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The rich Tiller seam in southwest Virginia averages 10 to 15 ft in thickness. But because it is separated into two benches, mining engineers for years considered it neither physically nor economically feasible to mine. Profitable recovery of this coal has been made possible only by: full-seam mining with automatic machines; and the largest and most highly automated coal preparation plant of its kind-a plant ten stories high which washes, screens, and dries at the rate of 1500 tph, and produces both metallurgical and steam coal products. The Moss No. 3 preparation plant of Clinchfield Coal Co. Div. of Pittston Co. is located at Clinch- field, Va., only a short distance from the 450-tph Moss No. 2 plant, and was designed, built and erected by Link-Belt Co.

Jan 7, 1959

By AIME AIME

FOR the purpose of subsequent discussion let me reiterate certain points in my paper. The things we are certain of are that individuals differ in their accident liability, and that the bulk of accidents in any industrial group is sustained by comparatively few individuals; further, that this difference in liability cannot be wholly accounted for by differences of exposure, since some of the personal factors involving a high accident rate have already been measured in certain industrial groups.

Jan 1, 1929

By M. M. Leighton

INASMUCH as the arrangements for the preparation of the review of progress and new developments in the field of industrial minerals (non-metallics) were not made until early December, the writing of this review could not be completed in time to appear in this issue and will, therefore, appear in the February issue. However, we desire to call attention to the steadily increasing importance of this group of mineral substances. The recent book, "Industrial Minerals and Rocks," published by the Institute, lists 47 principal varieties of nonmetallic minerals to which may be added several more of lesser importance. Because of the wide variety of uses to which many of these industrial minerals are put, it is difficult to classify them into categories, but to mention a few examples which indicate the widespread industrial employment of these minerals and their products, one may cite: the use of limestone, gravel, sand, clay products, lime, cement, and gypsum in the construction industry; fluorspar, lime, salt, borax, and sulphur in the chemical industry; diamond, corundum, emery, garnet, flint, quartz sand, tripoli. and diatomite in the abrasive industry; fluorspar, limestone, and magnesite in the metallurgical industry; clay, feldspar, fluorspar, flint, chalk, and limestone in the ceramic industry; and asbestos, gypsum, mica, vermiculite, magnesia, diatomite, and rock wool in the heat, sound and elec-

Jan 1, 1940

By AIME AIME

THE Institute of Metals Division of this Institute held a joint meeting with the American Foundry- men's Association on Oct. 5-9, at Syracuse, N. Y. The registration at this meeting was about 150. There were four meetings in all, three of which were in con- junction with the American Foundrymen's Association. This combination works out very nicely and gives the I Division a number of practical foundry papers that it would not get otherwise. The sessions were well attended and the discussion was active. The session on Monday morning was of a general nature and consisted of the following subjects : " Refractory Problems in the Non-ferrous Electric Furnace Casting Shop, " "Temperature Control of Non-ferrous Alloys," "Atomized Coal System of Non-ferrous Melting," "Material Handling in a Brass Foundry." On Tuesday morning, the session was on "Aluminum and Its Alloys." The paper on permanent mold castings created a large amount of discussion, in fact so much that it had to be renewed after the close of the regular program. Aluminum is assuming a more important place every year and adds greatly to the program as a whole. One of the most remarkable meetings that this Division has ever had was held on Tuesday at noon in the form of a Round Table discussion, headed by G. K. Elliott, chairman of the Division, Cincinnati, Ohio. Mr. Elliott divided the members present, numbering about 80, into groups as they were seated at the tables. Each of these groups suggested a topic for discussion. They were as follows : "Fluxes on Market ;" "Simplification of Alloys;" "Pyrometric Control;" "Effect of Gas- sing Metal and Control;" "Barium Sulfate Added to Electric Furnace to Create Slight Oxidation to Remove Aluminum and Silicon;" and" Nickel in Brass."

Jan 1, 1925

By AIME AIME

ABOUT 55 attended the general session of the Nonferrous Metallurgy Committee on Wednesday afternoon. In opening the proceedings the Chairman, Frank G. Breyer, served notice of his intention to make an early start this year in securing papers for his committee. He voiced the thought that more importance should be attached to the prompt publication of data on new advances in practice; the record of technical progress should be written before the sharpness of the current image becomes blurred by the veil of time. As an illustration, Mr. Breyer declared that great strides have been made in the zinc industry during the past nine years, whereby zinc ore is converted directly to the oxide in large mechanical furnaces, yet the literature is confined to patents.

Jan 1, 1933

HeRbert A. MeGRaw, San Luis de la Paz, Guanajuato, Mex. (communication to the Secretary*) :—Although Mr. Bordeaux prefaces his paper with the statement-that it is a general outline of practice in the Republic, many of his statements seem to be made from the view-point of a particular case, which does not always agree with general practice. For the purpose of calling attention to some of these variations, I respectfully offer the following comments: The operation of crushing and grinding is performed by so many different methods and systems that it is useless to select any one as the standard. However, primary crushing in rock-breakers followed by stamps is thus far so general that it might be so classified. Whether or not it is the best way, is open to question. Regrinding may be performed by any of the various types of Chilean mills, Huntington mills, or similar machines, or the material may be taken directly from the stamps and delivered to the tube-mills. Mr. Bordeaux's statement that " the slimes can be treated only by decantation; the new Butters slime-filter, as used in Nevada, does not seem to be successful with silver-ores," is surely an error. All over Mexico many of the purely silver-ores are being successfully handled by the Butters or similar filters, such as the Moore and the Burt filters, and a letter to the manufacturers of these filters will undoubtedly bring a list of the silver-ores now being successfully treated in this way. The statement that crushing silver-ores in solution is impossible is equally erroneous. Most modern mills crush the ore in solution, in some cases containing as much as 0.12 per cent, of KCN. I cannot for the moment recall any modern mill in Mexico which does not follow this practice. There may be some reason for it in particular instances, but, generally speaking, the practice is to crush in solution. Care in installation avoids any mechanical loss of cyanide, and the chemical loss is so small as to be negligible.

Jan 1, 1910

Albert Ladd Colby, New York, N. Y. (communication to the Secretary†):—I observed (Trans., xxxvii., 585) that to obtain tenders from several American mills, the foreign engineer should modify his maximum phosphorus to 0.10 per cent., not as Mr. E. Windsor Richards quotes me, that no American rail-maker can produce rails under 0.10 per cent. of phosphorus. Mr. Richards claims that no English engineer would agree to accept 0.10 per cent. of phosphorus on any terms whatever. Mr. Webster writes that only after an engineer has .been convinced that rails can be made in America equal in every respect to those he is getting abroad, should he be asked to modify ally conditions in his specifications. I know it to be a fact that during recent years in many cases, as, for instance, When delivery could be secured more promptly in the United States than in Europe, the consulting engineers of several British and colonial railroads have frequently agreed to modify their phosphorus requirement to a maximum of 0.10 per cent., and the rails delivered' under these modified specifications have, under like conditions, given just as satisfactory service and proved to be no more brittle than similar sections of 0.07 per cent. phosphorus rails, rolled in England under the same specification except without modification as to phosphorus. Furthermore, it would appear from the analyses of British rails, quoted by E. A. Dancaster,2 in his discussion of Mr.

Jan 1, 1908

By Carle R. Hayward

GENERAL conditions in the lead industry have registered a distinct improvement. The first signs of a strengthening market were found in an increasing demand for scrap. There is keen competition for old battery plates both by large and small dealers. The large operator smelts them either alone or in combination with ores or other lead-bearing material, giving an antimonial lead for which there is brisk demand. The small operator usually has three alternatives. He may simply melt out the metallics in a kettle at low temperature, giving an antimonial lead and a pulverulent lead oxide; he may fuse under oxidizing conditions, giving a soft lead and lead-antimony slag; or he may fuse under reducing conditions, giving a relatively low-grade antimonial lead and a low-antimony slag. In each case the metal product is used or sold, and the dross or slag sold to a large smelter. It will be interesting to see what the final outcome will be of this situation which is generally conceded to be unsatisfactory.

Jan 1, 1937

By AIME AIME

ANNOUNCEMENT on August 6 of the historic event of dropping an atomic bomb on Hiroshima, Japan, was more dramatic even than V-E day, since that had so long been forecast whereas the bomb production had been the best-kept secret of the war, even though at one time more than 100,000 people had been at work in connection with its production, and some two billion dollars had been spent on the project. Mining men had long been aware of an unexplained abnormal interest in uranium production, and suspected that something of the sort was on foot, while metallurgists were aware that various men of their acquaintance were engaged in some top secret research. The first announcement was soon supplemented by other official releases which told more about the research laboratories for theoretical and pilot studies, and the plants in Tennessee and Washington, but none of them made clear what the modus operandi is of these terrific bombs. Inquiry at Colum. bia University, where Dr. Dunning and his associates had succeeded in 1939 in splitting the uranium atom, and where laboratories known only as SAM have been feverishly active since the beginning of the war, was unproductive, since none of those officially connected with the project could give out anything beyond the official releases.

Jan 1, 1945

By Charles F. Park

CORRECTLY speaking, iron ore is limited to any naturally occurring rock from which iron may be extracted at a profit, but in practice the term is frequently used to indicate borderline material or inaccessible material that may in the future become commercially profitable. This distinction is much more than quibbling about terminology. When a layman hears that there are about 45 billion tons of iron ore in the world he naturally thinks that sounds like quite a bit of rock, and what is the use of worrying about the depletion of so plentiful a material. He does not realize, nor does he stop to analyze. why iron ore in Europe and Japan may carry no more than 30 per cent iron while tremendous quantities of 50-60 per cent iron ore in Brazil are not exploited. To people in the iron industry the answer is obvious: the Brazilian material is inaccessible, and there is no suitable fuel near-by. In places closer to home, submarginal ore in considerable quantity contains undesired impurities, such as sulphur, phosphorus, or titanium.

Jan 1, 1947

A. 11. P. WYNNE, San Jose de Gracia, Sinaloa, Mex. (communication to the Secretary): In the comparative tests reported by Mr. Tays, the stamp-batteries were provided with various styles and mesh-sizes of screens, while the Bryan mill was run throughout with a slot-punched Russia iron, equivalent to a 30mesh wire screen. This is a somewhat onc-sided method of comparison. Should not the Bryan mill also have had the chance to show what it could do with other screens? I cannot wholly approve Mr. Tays's proposed improvements upon the Bryan mill. In my judgment, the inventor has given us a machine well-adapted to the work for which it was designed, namely, the crushing and amalgamation of soft ores. In my judgment, the principal cause of failure to amalgamate satisfactorily in the Bryan mill is not, as Mr. Tays thinks, the shallowness of the basin, or the lack of copper plate about the inside periphery of the mill, but rather the want of experience and practical knowledge on the part of most amalgamators. Having had experience, not with one Bryan mill only, but with several, and taking into consideration the experience of other capable mill-men, I am positive that the proper way to save gold ill this mill is: first, to use enough quicksilver to keep the amalgam liquid, thus allowing it to accumulate in the annular space between the dies and the rims of the basin; secondly, to replace the old dies, when a little more than half worn-out, with new ones; and, thirdly, to clean up the mill at least every two weeks—or oftener, if rich ore is being treated. It is evident that Mr. Tap endeavored to amalgamate quite " hard," as is done in a stamp-battery, in which case the swash of the pulp would scour off portions of the hard amalgam adhering to the inside plates and dash it through the screens— after which a considerable amount would be lost through floating on, or in, the pulp in its journey over the outside plates, and

Jan 1, 1900

By Charles A. Bohn

WHEN the need for war work was ended, the late Mrs. Sidney J. Jennings felt that the members of the Woman's Auxiliary, who had worked together so successfully, would profit by having a common permanent aim through scholarship work, financed by annual contributions from the Sections. Under her leadership the Sections responded generously and the educational fund was started. Mrs. Jennings became the first chairman of the executive committee and so remained until her death. It was planned to begin with an award of $500 each year, and to pot aside 25 per cent of all moneys re¬ceived from the Sections to establish an endowed fund. In 1921 the first scholarship of a value of $500 per annum was granted, and an award of the same value has been made regularly every year since. It is called the Subscription Scholarship. The 25 per cent, which is set aside each year and carefully invested, is called the Engineering Education Endowment Fund. Three years ago this fund began to yield around $300 annually and this income has been used each year since to finance a scholarship under that name.

Jan 1, 1937

By R. G. Bowman

LEAD is a dull and sober metal, and in times of economic stress it en- joys, or at least occupies, a position which partakes somewhat of its physical lethargy and stability. The past ten years have witnessed in this country a decline in the production of lead, and a shrinkage of ore reserves, following closely the general economic situation. Metal prices have not justified exploration and development of new sources. Momentary rallies in industry have brought no response from lead.

Jan 1, 1940

By Noel Cunningham

MANY excellent descriptions of the mills of the, Porcupine district have been written, but no discussion exclusively devoted to the metallurgical technology has been given. These notes are intended to cover this feature briefly. They are based upon 2 ½ years' mill operation in the district-i.e., practically since the beginning of metallurgical operations. Character of the Porcupine Ore.-There is no oxidized ore in the district, the surface having been deeply planed by glacial action in recent geologic time. The precious-metal content is about in the proportion of 85 of gold to 15? of silver by weight; hence, the silver is practically negligible. There are two classes of Porcupine ore, having very different characteristics; these will be referred to throughout this paper as Class A and Class B. Class A ore is a pure quartz with inclusions of schist. Generally it is heavily fractured .and breaks down readily to sharp, hard grains, about minus 10 plus 20 mesh, requiring further comminution to release the gold. It carries very little pyrite; the gold is entirely free and apt to be coarse, but often spongy, going into solution readily on that account. This gold is 60 per cent. to 85 per cent. free milling, depending on the grade of ore. Class B ore is an iron silicate schist, strongly laminated, carrying 4 to 5 per cent. pyrite; its specific gravity is 2.8 to 3.0, depending upon the amount of mineralization. In breaking the ore in the mine, generally over 25 per cent. of material through a ½ -in. ring is made; the ore readily breaks down in milling and makes a comparatively large amount of non-crystalline slime; owing to its high specific gravity, however, it is quick settling.' In my opinion, the gold in this ore is free, but so finely divided that it will neither pan nor amalgamate; it appears to be disseminated through the rock and not chiefly associated with the pyrite. Veins of Class A ore occur with or without side walls of Class B, and veins of Class B occur unassociated with Class A; more often the veins are closely banded, Class A and Class B alternating, generally with Class B in excess. Both classes of ore are more-or less blocky at times, and with ref¬erence to Class B this is indicative or low gold content.

Jan 3, 1915

A. H. Bromly, Zihuatanejo, Guerrero, Mexico (communication to the Secretary*):—The following criticism of what "is offered as a summary which may be found useful by mining engineers," is not dictated by any captious spirit, but in the intereet of historical and scientific accuracy. The States of Queretaro and Oaxaca have produced sufficient silver to warrant more extended notice. Referring to Pachuca, State of Hidalgo, the eomewhat loose and inexact statement is made that "the ore-depdsit is an andesite, intermixed with quartz-veins, rich from the surface." A better description mould be,—the ore-deposits consist of quartz-veins in andesite. It is notable that many of the rich shoots worked in recent days did not come to surface. In consequence, Pachuca is often quoted by the ill-informed as a camp in which values improve with depth, the truth being that the veins carry shoots, or clavos, some of which were exposed at surface and some not. The name of " electric plow," applied to the mechanical stirrer of recent use, is certainly not to be recommended. The stirrer, or agitator, consists essentially of a traversing gang-plow, operated by power through shafting; drums, and wire-rope. The fact that in certain plants the motive-power used is electricity does not make it an electric plow. Such a name suggests a machine of which the motor is an essential and integral part; which is not so in this case. A lathe in a factory driven by water-power is not called a hydraulic lathe. My experience agrees with Dr. Raymond's note as to azulapue, which in some districts is also applied to blue copper carbonate. The El Oro, Esperanza, and Mexico mines should be allocated to the State of Mexico; the Dos Estrellas being in Michoacan, as stated. The El Oro quartz certainly does not appeal to me

Jan 1, 1910

By Carl Lee

OXYGEN-FREE high-conductivity copper (OFHC brand) that is now being commercially offered for the first time represents a notable achievement in electro-metallurgy and is the outcome of endeavors that have extended over a long period. Its manufacture is novel in that electrolytically refined copper is melted in electric furnaces and cast into vertical water-cooled molds. The ingots show the "pipe" characteristic of sound gas-free metal and microscopic examination even at high magnification reveals no cuprous oxide in the copper. Owing to the patent situation, the United States Metals Refining Co., the producers, cannot at this time divulge the details of manufacture, but the operations are under precise control so that the castings are of great uniformity and the copper contains no residual deoxidant. Figs. 1 and 2 show photographs of cross-sections of a wirebar and a billet, both vertically cast.

Jan 1, 1933

By Carl Lee

WITH the modern trend toward motor drive in coal mines, more careful forethought should be given to future layouts than has usually been done in the past. Both top and bottom equipment of future new mines is likely to differ radically from those of a decade ago. No one is able to predict very far ahead, but provisions can be made to allow for uncertainty. One thing stands out: the mine of the future will be laid out for long life compared to that of the small mine of the past, where an inexpensive top plant, simple equipment, a small timbered shaft, small cars, light rail, hand loading and mule haulage all contributed to a short economical life.

Jan 1, 1933

By John W. Padan, John E. Crawford

Beginning with a small but positive participation in undersea mining, the Bureau of Mines continues its active investigations into this potentially tremendous field. The Bureau began its active role in undersea mining in September 1963, with a small task force of three dedicated scientists and a secretary, establishing headquarters at the old Tiburon Naval Net Depot about seven miles up the coast from San Francisco. The past months have been both busy and productive. With 22 Federal agencies involved in oceanography, it logically was the intent of Congress that the Bureau of Mines undertake research concerned only with the technology of marine mineral production and utilization. The Bureau has maintained this purpose in its activities at Tiburon, for while institutes, universities, the Navy and other Government agencies have developed exceptional programs in the fundamental science of the oceans, commonly called oceanographic research, little has been done toward advancing man's ability to exploit the ocean floors other than by drilling for oil and gas and sulfur.

Jan 3, 1965

By ALBERT C. RUBEL

RECENT developments in the use of the core barrel in rotary drilling have led to its wide application in all types of development. Its use is essential to the wild-catter and a valuable guide and check even in the most closely developed areas. A perfect core would be an unbroken sample of formation whose length is equal to the amount of hole made by the core barrel, whose diameter is great enough to show the lithologic character, texture and attitude of the material encountered, whose formation is so unaltered in character and so free of contamination from outside sources that it represents a true and complete sample of the formation penetrated. From such a core it would be possible to determine the lithologic character and economic importance of the formation, whether it is oil bearing or barren, the nature and attitude of the sands and shale bodies, valuable fossil evidence and other points which would assist in the correlation or in the selection of suitable points for water shut off or production.

Jan 1, 1924

By E. Just

The mining industry is guaranteed an important future because its products are indispensable. However, this can be anything from a brilliant, efficient, profitable future to one of being a heavy-handed, dull-witted claimant for public handouts, according to the caliber and training of the young men who enter the industry. Many views have been expressed about the type of education needed for today's mining industry. Criticisms have been aired to the point that further controversy amongst ourselves could be detrimental to both mining education and the mining industry. It is time we get together and start going somewhere. To canvass the various attitudes of mining educators, a questionnaire was sent to a group of these dedicated, intelligent men, whose primary interest is to help the industry and the profession. The following is a summary of their views.

Jan 9, 1961