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By P. A. Toynbee

An experimental air-slide classifier1 has been applied to the de-dusting of ground dolomite in an attempt to produce a grade of -30 +150 mesh (B. S. Sieves) material from a raw material containing 30-35% of the -150 mesh fraction. Air flows varying between 1.5 and 2.5 cu ft/sec sq ft of screen area were used. The throughput of dolomite was between 80 and 100 lbs/h. inch of screen width. The size analyses of the de-dusted material and of the original dolomite are shown in table at right. The proportions of the +100 mesh material in the feed and in the de-dusted products have been used to calculate materials balances, on the assumption that there is no loss, as dust, of this +100 mesh fraction. By interpolation, it can be shown that a de-dusted product recovery of 68.5% will be obtained at an air flow of 2.13 cu ft/sec sq ft of screen area. The feed material contains 68.5% of +150 mesh material, so that if the de-dusting gave a perfectly sharp cut, the product would contain no material less than 150 mesh. Further calculations based on the size analyses, show that, at an air flow of 2.13 cu ft/sec sq ft of screen air, the -150 mesh fraction in the de-dusted product will fall just below the specified maximum limit of 5%.

Jan 1, 1964

By R. W. Nelson

Methods for determining permeability presented by W. D. Kruger3 in a paper entitled "Determining Areal Permeability Distribution by Calculation" have considerable merit. They can be expected to contribute significantly to analysis of flow in heterogeneous systems. Some rather subtle yet important conditions must be met, however, to assure that the computed permeabilities are correct. The conditions which insure a unique permeability distribution may have been overlooked in the method as proposed and presented in the subject paper. The subtlety of the special requirements may permit good agreement between computed and measured pressures in the reservoir; but the computed permeability may still be in error. The general theory and discussion of the requirements for a unique determination of the permeability distribution are presented elsewhere in more detail.7'8 Accordingly, only major features will be presented here in the notation of Kruger. GENERAL DESCRIPTION OF REQUIREMENTS A brief mention of the route to be followed in showing the special requirements may be helpful. The equation to be solved is a quasilinear, first-order, partial differential equation in the unknown permeability. This equation can be solved through an extension of Lagrange's method by reduction to a system of subsidiary ordinary differential equations. Through consideration of the identity of one of the Lagrange subsidiary differential equations with the stream function, a special interrelationship can be shown. The interrelationship has special significance with respect to the boundary condition. If the boundary function satisfies part of the subsidiary differential equation, no unique solution for the permeability distribution exists. In the physical problem this requirement for uniqueness indicates that the permeability measurements used as a boundary condition can not be along a stream tube. The boundary condition must be along a line, or series of lines, which completely traverse the region and pass through every stream tube.

THE International First-Aid and Mine-Rescue con-test, under the auspices of the U. S. Bureau of Mines, was held at Butte, Mont., on Aug. 20, 21 and 22. As usual, the first-aid elimination contests were held the first day, the finals the second, and the mine-rescue contest the third. While the number of teams entered was not as great as at some previous contests held nearer the coal-mining districts of the East, the atten-dance was much larger than usual, due to the great interest in first aid, rescue work, and accident preven-tion that has been created by the effective support and constructive policy of the Anaconda Copper Mining Co. toward them. The winner of the first-aid contest was the Great Falls Zinc Mill team of the Anaconda company, of which Fred Erickson is captain. Second place went to the Baton Rouge team of the Standard Oil Co. of Louisi-ana, and third to the Great Falls Furnace Refinery team of the Anaconda company.

Jan 9, 1928

By R. S. Shoemaker, F. W. McQuiston

EMPEROR GOLD MINES Vatukoula, Fiji 1974 Operating Data to July 1 ORE DESCRIPTION: Ore bodies occur in basalt and associated ash beds overlain by andesite tuffs and sediments. The basalt in much of the ore mined is weathered with alteration of olivine to serpentine and iron oxides, and augite to chorite. The most important host minerals for gold are the tellurides sylvanite and hessite. Next in importance the sulphide s, pyrite, marcasite and arseno-pyrite. A small amount of free gold also occurs. Chalcopyrite, sphalerite, tetrahedrite, bornite, galena and native tellurium are present in small quantities. TYPE OF MINE: Underground and open pit ORE HAULAGE TO MILL: 3.5 ton bottom dump skips from underground. 7 ton trucks from open pit. CAPACITY IN TONS/24 HRS: 1345 short tons ASSAY HEADS (1973): 0.232 oz Au per ton, 0.357 oz Te per ton PRODUCTS: Gold Bullion (400 oz bars) Metallic Tellurium (1 2 lb bars ) RECOVERIES: AU 86.2% Te 88.0% ORE GRINDABILITY: 9.25 Kwh/T TOTAL POWER: 25.7 Kwh/T WATER: Pumped 112 mile to a 318, 000 gallon head tank. Consumption: 2 140 gal per ton, no reclaimed water used. TAILINGS: Pumped 2 /3 mile through 8" pipe. Uphill sections are steel. Downhill sections are fibro asbestos.

Jan 1, 1975

The Industrial Board of the Department of Commerce has been formed under the chairmanship of George N. Peek, formerly vice-chairman of the War Industries Board. This Board is to put into practical effect a program for the readjustment of prices for basic materials in such a fashion as to create a firm foundation on which the consumer can base his future purchases, and the producer can form necessary estimates. It has the assistance of the Council of National Defense. One of the first steps off the Board was to call into conference the leaders of industry. At these conferences the general conditions of the country are carefully considered and an effort made to determine and understand the principles that should be applied to permit the successful solution of the problem. It will be the endeavor of the Board to act promptly by consulting and interchanging views with these representatives of industry in the fullest and freest manner possible with a view to aiding and assisting industry in general to resume activities to the fullest practicable extent.

Jan 4, 1919

By Y. Nakada, E. J. Fasiska, A. S. Keh, L. Zwell

DURING an investigation of solid-solution hardening of nickel by carbon,' we found that there were no reliable data on the dilating effect of dissolved carbon on the unit cell of nickel. Bernier2 reported an increase in lattice parameter of nickel (3.523A) when an unknown amount of carbon was introduced into solid solution (3.536A). Similarly KG, Tsien, and Misek3 found an increase from 3.523 to 3.531A when nickel was carburized. strong4 studied the variation of nickel lattice constant as a function of dissolved carbon. However, in his case carbon was introduced into nickel by solidifying the melt at 65 kbar. Therefore, his carbon concentrations were much above the highest equilibrium solubility limit5 (2.7 at. pct C at 1 atm). Knowledge of the lattice mismatch between solute and solvent is essential in understanding the mechanism of solid-solution hardening. Therefore, we decided to determine the dilation of the nickel lattice by carbon under the more usual conditions of atmospheric pressure. The material used was Inco Electrolytic Nickel of 99.95 pct purity, as specified by the supplier. The impurity contents in wt pct were: Fe, 0.01; Cu, 0.01; Co, 0.03; 0, 0.005; C, Si, S, N, trace. To this base material various amounts of AUC-grade high-purity carbon were added during vacuum induction casting. Ingots, 2 in. in diam, were heated in a muffle furnace at 1000°C for i hr., hot-rolled to 1/2-in. thickness, and quenched into brine. All ingots with carbon concentration greater than 0.98 at. pct were enclosed in a cast iron box during the heating to minimize decar-burization. Small pieces were then either swaged down to 0.028-in.-diam wire or cold-rolled to 0.010-in.-thick sheets. After the final cold reduction in area of 50 pct, the specimens were recrystallized by heating in evacuated capsules at 1100°C for 60 to 80 sec and then quenched into brine. The final grain size was 50 to 100 µ. The carbon contents of the alloys, Table I, were determined by a combustion method

Jan 1, 1969

By Henry H. Thomas

In Tasmania a tailrace tunnel to handle water discharged from a turbine generator has been successfully driven by a machine tunneling method similar to that described in the July 1962 issue of Civil Engineering. The Hydro-Electric Commission, Tasmania, is constructing a high- head (2750 ft) power project that will utilize the storage in the Great Lake (1,150,000 acre-ft) at an elevation of 3380 ft. The underground power station will house six vertical shaft turbo-generators, each rated at 50,000 kw. The tailrace tunnel, 16 ft diam and 14,600 ft long, was driven through a reasonably homogeneous hard mudstone. It was decided to excavate this mechanically in the hope of saving some money on excavation and a considerable sum on the ultimate lining of the tunnel. Mechanical engineers from Tasmania worked with the firm of James S. Robbins and Associates of Seattle, Wash., which designed and supplied the "mole."

Jan 4, 1963

By Akira Yokoyama

Japan is composed of four main islands: Honshu, Hokkaido, Kyushu, and Shikoku (Fig. 1). Between Honshu and Kyushu, a railway tunnel and a road tunnel have been open since 1942 and 1958, respectively. Hokkaido, [ ]

Jan 1, 1970

By E. E. ELLIS

THE zinc deposits under development by the Universal Exploration Co., a subsidiary of the United States Steel Corporation, are close to Jefferson City, Tenn., a small town about 30 miles northeast of Knoxville, Tenn., and are served by the Southern Railway. The first zinc mining in this district was in the old Mossy Creek mine at the north edge of the town, opened for oxidized ores in 1871 and later worked for sulfide ores. An oxidized zinc ore deposit (carbonates and silicates) was opened near New Market in 1900 and worked through the war period by the G1'8sselli Chemical Co., producing around 25,000 tons of oxidized ore. In recent years a sulfide deposit has been found and developed but is not producing. About 1% miles south of this a small body of sulfide ore was developed by open cut, but the operation was unsuccessful. The Universal Exploration Co. entered the district in 1926 and, after extensive exploration, has been operating an oxidized ore-body since Janual:y, 1928, and has been developing a sulfide ore body since July, 1928.

Jan 1, 1929

By R. J. Brison, O. F. Tangel

The development of a new method of mineral separation was sponsored by the International Salt Company, which requested Battelle Institute to investigate means for improving the quality and appearance of rock salt from the Company's Detroit mine. Although developed specifically for removing impurities from rock salt, the general method may be applicable to other separation problems. The principal impurities in rock salt from the Detroit mine are dolomite and anhydrite which represent 2 to 5 pct of the weight of the mined salt. In the size range from 114 to 112 in. (the range of primary interest in this project) the impurities are only partially liberated from the halite in normal production. Further size reduction to improve the liberation of impurities is not practicable in view of the market requirements for the coarse grades of rock salt. Laboratory separations in heavy liquids showed that, to improve the quality and appearance of the rock salt substantially, it would be necessary to remove not only free gangue particles but also a large proportion of the locked-in particles.

Jan 8, 1960

The following petition for amendment of the constitutional provisions relating to qualifications for membership in the Institute, signed by 75 members, of whom 27 are members of the Committee on Increase of Membership, was received by the Board of Directors, was printed on the program of the New York Meeting sent to all members early in January, and is now being voted upon by the membership: In accordance with the terms f Article X, we hereby propose the following amendment to the Constitution, Article II, Section 2: Members shall comprise all those persons who on the third Monday of February, 1918, were members of the Institute, and in addition thereto, all those thereafter, elected or transferred into the, class of Members. A person to he eligible for election or transfer into the class of Members must he at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. Graduation from the scientific course of a college, approved by the Committee on Membership, shall be considered equivalent to two years' employment, as required in the previous sentence.

Jan 2, 1918

Jan 1, 1942

LIST OF REFERENCES COMPILED BY ENGINEERING SOCIETIES LIBRARY FUEL POSSIBILITIES IN STEEL MAKING. Iron Age, November 6, 1913, p. 1056-1059. Paper read before the American Iron and Steel Institute, by William Whigham. The author discusses the use of pulverized coal as a fuel for open-hearth furnaces. IMPROVED PULVERIZED FUEL FEED DEVICE. Iron Age, November 6, 1913, p. 1024. Brief description of the Dunn apparatus, especially intended for cement kilns, but used also in the nodulizing of iron ore. WIDER UTILIZATION OF PULVERIZED COAL, H. R. Barnhurst. Iron Age, October 23, 1913, p. 906-908. Part of discussion of paper by James Lord on The Use of Pulverized Fuel in Metallurgical Furnaces, read before the Engineers' Society of Western Pennsylvania. POWDERED COAL FOR OPEN HEARTH FURNACES. Iron Age, October 16, 1913, p. 855. Abstract from the "Coal and Coke Operator." USE OF PULVERIZED COAL AS A FUEL FOR BOILERS, R. C. Carpenter. Sibley Journal of Engineering, December 1913, p. 85. COAL-DUST FIRED BOILER. Indian Engineering, November 29, 1913, p. 301. PROGRESS IN FUEL UTILIZATION. Mining and Scientific Press, October 25, 1913, p. 638. BUFFALO GRAIN-ELEVATOR DUST EXPLOSION. Engineering News, July 31, 1913, p. 223-24. Reprinted in the National Fire Protection Association Quarterly, October, 1913, p. 149-151. Mention is made of the danger of explosions in connection with the burning of powdered coal. POWDERED FUEL AND EXPLOSIONS. Railway Age Gazette, July 18, 1913, p. 53-84. Letter by W. D. Wood. USE OF PULVERIZED COAL IN METALLURGICAL FURNACES, James Lord. Engineers' Society of Western Pennsylvania, Proc., October, 1913, p. 363-371; discussion, p. 371-417. With bibliography.

Jan 3, 1914

By A. R. Sims

Are from the Greater Butte Project is hoisted through the new Kelley shaft. In 1946 when plans were formulated for the Kelley mine, two test cave blocks were mined by using the facilities of the old St. Lawrence mine. These blocks, known as the Adams No. 1 and Adams No. 2, produced more than half a million tons of ore. The experiment proved beyond all doubt that cave mining was possible- and economical-in Butte. Adams No. 1 was patterned after Inspiration cave blocks. Adams No. 2 was a slusher type, with the slusher lane on the first floor above the haulage crosscut and at right angles to it. Thirty-horsepower electric hoists slushed ore from 48-in. scraper buckets directly into cars for haulage to the shaft. These cars were the 57-cu ft Granby type hauled by 6-ton battery locomotives over 40-lb, 18-in. gage track. Prior to this time the largest slushing machines used at Butte were 15-hp electric hoists pulling 36-in. scrapers.

Dec 1, 1956

Geological Survey of Alabama, University, Ala. A complete list of publications will be sent upon request Requests for publications should be addressed to Walter B. Jones, State Geologist, University, Alabama Publications of the Survey, of most interest to the general public, comprise (1) Special Reports, (2) Monographs, (3) Bulletins, (4) Circulars, (5) Maps The Special Reports mostly deal with a special coal field, mountain, valley, or series of formations, while the Monographs treat of some industry, resource, or group of organisms throughout the state or as far as it extends The Bulletins deal with a variety of subjects, but are usually smaller and less technical than the Monographs and Special Reports Maps now available comprise a map of the Cahaba coal field, one of the Coosa coal field and a small geological map of the state, in addition to a large geological map, 28 by 42 inches, 8 miles to the inch (1926) (also bound with Special Report 14) Price of the large geological map of Alabama, folded in manila envelope, is $1.03 postpaid

Jan 1, 1933

By R. Adair, W. R. Hudspeth, W. T. McDaniel

A NEW method for concentrating the flake mica either from present washing plant tailings or from new feed has been developed. In this paper, flake mica refers to that which occurs in weathered granites, alaskites, pegmatites, and schists in a form too fine to be considered sheet mica. It ranges in size from 1 in. or more down to 200-mesh or finer and occurs with kaolin, quartz, and partially kaolinized feldspar. Scrap mica, a term often used indiscriminately to describe everything other than sheet mica, will be used to denote the waste product from sheet mica mines and fabricating plants. Both flake and scrap mica are used in the mica grinding plants to produce wet-ground or dry-ground mica, although some flake mica recovered from clay mining operations is fine enough to be marketed without grinding.

Jan 3, 1951

By Robert Maddin

crystal prior to, polishing in order to eliminate coring. This treatment may be accomplished by wrapping the single crystal tightly in very thin, dead soft, brass foil and annealing in the presence of air for 20 hr at 800°C. Since the wrapping encircles the sptcimen three to four times, only a very slight amount of oxidation occurs on the specimen surface. On unwrapping one of these cylindrical single crystals. in. in diam by ro in. long (72.75 pct cu, 27.23 pct Zn, 0.01 pct P11, 0.01 pct re), mall light-gray depnrrits in the form of circular arcs werenoted on the part nf the foil which had been in contact with the single crystal, Fig r. (By superim- approximatetl). These deposits, which, from their color, suggest the appearance of sublimated zinc, were found to coincide roughly with a set of octahedral planes nearly perpendicular to the rod axis. The pattern shorn in the figure held no relation to the profle of the sample since the markin~s on the crystal More annealing werc attributed to traces of cube planes. It seems very likely that the deposits were formed by sutllimation of zinc diffusing from octahrdral planes since diffusian would Eogically take place along planes of maximum atomic spacing. However, it is difficult to understand why a continuous sublimation of zinc should occur from a single crystat in contact with a wrapping roil OF the same composition, and why diffusion would take place along specific octahedral planes and in a regular pattern.

Jan 1, 1949

By Hallan N. Marsh, Bruce H. Robinson

It is generally believed that the flowing of wells through tubing instead of casing results in the conservation of gas. It is further believed that use of tubing prolongs the flowing life of a well and results in greater ultimate recovery, provided either that there are no adjacent wells, or that any adjacent wells are similarly operated. Recent experience in the flowing of Buckbee zone wells at Santa Fe Springs has not only substantiated both of these beliefs but has led to the further conclusion that the use of tubing results in a greater cumulative flowing production, ' even in a highly competitive field like Santa Fe Springs, where the wells concerned are closely offset by wells of both the same and other companies flowing through casing. Further, gas-oil ratio has been so reduced that greater ultimate recovery can be expected. In the belief that such would be the case, the majority of the Buckbee zone wells of one company were brought in through tubing, but enough wells were flowed through casing to form the basis for a comparison. For the purpose of this comparison, wells with flow strings 2½ or 3-in. dia. are designated as tubed wells, while those having flow strings larger than 3-in. dia. are designated as untubed wells. Casing used was mostly of 5 ¾-in. dia., the remainder being of 4¾-in. dia. There were 15 tubed wells and 8 untubed wells and they were scattered over the field in such a way that neither group appears to have any distinct advantage as regards location. Locations of all wells involved in the comparison are shown on Fig. 1. All the Buckbee sand wells of the company are included in the average production curves, with the exception of eight that were unsatisfactory for reasons other than the method of flowing. Findings 1. Buckbee sand wells flowing through casing larger than 3 in. had an average maximum production rate of 4670 bbl. per day, while wells flowed through straight tubing or 3-in. casing had an average maximum production of only 3300 bbl. per day. (See Fig. 2.)

Jan 1, 1932

By J. M. Lohr

A COMMERCIAL development requiring a suitable alloy or alloys for sealing into various grades of glass made it desirable to have a more exact knowledge of the expansion characteristics of the nickel-iron alloys than appeared in the published literature. The expansion of the more common. FIG. I.-EXPANSION CURVES OF SEVERAL FIG. 2.-EXPANSION CURVES OF TWO TYPES OF GLASS. (Courtesy of R. C. A.) TYPES OF GLASS. (Courtesy of R. C. A.) types of glass under consideration varies from 2.7 to 10.4 X 10-6 per degree Centigrade, over the range 20° to 400° C. For reference, the thermal expansion curves f several types of glass used for sealing by the lamp and tube industries are given (Figs. 1 and 2). This paper covers a detailed investigation of the thermal expansion of a series of nickel-iron alloys in which the nickel content varies from 30 to 70 per cent. Particular stress is laid on the alloys that contain between 40 and 55 per cent Ni.

Jan 1, 1938

Carlisle: This is August 1960 and I am sitting across the table from Henry DeWitt Smith. We both took the mining course at Yale the same year; and here we are, over fifty years later, at Nantucket Island where we have spent quite a number of summers together. Now, let's start the questions with something about the center of your career. Let's say Tsumeb; not about the mine itself which people know, but some of the details on how you happened to take it over for Newmont. Mr. Smith: I first heard of Tsumeb, a famous German mine, through our own associates O'okiep Copper Co. From 1935 on, the local management at O'okiep, being reasonably close, kept the New York office informed. It served as a listening post for new mine development, as well as being a highly profitable copper mine in the northwest Cape Colony. We had all known of a famous German mine in South West Africa called Tsumeb. But it had a reputation for not welcoming visiting engineers. One engineer who went to this property for the Ministry of Supply in 1943, '44 and '45 was Arthur Storke. He was much impressed with possibilities of profitable operation. This mine had been operated by a German company since 1910. It was finally taken over by the Custodian of Enemy Property for the Union of South Africa.

Jan 11, 1963