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Jan 1, 1946

Jan 1, 1946

By Allan J. Clark

THE September issue of MINING AND METALLURGY might almost have served as a review of the advances in the metallurgy of gold during the current year. In addition to a scholarly article by F. W. Bradley, there were able descriptions by W. W. Bradley and W. F. Boericke of the methods followed in California and in Ontario. Considered together, the two last-named articles indicate the many possible combinations of flotation with one or more of the older processes. This, the prominence of flotation as an aid in the beneficiation of gold ores, is probably the most striking of the year's developments. It would perhaps be nearer the fact to say that the year has not been marked by the gold metallurgists' discovery of the flotation process, but rather by the flotation merchandizers' discovery of gold metallurgy. I say this because native gold was floated successfully more than fifteen years ago, and a reference to these results was published six years ago.

Jan 1, 1933

By E. F. Northrup

THESE brief notes respecting the properties of pure tin that make it useful as a pyrometric substance summarize information gathered by the writer In an extensive experimental investigation on the electrical properties of metals in the molten state. Tin in quantities sufficient for pyrometric purposes may be obtained at relatively low cost and in a state of high purity. The metal melts at 232° C. and, according to determinations made by Greenwood,. 1909, does not begin to boil until a temperature of 2270° C. is reached. The writer can assert, from personal observations carefully made, that tin shows no tendency to boil at a temperature of 1680° C. If Greenwood's observations are correct the temperature interval, 2038° C., in which tin exists as a liquid under atmospheric pressure, exceeds that of any other substance. It has never been observed, as far as the writer is aware, that tin forms any chemical union, as carbide, with carbon at the highest temperatures at which it can exist as a liquid. It is quite certain from the writer's personal observation that tin heated in Acheson graphite to 1680° C. remains chemically uncontaminated. Wires of pure tungsten do not dissolve in molten tin at temperatures at least as high as 1680° C. Tungsten wires or rods may, therefore, be used as electrodes dipping into molten tin when required for measuring the resistance of the molten metal at very high temperatures. When tin is raised to a high temperature in a covered graphite container, the CO atmosphere that exists above its surface has a reducing action, which maintains this surface of mirror brightness. Incidentally, tin maintained molten in a crucible of Acheson graphite makes a most excellent bath into which may be inserted several pyrometers that are to be intercompared at the same temperature.

Jan 8, 1919

The evaluation of suppliers of BOP linings included only magnesitic and periclase compositions. Ford utilizes some dolomitic compositions. Do you care to comment on this subject?

Jan 1, 1972

Jan 1, 1937

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons. ) An experienced gold and silver metallurgist specializing in cyaniding is desirous of obtaining a position in 'America. Speaks, Mexican Spanish fluently. A member, a. technical graduate, with four years' experience in railroad work and-general construction, two years' on mine examination and geological reconnaissance, and two a half years' drilling exploration in placer work and petroleum, together with prospecting and geological interpolation, desires a position as a mining engineer or mining geologist. An experienced mine superintendent, manager, or field engineer, is open for engagement. He has had 12 years' experience as superintendent and manager of large mines in the United States and Mexico, and experience in mine examination. A member of the Institute with several years' experience in mining in the Lake Superior copper district, is open for engagement.

Jan 7, 1913

SECTION I Page Page Manuscript Closing Date, Febru- Forthcoming Meetings xxvii ary Meeting v . Library xxviii New York Section War Meeting on Membership xxxii Ferro-Alloys v Biographical Notices: Minutes of Meeting, Board of Robert Bell, by F. D. Adams. xlix Directors xvii H. J. Cantwell, by H. A. Members in Military Service xviii Wheeler 1 Personal xxiii Institute Committees Iii Employment xxv Officers and Directors Ix

Jan 11, 1917

PRESIDENT. CHARLES F. RAND,1 NEW YORK, N. Y. PAST PRESIDENTS. CHARLES KIRCHHOFF,1 NEW YORK, N. Y. JAMES F. KEMP,2 NEW YORK, N. Y. FIRST VICE-PRESIDENT. BENJAMIN B. THAYER,1 NEW YORK, N. Y. TREASURER. GEORGE C. STONE,1 NEW YORK, N. Y. SECRETARY EMERITUS. ROSSITER W. RAYMOND NEW YORK, N. Y.

Jan 5, 1913

By S. Jess Larsen

Modern technology has provided the world with many innovations to improve living standards, ease of job performance, efficiency, and managerial control. While not expected to compete with the computer revolution, Kerr-McGee Coal Corporation has found a way using laser technology to solve one of their haulage problems. Operating successful and profitable surface coal mine facilities in Wyoming's Powder River Basin require economies of scale, flexibility of operation, conscientious cost control, and ever-present innovative effort. Because haulage costs are the major source of expenditure in surface mining, Kerr-McGee recognized early the need for maximum haulage productivity and the economies of scale provided by large haulage trucks. Special conditions that exist in the Powder River Basin coal fields require consideration. The coal thickness (up to 100 feet and more) and varying depths of overburden dictate that a haulage unit with good gradability characteristics be used to avoid undesirable long ramps. Two and often three coal seams are encountered by most mines, which necessitates operating from several coal and parting faces simultaneously. This situation consumes much space, and to minimize the scope of problems, a coal haulage unit with good maneuverability and stability is needed. Finally, the low density of coal (±1500 pounds/loose cubic yard) demands a large volume capacity to utilize truck load carrying capability effectively. These conditions prompted Kerr-McGee to select unitized two-axle bottom dump trucks of the 160-170 ton size for primary coal haulage at its two Gillette-area mines. Use of 170-ton bottom dump trucks at the Clovis Point Mine handles most of the coal haulage, but the truck

Jan 1, 1983

GERMANIUM, once the metals industries' unwanted step-child, has suddenly blossomed into importance. As late as 1951 textbooks failed to mention it and the metal was considered no more than a nuisance that interfered with the electrolysis of zinc. Eagle-Pitcher is the only producer of Germanium, used in power rectifiers and the new transistors. Its basic quality is that its ability to carry current can be changed, and a current flowing through it can be controlled. Germanium is sold by Eagle-Pitcher for about $340 a lb, not bad for a metal that only a few years ago was totally ignored. Eagle-Pitcher gets germanium, cadmium and gallium by roasting the zinc concentrate to convert the sulphides to oxides, then adding coal and salt to the crude zinc oxide and sintering at a high temperature. The oxides of germanium, cadmium and gallium are converted to chlorides. Cadmium and germanium chlorides volatilize, and are gathered for additional processing. The important step is the distillation of germanium tetrachloride.

Jan 1, 1952

By G. F. Dillion, A. F. Armington

THE present method for the ultrapurification of boron involves the formation, distillation, and decomposition of boron tribromide.' However, the boron tribromide prepared contains several impurities in the ppm range, even after distillation. Some of these impurities, notably carbon, can be reduced after decomposition by zone refining. In this study, a comparison of the purity of boron tribromide at various formation temperatures is presented. The apparatus employed consisted of a bromine flask connected to a 22 mm ID horizontal quartz reaction tube packed with amorphous boron powder, which was in turn connected to a receiving flask cooled with an ice bath. Argon was used as a carrier gas. The approximate rate of passage of bromine to the reaction tube was 25 g per hr. The reaction was first investigated at several temperatures in order to determine the lowest temperature necessary to produce a colorless product which was assumed to be an indication of complete reaction of the bromine. The lowest temperature found in this study was 420oC. The amount of impurities found in the boron tribromide at various formation temperatures is shown in Table I. The data presented are emission spectroscopic results of boric oxide produced by the hydrolysis of 2 to 3 g of boron tribromide in 10 ml of distilled water. After hydrolysis, the samples were dried several hours on a hot plate. Assuming equilibrium conditions in the reactor, one can make approximate thermodynamic calculations estimatling the completeness of reaction of bromine with boron and its impurities at various temperatures. Data for these calculations were taken from Rossini,3 and must be taken as approximations since the T?S factor was not included in the calculations. The results of such calculations indicate that, with the exception of carbon bromina-tion, all impurities would react almost to completeness (> 99 pet) at all temperatures between 400" and 900oC. In the case of carbon, which cannot be accurately analyzed spectroscopically, it is estimated that only about one sixth as much carbon tetrabromide would be formed at 400" than at 900°C. Since some marked reductions in impurity content were observed at the lower reaction temperature which would not be predicted by thermo-

Jan 1, 1962

Jan 1, 1921

Jan 1, 1951

By AIME AIME

EUGENE AUSTIN STEPHENSON, better and affectionately known as "Steve," has long been an active and enthusiastic member of the Petroleum Division of the Institute. As its Secretary-Treasurer for several years, he was the spark plug that so successfully carried the Division over the trying period of the early thirties. "Steve" was born at Franklin, Mich., July 27, 1883; graduated from Adrian College in 1905, and later received his Doctor's degree from the University of Chicago where he was an instructor for two years. From 1917 to 1925 he was chief geologist for the South Penn Oil Co. and from 1925 to 1930 he was associated with Ralph Davis, Inc., of Pittsburgh, consulting engineers. In 1930 the Missouri School of Mines called him to Rolla to head a department of petroleum and natural gas engineering. and in 1938 he was invited to build up a similar department at the University of Kansas.

Jan 1, 1941

IN describing the mining and treatment of ore at the Broken Hill Proprietary mine E. J. Horwood, superintendent of mines, gave the following account of the development of flotation there. It was in 1902 that the recovery of zinc from the ore by flotation was hit upon. The former general man-ager, Mr. Delprat, directed our then research officer, Mr. Carmichael, to try boiling the tailing with salt cake of which there was a considerable tonnage left over from the leaching process. The idea was the possibility of dissolving the zinc. Carmichael made the. Experi-ment, but, rather discouraged, took the glass beaker down to the general manager's office, remarking that he could not get the stuff to settle. On showing the beaker to Mr. Delprat, the latter recognized the marked distinction between the black scum on the surface and the rest of the tailings, and exclaimed: "Why, this is the very thing we are after; the zinc is floating!" Patents were applied for at once, but later on it was found that another investigator, Potter, had already hit upon the idea of flotation. His patents, however, were so involved with other operations that his process was impracticable. Litigation followed, but in the end the B. H. P. paid the Potter Company a substantial sum as settlement. In the case of Carmichael's beaker, the acid in the salt cake acted on the small amount of carbonate present in the ore, producing CO. bubbles. Owing to the aversion of sulfide crystals to being wetted, the gas as generated attached itself to the zinc in in-creasing quantities until there was sufficient to buoy the zinc particle to the surface. This action went The next problem was to apply the principle on a commercial scale, and this involved much experiment and developmental work. Various kinds of sloping copper pans with gas jets below to maintain the tem-perature were first tried, but were found too slow and too costly in operation.

Jan 6, 1928

By S. P. Kinney, A. J. Boynton

This paper states that progress in blast-furnace engineering during the past five years is unimportant except for the advent of the electric precipitator for gas cleaning. It describes improvements in certain furnace details and in materials of construction. The paper is largely given over to a discussion of difficulties in operation due to disproportion between the diameter of the present-day furnace at the bosh and at the stock line. It is proposed to remedy this disproportion, and to restore relations in the diameter of stock line and bosh as they formerly existed, by a new method of filling. This method requires a double bell arranged to discharge towards the periphery or towards the center of the furnace. Coke is classified into two sizes, the small size going to the middle of the furnace, and the larger to the periphery along with the ore. By this means the resistance of the center of the furnace is increased, and the stock line diameter may be greatly increased. The writer believes that these modifications will result in a somewhat improved fuel economy and regularity of operation and also in a very greatly reduced production of flue dust.

Jan 1, 1935

By S. P. Kinney, A. J. Boynton

This paper states that progress in blast-furnace engineering during the past five years is unimportant except for the advent of the electric precipitator for gas cleaning. It describes improvements in certain furnace details and in materials of construction. The paper is largely given over to a discussion of difficulties in operation due to disproportion between the diameter of the present-day furnace at the bosh and at the stock line. It is proposed to remedy this disproportion, and to restore relations in the diameter of stock line and bosh as they formerly existed, by a new method of filling. This method requires a double bell arranged to discharge towards the periphery or towards the center of the furnace. Coke is classified into two sizes, the small size going to the middle of the furnace, and the larger to the periphery along with the ore. By this means the resistance of the center of the furnace is increased, and the stock line diameter may be greatly increased. The writer believes that these modifications will result in a somewhat improved fuel economy and regularity of operation and also in a very greatly reduced production of flue dust.

Jan 1, 1935

By V. M. Frey

IN 1936 the foreman at one of the oldest limestone quarries in northern Virginia discovered the remains of three old well-drill holes that contained dynamite. As consulting engineer for the property, I was then called upon to devise a method for removing the explosive. As no exact formula for the handling of unexploded dynamite exists, the proper steps for removing it must always be dictated by local conditions. A description of the procedure in this case may, therefore, be of interest to others faced with a similar problem.

Jan 1, 1939

Jan 1, 1947