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By Jerry Tien

Mine regulators are normally used for proper air distribution in underground mines. They are deliberately introduced resistance in the regulated airway, and by altering sizes, they can distribute specific air quantities to regulated splits and free splits (4, 5). The enactment of the Federal Coal Mine Health and Safety Act of 1969, the Federal Mine Safety and Health Amendments Act of 1977, and the regulations adopted by the Mining Enforcement and Safety Administration (now called the Mining Safety and Health ministration) prompted greater discussions of optimal mine regulator locations because of the Act's stringent ventilation requirements (2, 3). For example, by requiring the separation of the air used in the belt haulage entries from the intake and return airways, the regulations required the creation of a third type of airway---the neutral airway, as opposed to the intake and return airways, adding to the complexity of a mine's ventilation network. It is the intent of this report to show that panel regulators should be located in intake airways at the neck of a panel for a blowing fan system and in return airways at the neck of a panel for an exhausting fan system in order to achieve optimal air control. A computer simulation model is used to determine optimal mine regulator location.

Jan 1, 1983

By R. J. Woody

Design of the most economic continuous counter-current decantation (CCD) circuit is based on selection of the number of stages and the wash volume that will give the minimum summation of the following items: 1) Capital and operating costs of the CCD circuit. 2) Capital and operating costs of the precipitation circuit. 3) Value of the dissolved product lost.

Jan 1, 1959

By B. M. Larsen, L. S. Darken

SOME years ago we collated all laboratory data then available to us on the distribution at equilibrium of manganese and of sulphur between metal and simple slags, and used the results in setting up an equation, which proved to be in accord with determinations of the distribution ratio of manganese and of sulphur between liquid steel and open-hearth slag, over a wide range of operating conditions. We now present an outline of our calculations and inferences on these two closely related questions, which are of especial importance because of the advisability of conserving manganese wherever possible. In general, our results show that in the open-hearth furnace equilibrium between metal and slag, with respect to both manganese and sulphur, is substantially attained during the finishing period of the heat, or in about a half hour to an hour after any additions were made. This implies that the end result will be identical whether manganese is added as alloy or metal to the liquid steel or as oxide to the slag. The proportion of total manganese retained by the steel is favored: (I) by use of the minimum amount of lime, consistent with other operating limitations, required to give a lime-silica ratio of about 2.4, which usually corresponds to a minimum practical slag volume; (2) by a high concentration in the slag of MnO relative to FeO; (3) by high operating temperature. Absorption of sulphur by the slag from the liquid metal is favored: (I) by large slag volume; (2 by a high concentration of active (or "free") lime and of manganese oxide dis) solved in the slag; (3) by low concentration of silica, iron oxide, and phosphate dissolved in the slag. DISTRIBUTION OF MANGANESE BETWEEN SLAG AND METAL AT EQUILIBRIUM On the basis that the distribution of manganese between liquid steel and slag is controlled by the reaction [FeO + Mn = MnO + Fe [A]slag metal slag metal] the distribution at equilibrium, at a given temperature, is expressed by the equilibrium constant for this reaction, which is defined as [K" aMoO aFeI1 dFec) aMn] where a is the activity of the molecular species denoted by the subscript. The activity of each of the several components, although it is not known precisely, is approximately equal to the concentration of each component expressed as its mol fraction; that is, as the ratio of the number of mols of the given component to the total number of mols of all the molecular species present in the metal or slag, as the case may be. Moreover, since the activity, or concentration, of iron in the liquid metal is in fact substantially constant, the term [afe] may be combined with K" to give a new constant K'. Making these changes,

Jan 1, 1942

The selection of a particular machine for production drilling is the most critical drill evaluation the pit engineer is called upon to make. It is a true engineering design problem requiring value judgments. Generally, the procedure follows these steps: (1) Determine and specify the conditions under which the machine will be used, including such service factors as labor, site, weather, etc. (2) State the objectives for the rock-breakage phases of the production cycle of operations--considering excavation and haulage restrictions, crushing capacity, production quota, and pit geometry-in terms of tonnage, fragmentation, throw, etc. (3) On the basis of blasting requirements, design the drill-hole pattern (hole size and depth, in- clination, burden, spacing, etc.) (4) Determine the drillability factors and select the drilling methods which appear feasible for the kind of rock anticipated. (5) Specify the operating variables for each system under study, considering drill, rod, bit and circulation fluid factors. (6) Estimate and compare performance parameters, including costs. Major cost items are bits, drill depreciation, labor, maintenance, power and fluids. (7) Select the drilling system that best satisfies all requirements with the lowest over-all cost.

Jan 10, 1967

By E. C. Lee

THE safety of mine workers has received more attention from both State and Federal law-making bodies than any other industry, a fact that shows clearly the hazardous nature of the industry. The last, but by no means the least, of the measures adopted for the protection of mine workers, is workmen's compensation legislation. This is proving to be a powerful instrument for greater safety in the industries, from the fact that special stress is laid not on how the accident happened or who may have been responsible for it, but on how badly the employee is hurt by it. The injured person does not have to employ lawyers to prove his case, because the mere fact of his employment is proof of his right to compensation. The immediate effect of such legislation is the certainty confronting the mine operator that he must pay out large sums for every accident, regardless of its cause, thus adding materially to the cost of the production of his coal. This fact furnished to the operator the strongest incentive to reduce the causes of accidents; not that the operator has ever lacked reasonable consideration for the welfare of his employees and a proper humane interest in their safety, but his engrossment in earning his daily livelihood has been so great that he has not felt that he had the time to devote to the safety of the operation. This time he must now find because of the actual-cash value of the prevention of accidents in his mines. This agency alone proved inadequate to bring about a material improvement because operators have always been willing enough to improve safety conditions when possible to do so within reasonable limits of their financial ability. The requirement in the Workmen's Compensation Laws of several of the States, that the mine operator shall insure as a guarantee of his ability to meet his compensation obligations, has furnished the needed incentive, moral and financial, necessary to the prompt and effective dissemination of a more general knowledge of the causes and

Jan 10, 1917

By Evan Just

DIRECT subsidies for mine production in this country began as an outgrowth of wartime 'price regulation. The price-fixing authorities realized that the volume of production to be required from domestic copper, lead, and zinc mines would invoke costs of production considerably higher than the established ceiling prices. Accordingly, beginning Feb. 1, 1942 the Premium Price Plan was set up, which undertook to pay premiums to mines for production in excess of quota, of 5¢ per lb of copper and 2Y4¢ per lb of zinc or lead. Quotas, except for small mines, were initially established at the average rate of production in 1941, but were later reduced arbitrarily on an individual basis. Subsequently, additional "B" premiums were set for lead and zinc of 2Y40 per lb and a further "C" zinc premium of 2%¢. Additional copper premiums were negotiated on an individual basis, mainly with small mines. Quotas under each of these successive categories were the production obtained at the next lower premium level. In other words, under ceiling prices of 12¢ for copper, 6,14¢ for lead, and 83¢ for zinc, it was possible for high-cost operations to receive prices plus premiums of 17¢ or more for copper, 12¢ for lead, and 16% 0 for zinc on a portion of their production. On the other hand, some of the larger operators received only slight premiums and in at least one instance none at all. The average price plus premium for copper was 12.25¢ in 1942 and rose to 13.65¢ in 1945. That for lead was 6.99¢ in 1942 and 8.73¢ in 1945, and for zinc it was 9.06¢ in 1942 and 11.200 in 1945.

Jan 1, 1948

By R. W. Raymond

THE death of Privy Councilor Bruno Kerl, on March 25, 1905, terminated a distinguished and useful career. Bruno Kerl was born March 24, 1824, at St. Andreasberg in the Harz, and entered in 1840 the mining school of Clausthal, where he studied for three years, working at the same time in the mines and stamp-mills. After an additional year of practice in the silver-reduction and iron-works of the Upper Harz, he passed his examination as a metallurgical graduate, and studied for a year at Göttingen under WV filer in chemistry, Hausmann in mineralogy, and eminent teachers in other branches. In 1846 he was employed at the Oker works, but very soon left this post, to become a tutor in chemistry, metallurgy, etc., at Clausthal, where he continued to labor until 1867. During this period the Clausthal school became a completely equipped Mining Academy, and Kerl was made in 1862 a full professor. Meanwhile, in addition to the work of instruction, he discharged, simultaneously or successively, the duties of many responsible official positions in the Royal Hanoverian administration of mines and smelting-works, and also published many valuable books and treatises. Among these were professional guide-books to the Upper and Lower Harz, and their characteristic metallurgical processes; a manual of qualitative and quantitative blow-pipe analysis; another of metallurgical assaying ; and, most important of all, a Handbook of Metallurgy in four volumes, the second edition of which was issued in Leipzig, 1861-1865. This book was speedily recognized as the leading authority in its field. In this country, the English translation and revision, by Crookes and Röhrig, published about 1869, had a large circulation. In addition to these literary labors, Prof. Kerl became in

Jul 1, 1905

By D. L. Ritter, N. J. Grant, B. C. Giessen

The crystal structures of eight of the nine intermediate phases in the Nb-Rh system were investigated by X-ray techniques. The following structures occur: a,Nb3Rh (Cr3O type);o(ofe - cr type) (H.T. phase, structure unknown); Q2 (AuCU type); a, (orthorhombic, analogous to a,, (Ta-Rh)); a (AuCd type); a,, (monoclinic, related to samarium type); a-8 (VCo3 type); a, NbRh, (AuCu, type). Structural relationships between the six close-packed intermediate phases are discussed and a comparison with the Nb-Ir, Ta-Rh, and Ta-Ir systems is made. In the Nb-Rh phase diagram,' nine intermediate phases were encountered. In order to understand the phase sequence in the diagram and to be able to plot atomic volumes, several unknown crystal structures had to be worked out. These and the evi-

Jan 1, 1964

On Tuesday evening, February 21st, a reception of visiting societies was held in the Windsor Hall. Hon. George Irvine, Q. C., President of the General Mining Association of the Province of Quebec, occupied the chair, and, after welcoming the guests of the occasion in the name of that Association, introduced Mayor Desjardins, who expressed a cordial greeting for the city of Montreal. After appropriate acknowledgements from the President and the Secretary of the Institute, President Birkinbine delivered his presidential address. The first regular session of the Institute was held on Wednesday morning, February 22d, in the Physics Building of McGill University, where all succeeding sessions were also held. The annual report of the Council was read, as follows : Annual Report of the Council. In accordance with the rules, the Council makes the following report to the Institute:

Jan 1, 1893

Jan 1, 1944

Jan 1, 1944

C. Q. PAYNE, New York, N. Y. (written discussion*).-The method adopted by Mr. Lennox is a very interesting test of the practical application of Mr. Gates' crushing-surface diagram to a greet variety of gold and copper ores. His method of dealing with the material below 200-mesh is also a distinct contribution to the subject, although, as he suggests, it seems likely that some microscopic measurement of this material may be advisable before the mesh reciprocals of its group particles can be dealt with as accurately as can those coarser than 200-mesh. In examining the general results shown in Table 3, it is somewhat puzzling to perceive why Calumet &, Hecla jig tails should show a crushing resistance 3 - times greater than that of the ore from the Ray Consolidated copper mine. The latter is, I believe, an altered. Pinal schist

Jan 10, 1918

By George Otis Smith

A PHILOSOPHER has pointed out that inventive genius, in substituting mechanical power for human brawn, leaves' man the intellectual factor in the industrial life. "Almost human" is the description sometimes applied to the automatic machine, yet the true characteristic of the perfect machine is its unquestioning obedience. "Its not to reason why." The human operator, not the mechanism of gears and levers, has freedom of choice: he wills; the machine obeys: There map be a grinding monotony, a tiring rhythm, that passes from machine to man, but the responsibility resides in the man. In no proper sense call the machine worker be called the slave: whether he guides an electric shovel or tends a group of automatic 1athes.in the machine shop.

Jan 1, 1930

By WILLIAM J. LINNEY

MAGNETITE ore from Lyon Mountain, so- called "Low Phos Chateaugay," has long been known to the iron and steel industry for its almost complete absence of impurities. These magnetites occur along the northern foothills of the Adirondacks in several parallel and folded stringers which are continuous for several miles, striking generally northeast-southwest and dipping usually over 45° to the northwest, or roughly toward the St. Lawrence River. Ore of minable thickness is found in shoots of various sizes as to length and breadth, but of undetermined and possible great depth.

Jan 1, 1943

By Don Simon

In the late 1960s the mining industry was in an apparent slump due to a combination of factors. Enrollment dropped significantly at schools offering mining engineering degrees, resulting in a shortage today of experienced mining graduates to staff middle management positions. How has this limited supply affected salaries? Does the shortage impair the mining industry's ability to respond to national energy needs?

Jan 12, 1979

Arizona ROBERT E TALLY, Chairman CARL F MILLS, Secretary-treasurer, P O Box 1462, Jerome, Ariz W. S. BOYD THOMAS H O. O'BRIEN F. W MACLENNAN Boston Meets first Monday each winter month GALEN H. CLEVENCER, Chairman HOLCOMB J BROWN, Vice-chairman F LEROY FOSTER, Secretary-treasurer, Room 8-219, Mass. Inst of Tech, Cambridge, Mass A. E WELLS H A WENTWORTH

Jan 1, 1923

(Members are urged to send in for this column any notes of interest concerning themselves or their. fellow-members.) Members and guests who registered at Institute headquarters during the period Nov. 10 to Dec. 10, 1914: H. F. Grondijs, Oruro, Bolivia. E. B. Kirby, St. Louis, Mo. R. W. Shumway, Denver, Colo. W. R. Webster, Philadelphia, Pa. J. N. Houser, Mascot, Tenn. F. S.. Titsworth, Denver, Colo. F. L. Clerc, Denver, Colo. Frank R. Wicks, Butte, Mont. Robert Sticht, Queenstown, Tasmania. C. Q. Schlereth, Denver, Colo. Francis C. Phillips, Pittsburgh, Pa. Robert Hallowell Richards was given a dinner on December 7 at Boston by the corporation, faculty and alumni of Massachusetts Institute of Technology in recognition of his 50 years as a devoted alumnus and teacher and as an expression of the respect and affection in which he is held.

Jan 1, 1915

By Hermann Bach, Walther Hänig, Willi Gehrhardt, Ernst Theurich, Walter Langner

With the construction of the Magdeburg zinc works, the Georg von Giesche's Erben Mining Co. of Breslau has to a certain extent completed the program of reconstruction which it set as its goal after the boundaries of Upper Silesia were drawn by the Treaty of Versailles. During its history, covering.more than two centuries, zinc and lead mining has been its chief activity. Through the new boundaries established, it lost to Poland all its mines and smelters, including five distillation smelters. Of its extensive properties, there remained only an apparently unimportant and unexplored portion of the old Bleischarley ore field which, however, happily made possible the resumption of its old business. In 1925 the Deutsch-Bleischarley shaft-only a few kilometers from the old Bleischarley shaft—was sunk and developed, and in May 1926 production of lead and zinc ore was resumed. As facilities for smelting were lacking, the ore was at first delivered to the neighboring smelters, which had now become Polish. Realization of the plan to build its own zinc works had to be postponed at first for lack of capital. In the meantime, however, plans for the new works were worked out in all details. After extensive experimentation in a semicommercial pilot plant it was decided, at the end of 1928 and the beginning of 1929, to use the electrolytic process and, for economic reasons, to place the works at Magdeburg. With zinc at the approximate price level that had ruled since the Deutsch-Bleischarley mine had begun working, it was hoped that the plan could be completed in 1930 with the company's own resources. However, falling metal prices, already noticeable in 1929, made this impossible, and further postponement for a time became necessary. Finally, at the end of July 1933, the funds for building the works became available, in the form of a loan granted under the first employment

Jan 1, 1937

By William Meyer

DURING the seventeen years Fairchild has been making aerial surveys and aerial photographic equipment many changes and improvements have been made in the equipment and in the technique of using it. Aerial photographic operations have, been developed from the crude methods and apparatus of wartime to a science upon which exact engineer-ing calculations can be based. In the early days there was no airplane specially designed to meet aerial photographic requirements. One type of camera was used in all types of operations. Projects were made to conform to the products we could make and deliver. Obviously this entailed definite limitations. We now have airplanes designed specially for aerial photographic operations in accordance with the conditions encountered in actual service experience. We have cameras for every photographic purpose and our laboratory technique and equipment have been developed to the point where it is possible to make contour maps from vertical aerial photographs with contour intervals as close as five feet. Therefore, the selection of equipment now can be made in accordance with the time at our disposal, the justifiable cost, the scale desired, and the general requirements of the client. This does not mean, however, that arbitrary deliveries can be set for aerial photographic products. The factors in each project vary and each job must be considered in accordance with the factors involved. This accounts for the fact that products of aerial surveys may readily vary from $1.25 to $200 a square mile. Sherman M. Fairchild became interested in the design of a radically different aerial camera during the war. At its close he was about ready to demonstrate his design to the War Department. By 1920, he was able to bring out his first completed model. It had a number of radical features, one of which was the first dependable high-speed between-the-lens shutter, which makes for accuracy in aerial photographic work. Another feature was the use of metal throughout, eliminating the wooden parts that had been employed in wartime cameras. Another feature was the interchangeability of parts.

Jan 1, 1936

By F. H. Wilson, E. W. Palmer

The solid solubility of iron in 2 to 10 pct cupro-nickels increases with temperature and nickel content. Property changes accompanying various heat treatments indicate typical precipitation hardening behavior. Iron content also affects softening temperature and sub-scale formation. These factors, as well as impingement corrosion resistance, influence the optimum iron content of commercial alloys. FOR many years Cu-Ni alloys have been used extensively in the form of tubes, pipes, and plates for the construction of salt-water lines and surface condensers on shipboard and in tidewater power stations. The 30 pct Ni alloy has been considered more resistant to rapidly flowing sea water than alloys of lower nickel content, and has been standard on ships of the U. S. Navy. Some ten years ago, the still better corrosion resistance obtained by modifying the 30 pct Ni alloy with approximately 0.5 pct Fe was recognized, and the iron-bearing alloy rapidly superseded the plain alloy as the standard material for severe service. In 1945, Tracy and Hungerford1 published a study of the effect of iron on the corrosion of various cupro-nickels in sea-salt solutions, and their data indicated that the 10 pct Ni alloy containing about 0.75 pct Fe was equivalent to the 30 pct Ni alloy containing 0.5 pct Fe. This was confirmed by LaQue in discussion of the above paper, and by results in an experimental condenser set up at the Kure Beach marine test station of The International Nickel Co., reported by Freeman and Tracy.' The 10 pct Ni iron-bearing alloy is now being very widely used in applications where the 30 pct Ni iron-bearing alloy was formerly considered standard. While this "substitution" has undoubtedly been stimulated by the present extreme shortage of nickel, it must be emphasized that it involves no loss of service performance, and would have occurred anyway in the course of time, for economic reasons. In view of the increasing use of the 10 pct alloy, it seems desirable to make generally available the results of several investigations of Cu-Ni-Fe alloys carried out in the Metallurgical Research Laboratory of The American Brass Co. in recent years. The present paper, deals with the constitution of these alloys in the copper-rich corner of the system, and with the variations in hardness and tensile properties resulting from the heat treatment of alloys containing various amounts of iron. Most of this work is concerned with alloys containing 10 pct Ni. With over about 0.75 pct fe, the 10 pct Ni alloy is suscep- Alloys Several series of cupro-nickel alloys containing iron were used in these investigations. Most of them were prepared in the laboratory, but two samples of commercially fabricated alloys were included. Series A—Nominally 2 and 5 pct Ni, each with 0 to 1.5 pct Fe. Series B—Nominally 10 pct Ni with 0.1 to 0.4 pct Fe. Series C—Nominally 1.0 pct Ni with 0 to 2 pct Fe. Series D—Nominally 10 pct Ni with 3 to 5 pct Fe. Series E—Nominally 10 pct Ni with 1 and 1.5 pct Fe.

Jan 1, 1953