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By Alvin Kaufman

The industrial revolution of the early 1800's and the subsequent remarkable progress in raising American living standards are based not only on a constantly improving technology but on an ever increasing use of energy from mineral fuels and waterpower. Industrial nations require inexpensive energy sources in order to grow. The more complex the economy, that is, the more intensive the processing of raw materials, the greater the energy needs of that economy. As a result of the current international economic expansion, the worldwide search for sources of low-cost energy has accelerated. As a part of this search there is considerable interest in the potential for commercial development of geothermal power, particularly abroad and in the western United States. This interest is indicated by the fact that 40 exploratory wells have been drilled in the California thermal areas alone during the 1955-62 period. Of these, 24 were drilled in The Geysers, Casa Diablo, and Salton Sea areas.

Jan 9, 1964

By C. E. Jr. Reistle

ALL crude oils become more viscous when chilled, but the only oils that congeal and precipitate paraffin to such an extent as actually to cause production troubles are those that contain an appreciable amount of wax. In handling these oils of high wax content, three distinct problems may be encountered before the oil reaches the refinery. The first problem is the precipitation and accumulation of paraffin in the well, either in the oil string or on the face and in the pores of the sand. The second problem is the accumulation of paraffin and the congealing of oil in the transportation lines. The third problem is the precipitation of paraffin and the formation of tank bottoms.

Jan 1, 1927

By T. A. Rickard

The earlier paper (Trans., xx., 463) describing this Victorian mining district, to which the present is supplementary, was mainly confined to the consideration of the "saddle-reefs," as scientifically the most interesting and economically the most important of the

Jan 1, 1893

By Harold S. Morgan

INTRODUCTION The Waste Isolation Pilot Plant (WIPP) is being developed in southeastern New Mexico by the United States Department of Energy as a research and development (R&D) facility to demonstrate the safe disposal in salt of radioactive wastes resulting from defense activities. As part of the WIPP R&D program, a series of in situ tests will be performed to determine the behavior of drifts and storage rooms in the creeping salt medium (Matalucci, et al. 1982). Data obtained in these tests will be used to evaluate and improve numerical models used to compute the structural response of these drifts and rooms. Stress has been proposed as one of the parameters to be measured in the tests, and borehole inclusion stressmeters have been included in the instrumentation package. Cages of this type provide an indirect measurement of stress change in that they actually monitor borehole displacements which are then related to changes in the in situ stress away from the borehole. The relationship between stress and displacement is highly dependent upon the constitutive behavior of the rock in which the gage is emplaced. This relationship is well understood for rocks with linear stress-strain behavior (Fossum, et al, 1976), but, for creeping rocks like salt, the relationship has yet to be determined. Thus, inclusion gage response in salt must be investigated fully before stress measurements from the WIPP in situ tests can be used for comparisons with computed stresses The calculations presented in this paper were performed as part of an investigation of inclusion stressmeter performance in salt. They focus on the strain gaged stressmeter (SGS) (Cook and Ames, 1979) and on a hypothetical solid cylindrical inclusion with variable stiffness Issues addressed include the effects of creep and the effects of gage stiffness on stressmeter output for various loading conditions. The

Jan 1, 1984

The key-note of good writing, as of good manners, is B natural. Sincerity is the first requisite for effective writing. When a man says what he knows or believes, he is likely to be interesting, because each human being possesses an individuality, a point of view, or a range of sympathy that makes him different from his fellows. To say or to write what you do not think, for the mere sake of talking or writing, is a verbal exercise that must be performed with extraordinary skill if it is to be attractive. Affectations are rarely attractive, rarely effective. To be natural is to be yourself, not a poseur; to give the reader the best of yourself, instead of re-warming the baked meats of yesterday. Quotations-which are second-hand thoughts-will serve occasionally when the thing you want to say has been said so well by another that it would be waste of energy to try to say it better; gut, as a rule, the utterance of the writer himself is more interesting than the quotation, because the writer brings something of himself to bear on the subject, and for the moment is more in touch with the reader than any dear departed author. Therefore, say things as best you can in your own way, neither in borrowed words nor in the phraseology that mimics another. Write as if you were speaking to a person whom you desire to persuade or convince. You will then write better than you speak, because, in the first place, you can be more deliberate, and, secondly, you can revise what you have written. Speaking and writing are similar mental acts, with a difference: the difference between eating food raw and eating it cooked. Some kinds of food gain nothing by being cooked; likewise some kinds of utterance are not bettered by being written down first; but most expressions of thought, especially

Jan 1, 1931

INTRODUCTION The after-tax rate of return that properly discounts future cash flows is usually referred to as the "discounted cash flow-rate of return" (DCF-ROR). The method is also referred to as the internal rate of return, true rate of return, and investor's rate of return in some literature. According to Stermole (1974, p. 188) industry polls indicate that the DCF- ROR method is the number one economic evaluation decision method used by more than 90% of the industrial companies that use for- mal economic evaluation procedures. Other economic evaluation methods that have been used in the past, such as payback period, accounting ROR, etc., have largely given way to DCF-ROR analysis because they fail to account properly for the time value of money. DCF-ROR is generally defined as that rate of return that makes the present worth of future generated cash flow over the life of the project (including after tax salvage value) equal to the present worth of all after-tax investments. The "present worthing" of future cash flow involves discounting future cash flow to a present value according to the mathematics of compound interest at some interest rate. The determination of the interest rate that equates the present worth of future after-tax earnings with the present worth of all after-tax investments necessary to create such earnings is properly called the discounted cash flow rate of return analysis. Although present worth calculations are usually used for determining the DCF-ROR, the same results can be obtained by comparing income and costs of any equivalent point in time, i.e., future worth, etc.

Jan 1, 1980

By R. S. Knappen, D. V. Carter

In the states east of the Mississippi River, oil field operations were generally restricted during 1927. Active drilling was chiefly confined to the flood district of Bradford, and to the new areas in western Kentucky, Michigan, and southwestern Indiana. In spite of the general depression, production increased in every state, except Illinois. This unexpected increase is. due to several factors. First, in 1926 there was little flush production outside of Illinois, and the decline 'curves in all states are exceedingly flat. Second, the floods in Bradford, Pennsylvania, and Allegany County, New York, proceeded normally and increased production in those states for the fourth consecutive year. Third, new pools in Kentucky, Indiana and Michigan gave important flush production. Fourth, the general unsatisfactory market forced the operators to scrutinize carefully all their operations and improve efficiency and production in all possible ways. Increases amounted to approximately 2,000,000 bbl. Illinois lost, 900,000 bbl., leaving a net gain for the states east of the Mississippi River amounting to 1,100,000 bbl., or a total 40,268,000 barrels. Pennsylvania and New York In northern Pennsylvania and southern New York, the principal activity centered in the districts where flooding is being used to increase the recovery from the old districts. Once started, the flood cannot be shut off. The producer must drill wells and take his oil on schedule, or irrevocably lose it. Accordingly, in face of an adverse market Bradford and Bolivar operations increased 24 per cent. This area furnished more than 40 per cent. of the oil wells completed east of the Mississippi River last year, although the average initial production was less than 2.5 bbl. Unlike all normal fields, this production increases for several months until water appears in the well. For this reason, these wells will produce much more oil than would appear probable from the statement of initial production. During the year, air or gas pressure was applied to several new properties. Surplus gas is rarely available and air has been more commonly used. Two explosions occurred as a result of recycling air-gas

Jan 1, 1928

By D. W. Gillmore, C. C. Wright

DEWATERING is a major problem in the preparation and utilization of fine-sized coals now being recovered in increasing amounts from colliery effluents, refuse banks, and silt ponds. Of the various methods which have, been proposed for dewatering fine coal, gravity drainage is probably the oldest and most widely used, and yet little information on this subject has been published. Consequently a laboratory investigation of gravity drainage phenomena was undertaken not only to provide basic data for predicting the drainage behavior of fine coals in cars, bunkers, basins, and silos, but also to obtain some understanding of the moisture retention properties of fine coal. Because of practical interest in the problem, a reproducible laboratory technique, which simulated plant conditions as closely as possible, was developed for the evaluation of drainage variables. The ap- paratus selected consisted of vertically-mounted lucite columns, nominally 4 to 8 ft in length and 2, 3 or 6 in. in diam; the bottom of the column was provided with a rubber stopper through which was inserted a -in. diam drainage tube; a wad of glass wool was placed on the upper part of this outlet tube to retain the coal and a plug was temporarily located at the lower end to prevent drainage during charging of the column, see Fig. 1. The most satisfactory testing procedure is as follows: 1—The fine coal, which has been thoroughly

Jan 1, 1953

Discussion of the paper of FRANCIS S. PEABODY, presented at the St. Louis meeting, October, 1917, and printed in Bulletin No. 125, May, 1917, pp. 775 to 781. THE CHAIRMAN (CARL SCHOLZ, Chicago, I11.).-Coal wastage is undoubtedly one of the most prominent topics before the coal operators of the United States today. Even those who have been in the business only 25 years, like myself, know that the exhaustion of coal is something that should and must, be curbed. If it is not, before long we shall discover that the great coal resources of the country are not what we-thought they were; we have been so accustomed to work at the best and thickest coal alone, that it will be difficult for us to realize one of these clays-and that (lay is not far distant-that we are no longer the rich nation in coal that we thought we. were. In this connection I feel obliged to attach a little blame to the Geological Survey for misleading the people. There are several members ,here who assisted in that work, and I am going to ask them to defend themselves. The Geological Survey deals with coal seams of much less thickness than we could now expect to, mine, particularly with the present high wages, excepting at a prohibitive cost. The Geological Survey, in its estimates, does not discriminate between thick and thin seams, but simply estimates our resources at so many hundred thousand billion tons of coal. I believe they include seams from 15 to 18 in thick, but you all know that a vein below 3.5 or 4 ft. is not considered economical to mine at this time. R. V. NORRIS, Wilkes-Barre, Pa.-Mr. Peabody has evidently been thinking almost entirely of Illinois conditions, with which I regret to say I am absolutely unfamiliar. In some West Virginia mines the total recovery at present is considerably over 90 per cent. and extraction-, as high as 97 or 98 per cent. are claimed.

Jan 1, 1918

COAL is perennially -a subject of major interest at. Pittsburgh, but during the week of Nov. 19 to 24 it was especially to the fore because nearly two thousand persons gathered to take part in the second of the international conferences organized by President Baker of the Carnegie Institute. From the opening session on Monday morning when those attending were welcomed by President Baker and T. P. Gaylord, president of the Chamber of Commerce of Pittsburgh, until the party returned from the Clairton coke ovens on Saturday. afternoon, there was something going on all the time, and usually three sessions were in progress at once.

Jan 1, 1928

By Aug. J. Jr. Bowie

(Read at the Wilkes-Barre Meeting, May, 1877.) Brief Outline of the General Topography of the Gold Regions of California. THE topographical features of California, as demonstrated by the explorations of the State Geological Survey, are found to be exceedingly simple. Three equidistant parallel lines can be used in conveying a general idea of the physical geography of Central California. A straight or " main axial line," whose course would be north 31° west, passing through the culminating peaks of the Sierra for a distance of five hundred miles, can be assumed as the eastern boundary of the State. A second parallel drawn fifty-five miles west of the " main axial line" will skirt the western base of the Sierra Nevada, along the edge of the foot-hills. A third parallel run equidistant from the second will represent "as nearly as possible the western base of the Coast Ranges." These parallel lines divide the State into three belts, namely, the Sierra, the Great Valley of California, and the Coast Ranges. " This arrangement of the physical features holds good for a length of four hundred miles in the direction of the main axial line, comprising almost the whole of the agricultural and the greater part of the mining districts."* The section of the country which is of immediate interest to the miner is the western slope of the Sierras. These mountains, rising in a short distance from the Sacramento plains to elevations of over seven thousand feet, with occasional peaks ten and twelve thousand feet high, are cut by numerous deep and precipitous gorges or capons, through which drains the immense watershed of the Sierra, supplying the main rivers of the State and ultimately emptying into the Pacific Ocean. Between these capons, ridges or divides are formed, on top of * See vol. i, p. 5, Geological Survey of California. J. D. Whitney, State Geologist.

Jan 1, 1878

By Milton E. Wadsworth, W. Martin Fassell, William H. Dresher

A study of the rate of dissolution of molybdenite (MoS2) in alkaline solution was carried out under carefully controlled conditions. Effects of temperature, oxygen over-pressure, and KOH concentration were evaluated. Studies were made in the temperature range 100°C to 175°C and in the pressure range 0 to 700 psia of oxygen. Under these conditions molybdenite was found to leach according to a linear mechanism. Both oxygen over-pressure and KOH concentration were found to control the rate of leaching. The mechanism has been explained in terms of adsorption of oxygen at the molybdenite surface followed by configurational rearrangement of the adsorbed molecules. The hydroxyl ion dependency is believed to be diffusion-controlled. Laboratory batch studies have shown that molybdenite can be readily dissolved in alkaline solutions under moderate conditions of temperature and pressure. Commercial application of this process to the production of ferro-molybdenum and molybdenum chemicals is promising in view of the ease of dissolution of molybdenite and the relatively noncorrosive conditions involved in the process. HIGH temperature-high pressure techniques have long been used to great advantage in the organic chemical industry, the petroleum industry, and the paper industry. Only recently, however, have these methods been used to extract metals from their ores on a commercial scale. The Chemical Construction Corp., together with interested producers of nickel and cobalt, has done much to develop methods of producing nickel and cobalt powders by the use of high temperature-high pressure techniques.' The Howe Sound Co. is currently operating a plant near Salt Lake City in which the new Chemical Construction Corp. technique is applied to cobalt-arsenic sulfide concentrates. In this method the concentrates are leached in a dilute solution of sulfuric acid under air pressure at a high temperature. Near Edmonton, in Alberta, Canada, the Sherritt Gordon Co. is also using the new method in conjunction with its ammoniacal leach process.' National Lead Co., at Fredricktown, Mo., is operating a process similar to that of Howe Sound. In spite of the rapid growth of high temperature-high pressure hydrometallurgical processes, there has been very little work done on fundamental principles involved in this type of process. Conse- quently the literature lacks any significant data in this field. Oxidation of pyrite,3 phalerite,4 galena,5 and recently molybdenite" in alkaline solutions has been reported to some extent. This investigation was initiated, therefore, to broaden the application of high temperature-high pressure hydrometallurgy and also to contribute some insight into the basic mechanisms of oxidation in an aqueous medium under these conditions. In addition to the immediate consequences of these processes much valuable information remains to be learned about fundamental reactions when they are carried out at temperatures and pressures slightly higher than those normally encountered. Leaching of molybdenite by alkaline solutions under oxygen pressure has recently been reported in the Russian literature by E. S. Usataya,8 who found that leaching rate increased with an increase in the pH of the solution—the strongest effects being observed at a pH of 10—and also with an increase in temperature. Usataya also has reported the formation of a protective film on the surface of the molybdenite when the leaching solution was weakly alkaline, neutral, or acidic. He believes that this oxidation process explains the migration of Mo+ + in the oxidation zones of molybdenite ore deposits and the subsequent impoverishment of the ores. Equipment: The high temperature-high pressure reaction unit used in this work was especially designed for kinetic studies of this nature, emphasis being placed on accuracy of measurement and precision of control. As details of the unit's construction and operation have been discussed elsewhere,7 Only basic features and principles of operation will be discussed at this point.

Jan 1, 1957

By J. V. W. REYNDERS

THE principal manganese deposit of Russia, I one of the four principal sources of the world's supply, lies on the southern slope of the Caucasus Mountains, in what is now the Republic of Georgia, district of Sharopan. Tchiatouri, the principal town, is midway between Tiflis, the capital of Georgia, and Poti, the shipping port on the Black Sea, about 130 " miles distant. The deposit can be most easily visualized by thinking of a nearly horizontal coal seam about 6 ft. thick, outcropping on the slopes about 600 ft. above the Kvirila River. One of the accompanying illustrations shows the river, which nearly bi- sects the district, of approximately 50 sq. miles in area, and with its tributary streams makes the topography rugged, while in the background are the snow-capped peaks of the Caucasus range. Another of the illustrations gives a closer view of the outcrop. The roof and floor of the deposit are good, so the methods of working are quite similar to working a coal seam, especially as most of the mineral is soft enough to be mined with a pick. Little machinery is used, except small cars for underground transportation.

Jan 1, 1926

By AIME AIME

ABOUT 55 attended the general session of the Nonferrous Metallurgy Committee on Wednesday afternoon. In opening the proceedings the Chairman, Frank G. Breyer, served notice of his intention to make an early start this year in securing papers for his committee. He voiced the thought that more importance should be attached to the prompt publication of data on new advances in practice; the record of technical progress should be written before the sharpness of the current image becomes blurred by the veil of time. As an illustration, Mr. Breyer declared that great strides have been made in the zinc industry during the past nine years, whereby zinc ore is converted directly to the oxide in large mechanical furnaces, yet the literature is confined to patents.

Jan 1, 1933

By AIME AIME

THE non-ferrous alloys have been placed in the same class with steel by metallurgical research on hardening, and hardenable alloys of all metals except zinc are now manufactured. The hardening of the non-ferrous alloys is accomplished by a process of heating, quenching and ageing. R. S. Dean, head of the research department of the Western Electric Co., told of the results of this research in 'a lecture on "Recent Advances in the Art and Science of Fabricating Metals," given before the Missouri Mining and Metallurgical Association on Jan. 24, 1929.

Jan 1, 1929

By W. E. Keck, Paul Jasberg

The flotative properties of the principal minerals in Michigan's potential iron ores have been investigated to develop methods of bene-ficiation for the ores. One of these minerals, magnetite, is of considerable importance as a source of iron. Study of its flotation was similar to that of hematite1, another iron mineral in these potential ores. The present research consisted essentially of: (1) a survey of the literature on magnetite flotation, (2) the preparation of pure magnetite, (3) the development of laboratory procedure and (4) flotation experimentation. Literature on Magnetite Flotation.—For the purpose of this discussion, the results of previous work on the flotation of magnetite can be summarized as follows. The mineral has been floated with pine oil2, and it has also been separated from synthetic mixtures with silicates by the use of the same reagent2. Magnetite and apatite in iron-ore slimes have been separated by flotation of apatite with sodium palmitate3. These data were utilized in the present investigation. Preparation of Magnetite.—The pure mineral was prepared from the magnetic-separator concentrate of an iron ore (obtained from the Wither-bee Sherman Corporation, Port Henry, N. Y.). This concentrate was slowly comminuted with laboratory rolls and pulverizer to pass 65-mesh and was then tabled several times. Tabling yielded a relatively coarse magnetite concentrate, tailing and slimes. The two latter materials were rejected insofar as the present work is concerned, and treatment of the magnetite (table concentrate) was continued by separating it into — 65 + 200 and — 200-mesh sizes. Separation of the sizes was made by first dry screening and then wet screening. The —200-mesh material was rejected to eliminate possible introduction of error into flotation

Jan 1, 1939

By R. E. Head

Under existing economic conditions, the treatment of gold ores occupies an outstanding position in metallurgical activity. The increased price of gold has automatically brought about a reclassification of old dumps and low-grade orebodies, and many that formerly were considered valueless are now being vigorously investigated and worked. This situation has developed problems that have taxed the ingenuity and ability of metallurgists to the utmost. Some gold ores give a high extraction of gold by standardized methods of treatment; other ores of apparently similar character yield but a relatively small percentage of their gold when treated by the same processes. Surface Contamination The experience gained by microscopic study of numerous gold ores and tailings has shown that there are pronounced differences in the physical characteristics of the minerals composing them, more especially of the gold. Repeated studies of tailings from flotation and cyanidation of gold ores has established the fact that surface contaminations on gold particles are often directly responsible for high gold losses; comparison of gold particles isolated from flotation concentrates and the resulting tailings have showed that the clean gold has been recovered and the tarnished or contaminated gold invariably lost in the tailing. Obviously, it is not possible to make such a comparison of gold ores treated by cyanidation, as the clean gold has been taken into solution; but when the gold found in cyanide tailing has a tarnished or coated surface, one may infer, with a reasonable degree of certainty, that the clean gold has been extracted. This premise is supported by experimental evidence obtained by isolating particles of tarnished gold and exposing them to cyanide solution in small parting cups. In one such experiment, tarnished gold particles picked from a cyanide tailing showed but slight evidence 01 dissolving at the end of 27 days. In this test, a cyanide solution of 1.6 11). per ton was used and the leach solution was decanted arid renewed every

Jan 1, 1939

By Fred D. DeVaney and

The coercimeter, as its name implies, is an instrument for measuring the coercive forcet of magnetic substances. It was developed by Davis and Hartenheim in the Special Studies Section, Metallurgical Division. A detailed description of this apparatus may be found elsewhere.2 The coercive force determinations of magnetic materials are interesting because of the relationship established by Gottschalk,4 who showed a linear relationship between the magnetization coercive force and the specific surface of comminuted particles. The value of this relationship in determining grinding efficiency has been shown by Dean.3 The determination of the surface contained in the subsieve sizes has always been a difficult problem for investigators. They made approximate measurements of the surface of coarse materials by sizing on screens, but for the determination of the surface of the sub-sieve sizes it was necessary to make detailed grain counts or elutriation tests, or to study dissolution rates. The technical literature contains many references to other methods for determining these surfaces, either by some special apparatus or by mathematical calculations based on distribution lines. Many of the methods are long and tedious, and the results of some, at least, are questionable. he turbidimeter gives quick results on ground cement. By using magnetite as the material to be ground, a simple determination of its coercive force by the coercimeter, requiring 10 minutes or less, can be transposed directly and accurately into units of relative surface. This subject has been pursued further by the U. S. Bureau of Mines in cooperation with the Missouri School of Mines and Metallurgy, Rolla, Mo., and the following is a description of the results.

Jan 1, 1939

By James Douglas

The development of the copper-resources of this country has kept close pace with the unfolding of its geographical area to commerce. In colonial days, when our English ancestors occupied only the Atlantic seaboard, insignificant quantities of copper were mined in Connecticut, New Jersey, and Pennsylvania, and the ore was shipped for treatment to England. The first steam pumping-equipment

Jan 1, 1891

By V. R. Garfias

INTRODUCTION FOR a number of years the senior author has been interested in the various geologic and engineering problems involved in the development of the petroliferous districts of northeastern Mexico, having in a previous paper 1 endeavored to present a summarized statement of the information relating to the geology and soil resources of this region. Of the many interesting geologic phenomena, perhaps those which have been the object of more speculation relate to the igneous intrusions which, in places, have a controlling influence on the accumulation of oil in commercial quantities, a relationship which has been tentatively explained by various observers with as many interestingly different views. The authors of the present paper aim to record, in the course of a general discussion of the various viewpoints, some additional data, and present further tentative conclusions with a view to rounding out an up-to-date summary of the subject. The greater part of the area in question lies in the State of Vera Cruz, only a northwest fraction being in the State of San Luis Potosi. Vera Cruz is bounded on the north by the State of Tamaulipas, the northernmost of the Mexican States along the Gulf. The topography of the States of Tamaulipas and Vera Cruz and of Texas and Louisiana to the north, is controlled by the Gulf coastal plain which in northern Vera Cruz has an average width of about 60 miles, the transitional topography between that of the rugged flanks of the Sierra and the lowlands of the coast being made up of a series of terraces and irregular hills and valleys.

Jan 8, 1917