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By F. G. Tryon, F. E. Berquist

Our task is to make a prospecting trip over the whole field of mineral economics which other lectures of this series will explore in detail. The old timers who really understand mining warn us that its economic aspects are often neglected, and this we find to be true. We shall try to show that mineral economics deserves recognition as a separate branch of economic science with urgent and distinctive problems of its own; that to cultivate it requires a fusing of the viewpoint of economics with that of geology and engineering; and that the help of both economists and technical men is needed in exploring its problems and in training workers in the field. To save time, we shall pass over the familiar subjects of production, consumption, and distribution which bulk as large in the market analysis of the minerals as they do in other commodities. The existence of these problems may be taken for granted and attention centered rather upon those that differentiate mining from other branches of industry. What then is the case for an economics of minerals? Why set up a new compartment in a branch of knowledge that is already well subdivided? Do not the established principles of economic theory apply here as elsewhere? In pleading for recognition of mineral economics one often finds that

Jan 1, 1932

By Sidney H. Loram

As the work carried on by this Company, of which the writer has been in charge for the past two years, is somewhat unique, the following account of it may be of interest, and, on that account, is offered to the Institute without any attempt to claim this practice as the best. Mines. The mines supplying ore to the Company arc situated in three groups: the Guanaco field,.about 80 miles N.E. of the port of Taltal (lat. 25" S., long. 70" 30' W. of Greenwich); the Sierra Overa, about 63 miles S.W. of Taltal; and Paranao, about 42 miles due N. of Taltal (12 miles N. of the small town of Paposo, once famous for its copper-output). Guanaco. This field lies in the center of an absolutely waterless mountainous desert, where not a sign of vegetation can be found for miles. The dryness is such that ivory and horn crack and open, while raw-hide must be used in place of leather, which -would become worthless in a very short time. Water is brought about 21 miles by piping from the Cordillera, but only in small quantities, and costs in the Guanaco $7 (= $1.78 gold) per cubic meter. All supplies and food are sent from the port of Taltal, which in turn draws its supplies from the south of Chile, the

Jan 1, 1900

By P. H. Dudley

THE piping and segregation of ingots of steel is a comprehensive subject, and must be studied in reference to the different grades of soft, medium, and hard steel, rather than to discuss it in a general manner, as though applicable to all grades. Rail steel, however, will receive the most consideration in this paper, for the wheel-loads of the motive pourer and rolling stock have doubled from 1890 to 1910. Steel rails and tires which were efficient under the light loads, became less serviceable under the double wheel-loads, quadrupled tonnage, and higher speeds. Bessemer Steel. Bessemer steel of froth 0.10 to 0.15 per cent. of carbon, for splice-bars, spikes, and tie-plates, rises in setting, and is cast in bottle-mouthed molds, which must be capped to prevent an over-flow from the top. This grade of steel rises in the molds and makes a longer ingot than the volume of molten steel when first teemed. The ingots which are allowed to cool and then cut open, show, particularly in the upper part, large occluded blow-holes, and when they are Dot oxidized or do not contain foreign matter, weld more or less completely when the steel is rolled or forged above 1,100° C., and it :is in this way that the blow-holes are closed it the low-carbon steels.

Jan 4, 1913

By B. L. Landrum, P. B. Crawford

The rise of a new laboratory model for studying tran-sient fluid flow problems, is described. The theory of he model is based on the analogy between the equa-ions which describe the flow of compressible fluids in porous media and the conduction of heal m solids. The "thermal model" is used to study the Iransient Pressure distributions during fluid displacement in five Standard well patterns. The studies indicate quantita-ively how die pressures change with lane at any poit in the reservoir. It was found that, in general, the equipressure contours are more radial about the wells early in the program than after steady-state conditions are established. In addition two studies of fractured five-spot patterns are presented to illustrate the opplicability of the model for a wide range of reservoir conditions. INTRODUCTION In reviewing the oil recovery techniques involving fluid displacement it was found that a very considerable quantity, if not all of the fluid within the pattern, mav be displaced (during a time-dependent or transient period rather than the usually applied steady-state conditions. Since the oil is displaced during a transient period, it was believed desirable to study the nature of the transients for several of the commonly used fluid displacement patterns. A literature review indicated fairly complete studies of the streamlines and isopotentials for steady-state: yet few data were available on the transient displacement process. Several simulated steady-state multiwell displacement programs were carefully mapped by Foster and Lodge on an electrical conducting sheet as early as 1875, hut the more recent work of Muskat provides the best source for steady-state phenomena having direct petroleum production applications. In order to study the transient phenomena a new lab-oratory model was developed which is based on the similarity of the equations that describe the flow of fluids and the conduction of heal. The equations describing heat flow were developed early in the nineteenth century. Regorous solutions tor most transient problems are in gcneral complex and usually limited to fairly restricted houndary conditions.2 the thermal model may be used to obtain approximate solutions for many transient problems without some of the restrictions required for analytical solution. The application of the analogy between heat conduc-. tion in solids. electrical flow and fluid flow, in a porous media has long been recognised. Techniques originally developed for the solution of heat conduction prol?lems have in many instances proved useful in ohtaining solutions to fluid flow prohlcms. Ir is not surpri5ing then that a heat conduction or thermal model might bf usefull in sludying transient fluid flow. As an example ol the problems suitable for the study with the thermal model, transient pressure distributions during fluid displacement programs are studied for the five-spot, line-drive, staggered line-diibe. seven-spot 211 two fractured patterns. A model was constructed of an iron plate of geometry similar to the reservoir patterns under study. The principle of mirror images as suggested by Bryan was employed in shaping the model. A temperature differential was obtained by soldering two sections of copper tubing to the plate at points analogous to the well location in the field. Hot and cold water was passed through the tubing. The temperature distribution, analogous to the pressure distribution in the field. was obtained a a function of time from thermocouplcs distributed over the plate.

By L. O. Bond, R. P. Alger, A. W. Schmidt

Well logging provides valuable information for planning coal mining operations. In addition to locating, defining, and evaluating coal beds, electrical logs indicate the relative competence of roof and floor formations. Electrical well logging is the .recording of various physical, chemical, or physicochemical properties of the strata penetrated by a drill hole. To perform logging operations, borehole measuring probes, or sondes, are lowered on a cable into the drill hole. Insulated conductors in the cable pass power to the sonde and transmit signals to the surface. As the sonde is pulled up the hole, the measurements are recorded as a well log. These measurements serve to define the formation lithology. Common rock minerals exhibit characteristic log values such that computer analysis of the log data defines the mineral content of the formations. Shales, carbonates and sandstones, and coal beds are readily distinguished. Furthermore, preliminary results in coal studies indicate the log data delineates variations in ash and moisture contents. Of major concern in planning mining operations is knowledge of roof and floor competence. Here again the logs provide valuable information. Measurements of formation density and acoustic wave velocity provide data for computation of a compressional modulus. This compressional modulus is an effective index of formation competence. Electrical logging thus efficiently provides information for economic planning of mining operations.

Jan 1, 1972

By O. J. Huber, P. D. Frost, H. A. Robinson

URANIUM is a (ß-stabilizing, eutectoid-forming element when alloyed with titanium. Udy and Boulger1 have reported that an alloy of 48.6 pet uranium in titanium retains ß-phase when quenched from the ß-region, while compositions of approximately 30 pet uranium transform to martensite during such quenching. Since the eutectoid reaction is rather sluggish, titanium-uranium alloys should be capable of being strengthened by the ß — a trans-

Jan 1, 1959

[ ] (14) SCREENS: Description of Allis-Chalmers' complete line of vibrating screens for the mining industry is contained in a new 8-page bulletin. Primary scalping, secondary scalping, and conventional screens for wet or dry sizing and screens for heavy media separation are included. Also given is a typical fiowsheet showing how horizontally operated Low-Head screens are used in the sink and float process. (15) MILLS: Forty-six years of experience and 4000 installations throughout the world lie behind the seven basic types of mills illustrated in a recent bulletin from the Hardinge Co. Fields of application and materials handled in various installations are listed. (16) BLOWERS & COMPRESSORS: A brochure describing the manufacturing facilities and the axial and centrifugal blowers and compressors made by the Sawyer Bailey Corp. is now available. (17) LINATEX: The first catalog of the Linatex Corp. of America has been issued, outlining the advantages claimed for this special form of natural rubber, when used in corrosion, abrasion, and vibration resisting applications. (18) WIRE ROPE: Twenty-four pages packed with concentrated wire rope data is the way E. H. Edwards Co. describes a booklet which they are now making available. It was condensed from the Edwards general catalog to provide users with a concise guide to every important phase of wire rope production, maintenance, and use.

Jan 1, 1952

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made his gift which made possible a home for the engineering societies, a separate corporation was organized to act as a holding company and to manage the common property. This was long known as the United Engineering Society, but the name has now been changed to one which more nearly reflects the real function of the corporation. It holds title to the Engineering Societies Building and to various funds placed in its charge and is managed by a Board of Trustees, of which three are chosen by each of the four societies, American Institute of Mining and Metallurgical Engineers, American Society of Mechanical Engineers, American Institute of Electrical Engineers and American Society of Civil Engineers, which have equal and undivided interests in the property. The land and building cost two million dollars. The interest of the Founders societies, aside from especial trust funds, is now valued at $1,987,793. The A. I. M. E. trustees are William H. Bassett, H. G. Moulton and R. M. Roosevelt. The President of the Board is Harold V. Coes and the Secretary, Alfred D. Flinn.

Jan 1, 1934

By C. J. Wilhem, J. M. Devine

A corrosion-testing apparatus which operates in the field and which will determine the comparative resistance of various ferrous materials to corrosion by gaseous hydrogen sulfide at ordinary temperatures is described. The principle of the uniform method of testing is to allow natural gas containing hydrogen sulfide, direct from its source in the field, to flow over the group of specimens for a given period of time, and subsequently to estimate the corrosion sustained by each specimen by determining its loss in weight. The comparative results obtained when specimens of 47 representative ferrous materials of described typical composition \\ere tested at ordinary temperatures with natural gas containing hydrogen sulfide are given in tables showing average penetration of metal, Inches per year. The primary purpose of the work Mas to determine the possible utllity to the petroleum and natural gas industries of ferrous materials that are commercially available, and no attempt is made to discuss the results of the tests from the metallurgical standpoint. The following is a summary of the results obtained: 1. Steels containing 12 to 27 per cent of chromium showed the highest resistance to corrosion. The presence of nickel In these high-chromium steels did not affect their resistance. 2. Steels containing approximately 5 per cent of chromium showed comparatively high resistance, but somewhat less than that of the high-chromium steels.

Jan 1, 1934

By L. S. Panyity

The question of natural-gas supply is receiving careful consideration in many parts of the country, as in the winter months it is quite a problem to have on hand sufficient gas to satisfy the demand. Increasing the output of wells by the application of vacuum has been tried with various results and large companies have attempted to keep up the supply with gas compressors. The possibility of storing natural gas in the sands of exhausted gas pools has been 'tried in a few instances with satisfactory results. This method may prove of practical value in solving the problem, especially in the case of towns that formerly obtained gas from their immediate vicinity but now must search for new pools. In all cases, only part of the available supply is utilized during the warm weather, so that many wells are shut-in, yet during the winter months, the supply is not sufficient even with all the wells on the line; in such cases it would be of great value if a large volume of stored gas were on hand, obtained through wells that would have been standing idle during the summer. Idle producing wells having considerable "rock pressure" will force gas into the exhausted, or storage wells, and this gas will be used only when the regular supply falls short (Fig. I). If two gas wells of different

Jan 1, 1920

By Lawrence Addicks

Discussion of the paper of LAWRENCE ADDICKS, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 104, August, 1915, pp. 1471 to 1484. L. D. RICKETTS, New York, N. Y.--In the Southwest we have stored up millions of tons of tailings in which the copper exists partly as sulphide and partly in an oxidized condition. Mr. Addicks' first paper suggests a, likely process for the treatment of such material. His second paper 1 deals with the recovery of copper from clear solutions of notable strength, and such solutions may come from the sulphating roast or direct from the leaching of completely oxidized copper ores of which vast deposits are known to exist. What strikes me particularly about the latter paper is the keen perception shown and the clear manner in which the writer has attacked the fundamental principles of the process. He calls your attention to the fact that ferrous sulphate is necessary in the electrolyte and is an ideal depolarizer; that sulphurous acid must be, used to reduce the ferric sulphate produced and thus prevent re-solution of copper at the cathode; that mechanical agitation in the cell, in order to bring the ferrous sulphate in contact with the anode and the copper in contact with the cathode, is essential to efficient work; that lead anodes are

Jan 12, 1915

By P. Somasundaran, Y. H. C. Wang

A detailed study of carrier flotation of kaolin clay using calcite showed the major beneficiation mechanism to be enhanced aggregation between anatase and calcite under intense agitation conditions. To develop an understanding of this selective aggregation, surface charge characteristics of kaolinite, anatase, and calcite were studied under simulated flotation conditions. Zeta potential of all these minerals tended towards a constant negative value in oleate solutions under certain conditions possibly due to adsorption or precipitation of oleate on them. However, whereas the zeta potential of anatase in the oleate solutions was not influenced by the agitation level, that of kaolinite was found to be strongly dependent on the agitation intensity. The effect of oleate on zeta potential of kaolinite was reduced by an increase in agitation intensity. It is suggested that oleate is much more firmly bound to the surface of the anatase and that this preferential attachment is responsible for the enhanced selective aggregation of the anatase with calcite. Agitation level plays a major role in carrier flotation since intense agitation is considered to enhance both the chemisorption of oleate on anatase and preferential detachment of calcium oleate precipitate from the kaolinite surface, all of this producing a large difference in the surface Properties of anatase and kaolinite, and hence in their tendency to aggregate with calcite.

Jan 1, 1983

By Theodore Nagel

Fuel-oil, natural gas and coke oven gas, producing the higher temperatures of open-hearth current practice, have been gradually displacing producer gas the lowest cost fuel for open hearth operations. The lower temperatures of combustion products from producer gas is caused by nitrogen dilution. Practical Application of Combustion Thermochemistry One pound of carbon burned to CO produces 3,960 B.T.U. and one pound of carbon burned to C02 produces 14,140 B.T.U. The second unit of oxygen uniting-with gasified car-bon (-CO) produces (14,140 - 3,960) 10,180 B.T.U. which is;(10,180 - 3,960) 6,220 B.T.U. more heat than produced by the first, unit of oxygen forming CO by uniting with solid carbon. A review of the relative combustion heating values of commercial gaseous fuels reveals CO requires a minimum of air for combustion, and because of minimum nitrogen dilution and the high thermal release from CO higher temperature combustion products are produced from CO than from natural gas or from coke-oven gas under similar combustion conditions. Inert nitrogen diluent lowers the calorific value of fuel gas and its diluting effect is cumulative in lowering the temperature of the products of total, combustion. It is not only logical but, practical in partial combustion, converting bituminous coal to gas, to generate the gas, with reduced nitrogen dilution.

Jan 1, 1936

By Kermit Allen

Historically, major natural gas transmission companies have been faced with the problem of meeting peak demands when the source of natural gas is located hundreds of miles away from the marketing area. Transcontinental Gas Pipe Line Corp.'s position was further complicated when offshore gas supply wells were shut-in during hurricane alerts. Transco's solution to this problem was the construction of salt storage wells adjacent to their pipeline near Eminence, Miss. Storage caverns were constructed using conventional solution mining methods. Two 13 3/8-in.-diam cased wells were completed and a 1,000,000-bbl cavern was leached at an interval of 5700 to 6700 ft at the base of each well. The two caverns have a usable storage volume of 2.0 billion cu f t and each well has a deliverability rate of 375 million standard cfd. The caverns are unique in that brine is not used for product displacement-all brine has been removed from the caverns. Natural gas is stored at a maximum pressure of 4000 psia. During withdrawal the cavern pressure drops to a minimum of 1225 Asia-the volume of gas between these two pressures becomes "usuable or top gas." The Eminence storage terminal is located on the Eminence salt dome about 30 miles north of Hattiesburg, Miss. Construction began in July 1968 and was completed in October 1970.

Jan 1, 1972

By Theodore Nagel

Fuel-oil, natural gas and coke oven gas, producing the higher temperatures of open-hearth current practice, have been gradually displacing producer gas the lowest cost fuel for open hearth operations. The lower temperatures of combusts on products from producer gas is caused by nitrogen dilution. Practical Application of Combustion Thermochemistry One pound of carbon burned to CO produces 3,960 B.T.U. and one pound of carbon burned to C02 produces 14,140 B.T.U. The second unit of oxygen uniting with gasified carbon (CO) produces (14,140 - 3,960) 10,180 B.T.U. which is (10,180 - 3,960) 6,220 B.T.U. more heat than produced by the first unit of oxygen forming CO by uniting with solid carbon. A review of the relative combustion heating values of commercial gaseous fuels reveals CO requires a minimum of air for combustion and because of minimum nitrogen dilution and the high thermal release from CO higher temperature combustion products are produced from CO than from natural gas or from coke-oven gas under similar combustion conditions. Inert nitrogen diluent lowers the calorific value of fuel gas and its diluting effect is cumulative in lowering the temperature of the products of total combustion. It is not only logical but practical in partial combustion, converting bituminous coal to gas, to generate the gas with reduced nitrogen dilution.

Jan 1, 1936

By Aaron Miles

THE pressure distribution in a producing oil or gas reservoir has been obtained mathematically in a limited number of special cases where the boundary of the reservoirs are simple geometric figures with the wells conveniently located within them. Using some of the previous work as a basis, it can be proved that a number of additional problems of pressure distribution can be solved by use of soap film. This method is particu-larly applicable to a reservoir drained by a number of wells, or to a reservoir of irregular shape, or to both. Since this method obtains the pressure distribution, it also establishes the drainage boundaries of the wells. This paper derives the analogy between the equation representing the pressure distribution in a reservoir and the equation of the deflected membrane. It also describes the apparatus and the method of operation. The experimental method is employed to solve a problem whose mathe-matical solution is known and the results compared. These are found to be in good agreement. The method is applicable to any homogeneous liquid, compressible or incompressible, or to a gas, flowing in a reservoir of uniform thickness, permeability and porosity. The flow state may be either the steady state or the transient state wherein the density or pressure of the fluid in the reservoir declines at a constant rate.

Jan 1, 1938

C. W. GOODALE, Butte, ,Mont.-While there are many points in Mr. Read's, paper which I am not prepared to discuss thoroughly, I am inclined to believe that difficulties are involved in the establishment of all employment bureau, which shall have exclusive control over the employment and discharge of workmen. I suppose you .have heard a great deal: about the so-called "rustling card? at the works of the Anaconda company. That is a very innocent sort of card, although the I. W. W. organization has made a great deal of noise about it. An applicant for a job is handed a blank on which he tells his nationality, his age, whether married or single, and the place of his last employment. The company then writes to the place where he says he was last employed to find out whether he is telling the truth; we do not ask the previous employer whether the man is blacklisted or has anything; against his record; but simply, "Was this man formerly in your employ?" A great hullabaloo has been made, about this practice by some of the men in Montana who are afraid, of their own records; but out of 53,000 applications for employment received by the Anaconda company since the employment bureau was formed, only 647 were rejected, which does

Jan 1, 1918

By Edgar Kendall

A KNOWLEDGE of the fundamental principles of locating, sampling, testing and evaluating materials is essential in prospecting for mineral aggregates. In this discussion, mineral aggregates will be considered sand, gravel, crushed stone and slag that are used as materials of con-struction. The quantity of mineral aggregates produced in the United States during the year 1935 for such purposes was roughly 165,000,000 tons, about 60 per cent of which was sand and gravel, 37 per cent crushed stone and 3 per cent crushed slag. The total value of this material was approximately $100,000,000. It is apparent therefore that the prospect-ing for suitable mineral aggregates is of considerable economic importance. In prospecting for mineral aggregates, the methods employed are the same whether the organization is large or small. In the large organiza-tion there may be available geologists for locating sources of supply, a land acquisition department to arrange for the necessary options or permits, engineers to do the sampling, a laboratory for testing, and a board of consulting materials engineers to make the final selection. Even small organizations must follow the same general procedure, though the respon-sibility for the selection of aggregates may rest with one man, who may or may not be an engineer, but who must depend entirely upon his own judgment.

Jan 1, 1939

By William A. Kennedy, Jonathan R. Stahl

This paper deals with the phenomenon of water held in a leach dump due to capillarity. Water is shown to be retained in the fine pores of the ore as well as in the interstices between the rock and soil particles. Upon drainage, Chino leach dump material shows two distinct capillary systems and a double capillary curve is often obtained. Both the igneous and the sedimentary rocks composing the leach material are shown to have appreciable porosity but little permeability. Fluid flow is, therefore, restricted to the interstices between the rock and soil particles. The irreducible water saturation for the aggregate is found to be 884 for the -48 mesh material and 235 for the448 mesh to one inch material. The composite sample of minus one inch dump material had an irreducible water saturation of 52 percent. The irreducible water saturation in the fine pores of the ore was found to be between 73 and 76 percent. Very coarse pores or channels between large rocks exhibit essentially zero capillary retained water. The presence of fine material in a dump can cause high water saturations to be retained and these saturations may be mistaken for perched water tables. Perched water tables can be drained but capillary water will be retained. Capillary pressure data can aid in distinguishing between perched water tables and capillary retained water.

Jan 1, 1974

By F. D. Patchen

Changes in the properties of partland cement upon the addition of fine-ground silica are discussed. Data were collected from formulations cured for periods up to 60 days at temperatures varying from 180" to 350°F. Compressive strengths, permeabilities and thickening times are compared. It is demonstrated that addition of find-ground silica in proper proportion results in a hydrated cement with superior properties above 230°F; i.e., early compressive strengths are higher and increase with additional curing, permeabilities are significantly lnrver and thickening times are increased. X-ray analysis of hydrated cement samples have been used to determine more fully the complex chemistry of these systems. Dicalcium silicate alpha-hydrate was found in all neat cements cured above 260°F. A 10 weight per cent silica addition produced a maximum amount of this phase. Xonotlite and tobermorite have been identified as hydration products at 320°F in systems containing 35 or more weight per cent silica. Formation of these components appears to be primarily responsible for the gain in strength and reduction of permeability observed after the addition of silica. INTRODUCTION For several years it has been recognized that loss of compressive strength occurs when portland cement is cured at a temperature above 250°F. This phenomenon has been called "strength retrogression". More recently it has been recognized that increased permeability usually is associated with decreased compressive strength at these temperatures. At curing temperatures above 300°F, these factors reach serious proportions. A compressive strength loss of 50 per cent between curing times of 24 hours and 14 days has been reported,' and permeabilities as high as 10 md have been measured in neat cements cured at 320°F for seven days.' Earlier investigators,' although unsuccessful in eliminating strength retrogression, stated ". . . .it appears possible that by the proper selection of additives for cement, strength loss with age at high temperatures can be either eliminated or considerably lessened". One solution suggested was the use of a pozzolanic material, hydrated lime, and a retarder. Menze15 in 1934 discovered that portland cement containing finely divided silica possessed high compressive strengths when the curing temperature was 350°F. The use of such a composition is now an established practice in the manufacture of steam-cured cement blocks. It is reasonable to assume that the same beneficial effect can be used advantageously in high-temperature oilwell cementing operations. Ludwig first mentioned the use of sand for this purpose. Later, a portland cement containing moderate additions of silica flour and retarded with CMHEC, a cellulose derivative. was recommended for high-temperature application." These formulations have been successfully employed in the field."'" This paper presents the results of a research program to test the efficacy of finely ground silica in increasing the compressive strength and reducing the permeability of oilwell cement compositions containing portland cement. Included also are X-ray diffraction patterns of powdered samples which have been used to determine some of the important chemical reactions occurring in these systems. LABORATORY PROCEDURES AND MATERIALS All compressive-strength test specimens were prepared and cured from a slurry in accordance with API RP 10B, with two modifications. A final curing pressure of 5,000 psi was maintained for a one- or three-day period; but, for further curing, pressures were reduced to the vapor pressure of water at the curing temperature. Also, the water content was varied in samples containing silica to maintain the slurry viscosity within a range of 5 to 15 poise as measured on a consistometer. Test specimens at 180°T were cured in a water bath at atmospheric pressure. At higher temperatures the specimens were cured in a steam-jacketed high-pressure curing vessel at 5,000 psi for a one- or three-day period. cubes cured for longer periods were removed from the pressure-curing vessel after 24 hours, sealed in small bombs containing water and placed in an aging oven.