Search Documents

By Stein Wennberg, Snorre Tessem

INTRODUCTION The mine is situated in the middle of Norway 150 km north of the town Trondheim. The iron ore deposits were discovered in 1906 and have been continuously mined since. The first owner was A/S Nordiske Grubekompagni. In 1912 Fosdalens Bergverks-Aktieselskab was established; since World War II it has been a wholly state-owned company. The location is advantageous, with mining facilities, ore dressing plant and stockpile situated near the northern head of the Trondheimsf jord. The iron ore always occurs in Ordovician lavas and sediments, now altered to greenschists, keratophyres and limestone. The ore bearing zone is 150 km long. The deposits consist of two parallel linear ore bodies lying one above the other in the same stratigraphic horizon which dips 70' to the south. The upper body is 50-100 m high, the lower one 250 m high, while the distance between the two bodies in the East mine varies between 20 and 60 m. The ore width varies between 5 and 8 m. The ore bodies strike WSW and plunge between 10' and 15" in this direction. To date continuous ore has either been worked or opened up along a total strike length of 10 km. Until 1969 all ore was mined in the western part of the deposit called the Western mine. In the spring of 1969 production started in a new mine, the Eastern mine. The ore bodies in this new mine are geologically the same as in the old mine, but they have been displaced 700 m downwards along a major fault in the Fosdalen valley.

Jan 1, 1981

By A. Ghosh, T. B. King

The kinetics of the discharge reaction: 20'- (in silicate melt) = O,(g) + 4e- at a platinum anode in lithium silicate melts have been studied al 1350°C by galvanostatic methods. Plots of the sleady-state overpotential, q, as a function of the logarithm of the current density, i, showed injlections and were linear only at high current densities. The value of the overpotential was influenced by bubbling gas through the electrolyte. The ocer potential was also studied as a function of time. The rise and decay of overpotential were very slow processes. At low current densities transport is the likely rate-controlling process but at high current densities passivation of the electrode, Presumably by an oxide film on the surface, seems to be a contributory functor. IT is well-established that molten silicates behave as electrolytes'5 and, except in a few cases,6 conduction is entirely ionic. Moreover, it is supposed that a possible, and perhaps predominant, mechanism for phase boundary reactions between metals and slags is similar to that in corrosion whereby anodic and cathodic processes occur at unrelated sites, the metal serving to conduct electrons.1'8 Thus electrochemical studies of some slag-metal reactions would seem to be a useful way to diagnose the rate-controlling steps in the overall reaction. The electrochemical method is, in principle, a better diagnostic tool than the direct chemical method for the following reasons: 1) The partial electrochemical reactions, which are simpler than the overall reaction, may be studied individually. 2) The rate of reaction can be controlled at will and independently of the concentrations of reactants. 3) Fast reactions can be studied by relaxation methods.' Esin and his coworkers5'10"12 have pioneered such studies in silicates and have deviloped some ingenious techniques. Not all of their findings, however. can be accepted without a good deal of further work. In this investigation, the kinetics of the oxygen discharge reaction: 202- (in silicate melt) = Oz(g) + 4e- [I] at a platinum electrode were studied by both steady-state and transient galvanostatic techniques. Interest in this reaction was first developed as a result of the findings of Fulton and chipman13 that the reduction of silica, in a silicate slag, by carbon, dissolved in liquid iron, is a very slow reaction. Subsequent work, for example, by Rawling and ~lliott,'~ has demonstrated that the reaction under these conditions must be slow, because the rate is limited by diffusion of oxygen in the iron to the metal-crucible phase boundary at which a CO bubble may be nucleated. Further work by Tarassof,'~ in which the reduction of silica by aluminum dissolved in copper was studied, has shown that under these conditions, where carbon monoxide evolution is not involved, control of the reaction rate resides in diffusion of silica in the slag phase. However, there is no practical way of inducing sufficient convection in the system to make it clear that the phase boundary reaction is indeed fast. The overall reaction of silica reduction involves the discharge of silicon ions at cathodic sites and oxygen ions at anodic sites. In the examples cited, the discharged ions are dissolved in a liquid metal. In the present study of oxygen ion discharge, gaseous oxygen may be evolved at high current densities or oxygen may simply dissolve, possibly as oxygen molecules, in the silicate at very low current densities. The discharge of an oxygen ion at an anode must, in silicates less basic than the orthosilicate composition, be preceded by a reaction in the vicinity of the electrode, such as: which makes oxygen ions available. Platinum was chosen as the working electrode since it is comparatively inert to oxygen and is, therefore, expected to come rapidly into equilibrium with the electrolyte and with gaseous oxygen. Minenko, Petrov, and Ivanova16 have measured the electromotive force at a platinum electrode in molten silicates as a function of the partial pressure of oxygen in the atmosphere, the concentration of oxide ions in the melt, and the temperature. They found platinum to behave as a reversible oxygen electrode. At two different oxygen pressures, Po2 (I) and Pq (11). the electromotive force is given by: where F is the Faraday constant, equal to 23,060 cal per v equivalent, indicating that the electrode reaction is as written in Eq. [I.]. Platinum has been similarly used in molten silicates by other inve~ti~ators. "'~~ In this investigation platinum was used only as an anode, since a current deposits other elements on its surface and changes its characteristics.

Jan 1, 1970

By J. W. Dougherty, J. M. Douglas

THE Hollinger gold mine is in the Porcupine mining division, District of Cochrane, in the northern part of the Province of Ontario. The adjacent town of Timmins, with a population of 25,119, lies 490 miles by railway north of the city of Toronto. GEOLOGY The property is situated on the northwest limb of a major syncline, which pitches northeast at approximately 50°. The principal rocks of the Hollinger area are of pre-Cambrian age and consist of altered, schistose, Keewatin lava flows intruded by stocks of schistose, quartzfeldspar porphyry generally assigned to the Algoman period. The structure of the Keewatin series is extremely complex as a result of close folding and some faulting. The schistosity, trending north 70° east and dipping steeply to the southeast, is most highly developed along a subsidiary anticline in which the major porphyry bodies occur. The ore bodies, which exhibit three principal structures, consist of quartz veins and associated pyritized wall rock. Some lodes are composed of en echelon veins, others exhibit a main quartz body with branching stringers and a third consists of a single definite lead. Gold, in a coarse visible form, may be confined to quartz in some ore bodies but in others it is finely divided and is found not only in quartz but also associated with pyrite in the adjacent wall rock. In many veins the distribution of gold is such that there are several ore sections, separated by areas of low-grade material, in the same vein although its physical appearance remains unchanged. The veins form a very complex pattern in an ore zone which in places attains a length of 6000 ft. and a width of 4000 ft. They are most abundant in the Keewatin lavas in the neighborhood of the porphyry bodies. Few of the veins are persistent for long distances, though some

Jan 1, 1940

By Harvey T. Kennedy, Charles R. Olson

In many investigations of the performance of petroleum reservoirs the assumption is made that the liquid, if below its bubble-point pressure, is at all times in equilibrium with gas. On the other hand, observations by numerous investigators have indicated that gas-liquid systems including hydrocarbon systems, may exhibit supersaturation to the extent of many hundred psi in the laboratory. Up to the present, there has been no reliable data on which ti judge the actual extent of supersaturation under conditions approaching those existing in petroleum reservoirs. The work reported here deals with observations and measurements on mixtures of methane and kerosene in the presence of silica and calcite crystals. Bubbles were observed to form on crystal-hydrocarbon surfaces in preference to the glass-hydrocarbon interface or to the body of the liquid. Statistically, it was found that the number of bubbles formed per second per square centimeter of crystal surface was a function of the supersaturation only. and the function was evaluated graphically. Supersaturations were observed up to 770 psi, under which condition bubbles formed quickly and with considerable violence. With decreasing degrees of supersaturation, the frequency of bubble formation became less, until at 30 psi supersaturation and lower, no bubbles were observed to form, even though the observation at 30 psi was continued for 138 hours. It was found that silica and calcite crystals had identical effects, within experimental error, in accelerating the formation of bubbles, and that small amounts of water and crude oil had no effect on the results. It is shown that the maximum supersaturation that can exist in a reservoir may be calculated from the data presented and from the area of the rock surface. It is also shown that the number of bubbles formed in the reservoir, in order of magni- tude, may be calculated for any rate of pressure decline imposed on the reservoir by production. The bearing of the number and distribution of bubbles on reservoir performance is discussed. INTRODUCTION A liquid system is supersaturated with gas when the amount of gas dissolved exceeds that corresponding to equilibrium at the existing pressure and temperature. The degree of super-saturation may be conveniently expressed as the difference between the bubble-point of the mixture and the prevailing pressure. Thus, if a mixture having a bubble-point of 1,000 psi at a given temperature exists in single liquid phase at 700 psi at the same temperature. it is supersaturated to the extent of 300 psi. There are many examples of high supersaturations, mostly in aqueous solutions, reported in the literature. Thus, Kenrick, Wismer and Wyatt1 showed that water may be saturated with oxygen, nitrogen or carbon dioxide at 100 atmospheres, and the pressure reduced to one atmosphere without producing bubbles immediately. When liquids are in a state of tension, they may be considered as supersaturated at least to the extent of the tension. The tensile strength of water has been reported as 30 atmospheres by Meyer,1 60 atmospheres bv Budgett. 30 to 50 atmospheres by Temperley and Chambers,4,5 200 atmospheres by Dixon6. and 223 atmospheres by Briggs.7 Vincent8,9 determined the tensile strength of a mineral oil as 45 psi. Gardescu1 maintained pressures for short times in a model reservoir at 115 psi below the bubble-point. It should be noted that the high supersaturations observed were obtained on systems carefully purified to remove particles or surfaces which might promote the formation of bubble; These "nuclei" were considered as contaminants which interfered with the determination of a property of the liquid. In

Jan 1, 1952

The University of Chicago Press, 5750 Ellis Ave , Chicago, Ill This Press publishes books on a wide variety of subjects of scientific interest, as well as several journals Only a few books on geology have been published, however, and the Journal of Geology. The Journal of Geology: A semiquarterly standard American publication in the geological field. $6 per year, single copies, $1, back numbers, within the past five years, $6 per volume Books on geology: The origin of the earth, by T. C Chamberlin, $2 50, Two solar families, by T. C Chamberlin, $2 50, Quantitative classification of igneous rocks, by W. Cross, J. Iddings, L V Pirsson and H. S Washington, $1.75; Studies in minor folds, by C. E. Decker, $1 50; An introduction to the study of ore deposits, by F. H Hatch, $3, A descriptive petrography of the igneous rocks, by A. Johannsen, $4 50, Essentials for the microscopical determination of rock¬forming minerals and rocks, by A. Johannsen (revised ed ) $3, Outlines of geologic history, with special reference to North America, edited by R D. Salisbury, 8150

Jan 1, 1933

United Engineering Trustees, Inc Engineering Foundation Engineering Societies Research Board Other Committees United Engineering Trustees, Inc. ARTHUR S. DWIGHT GEORGE D. BARRON J. V. N. DOER Engineering Societies Library Board ROBERT PEELS PHILIP W. HENRY GEORGE C. STONE JOSEPH E. POGUE The Engineering Foundation H. C. BELLINGER GALEN H. CLEVENGER J. V. N. DORR

Jan 1, 1929

By J. T. Norton

As cold working is an important feature in a great many of the fabricating processes now applied, this paper presents some ideas of the nature and results of the plastic deformation produced in this operation. The art of manufacturing metal for practical uses is very old and has undergone very great development. The science of metals has also developed very rapidly recently and the various processes to which ,metals are submitted are much better understood now than they were even a short time ago. All the knowledge that can be obtained on this subject is useful because it promotes efficiency in converting metal into finished articles. ATOMIC ARRANGEMENT IN CRYSTALS In the solid state all metals are crystalline. The atoms are arranged in, a definite symmetrical configuration, which is repeated at regular intervals, and thereby defines what we may term a lattice. Presumably . the atoms exist as positive ions. The dissociated electrons place themselves between groups of positive ions, and thus define a second lattice, an "electron lattice." From such a point of view, the crystalline forces which hold a metal together are the electrostatic attractions between positive ions and negative electrons. The particular type of lattice into which a metal crystallizes depends on the number of these lattice electrons given up by each atom, and is thus connected very closely with the chemical valence of the metal.

Jan 12, 1926

Jan 1, 1937

By J. Versluys

When a well strikes an oil-bearing layer, the oil has a pressure which is generally sufficient to enable it to rise to near the surface (sometimes above the surface). As soon as a well begins to produce, however, the liquid moves through the pores of the reservoir bed and the pressure in the well becomes much lower than the pressure originally prevailing there. At some distance from the well, however, the pressure in the reservoir bed remains unaltered; thus the pressure of the oil has not only to lift the oil, but also to overcome the friction resistance in the pores. The fact that so many oil wells are gushers is a consequence of the energy accumulated in the gas. In gushing the well acts as a gas-lift. A mixture of liquid and gas (the latter partly dissolved in the former) rises vertically from the oil-bearing layer through a cylindrical casing to the surface. In time conditions alter and the well ceases to gush regularly, then the gushing can be further promoted by inserting a narrower tube in the well and connecting the top of the oil string to the tubing. If the action in time becomes irregular, the gushing can be kept up for a further period by forcing gas between the two tubes. In the oil fields the term "gas-lift" is used actually only where extraneous gas is applied, as in the last of the stages mentioned. The action, however, is just the same whether the gas exclusively originates from the formation, or is partly applied artificially. Thus by gas-lift we simply mean a vertical tube in which the energy of gas under pressure, and of dissolved gas, is utilized for raising a liquid. In gushing oil wells the pressure is frequently very high and the absorption coefficient 0.4 (expressed in vol. ratio) of the coexisting gas is not particularly high, so that in reality it should be assumed that a considerable portion of the gas, at any rate at the bottom of the gas-lift, is dissolved in the oil. For water-producing wells this is not usually of such importance. Where the volume of the flowing gas is much greater than that of the flowing liquid, the latter can be suspended in the former in the form of

Jan 1, 1930

By M. S. Burton, J. E. Ritter

The sessile-drop technique was employed to study the effect of atmosphere and alloy additions of titanium and chromium on the surface tension and contact angle of nickel on sapphire substrates at 1500oC. Shear tests were conducted on the solidified sessile drops. The liquid-gas surface tension of pure nickel on sapphire was found to be 1747 ergs per sq cm, with a contact angle of 109.6 deg. The surface tension and contact angle were not affected significantly by the four atmospheres, vacuum, impure argon, pure argon, and pure hydrogen. Small additions of titanium and chromium decreased the contact angle and for the same alloy content, contact angles were lower in pure argon than in pure hydrogen. On the basis of shear-test results , the most probable cause for adhesion in the Ni-Al2O system is the formation of NiO:Al2O3 spinel at the interface; in the titanium alloy-Al2O3 system adhesion is thought to be due to a mechanical interlocking effect; in the chromium alloy-Al2O3 system adhesion is believed to be the result of solid-solution formation involving Cr2O3 and Al2O3 at the interface. In the last few years there has been considerable interest in reinforcing metals with ceramic whiskers. It has been postulated that, by reinforcing nickel with sapphire whiskers, high-temperature strengths su- perior to those of the best current nickel alloys can be achieved.' To fabricate a whisker-metal composite having optimum density and strength, understanding of wettability and adherence in the system is of prime importance. Although there has been some previous research in this a a need for further studies has been cited4-8 to understand better the effects of impurities, alloys additions, and atmosphere on the wetting and bonding of metals to metal oxides. The purpose of this research was to investigate the factors involved in the wetting and adherence of nickel/nickel alloys to sapphire (single-crystal a Al2O3). Sessile-drop experiments were conducted in vacuum, impure argon, pure argon, and pure hydrogen, to determine the effect of atmosphere on the contact angle of the metals on sapphire, and the liquid-gas surface tension of pure nickel. The solidified sessile drops were sheared from the sapphire substrate to measure the bond strength between the metal and ceramic. The alloy additions chosen were titanium and chromium since both enhance the wetting of nickel on sapphire.2, 3c Also, titanium is commonly used when brazing metal-to-ceramic seals to improve adherence. Since chromium forms an oxide that is completely soluble in sapphire, it was thought that the oxide could serve as a transition phase to promote bonding between the Ni-Cr alloy and sapphire. I) EXPERIMENTAL APPARATUS AND PROCEDURE The sessile-drop apparatus was a horizontal furnace, with an induction-heated, cylindrical molybdenum susceptor in a water-cooled Pyrex chamber. This apparatus was patterned after that of Williams and Nielsen.7 A flat Pyrex window at each end of the furnace allowed temperature measurements to be made at one

Jan 1, 1968

By Theo W. Robinson

The evolution of the modern blast-furnace from the embryonic stages of comparatively few years ago, has been the work of wide praetiee and experiment. That much is still to be desired, the experience of every furnace-manager mill testify. Mr. Walsh's paper on "The Irregularities of the Blast-Furnace Process, and a Practical Way to Avoid Them" (Trans., xv., 419), proposes a new solution of the problem of interior lines, and one that has given rise to not a little speculation and controversy. The investigation described in this paper was undertaken to test experimentally the theory of Mr. Walsh as to maximum reducing capacity. Briefly explained, Mr. Walsh's views (outside of his claim for increased efficiency due to having the bosh wholly within the meltingzone) are, that a furnace of contracted stack and throat, on his lines. may equal in product one of considerably greater cubical capacity. The explanation offered for the theoretical greater capacity per cubic foot of his furnace is, that the increased tension of gases caused by passing through the small area mill promote transpiration, thus facilitating reduction and permitting more rapid driving. This alleged relation will appear from a hypothetical case in which a furnace, A, constructed on Mr. Walsh's lines, has but 1/x of the cubical contents of a furnace, B, of modern type; the two being equal in height. In order that A shall have the same capacity as B, both working normally with the same mixture and burden, and

Jan 1, 1889

By Smith, George Otis

ENGINEERING is in essence quantitative, and the engineer must deal with exact figures when he plans and, constructs. Engineering truths are not best expressed by adjectives, yet my wish, today, is not to attempt a quantitative measure of the dominant position of the mineral industry of the United States in the existing scheme of material things, but rather to seek a clualitative appraisal of what mining and metallurgical engineers are doing to promote and make secure our , national progress. Statistics help when we wish to gage material prosperity, but they fail when we desire to determine what share the engineers have in adding to the happiness and welfare of our people

Jan 1, 1928

Committee on Reduction and Refining of Copper............ 3 A.I.M.E. Officers and Directors.................... 4 Preface. By C. R. Kuzell....................... 7 Career and Achievements of James Douglas. By Arthur L. Walker. . 9 PAPERS Smelting 1. Reverberatory Smelting Practice History of Reverberatory Smelting in Montana, 1879-1933. By Frederick Laist..............................23 Reverberatory Smelting of Raw Concentrates at the International Smelter, Miami, Arizona. By P. D. I. Honeyman (With Discussion)...... 88 Development of Gun-feed Reverberatory Furnaces at Garfield Plant of American Smelting and Refining Company. By R. A. Wagstaff (With Discussion)........................99 An Experimental Combination of Shaft Roasting and Reverberatory Smelting. By Frederick Laist and J. P. Cooper (With Discussion).... 104 Forms of Copper Found in Reverberatory Slags. By Royal B. Jackman and Carle R. Hayward (With Discussion).............111 2. Converting Practice Development of Copper Converting at Butte and Anaconda. By William Kelly and Frederick Laist...................122 Developments in Converting Lead and Copper Matte at Tooele. By B. L. Sackett.............................132 Messina Stationary Basic Copper Converter. By R. G. Knickerbocker (With Discussion)........................140 Smelting Copper Concentrates in a Converter. By George E. Beavers. 149 Sulfuric Acid from Converter Gases. By George E. Beavers......151 Development of Monolithic Tamped Periclase Converter Linings at United Verde Copper Company Smelter. By F. H. Parsons (With Discussion) . 153 3. Descriptions of Plants The Noranda Smelter. By W. B. Boggs and J. N. Anderson......165 Smelting Operations at Roan Antelope Copper Mines, Limited. By Charles R. Wraith.......................202 4. Waste-heat Boiler Practice Copper-refinery Waste-heat Boilers at Great Falls Reduction Department, Anaconda Copper Mining Company. By E. S. Bardwell......225

Jan 1, 1934

By Robert E. Cuthbertson

IT is the purpose of this paper to describe in detail the laboratory development and mill application of an unusual combination of flotation reagents employed in the concentrator of the Climax Molybdenum Co., on the Continental Divide, near Leadville, Lake County, Colorado. This development originated in an ore-dressing research laboratory maintained by Climax at the experimental plant of the Colorado School of Mines, which is staffed by men directly employed by the Climax Molybdenum Co. Mill-scale testing of laboratory developments was supervised by a representative from the testing laboratory, working in close cooperation with the operating staff at the mill. General milling practice at Climax is ably described in a paper by E. J. Duggan,1 mill superintendent. Other aspects of the Climax project have been described in papers by W. J. Coulter,2 by Butler, Vanderwilt and Henderson3 by Allen Kissock,4 and by Leo H. Glanville.5 Consequently, this paper will be confined to the metallurgical aspects of recent reagent developments, avoiding, as much as possible, repetition of material covered in these earlier publications. BRIEF HISTORY OF REAGENT PRACTICE AT CLIMAX Prior to the year 1937, the only reagents employed at Climax for froth production and collecting action in the flotation of molybdenite were steam-distilled or destructively distilled pine oils. The only exceptions to this practice were brief periods of mill testing, when reagents of various types were tried on an experimental basis. None of these experimental runs was sufficiently encouraging to justify its continuation as regular practice. Sodium, cyanide has been employed since the very early days of milling at Climax as an inhibiting agent for control of pyrite and chalcopyrite. Alkaline reagents such as lime or soda ash have been used in recent years to minimize the detrimental effect of iron salts on flotation of molybdenite. The presence of these harmful salts is attributed to the decomposition of fine metallics abraded from liners and balls in the first stage of regrinding rougher concentrate. Flint pebbles are used in subsequent regrinding, since alkaline reagents are not entirely adequate to offset the inhibiting effect of iron salts as the grind becomes progressively finer and the grade of concentrate progressively higher. Climax metallurgists were familiar at an early date with the use of petroleum products such as kerosene and gas oil as promoters of flotation of molybdenite. Charles C. Oliver6 discussed the use of pine oil and kerosene as early as 1920, in connection with the milling practice at Dominion Molybdenite Co., Quebec. Never theless, the early attempts to apply this knowledge in the Climax concentrator were complete failures. In the light of recent experience, it may seem strange that the early mill tests with petroleum

Jan 1, 1944

By C. P. Fiske

The pottery of the New Jersey Zinc Co. (of Pa.) is equipped to make three classes of refractories; namely, spelter vessels, spelter condensers, and high-grade fire-brick. The most important of these are the spelter vessels, on account of the extreme severity of the service which they must perform, necessitating great care in the selection of materials and in the whole process of manufacture. Next to the spelter vessels in importance come the condensers, as large numbers are used in the manufacture of spelter, and improvements in quality result in material decreases in working cost. While the fire-brick which form the laboratory, or high-temperature portion of the spelter furnaces, are placed at the foot of the list, they are nevertheless of much importance, since high quality will decrease the frequency of the always expensive shutdowns for repairs. To promote simplicity, the manufacture of these three products will be described separately in this paper, except in so far as materials and the crushing and handling system common to all are conccrned. Materials Bond Clay.—The bond clay used entirely at the Palmerton pottery is a St. Louis clay furnished by the Grand View Fire Clay Co. It is stored in a system of covered bins, and no attempt is made to weather it in the accepted sense of the term " weathering." Some years ago our clay was weathered before pugging, but we did not find the benefit sufficient to offset the additional handling and the loss of clay incurred. Furthermore, we believe that the rotting of the pugged mix (described later) accomplishes the same results to better advantage. That there is some action taking place in the clay while stored in the covered bins, however, is evidenced by an increase in volume which at times has caused damage to the retaining walls of the bins. We have at present a stock of bond clay weathering in the open, and when this is put into service an opportunity will be afforded for making comparisons with the clay as usually handled.

Jan 1, 1918

By Howard N. Eavenson

From the Pittsburgh coal bed in the four states of Pennsylvania, Ohio, Maryland and West Virginia has been produced an output that, at mine prices, represents a greater value than any other single mineral deposit in the world has yielded.12 While this distinction may in a few years pass to the gold reef of the Witwatersrand, it is possible that eventually, owing to the tremendous reserves still remaining, the ultimate yield of the Pittsburgh bed will be greater than that of any other known single deposit. Considering its importance, not a great deal has been written of its early history and development as a whole; most of the accounts have been of limited localities, or, at the most, of the area within a single state. In "Coal through the Ages" the writer mentioned some references to its early history, but this study will deal not only with its history but with the character of the bed, where and why it was first developed, and its effect upon the states in which it is found. It has not been the intention to write a detailed history of the development of the seam in each locality, as neither time nor inclination were available for doing such work, but only to show the influences that tended to hasten or retard such development. In general the historical matter ends about 1830, when geological surveys began to be made. Some of the maps show data available only since that time, and the sections about coal preparation and coking have been extended to the present time to show the changing conditions. It is believed that the early history includes all published records, and many more sources than those shown in the bibliography were consulted. It is quite likely that some references to coal in this area may be found in the unpublished papers of some of our early soldiers and colonizers, which exist in several libraries, and it is hoped that some future * Dedicated to Dr. Thomas S. Baker, President Emeritus, Carnegie Institute of Technology, whose labors in promoting the International Coal Conferences and in establishing the Coal Research Laboratory have done much in showing the industry how science can be of help to it. Manuscript received at the office of the Institute Feb. 15, 1938.

Jan 1, 1938

By Howard N. Eavenson

From the Pittsburgh coal bed in the four states of Pennsylvania, Ohio, Maryland and West Virginia has been produced an output that, at mine prices, represents a greater value than any other single mineral deposit in the world has yielded.12 While this distinction may in a few years pass to the gold reef of the Witwatersrand, it is possible that eventually, owing to the tremendous reserves still remaining, the ultimate yield of the Pittsburgh bed will be greater than that of any other known single deposit. Considering its importance, not a great deal has been written of its early history and development as a whole; most of the accounts have been of limited localities, or, at the most, of the area within a single state. In "Coal through the Ages" the writer mentioned some references to its early history, but this study will deal not only with its history but with the character of the bed, where and why it was first developed, and its effect upon the states in which it is found. It has not been the intention to write a detailed history of the development of the seam in each locality, as neither time nor inclination were available for doing such work, but only to show the influences that tended to hasten or retard such development. In general the historical matter ends about 1830, when geological surveys began to be made. Some of the maps show data available only since that time, and the sections about coal preparation and coking have been extended to the present time to show the changing conditions. It is believed that the early history includes all published records, and many more sources than those shown in the bibliography were consulted. It is quite likely that some references to coal in this area may be found in the unpublished papers of some of our early soldiers and colonizers, which exist in several libraries, and it is hoped that some future * Dedicated to Dr. Thomas S. Baker, President Emeritus, Carnegie Institute of Technology, whose labors in promoting the International Coal Conferences and in establishing the Coal Research Laboratory have done much in showing the industry how science can be of help to it. Manuscript received at the office of the Institute Feb. 15, 1938.

Jan 1, 1938

By Sherwin Kelly

The prime objective of geophysical exploration is to promote the economical and rapid dis-covery of mineral or oil deposits of commercial value. To a few this concept as applied in min-ing may signify the direct discovery of ore-bodies, but to the geophysical engineer this latter Idea is one of the most insidious and detrimental misapprehensions which he has to combat. The destruction of this annoying obstacle to the progress of geophysical exploration reveals the kernel of truth behind it, that the exploration geophysicist has for the better part of two decades been concerned primarily with the discovery of mineral formations favorable to the occur-rence of commercial ore. There is a very real distinction here, since geophysical methods are capable of discovering certain mineral formations such as sulphide bodies or quartz veins, but are totally incompetent to predict whether or not they constitute ore; that is. whether or not they contain minerals of economic value in the amounts requisite to repay extraction. The art of geophysical exploration is now, however, rapidly outgrowing these early limita-tions. The rate of this growth will in large measure depend on the recognition by the mining industry of the fact that geophysics can play a role far wider and more important than it usual-ly does now, in guiding the future exploration and development of mineral deposits. It is my own firm conviction that as time marches on we will see the methods of applied geophysics turned more and more to the delineation of both minor and major structural features. The outlining of such features having a bearing on the probable loci of mineral deposition will be of inestimable value in guiding the development of a mining district. It is in this field that there will In-evitably occur a meeting and overlapping of the activities of the exploration geophysicists and

Jan 1, 1940

By James H. Boettcher

INTRODUCTION A complex interaction of worldwide economic and political forces is increasingly requiring 3 primary participants for the successful development of large natural resource projects in developing countries. They are the host government of the developing country (the "host government"), one or a consortium of international natural resource companies, (the "Resource Company") and one, or more likely, a syndicate of international lenders. The host government typically controls the rights to its country's natural resources and establishes the economic ground rules for their development. However, because of worldwide inflation and the depletion of easily accessible, high-grade resources, the nominal and real capital development and operating costs of projects have been spiraling. Moreover, the depletion of high-grade and mineralogically uncomplicated resources also raises the technical and operating risks associated with resource recovery. Thus, despite increasing political self-consciousness and economic nationalism in developing countries, international resource companies are still often necessary project sponsors since they can provide, among other things, the required technical and management expertise and equity capital. The presence of these factors, and often the addition of worldwide market access in a project, is often critical in determining whether or not the project will be considered creditworthy by international commercial lenders. The international commercial lender is often the critical third party in project development, due in a large part to the ever escalating-costs of project developments relative to the financial resources of many companies and even a growing number of countries. In addition, lenders have other reasons for taking more than a passive interest in all aspects of a project's development. These reasons include the following: 1. Projects are often financially structured such that the primary security for a loan, once completion and performance standards are met, is the cashflow of the project rather than recourse to its sponsors. 2. Lenders, in addition to the "project risk" just described, are frequently asked to assume various elements of "political" risk which nay put them in a sensitive economic position between the host government and international resource firms (This is discussed later). 3. International banks today have large loan portfolios of developing country debt with final maturities ranging from one to fifteen years. The various current projects undertaken are the building blocks of most developing country economies that will hopefully contribute to the long run economic development of a country as well as generate the foreign exchange necessary to repay foreign loans in the future. In this regard it is useful for lenders to realize whether a given project "makes sense" in terms of a country's natural resource endowments and competitive advantages over other countries. The type of framework discussed in this article would help lenders to better make such assessments. In order to facilitate the continued international flow of capital and technology to developing countries and of readily available supplies of raw materials from them, it is important for each of these three parties to increase its awareness of the goals and objectives of the other parties as well as the bargaining process that results in the legal, financial, credit and fiscal structures by which a joint venture project ultimately proceeds. Each of the parties faces increasingly complicated accept/reject decisions when they are faced with difficult choices among. a wide range of alternative structural combinations each of which has different implications for risk and reward to them. Therefore, by increasing the mutual, 3-way awareness of the decision processes of the other parties, it should be possible to: • provide better information and results in the formation of more rational expectations by all parties going into negotiations, • facilitate the project formulation process by allowing parties to focus more clearly on the areas of common interest and conflict, • result more frequently in final structures and agreements that better reflect the economic and political realities associated with a project and thus • result in more creative, innovative agreements that should reduce the need for changes to them and thus promote the kind of long run political stability conducive to attracting capital and further investment.

Jan 1, 1982

Secretary Membership Committee Increase of Membership Papers and Publications Committee Library Committee Treasurer Report of the Secretary TO THE BOARDOF DIRECTORASN D THE MEMBEROS F THE AMERICANIN STITUTE OF MINING AND METALLURGICAENL GINEERS GENTLEME:N As will be shown by the special reports of the Finance, Membership, Library, Papers and Publications, Increase of Membership, and other standing Committees, together with that of the Treasurer, the year 1927 was one in which the Institute made very satisfactory progress in a number of directions. In total numbers the membership is no larger but in revenue from dues there has been a marked increase. This has been due to the promotion to full membership of Junior Associates of earlier years, to the larger proportion that come in originally as members rather than juniors, and to the keener interest in the work of the Institute reflected in prompter payment of dues. The latter is important, since experience shows that of those who fall behind a large number must ultimately be dropped for non-payment. Conditions in the mining industries have been healthy though not booming. It has been much easier for members to find employment and meet their financial obligations but there has not been that flow of young men into mining, and hence in part into the Institute, that characterized certain earlier years. Rather the tendency toward centralization and larger industrial units has restricted the number, though not the scope, of opportunities for technical men in the mineral industries. The Institute is constantly receiving resignations from members crowded out of mining into other lines of activity. On the other hand, those who remain in mining and metallurgy have a greatly increased necessity for i,dormation and contacts with technology. A few years ago many superintendents and most foremen were non-technical men. Today the reverse rule obtains and shift bosses and men who occupy even lower positions in industrial units are called upon to know and to apply such an amount of technical knowledge that graduate engineers are the rule rather than the exception. The curious situation has obtained that with a much smaller enrolment of students in the schools of mining and metallurgy there has been at times an actual shortage of young engineers for beginners' jobs. The young men retort that the conditions of employment and pay offered in mining are not equal to those in other lines and, while it is undoubtedly true that the young engineer beginning in mining is able to start under conditions markedly better as to pay, living, and responsibility than did the men who are now leaders, they are required to know much more and have usually spent more in time and money to qualify for their jobs. The whole matter is one which warrants much more attention than has been given to it. For the Institute it is important since the young men

Jan 1, 1928