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Jan 1, 1938

By F. G. Robb, D. N. Madge

This paper details some of the specifications and problems associated with implementing on-line control of a potash concentrator. The computer system described has the capability of three levels of control, including DDC with a single central processor. The system is also capable of on-line program compilation and modification through an extension of vendor utilities. The system is now in operation.

Jan 1, 1969

By A. Sauveur

At the New York meeying of the Institute, February, 1914, Professor Hopkinson and Sir Robert Hadfield presented an important paper entitled Research with Regard to the Non-Magnetic and Magnetic Conditions of Manganese Steel.

Jan 1, 1915

By W. Arthur White

Underclay squeeze is the plastic flowing of underclay below coal pillars into mined-out entries and rooms. Squeezes may be caused either by wet mine conditions where the moisture is taken up by the clay-making it more plastic-or by the presence of certain clay minerals, such as mont-morillonite, which are plastic when there is enough natural moisture. Under either condition, sufficient stress will cause the underclay to flow. Squeezes may fill an entry or room within several hours, or it may be several months before movement stops. Squeeze areas commonly cover hundreds or thousands of square yards.

Oct 1, 1956

By Öner Yücel, M. Zeki Dogan, A. Metin Ger

Technical and financial feasibility studies conducted at the Middle East Technical University, in Ankara, Turkey, have revealed that a 400 km long prospective slurry pipeline between Hasançelebi and Iskenderun could efficiently and economically transport iron concentrates, with a size of 55%-325 mesh and of amounts varying between 0.25 and 8.0 million tonslyear. Particularly for annual throughputs above 500,000 tons, favorable results have been obtained regarding the processing of the ore, the applicability, the transport cost, and the foreign ex- change currency savings.

Jan 1, 1980

By I. Iwasaki, R. Titi-Manyaka

Chlorination and chloridization behaviors of pyrite, pyrrhotite, marcasite, chalcocite, covellite, galena, sphalerite, heazlewoodite, and elemental sulfur were investigated by thermogravimetric analysis. The possible reaction mechanisms are discussed on the basis of the theoretical weight changes and thermodynamic considerations. Chlorine is a more effective chloridizing agent than hydrogen chloride. In the light of the experimental results, a scheme for producing nonferrous metal chlorides, molten sulfur, and ferric oxide from complex sulfide flotation concentrates is discussed.

Jan 1, 1974

By S. N. Sharma, William Davis

Because of diminishing energy resources and rising energy costs, every industry is forced to carefully examine its pattern of energy consumption. The copper industry is no exception; current smelting practice begs for technological innovations that would improve the efficiency of its energy utilization. The thermochemical simplicity of copper metal production, as shown in Fig. 1, is deceptive. Designed from the same basic principles, there are four major commercial processes either in use or under construction; and others, such as the Mitsubishi process, are being developed.

Jan 5, 1977

By Alfred E. Hunt

Professor EGGERTZ first published a method based upon the fact that, when steel is dissolved in dilute nitric acid, and heated until the separated flocculent carbonaceous matter goes into the solution, the liquid assomed a brown color proportionate in intensity to the amount of the combined carbon in the steel. This method has been so variously modified that at present but few chemists use exactly the same procedure. It is the object of this paper to present

Jan 1, 1884

Executive SIDNEY J. JENNINGS, Chairman GEORGE D. BARRON J. E. JOHNSON, JR. EDWIN LUDLOW ROBERT-M. RAYMOND Membership LEWIS W. FRANCIS KARL EILERS, Chairman J. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR L. WALKER Finance GEORGE D. BARRON, Chairman CHARLES F. RAND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY.1 Chairman. ALEX C. HUMPHREYS3 GEORGE C. STONE2 J. H. JANEWAY4 BRADLEY STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 2, 1919

By Paul H. Lu

This paper proposes an unconventional, simple, and practical method of measuring mining-induced ground stresses with hydraulic borehole pressure cells. The method is a direct ground stress measuring technique. It does not require the value of deformation modulus for back-calculation of stresses; instead, it directly measures the ground stress in situ. The applicability and practicality of the technique are shown by two case studies. The technique may be applied to monitoring a stress buildup that may lead to mine roof failure or to rock and coal outbursts.

Jan 1, 1984

By W. F. Mullen

WITH few exceptions, unit operations in the Pennsylvania slate industry in 1950 did not differ appreciably from production methods described by Behre1 and Bowles 2-4 several decades ago. Many traditionally picturesque but relatively inefficient hand operations continued to contribute to high operating costs in an industry in which the margin of profit, for various reasons, was admittedly low. As part of a general program in which the Pennsylvania State College has been assisting the slate industry to solve some of its problems, time and method studies were used in an effort to determine the bottlenecks of production flow. The results are as applicable to other stone industries as they are to slate.

Jan 12, 1951

By H. B. Emerick

An effort has been made to evaluate the individual influence of various factors in steel making and rolling operations upon the surface quality of semi-finished steel products. The thoughts expressed are not entirely theoretical, but rather are based upon several years critical observation of mill yields and rejec-tions and are supported by actual data wherever this has been possible.

Jan 1, 1940

By C. E. Shoenfelt

The discovery of oil in the Powder Wash stricture in northwestern Colorado late in the fall of 1936 is the most important development in Colorado since oil was first discovered in the Moffat dome in the same county in 1923. The Powder Wash structure gives promise of developing into an oil and gas field of major proportions and is of particular interest because the oil was found in Tertiary rocks of Eocene age, which heretofore had been productive in the Rocky Mountain region of gas only, and very few of the many structures of this kind have been tested because it was believed that oil production probably would be confined to rocks of Cretaceous age only, and these were, in most instances, at excessive drilling depths. Powder Wash is one of a series of small domes in the belt of folds and faults on the south side of the large but shallow depression known as

Jan 1, 1937

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 H. L. Armstrong

SOLID-STATE diffusion is an important technique in certain aspects of metallurgy, and especially the metallurgy of semi-conductors and semi-conductor devices. If the diffusion is carried out under constant conditions for a time, t, the concentration, C, of the diffusant at a depth, x, below the surface from which the diffusion is carried out is given by an expression of the form. C = Cof(x,Dt) [I] Co being a constant, and D the diffusion constant of the diffusant in the material and at the temperature

Jan 1, 1959

By S. J. Shale

Recent changes at Cornwall are highlighted by development of a panel caving method, with slushing drifts, for underground practice as open pit operation nears close. Metallurgy keeps the pace with high recovery from increasing amounts of harder to liberate, higher sulphide content, underground ore.

Jan 7, 1953

By Henry A. Gordon

Under the title " Hysteromorphous" it is proposed to include deposits which have been formed from original deposits by the influences of the surface-region. The term Hysteromorphous—later-formed—has been used by Prof. Posepny, of Vienna, to distinguish secondary from primary deposits and is more comprehensively applicable than the terms or designations hitherto used for the same thing.

Jan 1, 1896

By Donald E. Freshcorn

The minimum sulphur level which can be attained during fluid bed roasting of zinc sulfide concentrates is largely determined by the residual sulfates of calcium, magnesium, and zinc. The fractional conversion of these elements to their respective sulfates is derived from semi- empirical relationships, and multiple regression analysis is used to fit the relationships to experimental data from a commercial fluidized bed roaster. The resulting equation shows that the calcine leaving the roaster contains almost no zinc sulfate, nearly all of the calcium is present as calcium sulfate, and the amount of magnesium sulfate formed is primarily dependent upon the roaster temperatures.

Jan 1, 1976

By H. F. Walther

Basic electric-are furnace steel production mainly involves the use of two separate types of slags. The first, known as the "melt down" or oxidizing slag, which is in most cases removed from the furnace mechanically, and the heat finished under the second or deoxidizing slag, which is commonly known as the "finishing slag.'' The melt down slag is formed by the addition of lime or limestone to the charge, which combines with the oxides formed during the melting period and the product of any bottom erosion that may take place.

Jan 1, 1935

By Stuart M. Buck

THE term "splint" seems to have been adopted to describe the fracture of the hard bituminous coals of West Virginia. It is not a scientific name,, but rather a trade term, and does not indicate a correspondence with English splint. At present it is a popular word, and is very loosely applied to coals of various qualities, in the desire to improve their sale. The Kanawha splint is distinguished by its hardness, dull lustre, coarse fibrous structure, its purity, and especially its resistance to atmospheric influence. It kindles very readily, burns with a bright flame, but does not cake, so that a lump when half consumed, may be broken by a slight blow in its plane of cleavage, though 'it will resist a' strong blow in any other direction. I have seen pieces that have been exposed to frost and sun

Jan 1, 1882