solid solution into the s phase, and the change in volume accompanying the transformation. Since previous measurements on the rate of formation of a from s indicated that the reaction was quite fast as soon as the equilibrium temperature of 820°C was exceeded by some 50°, standard thermal analysis experiments were performed on heating specimens of s at the rate of approximately 40°C per sec. A definite thermal arrest was observed at 870"C, Fig. 1. This result indicates that the reverse seaction of into a is exothermic. From the heating curve of Fig. 1, taking 15°C per sec as the heating rate in the neighborhood of the transformation, 2.4 sec as the time for transformation, and assuming that the specific heat of the alloy at 850°C is an average between iron and chromium, namely 9.5 cal per mol per "C, the latent heat of transformation is approximately 342 cal per mol. The order of magnitude of this latent heat was also obtained by comparing the heating curve of Fig. 1 with a similar curve obtained with pure iron under identical experimental conditions. It was found that the length of the thermal arrest for s was about 1.8 times as long as that for iron. Since the latent heat of the a to 7 iron transformation is 203 cal per mol1, 2 the latent heat of it to a would be 365 cal per mol, which is in relatively good agreement with the value determined from the heating curve. For the determination of volume change, thermal expansion curves were recorded using a specimen containing 44.7 pet Cr and completely transformed to cr by previous treatment. The curves were recorded at a rate of heating of about 4°C per min and at approximately 840°C a sharr, increase in length of about 0.08 pet took place. Fig. 2. It is therefore established that the specific volume of a near the transformation temperature is about 0.24 pet smaller than that of a, and consequently, when the s phase forms in an a matrix, it would tend to shrink away from the matrix. Since the s phase is known to be extremely brittle, these results offer an explanation for the microscopic cracks often observed in the a phase under the microscope. The results of this study are in qualitative agreement with previously published data on stainless steel 19-9DLa and on a Cr-Fe alloy containing 45 pet Cr.' The increase in density due to the transformation from n to s given in ref. 4 is 0.90 pet. These measurements, however, were made at room temperature. whereas the presently reported 0.24 pet is the change at the temperature at which the transformation takes place during heating. In the graph of Fig. 2, the percentage change in length that would be observed at room temperature is given by the length X, which is about 0.27 pet. This would correspond to 0.81 pet in volume change. Acknowledgment This work was done at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. DA-04-495-ORD-18 with the Army Ordnance Corps, Washington, D. C. The authors wish to thank this agency for permission to publish the results of this investigation. References I H. Klinkhardt: Measurements of True Specific Heats at High Temperatures. Annalen der Physik (1927) 84, pp. 167-200. - H. Esser and W. Runghardt: Influence of the Method, of Dctcrmination on the Measured Heat Content of Iron. Archtvo ffur Dct Eisenhiittenwesen 11934) 8, pp. 37-38. J. J. Gilman, P. K. Koh, and 0. Zmeskal. Delta Ferrite Formation and its influence on the Formation of Sigma in a Wrought Heat Resisting Steel. Trans. ASM 1 1949) 11, pp. 1371-1388. 1 J. M. Thomas: Discussion of ref. 3. Trans. ASM (1949) 41, pp. 3 390-1392.

Jan 1, 1957

Jan 1, 1879

Jan 1, 1970

[A Aall, Christian H., M49 A Dir, Smelt & Ref, Am. Metal Climax, Inc., 1270 Ave. of the Americas, New York 20, N. Y. Aaroe, S. L., A54 A VP, W. S. Tyler Co. of Canada Ltd., P. O. Box 100, St. Catharines, Ont., Canada Abalos, Teodulo Q., J57 A Prod Frmn, Lepanto Cons. Mining Co., Lepanto, Mt. Province, Philippines Abbitt, James M., A54 770 Sole Blvd., Bartow, Fla. Abdullah, M. Y., J53 Dept. of Mines Res. Div., P. O. Box 1016 Tiger Lane,-Ipoh Peram, Malaya Abel, John F., Jr., J53 F Mine Engr, Thompson Creek Coal & Coke, Carbondale, Colo. Abell, Leo M., M31 B Const Supt, Phelps Dodge Corp., Morenci, Ariz. Abendroth, H. E., A57 Mangore Australia Pty. Ltd., 901 Hay St., Perth, W. Aust.,, Australia Abenius, Hakan V., M52 Falun, Sweden]

Jan 1, 1961

THOSE NOT MARKED ARE MEMBERS; MARKED THUS ? ARE ASSOCIATES. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. JUNIOR ASSOCIATES ARE MARKED II. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. ?AARONSON, ALFRED E Pres., Tuloma Oil Co., Unity Bldg., Tulsa, Okla. '18 ABADIE, EMILE R., Min. Engr Box 291, Porterville, Tulare Co., Cal. '76 ABBOTT, CLARENCE E., Gen'l Supt., Iron Mines Div., Tenn. Coal, Iron & R. R. Co. 1405 Minnesota Ave., Bessemer, Ala. '04 ABBOTT, LOUIS BENJAMIN, Chief Engr., Consolidation Coal Co., Elkhorn Div. Jenkins, Ky. 115 ABBOTT, ROBERT R. Met. Engr., Peerless Motor Car Co., Cleveland, Ohio. '12 ABE, ASAKA Fujitagumi Taiwan Office, Taipeh Formosa, Japan. '14 ABEEL, GEORGE H., JR., Cons. Min. Engr., 4111 Lafayette Ave., St. Louis, Mo. '18 ABEY, HIROSHI, Min. & Met. Engr., Arakawa Mine, Mitsubishi Co., Senpoku-gun, Akitaken, Japan. '17 ||ABOUCHAR, S. S., Cia. de Minerales y Metales, S. A. Santa Eulalia Unit, Apt. 70, Chihuahua, Chih., Mexico. '17 ABRAHAMS, A. I 1391 Madison Ave., New York N. Y. '14 ?ACKER, E. O'C., Met., 128 East Washington Lane, Germatown Philadelphia, Pa. '86 ACKER, WILLIAM L., Diamond Drill Contractor... Mears Bldg., Scranton, Pa. '18 ?ACKERMAN, ERNEST R., Pres., Lawrence Portland Cement Co. Plainfield, anion Co.. N. J. '15

Jan 1, 1923

By S. B. Casey

[ ] IN 1880, an electric arc was struck over metal for the first time to experiment with controllable melting. The glare of this arc has reflected on the stacks of the steel industry and continued to light the path of steelmakers in their never ending quest -for faster, more economical, and better ways of producing steel. William Siemens is credited with first employing the electric arc to melt metal in a closed hearth and produce basic metallurgical reactions. By the turn of the century, an Italian, named Stassano, was experimenting with ore reduction by the electric arc. In 1899, Dr. Paul Heroult, in France, used the direct arc principle for producing ferro-chromium. His experiments quickly led him to develop a dosed-top arc furnace for the production of steel, and his first commercial shipment was recorded in December, 1900. American steelmakers, quick to sense the possibilities of this method of melting, invited Heroult to our shores, where, in 1905, he was responsible for installing the first arc furnace on the North American continent. This furnace, at Sault Ste. Marie, was built for ore reduction. But Charles Holcomb, founder of Holcomb Steel. Co. of Syracuse, N. Y. contacted Heroult in 1905 and contracted for the first American direct-arc electric furnace for steelmaking. On April 5, 1906, the first heat was tapped from this 3-ton unit. The furnace was basic lined and powered by a single-phase, 500 kw generator, -producing high amperage at low voltage. It is interesting to note that, although the first few heats were made with cold charges, subsequent heats were duplexed. R. H. Bully, first superintendent of Holcomb Steel, persuaded the directors to purchase the unit to effect a more economical and efficient means of making tool steel by duplexing prime melting in a combustion fired furnace, and transfer of hot metal to the arc furnace for temperature adjusting, refining, and adding carbon and alloying elements. Today, duplexing is foreseen by some as the steelmaking process of the future. The promise shown by America's first arc furnace for ingot production quickly led to the purchase of a similar unit by The Firth Sterling Steel Co., in 1909, and to the purchase of the first arc furnace for production of steel castings, by the Treadwell Engineering Co., in 1911. From its humble start in 1906, production of arc furnace steel has never ceased to increase its yearly percentage of total steel production in the U. S., although certain other methods have declined or almost disappeared. By its ability to be used intermittently, the arc furnace gained favor and enhanced its reputation during depression days. When the attack on Pearl Harbor plunged us headlong into the long days of World War II, the arc furnace stood ready, flexible enough to be overburdened hearth wise 30 pct and power wise 25 pct, pouring its endless flood of alloy for the guns, tanks, ships, and planes which ultimately brought victory. During the post war boom, the now, proven virtues of low initial cost, faster installation, better yield, improved availability, and lower operating cost, enabled industry-particularly the small, new, independent producers-to locate strategically and profitably to meet the demand of an America that had been starved for new homes, appliances, cars, and highways. In the Korean police action, the arc furnace again proved itself by providing the latest alloys metallurgists could develop to meet the demands that the jet age and the innovations of guided missiles required. In today's peacetime prosperity, the arc furnace is continuing to provide the economic flexibility required to meet an ever increasing demand for better steel in the face of mounting costs, scrap shortages, and pressure toward decentralized location of industry.

Jan 1, 1961

Jan 1, 1967

By AIME AIME

WITH the example of the steel open-hearth men and their round table conference before the copper men, the query naturally arose "Why cannot we do likewise?" The advantage of pooling and comparing knowledge on smelting in the copper reverberatory furnace seems particularly pertinent at this time when all metallurgical economies possible must be rigorously enforced. A great deal of data had also been obtained and filed during the period of litigation over the Carson patent, and it would naturally be available with the cessation of further suits. With these ideas in mind, H. Foster Bain took up the advisability of holding such a conference directly with the heads of all the companies in the United States operating copper reverberatories, and found a nearly unanimous response. The mining companies appointed representatives directly, or indicated to the heads of various metallurgical operations what members of their staffs should be sent to such a conference.

Jan 1, 1930

By C. S. Anderson

Georgia, since 1829, has produced nearly $18,000,000 from her gold mines, but in late years the output has dwindled to insignificance. In view of present universal efforts to increase gold production, it seems pertinent to record some recent observations in that field, briefly review its past and weigh probabilities of reviving gold mining there. Little in this paper can be claimed as new or original, and it does not present results of a detailed or profound investigation of the whole region. The Allatoona gold mine was reopened in January, 1932, and explored at greater depth during the period from January to June of that year. A number of other abandoned mines were visited, but since the workings, in common with most such mines in Georgia, were flooded or caved, underground conditions could not be examined. For a wider knowledge of the subject, a search was made through available pertinent literature and statistics, a bibliography of which is appended hereto. To all the sources obligations are gratefully acknowledged. Production The discovery of gold in Georgia, in 1829, led to an influx of 6000 to 7000 miners and a production of over $200,000 in the following year. A branch of the United States Mint, established at Dahlonega in 1838, accounted for $6,115,569 up to the time of the Civil War. The output fluctuated greatly from year to year, with an all-time peak of $582,782 in 1843. In only one other year, 1845, was the half million mark exceeded. After the war mining began again, but 1883 is the last year for which an output of $200,000 is reported. Placers, always the main source of production, were yielding less and less, and in spite of increased quartz-mining activities the downward trend continued. The last year in which there was a production of $100,000 was 1902. In 1914, $16,270 came from 26 placers and 11 deep mines, with the latter reporting 1750 tons of $3 average value. In 1925, one placer and four lode mines that mined 8100 tons assaying $1.19 per ton produced $9500. One placer and one quartz mine, operating in 1930, reported a total output of $4194. Table 1 pictures the waning output.

Jan 1, 1934

By Henry N. McCarl

Mineral aggregates are those natural and manufactured industrial mineral and rock materials that provide bulk and strength in port- land cement concrete, bituminous concrete mixes, and plaster or stucco surfaces. They may also provide special characteristics such as thermal and acoustical insulation, weight, surface textures, abrasion resistance, and impermeability to various concrete products and mixes. Most aggregates are relatively inexpensive materials, but despite their low unit value, the tonnages consumed each year in the United States and throughout the world make mineral aggregates by far the leading industrial mineral and rock materials both in terms of volume (tonnage) produced and value consumed. The major use of mineral aggregates is in concrete. The low cost, high bulk aggregates tend to keep concrete construction costs at levels competitive with other building materials. Other major uses of aggregates include highway and railroad base or ballast materials, graded fill, and various industrial uses such as metallurgical and chemical fluxes and raw materials-these latter uses are often considered nonaggregate uses of mineral aggre- gate materials. The value of mineral aggregate materials at the production plant varies from less than a dollar per ton to several dollars per ton for most crushed stone and sand and gravel, $2 to $15 per ton for slag and expanded clay or shale aggregate, to as much as $60 to $100 per ton for expanded perlite or vermicu- lite. The more specialized the use, the higher the price-although there are naturally some exceptions to this rule of thumb. The first four parts of "Construction Materials" deal with the utilization of four major mineral aggregate types: Crushed Stone, Light- weight Aggregates, Sand and Gravel, and Slag. While the focus will be on the use of these industrial minerals and rocks there will also be some coverage of sources, mining and production, especially in those cases where they are

Jan 1, 1975

By AIME AIME

N EARLY 1300 members and guests crowded the halls of the Engineering Societies Building during the winter meeting of the Institute just closed, and more than 600 attended the banquet. In variety of program, quality of papers, interest in discussion, and brilliance of social features, the meeting maintained the high reputation of the past. Nothing elaborate in the way of excursions was attempted, experience having proved that February weather in New York is much too uncertain to warrant extensive field trips. A sight-seeing journey up the Hudson to the Bear Mountain bridge was, however, made despite the snows of the week before and the week after. The annual business meeting, while attended by a minority of the members in the building, was marked by the display of keen interest in the work and called out several interesting discussions. The excellent reports of the committees that had organized their work and directed it along definite lines, emphasized the need of funds with which to support assistants or Fellows who shall correlate and put to the highest use the facilities of the Institute in research along technical lines. This thought was developed at the banquet by the retiring president, J. V. W. Reynders, and it is expected that the Directors will take early steps to collect a fund for this purpose. The number of the individual sessions was too great and the papers and discussions too numerous to permit mention here of all the features of inter- est. A general review only follows. The papers and detailed discussions will be printed and sent to members as promptly as possible.

Jan 1, 1926

Jan 1, 1967

The new Ceramic Engineering Building of the University of Illinois is to be formally dedicated on Nov. 20 and 21. The occasion will be made one of great interest to the clay-workers of the country. It is expected that the exercises will be attended by many representatives of the architectural, structural, mining, geological, chemical, and manufacturing interests. In connection with the dedication exercises, an industrial conference will be -held, in which a number of topics of current interest to the ceramic engineer, the clay-worker and the manufacturer will be discussed by well-known experts. : The number of students registered in the College of Engineering of the University of Illinois eleven days after the beginning of registration - for the new year, is as follows: Architecture, 116; Architectural Engineering, 167; Ceramic Engineering, 46; Civil Engineering, 190; Electrical Engineering, 266; Mechanical Engineering, 273; Mining Engineering, 25; Municipal and Sanitary Engineering, 26; Railway Engineering, 34; total, 1,143. The enrollment of students in the whole University, not including the College of Medicine, the College of Dentistry and the School of Pharmacy, which are located in Chicago, is 5,21.4.

Jan 10, 1916