Search Documents

Bureau of Mineral and Topographic Survey, University of Kentucky, Lexington, Ky. Arthur C. McFarlan, State Geologist The Kentucky Geological Survey was abolished by a recent legislative act and the Bureau of Mineral and Topographic Survey at the University of Kentucky was created in its place Publications of the former Survey are distributed by the present Bureau Several series of papers and volumes have been issued but only those of Series 3, 4 and 6 are now to be had in whole or in part Of Series 4, (1912-18) only one group of papers is available Vol: 1, pt. 2, Miscellaneous papers on fire clays, limestones and coals of parts of the state (1913), $125. Of Series 3 (1904-1912), the following bulletins are pertinent and may be had. Bulletin 3, Coals, clays, etc., of Kentucky (1905), 50 cents, 14, Coals of the Pineville Gap region (1912), $1.25, 16, The Waverlain formation of east central Kentucky (1912), 50 cents, 17, Coals of the Tradewater region (1912), 50 cents, 18, Coals of Quicksand region (1912), 50 cents; 19, Geology and coals of the Central City, Madisonville, Calhoun, and Newberg Quadrangles (1912), 50 cents

Jan 1, 1933

By H. C. Rogers, B. W. Roberts

Vanadium foils and wires, either cold-worked or recrystallized, show a ductile-brittle-ductile fracture sequence with temperature. At about 150°C the hydrogenated vanadium wires are found to be ductile. At room temperature the wires show brittle fracture, and at liquid nitrogen temperature the wires are again ductile, although to a lesser extent than found at 150°C. Hydrogenated cold-rolled vanadium foils have been found to fracture in unusually straight lines along the [100] texture directions. The hydrogen content required to show this [loo] texture fracture is limited to a few atomic percent in range. Hydrogen content above this range causes fracture to occur in random directions. PRELIMINARY experiments with hydrogenated vanadium foils indicated that the embrittling effect of the hydrogen on the vanadium, which was severe at room temperature, was reduced at both lower and higher temperatures. In order to investigate more quantitatively the ductility changes with temperature, vanadium wires were tested in tension at three temperatures. The reduction of area was measured and the fractures examined. Specimen Preparation—The material used was kindly supplied by A. U. Seyboltl in the form of M-in. rod. The nominal analysis was: 99.2 pct V assay, 0.2 pct C, 0.01 pct Si, 0.01 pct Fe, 0.015 pct Ca, 0.02 pct O,, 0.01 pct N2, and 0.003 pct H,. The specimens were 0.035-in. diam wires. These were prepared by cold-swaging the supplied rod to the final diameter without intermediate anneal. They were finished with long-bearing dies. The surface was then given a light polishing with 0 emery paper and degreased in trichlorethylene. An X-ray check indicated that the cold-swaged wire had a fairly strong [110] fiber texture. The wires were then recrystallized in vacuum in continuously pumped quartz tubes at two temperatures to give two different grain sizes. One group of wires was given 45 min at 800°C; another, 60 min at 1000°C. The microstructures in Fig. 1 show the wires after they have been electropolished and elec-troetched in 10 pct HCI. After the 800°C anneal, the vanadium grains had a diameter of 1 to 2p and there appeared to be a tendency to elongation in the longitudinal direction. However, the latter may be an etching effect. After the 1000°C anneal, the grains appeared to be equi-axed, but there was a very large spread in grain size, probably due to some impurity segregation in the wire, Fig. 1, right. The grain diameters varied between the limits of 1 to 150p. The small particles shown particularly clearly in Fig. 1, left, are also visible on the polished surface of all samples before etching and are undoubtedly carbides and nitrides of vanadium. An X-ray check indicated these annealed wires had a strong [110} recrystallization fiber texture. The hydrogenation was carried out in an iron retort with dry hydrogen flowing through it, the retort and contents being heated in a tube furnace with a hydrogen atmosphere. The hydrogenation temperature was approximately 500°C. The hydro-genation times chosen were approximately those which would be just enough to cause the vanadium to be brittle at room temperature and thus allow the greatest chance for ductility to occur at the other two temperatures. Part of the fine grained specimens were hydrogenated for 21/2 min at 490°C. Part of the coarse grained specimens were hydro-genated for 11/2 min at 515°C.

Jan 1, 1957

By Strathmore R. B. Cooke, Emert W. Lindroos, Norman F. Schulz

DURING the course of an investigation of the effects of various starch products on hematite and quartz in regard to their separation by' flotation, it was found that whereas most starches flocculated suspensions of hematite in water, they did not flocculate similar suspensions of quartz. However, a derivative of whole corn starch containing approximately one tenth aminoethyl group (--CH2CH2NH2) per glucose unit proved to be an exception. This aminoethyl starch was a very good flocculant for both hematite and quartz, and also possessed the property of depressing both minerals in cationic flotation tests. In view of the widespread use of starch as a flocculating agent of solids in tailing water, pulps, and for coal slimes, ore and various other purposes in sulphide and nonsulphide flotation, attention is called to the effective surface activity of aminoethyl starch in flocculating suspensions of the two minerals investigated. Test Materials The starch products employed included Globe Pearl starch No. 144 and fresh aminoethyl starch, both supplied by the Corn Products Refining Co. Dr. A. L. Elder[4] has kindly furnished a description The minerals used in the various tests are listed in Table I. Their specific surfaces were determined by the air permeability method, which gave results reproducible to within plus or minus 3 pct. Surface areas obtained by krypton adsorption were greater than the air permeability values by a factor of 2.0 for quartz and 62.4 for hematite. Starch Adsorption on Mineral Surfaces Starch adsorption data were obtained by agitating for 1 hr measured volumes of neutral starch solutions of known concentrations with weighed quantities of finely divided mineral of measured specific surface. The mineral then was separated from the pulp liquor by centrifugation and the residual starch content determined by chemical analysis. The analytical procedure consisted of oxidizing the starch with an excess of dichromate in acid medium at elevated temperature and titrating the excess dichromate by the ferrous ammonium sulphate-potassium permanganate method. Analytical results were reproducible to within less than 1 pct. Adsorption data obtained in unbuffered solutions near the neutral point are plotted in Fig. 1. The adsorption on either mineral was far greater for the aminoethyl starch than for the Pearl starch. Flocculation The degree of flocculation was determined for a given pulp by measuring the time required for the supernatant liquid to reach a certain degree of clarity. This was accomplished by passing a standard light beam through the pulp, contained in a glass settling tube, and measuring the time required after agitation ceased for the intensity of the transmitted beam to reach a predetermined value. Starch reagent was added to each pulp in small uniform increments, and the settling time was determined after each such addition. Increase in pulp liquor volume due to the added starch reagent was ignored in these tests. Pulps were maintained at or near neutrality.

Jan 1, 1952

By R. W. Raymond

Samson Jordan was born at Geneva, Switzerland, June 23, 1831. At the age of 20 years he entered the Ecole Centrale des Arts et Manufactures, at Paris, from which he was graduated with high honors in 1854. After some months of service with the Compagnie du Chemin de Fer du Nord, he was employed (upon the recommendation of his former instructor, Prof. Burat, who had recognized his remarkable ability) at the mines of Portes, belonging to the Société de l'Elairage au Gaz et des Hauts Fourneaux, etc., of Marseilles, and subsequently to construct the St. Louis iron blast-furnaces of that Co. After finishing this work, he remained at Marseilles as a member of the directory of the Co., particularly connected with the development of its mines. In 1862 he became the general advisory engineer of the Co., and still later (1873) its general manager (Administratet~r), a position which he retained until his death, February 24, 1900. He became subsequently Administrateur of other important French industrial enterprises, including those of the Compagnie des Naut Fourneaux, Forges et Aciéries de Denain et Anzin, and the Compagnie Banco-Belge des Mines de Somorrostro ; and he was also, at various times, President of the Société technique du Gaz, Vice-President of the Comité des Forges de France, mepber of the Council of the Société d'Encouragement pour l'Industrie nationale. In all these positions, it is the unanimous testimony of his colleagues that he was no mere ornamental figurehead, but a profoundly wise, practical and industrious laborer and adviser, both patient and keen in the mastery of details, yet at the same time competent to apprehend the wider bear-

Jan 1, 1902

By H. J. Stehli

Probably the earliest sinter from lead ore was made in the product sinter boxes attached to some hand reverberatory roasters. The ore was drawn from the roaster bed when dead roasted, and then by laborious effort fritted together by rabbling at a high temperature in the sinter box. This was not a true sinter, but was a great improvement over the dusty dead-roasted fine ores. The Huntington-Heberlein pots were the first real advance in the art, and produced some real sinter. They required that the sulphides be preroasted to 5 or 6 per cent sulphur, and the long cycle of operating and deep bed of material used in the pots fostered the formation of densely fused material and fines. This necessitated crushing of the densely fused cake and returning to the next charge large amounts of fines screened out. The Huntington-Heberlein pots made comparatively high lead losses because the deep bed and high internal temperature together favored the volatilization of lead. Lime (CaO) was added to the charges, and this addition constituted the patented feature of the Huntington-Heberlein process. Its sole function we now know was to act as an isolator of the sulphide particles, and any other substance—for instance, iron oxide—of equal fineness performed the same function. The Savelsberg process used limestone instead of burned lime, and in this there was a definite advantage. The converting of CaCO3, to CaO is a highly endothermic reaction, so the lime acted not only as an isolator of sulphide particles but absorbed excess heat and to some extent prevented premature fusion of the sulphides. The Carmichael-Bradford process used gypsum instead of limestone, and had the disadvantage of adding more sulphur to a charge from which it was desired to eliminate sulphur. Here again the gypsum served only as an infusible isolator of sulphide particles. The first Dwight-Lloyd apparatus to sinter lead ores commercially was installed at Perth Amboy in 1907. The fact that lime in any form was necessary to sintering was quickly disproved by making excellent sinter from Bunker Hill and Sullivan table concentrates, silica sand and iron oxide only.

Jan 1, 1937

By J. B. Mitchell

The intelligent selection of comminution systems for industrial minerals requires a broad background of comminution experience. At the same time a thorough knowledge of the specific mineral occurrence, the applicable process and the product end use is required. To illustrate the different ways to process potash ores three flow sheets have been selected for presentation.

Jan 1, 1970

By Shun-ichi Satoh

Studies by many authorities have proved that nitrogen exerts an injurious influence upon iron and steel, but in the casehardening of steel by carbon, nitrogen has the advantage of accelerating the process of cementation. Its influence upon special steels is quite remarkable; it can produce the hardest layer ever known in metallurgical products—a fact hit upon by A. Fry and studied and ascertained by L. Guillet. As there have been very few investigations on the influence of nitrogen on special steels, the writer has listed important articles dealing with this problem and has conducted experiments on nitrification. He also has tested the influence of nickel upon the penetration of nitrogen in electric-arc welding. Nitrogen Process for Surface Hardening In 1919, Siegmonl conducted an experiment known as "Versticken" by treating steel with ammonia gas and found that the steel thus treated has the properties of resisting corrosion. In 1922, L. E. Benson3 nitro-genized iron and steel by sodium nitrate. Fry3-"studied the nitrogen process for surface hardening and published the results of his studies in 1923, 1924 and 1926. Guillet tested special steels containing various elements with the current of ammonia at 500' to 510' C.10, 11, 12, and determined the hardness of some of them at various temperatures.13 He also conducted corrosion tests14 in 1927. Fry15 stated that tinplat-ing could prevent nitrogen from penetrating into steel in the course of nitrification. In 1927, Guillet 65 described the historical notes of the nitrification; and many applications of nitrification were published in the Kruppsche Monatshefte.51, 59, 62, 63, 64-74~75 H. K. Herschman66 conducted the wear test of the nitrified steel. Gunnar Hägg investigated

Jan 1, 1930

By D. J. Carney, C. W. Boquist, E. C. Rudolphy

Effect of variations in sinter feed composition on sinter strength, bulk density, re-ducibility, chemical composition, and microstructure were determined by sintering experimental samples on a production sintering machine. Increasing amounts of roll scale, ore fines, return fines, and blast furnace slag were most beneficial to feed permeability, sinter bulk density, and strength. Burnt lime additions improved feed permeability but were not beneficial to sinter strength or bulk density. Sinter reducibility was adversely affected by all additives. DEVELOPMENT of methods for evaluating sinter quality, which would in some way predict the behavior of the sinter during charging and smelting in the blast furnace, has been given considerable attention in recent years. In a previous investigation at South Works of the United States Steel Corp., standard sinter sampling and testing procedures were developed.1,2 By modifying the sinter sampling device, a method of sintering experimental mix sinter samples upon a production Dwight-Lloyd sintering machine was also developed. This technique afforded a rapid and controlled method of investigating the effects of the various raw materials and additives on sinter quality and was used in this present investigation. Since the beginning of the present study in 1953, the results of numerous sinter investigations have been published, most of which were concerned with production tests of iron ore sinter, both here and abroad. Three groups of investigators reported results of experimental sinter studies that were related to this investigation. Voice et al.3 studied the effects of controlled variables on sinter quality by producing and testing experimental Northants iron ore sinter using an experimental sintering unit. Mor-rissey and Powers' determined the relationship between iron ore sinter quality and the moisture and coke content using a small laboratory sintering system. Burlingame et al.5 studied the effects of "additives" upon iron ore sinter using a laboratory sintering apparatus and laboratory grade raw materials. At South Works, it was considered desirable to study the effects of sinter mix composition and additives upon the quality of a flue dust-base sinter produced on a production sintering unit. Extrapolation of controlled laboratory test data to sintering plant operation lacking such precise control is not altogether satisfactory. Therefore, the present study was conducted in a manner which approximated production conditions as closely as possible. The raw materials used were those commonly encoun- tered in the production of flue dust and flue dust ore-type sinters and these were varied within extremes encountered in this type of sinter production. Experimental Procedure The experimental sinters were produced from 100 lb mixtures of sinter feed. The principal raw materials and additives used, their particle size, and approximate chemical composition are listed in Table I. The mixing of the raw materials was accomplished by means of a miniature single shaft pug mill shown in Fig, 1. The use of the pug mill as a mixer was decidea upon after encountering difficulty in reproducing the mixing and chopping effect of the sinter plant pug mill with other types of available small mixers. The miniature pug mill was constructed, consisting of 31/2x2x1/4 in, blades spaced 3 in. apart along a 3 ft shaft. Preliminary tests were run with this small mixer to establish the proper rotation speed and the required number of passes through the pug mill to thoroughly mix and distribute all the raw materials in a manner approximating the production Pug mill- Although the effects of varying the mosture content were determined in one particular series of tests, the amount of moisture added was changed as the composition of the experimental mix was varied. The aim in making water additions was to achieve a permeability as high as possible for each particular

Jan 1, 1956

By Charles M. Romanowitz

The motivation for the art of dredging for placer mining can be compared in a slight degree to the spread of civilization which started in the Near East and spread both east and west. Dredging started with the "bag and spoon" dredge in the lowlands of Europe reportedly about 1565, went southeast to New Zealand where designs were developed for a bucket-line mining dredge known as the New Zealand type, and westward to the eastern United States where a dredge was developed and used exclusively for excavating. Then it moved to Montana, where it was first used for mining in 1895. The New Zealand-type dredge was imported into California in 1898 (Fig. 1) and was followed shortly by the Montana design. As today, these early dredges were equipped with continuous bucket- line chains, a treatment plant, and a means of waste disposal mounted on a wooden hull. Both types of dredges are complete mining units: they dig the formation, transport the dug materials, and concentrate the valuable ore. After sizing, the fines containing the ore are passed by gravity to the treatment unit, while the barren materials are discharged overboard. By digging the materials to be treated at the bow and depositing all the waste, at the stern, the dredges automatically advance to new reserves without presenting any transportation problems. The main differences between the two types are in the method of holding the dredge in the digging position and in the disposal of the tailings to the rear. The New Zealand type (Fig. 2) uses the headline system with a bow anchor for holding the dredge in the digging position and long tailing flumes or short stackers off the stern for disposal of the barren materials. The California type (Fig. 3) uses box girder spuds projecting into the ground in a vertical position at the stern of the

Jan 1, 1969

By Oliver U. Bradley

The conditions affecting the supply of casinghead gas, the different degrees of productivity, the difficulty of determining the quantities utilized, and the evaluation of the gas in casinghead-gasoline units and related data, having an economic bearing on the industry as a whole, are important questions and offer an interesting field for study. Casinghead-gas data have been gathered in some of the oil fields of Oklahoma where testing work has been done regularly and the volumes of casinghead gas were available. The area covered embraces 219 scattered leases in 29 townships, with a total of 18,039 acres and 1921 wells. The accompanying table gives specific locations of the areas under consideration, number of leases, range depth of wells, average age of production, sand depths and oil production data. The results of this investigation are set forth in the accompanying charts, showing volumes of casinghead gas in 6-month periods from Jan. 1, 1918, to June 30, 1921, when full record was available, production of casinghead gasoline, average productivity of the gas in gallons per thousand cubic feet, average price of the gas and the market price of the casinghead gasoline. The cases enumerated in the table and the data shown in the graphs do not represent the greater part of oil or casinghead gas production from any one township, nor are the leases contiguous. The properties in each township, however, may be considered as typical of general conditions, such as the date of completion of wells, depth, character, and thickness of oil sand, time of pumping, present oil production, Vacuum carried on wells, and usual operating practices. It was deemed advisable to subdivide the time into 6-mo. periods, as it was impracticable to make the tests more frequently, furthermore 6 mo. is probably the minimum period within which there would occur a noticeable increase in the productivity of the gas. It must be remembered that the figures on volumes are subject to the usual irregularities and relative inaccuracies of meter measurenlents of gas under varying degrees

Jan 1, 1924

Discussion * of the paper of H. M. Chance, presented at the butte meeting, august, 1913, and printed in bulletin No. 79, July, 1913, pp. 1315 to 1341. George H. Ashley,+ Washington, d. C.:-Mr. Chance's long practical experience in reporting on coal lands admirably fits him for a discussion of the value of such lands. On behalf of the government geologists, I wish to express my appreciation of Mr. Chance's friendly, constructive criticism of the government method of valuing coal land in the first part of his paper and, at the same time, to reply to some queries he makes. All admit that coal has no " intrinsic "-monetary value, in the sense that a pound of coal of certain chemical and physical characters is worth " intrinsically " so many cents or fractions of a cent. The term has, however, been found very useful as including those natural factors of coal value, among which are its position and location in the earth, that affect its sale price in contrast with the other cost elements involved in the labor and capital necessary in mining, preparing, transporting, and selling the coal (extrinsic factors). Mr. Chance, while recognizing the " dual origin of value," does not offer any better terms. The survey agrees with Mr. Chance in his definition of coal conservation, that it means the fuller utilization of the heat contents of the coal, and the more complete recovery of the coal from the ground. Coal land withdrawals have not been made to keep such lands off the market, but to prevent their acquisition as non-coal lands before they could be classified so as to be disposed of under the proper law. Nor has the pricing of the more valuable coal lands above the minimum been to raise money for the reclamation fund, to which the money goes, but primarily to discourage the alienation, for holding or speculation, of coal lands not intended or needed for development, and, secondarily, to secure to the people the ?unearned increment," which they are certain in any case to be charged.

Jan 11, 1913

By S. C. Dhara

A process of solvent extraction and separation of platinum group metals (PGM) and gold using primary, secondary, tertiary, and quarternary organic amines has been briefly described. The effects of amine structures; the use of diluents; the principle of synergism and antisynergism in the mixed extractants; the oxidation states of metal ions are explained in the amine extraction process of precious metals.

Jan 1, 1984

By B. F. Decker, J. H. Keeler, W. R. Hibbard

Textures of hot-rolled, of cold-rolled, and of cold-rolled and annealed zirconium sheets were determined by use of an X-ray spectrogoniometer. All textures showed a tilt of the basal planes 240" from the rolling plane about the rolling direction. Deformation textures showed the [1010] direction to be approximately in the rolling direction. After recrystalliza-tion, the 111201 direction was approximately in the rolling direction. This texture was sharpened by annealing above the allotropic transformation. Textures of sheet produced by alternately cold rolling and then annealing were less strongly oriented than sheets that underwent severe deformation without intermediate anneals. THIS study of the deformation and annealing textures of high purity zirconium was carried out to supplement an investigation of zirconium and zirconium-base alloys. The spectrogoniometer method of pole figure determination was used and yielded more detailed and precise information than the photographic techniques used by previous investigators. Earlier investigations of the rolling textures of hexagonal metals titanium,1,2 beryllium," and zirconiumL having a c/a ratio slightly less than 1.6 disclosed a rotation of the basal planes from the rolling plane about the rolling direction so that the basal poles were inclined toward the transverse direction, and with one exception,& the [1010] direction was found parallel to the rolling direction. Similarly, hot rolling produced a spread of the basal poles in the transverse direction,2,3,5 With the [1010] direction parallel to the rolling direction. The textures of these metals after recrystallization differ somewhat from each other although still exhibiting the transverse rotation of the basal poles about the rolling direction. Zirconium" was found to have the [1120] direction in the rolling direction, beryllium" continued to have the [1010] direction in the rolling direction, and titanium' was shown to have the [1010] direction in the rolling direction (the cold-rolling texture) when annealed at 1000°F, changing to the [1120] direction in the rolling direction when annealed at 1500°F. It was suggested2 that the titanium retains the deformation texture after re-crystallization, and preferred grain growth at higher temperatures produces the second texture. Annealing above the allotropic transformation temperature did not appreciably change the high temperature recrystallization texture for titanium.' Coarsegrained zirconium showed more spread" in the transformation texture than in the recrystallization texture. The material used in this investigation was crystal-bar zirconium prepared by the iodide process. The major impurity was hafnium which was less than 0.3 pct. The composition obtained by spectro-graphic analysis is given in Table I. The hot-rolled specimen was prepared from a 50-g button of zirconium arc-melted in a water-cooled crucible under an argon atmosphere. This button was enclosed in a welded sheath of soft iron and the ensemble was rolled at 825°C. After each pass the sheath was put back into the furnace to allow it to return to the desired temperature. The zirconium ingot was reduced in this manner to a thickness of about 0.035 in., a reduction of approximately 90 pct. The sheet after removal from the sheath was alternately polished and etched to a thickness of 0.001 in. Cold-rolled specimens were prepared from crystal bar by a series of reductions of approximately 0.010 in. until the sheet reached a thickness of 0.010 in. after which it was cold-rolled to 0.001 in. thickness between sheets of alloy steel. The total cold reduction amounted to about 99.8 pct. Specimens were annealed in an evacuated Vycor or quartz tube. The transmission pole figures were obtained by the quantitative method of Decker, Asp, and Harker6 modified by Geisler7 using an X-ray spectrogoniometer with Cu Ka radiation. Unless otherwise specified all four quadrants were examined with 5" increments along the radius of the pole figure. Absorption corrections were made for changes in length of the X-ray path through the sample as inclination of the

Jan 1, 1954

By J. M. Hodge, H. M. Reichhold, R. D. Manning

The work reported in this paper represents the first of a series of investigations of the factors governing notch toughness in ferritic materials. This paper is concerned with two of these factors, namely, the effect of ferrite grain size, and the effect of an alloy content of 3.64 pct nickel. Every effort has been made to hold other variables constant in order to isolate the effects of these two. The compositions chosen for study were 0.02 pct carbon in order to eliminate the variable of carbide distribution, one steel being a plain carbon steel and the other alloyed with 3.64 pct nickel. Both steels were fully killed with silicon, without an aluminum addition, so that the variable of deoxidation practice was held constant. Finally, all samples were water quenched from 1200°F and tempered 24 hr at 300°F in order to hold the quench aging variable constant and to decrease the tendency for grain boundary carbide precipitation. The ferrite grain size was varied by heat treatment over the range of A.S.T.M. grain size numbers of about 2 to 6 in each steel so that the effect could be evaluated individually and the notch toughness of each steel could be compared at comparable ferrite grain sizes. Materials and Experimental Procedure MATERIALS The materials for this investigation were obtained from Battelle Memorial Institute as 250 Ib induction melts which were forged into 134 in. square bars and then rolled into 0.6 in. square bars. Both steels were deoxidized with silicon, the aluminum content being held to a minimum. Check analyses of these materials are shown in Table 1. HEAT TREATMENT FOR GRAIN SIZE The grain size was varied by varying both the cooling rate and the austeni- tizing temperatures. The heat treatments used and the corresponding grain size values are tabulated in Table 2. A semicontinuous network of grain boundary carbide was observed in the microstructure of both the plain carbon and nickel steels in the as rolled condition and an additional heat treatment was necessary to eliminate this variable. Therefore, all samples were water quenched from 1200°F and tempered 24 hr at 300°F as a final treatment before testing. This heat treatment served to eliminate to a great extent the grain boundary carbide network and to hold the quench aging effect constant. IMPACT TESTING Standard keyhole Charpy impact tests were machmed after heat treatment. A bath of acetone and dry ice was used for refrigeration of the samples down to temperatures of —94°F (—70°C) and a bath of either methyl-cyclohexane or isopentane, cooled by

Jan 1, 1950

As reported in Drift last month demolition of old buildings on the 47th St. site has been completed, and detailed plans and studies for the new structure are well underway. As this issue was being sent to press the $5 million industry- business phase of the fund campaign had passed the half- way mark toward its goal. Target date for the building program is 1960.

Jan 5, 1958

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

By S. Wallden, R. Lindstrom

The electrolytic copper refining process is an excellent method for producing high-purity metal for electric conductors and other demanding applications. However, the process involves very high capital expenditure, especially the amounts of metals bound in the process. Efforts have therefore been made for many years to increase the production rate by increasing the current density, without impairing the quality of the copper. One of the approaches has been to diminish the polarization by mechanical means, while another was to "polish" the cathode surface by periodic brief reversals of the current. Reversed current electrolysis was first developed for electro- plating purposes and in 1952 Boliden AB and the Dept. of Electrochemistry at the Royal Inst. of Tech., Stockholm tested the method for copper refining with good results. However, no suitable electrical equipment for current reversal was then available. The thyristor-controlled silicon rectifier became available during the '60s and provided the scope for industrial application of the process and the first large-scale development was made by the Bulgarian copper refinery in Pirdop. Many copper refineries are now studying or adapting the reverse current process. Further lab and pilot investigations have been carried out at Boliden AB during the past 4 years and these were mainly aimed at studying the optimization of factors influencing the quality of copper. A production unit containing two tank sections with a total of 56 cells and equipped with a rectifier for cur- rent reversal has been installed and will be started during 1973.

Jan 1, 1973

By Michael Tenebaum

IN a previous investigation1 the authors studied the effect of pressure on the reduction of iron ores by hydrogen. With hydrogen as a reducing agent, the rate of reduction was increased substantially by increasing the pressure from 1 to 2 atmospheres. The results with hydrogen prompted the present study of the effect of pressure on reduction with carbon monox-ide and with mixtures of carbon monoxide and nitrogen. FEATURES OF REDUCTION PROCESS The gas stream in the lower part of the blast furnace always contains sufficient concentrations of reducing gases to complete reduction provided sufficient time is allowed for the reaction to proceed. Reducing gases react immediately with the iron oxide on the surface of lumps of ore. However, as the unreduced surface recedes from the easily accessible exterior of the lump, the reaction proceeds by virtue of the diffusion of the gases into and out of individual pieces. The rate of diffusion of gases, which undoubtedly plays an important role in the reduction of iron ores, depends on several factors, most impor-tant of which are: (1) molecular weight or density, (2) pressure, (3) tem-perature, (4) concentration gradient. Thus, the rate of reduction of a lump of iron ore at any temperature will depend not only on the specific reaction rate but also upon: (1) available surface of unreduced iron oxide, (2) rate of diffusion of the reducing gas to the reacting surface, (3) rate of effusion of the gaseous products of the reaction from the reacting surface, (4) adsorption of the gases on the reacting surface.

Jan 1, 1939

By John D. Price

COAL blending, in the preparation of coal before coke making, is so commonly practiced as to be almost universal. But the reasons underlying this practice, the benefits resulting from it, and the materials used in blending vary widely. This paper will outline the various phases of the subject and present information which may be correlated with work that has been done elsewhere. It will deal entirely with work done on the high-volatile coking coals of the western part of the United States, special emphasis being given to the coals of Colorado and Utah.

Jan 7, 1953

By R. V. Norris

LAST October, Mr. R. V. Norris and Mr. Matthew C. Fleming were appointed to represent the Institute at the Second National Industrial Tax Conference, which was held in New York City on Oct. 22 and 23. After reading the report submitted by the Committee, Mr. Norris and Mr. Fleming addressed the following to the Tax Committee of the National Industrial Conference Board: The tentative report of the Tax Committee of the National Industrial Conference Board was received too late to make it possible to lay it before the Board of the Institute, and the undersigned themselves have not had sufficient time to digest its interesting contents and recommendations carefully. So that we desire to make it clear that the comments we make on the report are the expression of our personal opinion only. In the first place, we feel that the Committee which drew this tentative report is entitled to the commendation and thanks of the country for what has been manifestly a work of tremendous labor and for the able and conservative report which they have presented. With

Jan 1, 1921