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By Harry A. Roe

The power drag scrapers and the slackline cableway excavator have been called "long-range excavators." Broadly, their field of usefulness is restricted to work in which their long range of action permits them to operate economically, and which other, possibly more conventional, excavating units cannot do. Both of these machines dig or lift material and transport it to a remote dumping point. They combine these two functions in a single machine, nearly always in a single straight-line motion. The purpose of this paper is to examine the important features that distinguish the machines in this group from each other, as well as from other groups. The Machines The "power drag scraper" is a long-range excavating machine that employs a bottomless drag scraper operated back and forth between digging and dumping points by two haulage cables. The typical arrangement is that of Fig. 1. This is the "slusher" of the underground mine, as well as the "dragline scraper" of the sand and gravel industry, and other open-pit mining operations.

Jan 1, 1938

By Harry A. Roe

The power drag scrapers and the slackline cableway excavator have been called "long-range excavators." Broadly, their field of usefulness is restricted to work in which their long range of action permits them to operate economically, and which other, possibly more conventional, excavating units cannot do. Both of these machines dig or lift material and transport it to a remote dumping point. They combine these two functions in a single machine, nearly always in a single straight-line motion. The purpose of this paper is to examine the important features that distinguish the machines in this group from each other, as well as from other groups. The Machines The "power drag scraper" is a long-range excavating machine that employs a bottomless drag scraper operated back and forth between digging and dumping points by two haulage cables. The typical arrangement is that of Fig. 1. This is the "slusher" of the underground mine, as well as the "dragline scraper" of the sand and gravel industry, and other open-pit mining operations.

Jan 1, 1938

DISCUSSION, G. Derge and D. J. Girardi presiding N. A. Gokcen (Michigan College of Mining and Technology, Houghton, Mich.)—While the authors present very interesting results on the effect of sulphur upon the solubility of oxygen, they have not established convincingly the lines of two-fold saturation (the valleys in Fig. 2) and the ternary eutectic point. Their contention that sample S-7, upon melting at

Jan 1, 1954

By W. Buchanan, O. Johari

STEREOGRAPHIC projection has been one of the most useful aids in crystal-structure studies. With the increasing use of electron microscopy in metallurgy and other fields, stereographic projection is being used in many ways1 to interpret the results from electron diffraction patterns and transmission micrographs. For many of these applications, e.g., trace analysis, twinning, and so forth standard projections of various indices are required.

Jan 1, 1967

By S. A. Falconer

Much attention and publicity has been given, during recent years, to grinding, classification, flotation, and thickening. The various technical papers, and symposiums held to discuss these important phases of milling, have contributed to a better under- standing of the fundamental principles and operating variables involved. Another important part of milling- to the flotation operator-is a treatment step to which frequently too little attention is given-" conditioning," or the treatment the ground mineral pulp receives before it enters the flotation machines. Conditioning" is a hackneyed and frequently misused term, commonly employed to describe the pretreatment of surfaces of minerals in ore pulps or mill pr6ducts prior to froth flotation. In general, such pretreatment is for the purpose of changing the flotation characteristics of these mineral surfaces to enable them to respond in some desired predetermined manner when subjected to flotation. Taggartl states that the function of conditioning is "either to insure selective collector coating of one mineral species while another species is not; or to take such steps as will compensate for departure there from."

Jan 1, 1949

By D. M. Kehn

A method has been devloped for chromatographic analysis Of the vapor and liquid phases Of a a system containing methane to components having 20 or more carbon atoms. The method uses a windowed equilibrium cell in which volumetric phase behavior of the system can be observed accurately and from which small samples of gas or liquid can be withdrawn for analysis. Analyses are made using two chromatographs, one for the lighter and one for the heavier components in a sample. Combination of the two analyses yields a detailed analysis of the gas or liquid sample. The complexity of the condensate heavy ends is evident from the chromatograms of these fractions, and the predominance of the paraffin hydrocarborn serves as a useful marker in interpreting the chromatograms. The K-values obtained in this analytical method are presented for a high-pressure condensate system and predict closely the observed volumetric behavior of the system. INTRODUCTION Quantitative analysis of hydrocarbons from natural gas reservoirs is necessary for several reasons—to calculate the amount of sales gas produced, to calculate the amount of natural gasoline produced, to plan a liquid recovery system, or to calculate the potential economic value of a reservoir produced under one or more of several different conditions. Analysis of natural gas fluids produced to the surface consists of identifying and computing the mol fraction of each component of the mixture. Although methane is the predominant component, varying amounts of ethane, propane, butane, pentanes and heavier components are also present. Materials containing up to 30 carbon atoms occur in amounts which decrease with increasing molecular weight. However, the quantities of components in the 20 to 30 carbon atom range are usually so small that their importance is negligible, and they are undetect-able in natural gas by ordinary analytical methods. All the components up to those having 20 carbon atoms may sigsficantly affect phase behavior, however. Commonly, only the methane-through-pentane fraction is analyzed quantitatively for each component, while components heavier than Pentane are lumped and repored as "hexane- plus". Expensive, tedious techniques are required for analysis of this fraction. Consequently the detailed analyses needed for prediction of reservoir behavior are usually undertaken only when major gas fields are being developed. The need for complete analyses of condensate systems is apparent when it is recalled that most gas fields are produced by pressure depletion. As the pressure declines, some of the heavier hydrocarbons are lost as liquids which are in the reservoir. In many instances the amount of liquid in equilibrium with the gas phase at high pressure constitutes only 1 or 2 mol per cent of the total system. Flash calculations generally must predict the actual amount of liquid with an accuracy of a few per cent in order to be useful. This retrograde condensation has been understood for years, but accurate correlation methods to permit quantitative prediction of phase behavior in the retrograde region are not presently available. The increasing importance of natural gas has made accurate prediction of phase behavior and composition of produced natural gas streams an economic necessity. The work reported here was undertaken to provide a rapid, economical method for obtaining the vapor-liquid equilibrium information needed to predict accurately the composition of the fluids produced from a gas reservoir throughout its life. TO develop this method, a pressure cell equipped with windows was designed and built for observing the volumes of liquid and gas present at reservoir pressures and temperatures. Use was made of established chromatographic methods for rapid and detailed analysis of both phases. This paper describes the equipment and techniques developed for obtaining vapor-liquid equilibrium data, presents the results of analyses of a condensate system, and indicates the usefulness of these data in predicting hydrocarbon phase behavior. DESCRIPTION OF EQUIPMENT USED The equipment used in obtaining the required information on phase behavior and the complete analysis of hydrocarbon mixtures through C, will be described first, followed by a discussion of the operation of the equipment. It will be helpful, however, to consider first a brief outline of the technique used. A sample of separator gas and liquid is charged to the windowed cell (see Figs. 1 and 2) where volumetric equilibrium phase behavior at reservoir pressures and temperatures can be determined. Then samples of the coexisting phases are withdrawn. The methane-through-pentane fraction is analyzed with a chromatograph equipped with a hot-wire detector, and the pentane-plus fraction is analyzed with a second chromatograph equipped

Jan 1, 1965

Report of President The important fact of the year 1916 is that on July 25 contracts were executed by which the American Society of Civil Engineers because an additional Founder Society and arranged to make its permanent home in our building. The contracts provide for the construction of three additional stories to the building, the American Society to pay the cost tip to $250,000, this being considered equivalent to what each other Founder Society had contributed, the American Society to participate in the original Carnegie gift and have an equal share in the property with each other Founder society. The construction of the addition to the building is under way, $62,525.04 having been expended thereon in 1916. It has been found that, clue to war conditions and the advanced price of materials, the cost of the addition will be $300,000. The founder societies have been requested to assume the extra $50,000, one quarter each. This work is in charge of a Building Committee consisting of H. H. Barnes, Jr., Chairman, E. G. Spilsbury, Charles Warren Hunt and Charles F. Rand. At the request of the Founder Societies, important alterations were made in the lecture halls on the fifth floor of the building to make the same suitable for social functions of the societies. The cost, $6,642.08, was advanced by the United Engineering Society but is to be paid eventually by the Founders. The Library of the civil Engineers is being merged with the Library of the United Engineering. Society and the other founder societies. At the present time the membership of the four founder societies is 29,000 and of associate societies 23,000, so that a total of 52,000 engineers now have their headquarters in our building. The value of the real estate now owned by this Society is $1,647,171.16. This sum will be increased at the end of 1917 by the amount of the cost of the addition to the building.

Jan 3, 1917

By E. P. Klier, V. Weiss

IN studies of the X-ray diffraction line geometry of iron with chromium radiation using techniques aimed at minimizing the background intensity, Kp and Ka emission satellites* were resolved with three techniques. These satellite lines are present with sufficient intensity to lead potentially to erroneous structure analysis, if not properly interpreted. The techniques used were: 1) film technique with un-filtered radiation and polycrystalline specimen, 2) film technique with unfiltered radiation and single crystal, and 3) counter technique with unfiltered radiation and single crystal. An example of results obtained with technique 1 is given in Fig. 1.

Jan 1, 1958

By S. P. Burke

THE presence of gas in coal mines necessitates the use of costly ventila-tion arrangements and the use of expensive mining methods. On the other hand, the gas itself in many instances is of considerable intrinsic value, and its separate recovery might conceivably be a profitable under-taking. This paper is concerned with a study of the movement of gas in coal strata with the object of determining the laws governing gas move-ment and thus making at least a preliminary step toward the solution of the more practical problem of its control or recovery. Naturally, so important a subject has received much attention from scientists and engineers. In most cases, however, the studies have been concerned with the origin1?, the amount2, the composition3 and the method of retention4 of the gas in coal; or, from the more practical side, have been concerned with the phenomena and conditions associated with outbursts5 or explosions and their control. Numerous studies also have been made of the permeability of coal to gas6, of gas pressures measured in coal seams, etc. The authors are unaware, however, of any attempt to present a consistent or complete picture of the laws governing the movement of gas through the coal.

Jan 1, 1935

Executive.. CHARLES F. RAND, Chairman. JAMES F. KEMP, JOSEPH W. RICHARDS. ALBERT R. LEDOUX, BENJAMIN B. THAYER. Membership. BENJAMIN B. THAYER, Chairman. WALTER R. INGALLS, JOHN H. JANEWAY, Jr., JOHN D. IRVING, HERMAN A. PROSSER. Finance. EDWARD L, YOUNG, Chairman. KARL EILERS, JAMES GAYLEY. Library. JAMES F. KEMP, Chairman. JOHN HAYS HAMMOND,3 E. GYBBON SPILSBURY,2 ALES. C. HUMPHREYS 4 BRADLEY STOUGHTON.

Jan 7, 1913

A. K. McCosh, Coatbridge, Scotland (written discussion*).-It is well known in Great Britain that oven operators in the United States have been able to reduce the coking time much below European standards by the employment of higher temperatures. Our linings have always been the factor that has prevented our doing the same, and it would be of much interest to coke-oven operators here if Mr. Blauvelt would give a typical analysis of the bricks his company uses for the linings of its ovens, and if he could see his way to send me a sample so that I could have the texture examined, I should personally be very much obliged. The lining brick which my company has found most successful is of a ganister variety, and has the following analysis: Silica, 80.8 per cent.; alumina and iron oxide, .17.8 per cent.; lime, 0.8 per cent.; magnesia, 0.07 per cent.; but with this brick the least carelessness on the gas regulator's part may destroy the lining. It would also be of interest if Mr. Blauvelt could give the temperatures of the air leaving these generators and also of the oven flues.

Jan 10, 1918

By M. R. Meyer, W. T. Walter

A great deal is known, in a qualitative sense, about the performance of CMI EB-36 centrifuges. The manufacturer can give reliable guidance for the proper operation of its centrifuges and can give general estimates of expected product moisture and recovery. Quantitative estimates of the effects of changes in the various operating parameters are more difficult to find. The engineer faced with designing a preparation plant may be without the specific data needed to make decisions. For example, to obtain optimum product moisture when drying 9.5 mm X 595 µm (0.4 in. x 28 mesh) coal the centrifuge manufacturer recommends having no more than 5% -595 µm (-28 mesh) material in the centrifuge feed. They know that more -595 µm (-28 mesh)material in the feed will cause higher product moistures, but they usually cannot quantify the increased moisture or describe the shape of the product moisture versus -595 µm (-28 mesh) in the feed curve. This study was conceived to provide quantitative information on the EB-36 centrifuges, focusing on product moisture, recovery, and size degradation. All of the centrifuges tested were Model EB-36 dryers from Centrifugal and Mechanical Industries Inc. (CMI), with feeds in the nominal 9.5 mm x 595 pm (0.4 in. x 28 mesh) range. These are typical centrifugal dryers in this application, and many were available for testing.

Jan 1, 1984

By W. R. Crane

While professiorlally engaged in the oil- and gas-fields of Kansas, in measuring the pressure and flow of gas-wells, and studying the phenomena attendant upon the production of both oil and gas, I noticed in the flow of gas a peculiar and interesting feature. That there are actual lines of flow in liquids (non-compressible fluids) discharged through an orifice, or a short section of pipe, is shown by the external shape of the discharge—the vena contracts. Such lines of flow are not observable in the discharge of gas from an orifice. It can hardly be questioned that they exist. That they are not apparent is probably due to the very small weight of the gaseous particles, which climinishes the momentum of their movement in a given direction, acquired before they issue from the orifice, and also to the expansion of the gases, which would exert a powerful influence in overcoming any such tendency in their flow. Gas flowing from an orifice, supplied by a large reservoir or blowing-engine, exhibits almost the reverse of what is noticed with liquids. Namely, the gas assumes the form of an inverted truncated cone, of large angle: with its apex-end at the orifice. (See BB, Fig. 1.) This external ahape assunled by the flow of gas shows, however, marked differences under varying conditions of volume and pressure. For instance, a large volume of gas under high pressure, flowing through a 2- or 3-in. pipe, as in the case of a natural gas-well, assumes a more definite conical form, the angle of which increases as the pressure falls. Moreover, outside of the well-defined inverted cone is a thin conical heath or zone of gas, A A, the angle of which is considerably greater than that of the main cone, and increases with +1UNIVERSITY OF KANSAS, LAWRENCE, KANSAS.

Jan 1, 1905

By P. T. Carter, A. B. Murad, H. B. Bell

N. A. Gokcen (Michigan College of Mining and Technology, Houghton, Mich.)—The activities of silica, represented in Fig. 5 for the systems MnO-SiO2 and CaO-SiO2, are in disagreement with the established binary phase diagrams. At Ns102 = 0.50 in MnO-SiO2, and at Ns102, = 0.65 in CaO-SiO2, each binary system is saturated with respect to silica at 1550°C, and therefore as102, is unity in each case. The curves for as102 (FeO-SiO2) and as102, (MnO-SiO,) should nearly co-

Jan 1, 1953

[THE BLAST FURNACE Blast Furnace U. S.A., M. O. Holowaty, and C. M. Squarcy Part I - Colonial Ironmakers (JOURNAL OF METALS, May, 1957)3 Part II - The Age of Mineral Coal (JOURNAL OF METALS, July, 1957) 9 Part III - From Falling Creek to Zug Island (JOURNAL OF METALS, October, 1957 17 Sterling, Ringwood, and Greenwood, R. W. Shearman and F. Weston Starratt (JOURNAL OF METALS, September, 1959) 23]

Jan 1, 1961

[Allen-Sherman-Hoff Pump Co Third Cover Dee Carlton Brown, Advertising Allis-Chalmers Mfg. Co 625,654 Compton Advertising, Inc. American Cyanamid Co 638,639 James J. McMahon, Inc. American Manganese Steel Div., American Brake Shoe Co 642 Fuller & Smith & Ross, Inc. Anaconda Copper Mining Co * Kenyon & Eckhardt Inc. Carlon Products Corp * Penn and Hamaker, Inc. Chicago Pneumatic Tool Co 627 G. M. Basford Co.]

Jan 1, 1952

By Frederick Burbridge

The Morning silver-lead-zinc mine of the Federal Mining & Smelting Co. is about 'two miles northwest of Mullan, Ida. The lode is a metasomatic fissure vein. The orebody is approximately 2000 ft. long within the bounds of the property and varies in width from knife edge stringers to 50 ft. It has been developed to a depth of 3600 ft. and stands nearly vertical in Revett quartzite, which .strikes north 65" west. The high-grade veins and lenses are generally mixed with waste (siderite, quartz, and quartzite). The average grade of ore to sorting plant in 1921 was 4 oz. silver per ton, 8.6 per cent. lead, and 4.1 per cent. zinc. Wall rock stands only a short time without timbering. The minimum angle of gravity flow is 45". The ratio of waste sorted out to ore is 6 per cent. No gases are generated underground and temperature has no influence on mining operations. Fresh air is forced down the air raise and up the main shaft. Drifting and Stoping Main drifts 12 ft. wide and 13 ft. high are driven every 200 ft. (vertically) and are connected by raises 125 ft. apart. These raises consist of three compartments (chute, tramway, and timber slide) and are for the purpose of ventilation, access, and hoisting supplies to stopes. Ground is stoped between raises. Chutes are placed every 25 ft. for drawing off ore broken in stopes. Waste for filling is obtained from waste raises off the stope in walls or waste is dumped from the level above down the chute compartment of raises, which is bulkheaded so that waste can be drawn off at any floor as required. Timbering Posts and caps for square sets (varying in diameter from 6 to 24 in.) are cut to length in a sawmill on the surface. No preseratives are used. Timber is taken on a flat car along drifts to a raise nearest the working place and hoisted as required. Practically no timber is salvaged for

Jan 1, 1925

PRESIDENT AND DIRECTOR D.C. JACKLING SAN FRANCISCO, CALIF. PAST PRESIDENTS AND DIRECTORS NEW YORK, N. Y. R. C. ALLEN- CLEVELAND, OHIO VICE-PRESIDENT, TREASURER AND DIRECTOR KARL EILERS-* NEW YORK, N. Y. VICE-PRESIDENTS AND DIRECTORS HENRY KRUMB NEW YORK, N. Y. PAUL D. MERICA . NEW YORK, N. Y. H. G. MOULTON NEW YORK, N. Y. HARVEY S. MUDD Los ANGELES, CALIF. WILFRED SYKES CHICAGO, ILL.

Jan 1, 1938

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) No. 544.-Mining engineer, 39 years of age, graduate E. M. with extensive experience in the United States, Canada and Spanish-speaking countries. Good organizer, energetic and resourceful. Experience covers mining and milling of gold, silver, lead, copper, zinc and tungsten. At present a Captain of Engineers, U. S. A., expecting to be released shortly. Open for engagement as manager, superintendent or examining engineer. Correspondence and personal interview solicited. No. 545.-Engineer and geologist, member, age 29 years, technical graduate and married. Six years' practical experience as surveyor, chief engineer and in exploration work in West, Southwest and Mexico. Speaks French and Spanish. Desires position with exploration company or as engineer and superintendent of small mine. Will be released from commission in United States Navy about February 1. No. 546.-For staff position-or manager. Member, married, graduate mining and metallurgical engineer, 18 years' experience in underground and metallurgical work on gold, silver, copper, lead and zinc ores. Details, references, and qualifications will be sent if requested, or may be seen at Institute office. Available immediately in United States or Canada. Would go reasonable distance for an interview if desired. No. 547.-Member, experienced in mine operating, engineering, general contracting and constructing. Technical graduate, mining engineer, married, age 38 years. Many years' practical experience while advancing through different positions to manager. Best of references and rating. Desires change. Position with future. Can obtain results. Salary commensurate with position. Available on short notice. No. 548.-Mining engineer, member, technical graduate, age 31, on military service since August, 1914, available after January 31. Best of references.

Jan 3, 1919

By B. F. Peters, J. Gordon Parr, E. R. Macgregor

A SERIES of seven hypoeutectoid alloys, up to 18.2 atomic pct Mn, was made by the levitation melting technique. The loss of weight on melting was considered to be entirely due to volatilization of manganese, and compositions were computed on this basis. Filed samples (—200 Tyler mesh) were helium quenched from 1000°C after soaking for 5 min by a technique already described.' Quenched Alloys -Assessments of the amounts of a phase produced and the hardness of the quenched alloys are summarized in Fig. 1. The experimental techniques and calculations involved have been described previously. The amount of a decreases as manganese content increases, until at 10.6 pct Mn only a trace of a' is observed. Previous

Jan 1, 1957