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By W. G. Bearden, P. P. Scott, G. C. Howard

This paper concerns the rupture or breakdown of rock formations as related to drilling, completing, and stimulating production of wells, and comprises data compiled from a study of literature and records of treatment of oil and gas wells. and from tests conducted in bores drilled into rock cores and outcrops of rock. Results of the investigation indicate that the internal pressure to rupture cylinders of rock and to breakdown rock formations surrounding a bore in the earth is dependent upon the extent of intrusion of fluids. the position of bedding planes. the ratio of internal to external diameter, the tensile strength of rock, and magnitude of confining pressure, and is independent of the size of bore, degree of fluid saturation. and temperature of rock within practical limits. It is concluded that the mathematical relationship of pressure in bores and stresses in the surrounding rock must not be limited by the simplifying assumptions of homogeneity. isotropy, and impermeability; that the incidence of lost circulation of drilling fluids to induced fractures may be reduced by preventing intrusion of fluids into the small intrinsic fractures along weak bedding planes; and that the magnitude of the breakdown pressure of wells to be treated may be lowered by removal of mud cake. INTRODUCTION The purpose of this paper is to present and discuss the results of tests which may serve to broaden the understanding of the phenomena of rupture or breakdown of rock and thus contribute to the improvement of the techniques for drilling and completing wells. including such operations as preventing lost circulation, stimulating production, and placing cement. Since the early recognition of the possibility of rupturing rock adjacent to a well by fluid pressure, the distribution and magnitude of stresses around a well and the internal pressure to cause failure have been expressed mathematically by application of the principles defining the elastic and inelastic behavior of thick-walled cylinders of a homogeneous. isotropic, impermeable material. In either the elastic or plastic state, if the conditions of homogeneity. isotropy, and impermeability were the normal characteristics of rock. there would be no reason to question the validity of the above principles when applied to rock. However. since most rock formations are characteristically permeable to some degree, contain bedding planes and small intrinsic fractures. and are heterogeneous, rendering invalid the assumptions of homogeneity, isotropy, and impermeability, the application of the thick-walled cylinder theories to the behavior of rock formations penetrated by a bore appears illogical. Also the failure to consider the effect of the properties of the drilling fluids, which certainly intrude in various degrees into most rock formations. is further cause for questioning the application of these principles. Even in the case of cylinders of hardened chrome-nickel steel, which would he considered relatively homogeneous isotropic. and impermeable, as compared to rock, it has been observed that the internal pressure capable of being withstood by the cylinders varied with the sizes of molecules comprising the rupturing fluid used. Because of these apparent weaknesses in the theories of the behavior of thick-walled cylinders when applied to bores in rock, and the importance of knowing the true behavior of rock under the influence of fluid pressure when planning drilling and completing procedures for wells, tests were undertaken to determine by observation the actual rupturing pressure of cylinders of rock and the effects of such variables as environmental conditions and characteristics of rock formations, fluid properties, and bore dimensions. It was intended that by these tests the validity of the thick-walled cylinder theories when applied to rock would be determined and, if found invalid, mathematical expressions would be derived for predicting stress and rupturing pressure of rock formations under various conditions. Since the derivation of mathematical expressions has been only partially completed, all of the results of the latter phase are not included in this paper. PROCEDURE The investigation was initialed with a study of the theories pertaining to the rupturing of thick-walled cylinders of homogeneous. isotropic, impermeable material and a study of the

Jan 1, 1953

By John Freeman

THIS paper relates entirely to the casting of brass under fluid pressure in steel dies. Die castings of metals and alloys of low melting point have been available for many years but the development of brass die castings has been relatively recent, occurring within the past five years. The successful development of brass die castings has resulted from the availability of alloy steels that would give satisfactory life as dies and the development of suitable die-casting machines. The melting point of copper is 1084° C. (1983° F.) and of a high brass about 900° C. (1652° F.), as compared to 327.5° C. (621.5° F.) for lead, 419.4° C. (786.7° F.) for zinc and 658.7° C. (1217.7° F.) for aluminum, temperatures that are indicative of the casting temperatures required for the various types of alloys, of which the melting points are somewhat lower than those of the pure metals.

Jan 1, 1935

By C. B. Murray

"OUR experience from time immemorial has been that the furnace sampler and analyst usually find one or two, and sometimes more, points less iron than the Lake Superior shippers, but, fortunately, their contracts are `iron bound'; and, generally speaking, analyses at this end are practically useless, for we are obliged to settle on basis figured out to a half dozen decimals, and, as a rule, without recourse in the event of flagrant discrepancies between the two analysts." The above is an extract from a letter received by the writer of this paper from the President of an iron company, discussing the question of sampling. It so well expresses the opinion of many blast-furnace owners and managers that it seems a suitable text for a discussion concerning the need of uniform methods of sampling. If all railroad cars were loaded the same, if all stock piles were the same shape, and if ore was received regularly each day, the problem of sampling would be comparatively simple. The conditions, however, vary widely at different places, and at the same place from day to day, and it is probably impossible to determine upon any one method of sampling which will apply at all times and in all cases. However, it would seem as though some general principles might be suggested which would tend to overcome these wide differences in samples of the same thing. The sampling of a cargo of iron ore begins at the breast of ore in the mine. The ore is sampled from the mine cars, from the stock piles, and from the railroad cars at the mines. At the lower Lake ports the ore is practically all sampled from the boat, occasionally from railroad cars. At the furnaces, the ore is nearly all sampled from railroad cars and occasionally from stock piles.

Jan 1, 1914

By Edward L. Clark

The year 1954 witnessed great activity in the field of geology as applied to mining. The search for in nearly all districts is becoming more and more intensified as established reserves are being depleted. Much geologic work has been directed to finding extensions of known orebodies, but prospecting in new areas has constituted a large part of the program of many operators. The acute need for additional reserves has brought into the search all the tools known to the geologic profession. This is reflected directly by frequent references to geophysical and geochemical methods in the regional reviews that follow. The lone prospector of the early days of metal mining has been eliminated almost completely by modern scientific methods involving surface and subsurface geology, exploratory drilling, geophysics, and geochemistry. Nearly all new exploration is based on long-range programs coupled with studies of regional geology to determine the structural environment of areas of mineralization. The success of this approach has encouraged new operators in the field of exploration to adopt similar policies. Only in the search for uranium ores is the individual prospector still active, but the familiar picture of the burro heavily loaded with grubstake, gold pan, and pick and shovel has been replaced by the Geiger counter and the scintillometer carried by hand, by truck, or by airplane.

Jan 3, 1955

By E. B. Hunt, T. M. Geffen, C. R. Stewart, V. J. Berry

Laboratory data .show that the gas-oil ratio performance of non-uniform porosity limestones produced by solution gas drive is sensitive to producing rate and to fluid properties. Nan-uniform porosity limestones are those for which laboratcry solution and external gas drive tests yield considerably different relative permeability ratio characterislics. The oil recovery performance by solution gas drive depends directly on the number of gas bubbles formed. Laboratory rates of pressure decline, which are 100 to 10,000 times greater than normal field rates. cause the formation of an unusually large number of gas bubbles. This results in abnormally high oil recovery efficiencies. Since it is impractical to reproduce the number of bubbles formed under field conditions, laboratory solution gas drive data on non-uniform porosity limestones are therefore not directly applicable to field operations. However, certain laboratory data can be used to make a conservative estimate of field performance. The concepts presented in this paper indicate the possibility that increased field oil recoveries may he obtained from non-uniform porosity limestones by rap- idly reducing reservoir pressure for a short interval of time. It has yet to be established that significant improvements in oil recovery from such reservoirs can he realized by varying the pressure decline rate within limits possible in the field. However, the possibility that recovery may be increased in this manner warrants further study. INTRODUCTION Limestone reservoir rocks can be divided into two general classes according to the nature of their pore space. One class has a comparatively uniform pore system composed mainly of voids between grains of the rock (intergranular type porosity). The other class, in addition to having intergranular porosity, has a secondary pore system composed of combinations of solution cavities, fractures, etc., and is considered to have non-uniform porosity. It has been shown in a previous publication' that the laboratory measured gas-oil flow behavior of uniform type porosity limestones is essentially the same for a test simulating a field solution gas drive as for one simulating an external gas drive. For non-uniform porosity type limestones a significant difference in gas-oil flow behavior was found. More efficient behavior was

Jan 1, 1955

By Parke A. Dickey

Potential differences between strata of shale and sandstone have been recognized for about years, and they form the basis of the electrical logging of oil wells. Hitherto these potentials have been ascribed solely to electrochemical reactions caused by the disturbing effects of the water in the drill hole through which they are generally measured. Observations by the author in wells empty of water and in a mine shaft suggest that potential differences between sandstones and shales are natural and specific properties of the rocks, although they are modified in measurement by the disturbing effects of the water in the drill hole. The cause of these potentials probably is to be sought in the relative polar adsorptive capacities of quartz and clay particles. Introduction The existence of potential differences in the surface of the earth has been known for some time, and their measurement has facilitated the discovery of geological discontinuities such as ore bodies. The technique of measurement has been well established.'-a In measurements in oil wells, it has been found that the potential of shales with respect to some arbitrary reference is very nearly constant in any one well, at least below the zone to which meteoric water has gained access. Sandstones and some other types of sedimentary rocks have a difference of potential with respect to shale that is negative and may attain a value of 200 millivolts or more. The difference of potential, as usually measured commercially with water in the hole, is distributed over about one foot vertically at the top and bottom contacts of the sandstones. The sharpness of the curve at the formation contacts can be improved by using a short electrode that is close to the wall of the hole. These potentials generally have been ascribed to the disturbing effects of the water in the drill hole. Potentials have been found, however, in wells in which no water was present. In the course of experiments in electrical logging in Pennsylvania, carried out by the Pennsylvania Geological Survey, observations were made of several phenomena that hitherto have not been described, to the author's knowledge, in the published literature. The potential differences across the contacts of sandstone and shale are called in this paper "natural potentials," as distinguished from the potentials caused by electroendosmosis (electrofiltration) and concentration differences, which will be discussed subsequently. Potentials in Cored Well In the spring of 1942, the author measured the potentials in an exploratory well (Day 13, near Grand Valley, Pa.) which had been cored with diamond tools. The potentials were first measured with fresh water in the hole. A null balance potentiometer was used in this and all the other measurements described in this paper. One nonpolarizing porous pot electrode, containing copper sulphate solution and crystals surrounding a pure copper elec-

Jan 1, 1944

By Parke A. Dickey

Potential differences between strata of shale and sandstone have been recognized for about years, and they form the basis of the electrical logging of oil wells. Hitherto these potentials have been ascribed solely to electrochemical reactions caused by the disturbing effects of the water in the drill hole through which they are generally measured. Observations by the author in wells empty of water and in a mine shaft suggest that potential differences between sandstones and shales are natural and specific properties of the rocks, although they are modified in measurement by the disturbing effects of the water in the drill hole. The cause of these potentials probably is to be sought in the relative polar adsorptive capacities of quartz and clay particles. Introduction The existence of potential differences in the surface of the earth has been known for some time, and their measurement has facilitated the discovery of geological discontinuities such as ore bodies. The technique of measurement has been well established.'-a In measurements in oil wells, it has been found that the potential of shales with respect to some arbitrary reference is very nearly constant in any one well, at least below the zone to which meteoric water has gained access. Sandstones and some other types of sedimentary rocks have a difference of potential with respect to shale that is negative and may attain a value of 200 millivolts or more. The difference of potential, as usually measured commercially with water in the hole, is distributed over about one foot vertically at the top and bottom contacts of the sandstones. The sharpness of the curve at the formation contacts can be improved by using a short electrode that is close to the wall of the hole. These potentials generally have been ascribed to the disturbing effects of the water in the drill hole. Potentials have been found, however, in wells in which no water was present. In the course of experiments in electrical logging in Pennsylvania, carried out by the Pennsylvania Geological Survey, observations were made of several phenomena that hitherto have not been described, to the author's knowledge, in the published literature. The potential differences across the contacts of sandstone and shale are called in this paper "natural potentials," as distinguished from the potentials caused by electroendosmosis (electrofiltration) and concentration differences, which will be discussed subsequently. Potentials in Cored Well In the spring of 1942, the author measured the potentials in an exploratory well (Day 13, near Grand Valley, Pa.) which had been cored with diamond tools. The potentials were first measured with fresh water in the hole. A null balance potentiometer was used in this and all the other measurements described in this paper. One nonpolarizing porous pot electrode, containing copper sulphate solution and crystals surrounding a pure copper elec-

Jan 1, 1944

By Francis P. Sinn

IN the zinc smelting industry the year 1947 seems to have been one of putting one's house in order rather than one of any material technical development or radical change in operating conditions. Labor generally has been in better supply but several plants report a scarcity of skilled workmen. Some plants continue to operate on the basis of a six-day week and will probably continue to do so until labor is more plentiful. Only one plant is known to have operated on a curtailed basis because of labor shortage, but here the difficulty was lack of proper housing facilities. Necessary materials and equipment for much-needed maintenance and modernization have been in short supply so these programs have often been delayed. Laborsaving devices of the "Payloader" type have been more generally used for handling materials. Slab zinc production was discontinued during the last months of the year at Danville, 111. and at Langeloth, Pa. Both of these plants used the Hegeler type of furnaces fired with producer gas. It is understood that the rolling mill and possibly the acid plant at Danville will continue to operate. At Langeloth acid will be produced from

Jan 1, 1948

By Granville S. Borden

The fruits of industry are divided between capital, labor, and governments. Capital takes its redemption and remuneration through profits or dividends; labor takes its share through wages; governments take their share through taxes. Each must have a just share, and the question of what is a just share and the question of who-shall make the allocation are vital current political and economic issues. Certain political philosophies con- tend that government should take all the fruits and that some dictator or politician should have irrevocable discretion and power to distribute the fruits. Believers in democracy and free enterprise adhere to the view that capital is entitled to redemption and fair remuneration; that labor shall have a fair wage; and that governments shall make equitable levies. But since all human beings, both individually and in groups, are inherently selfish, there are many variable views in regard to the question of what ratios shall be applied in a division of the fruits and who shall have the power to fix these ratios. Perhaps all parties should devote more energy to means of increasing the crop, and not so much time to quarreling over a division of the existing crop. Moreover, all three parties must guard against killing the goose that lays the mineral eggs. For example, if the tax burden becomes oppressive and the taxpayer refuses to carry it, then business stagnates, with consequent unemployment, reduction of profits, and curtailment of government revenue. If a producer assumes the increased tax burden, marginal operations must be closed down, and again the consequences are increased unemployment and diminished government revenue. Quite often an increase in a rate of tax results in a reduction of government revenue. Perhaps the worst detrimental feature of selfishness and greed on the part of any one of the three distributees of the fruits of industry is the retardation of expansion of the enterprise. Growth means new jobs, more government revenue, better trade, and better standards of living. Explorations and discoveries have resulted in tremendous contributions

Jan 1, 1959

By E. E. Bach

The administration of industrial organization today embraces more than the cost of production and selling prices. Competition is deeper seated than mechanical devices, overhead charges, and a shrewd manipulation of the markets. Despite the " down-to-the-minute " equipment and the "last word in organization," it is quite evident that "capacity production" will be an unknown quantity until the workman is considered as a producer, in relation to his home, as he is now considered in relation to industry. Whether or not a man shall do an honest day's work is as much a psychological condition as it is a matter of physical strength or skill. His attitude toward his work each morning is determined, to a large degree, by the environment of his home. Whether this attitude, good or bad, obtains the day through will depend entirely upon the one fact as to whether the corporation which employs him does or does not differentiate between the mechanical factor and the human factor in industry. To be more specific, sociological work, under whatever name, should be of such a character as to influence the life of a workman in such a manner as to establish a cooperative interest in his work, foster within him a spirit of contentment in his home, lead him so to employ his leisure time that he will not lower his efficiency as a workman, destroy his domestic happiness, or endanger his standing in the community as a citizen. While no fixed rules of procedure can well be formulated for the development of the work, yet definite lines of activities will readily present themselves as applicable to the individual needs of a community. This is especially true where community influences and agencies pertaining to general welfare are easily correlated. Any definite work attempted must be determined by the type of the

Jan 1, 1918

By A. S. Richardson

The design of mine airways receives, in general, very little engineering treatment. To a large extent this is, of course, due to the fact that information upon which to base calculations is seldom available in definite form. In many rnines the extent of the workable deposits may not be known at the time an air course is planned, and the length of service is indeterminable. Volume of air required for ventilation rnay also increase with extension of the life of a property, and natural obstacles, such as heavy ground, often place limitations upon the size of opening that can be maintained. Perhaps most of the shafts used in the ventilation of metal mines were originally intended as hoisting shafts, and many of the tunnels and crosscuts similarly used, were also designed as haulage ways or for other operating purposes. Even when a shaft is sunk solely for ventilation, custom usually dictates a size and shape consistent with the type commonly used for ordinary operations, because experience has demonstrated it can be excavated and maintained. In fact, most ventilation openings were never made with any consideration as to economic design for such use. When an air course is required to pass air between different parts of mine workings under a fixed pressure, the size of opening required for a given volume of flow, is, of course, determined by the resistance factor of the air course. It is then impossible to proportion the opening with reference to economics of power consumption, and this paper is limited to the design of openings where ventilation pressure or power consumption may he varied for economic advantage. As the size of an air course is increased, the expense involved in excavation and support is, of course, also increased, but the charge for power is decreased. In the case of a mine that has only a short assured operating life, it would not be ecouomical to provide large openings in order to reduce power bills; but when operations are likely to continue for a long time, the power charge becomes a very important economic factor. Although lack of definite information on such factors as service life and costs of excavation and support affects the design of an air course, it appears, from a mathematical analysis of the problem, that considerable variations may be made in estimating these factors, without greatly

Jan 1, 1927

By Milton H. Fies

THE writer wishes to acknowledge at the outset his great sense of obligation to those who contributed so broadly and expertly to the preparation of this paper: Dr. Albert DeSmaele, Chairman of the Board of Directors of Socogaz, Belgium; Dr. Julien Venter, Director of the National Institute of Coal Mining, and Coal Utilization Industry, Belgium; Dr. Roger Loison, Chief Engineer, French National Coal Research Board, France; and Dr. Erich Sarapuu of the Sinclair Coal Co., Kansas City, Missouri. Liberal use has been made in this paper of a recent publication on Russian, Italian, Belgian, and French experiments prepared jointly by the Centre d'Etudes et Recherches des Charbonnages de France (Cerchar) and the Institut National de I'Industrie Charbonnière of Belgium (Inichar) .l The writer is particularly indebted to Dr. E. T. Wilkins, of the Fuel Research Station, London, and to Mr. James L. Elder, of the Alabama Under- ground Gasification Experiment at Gorgas, Alabama, for their unfailing patience and effective support. Not only did these experienced and capable men edit and revise this discussion, but much of its content is a direct contribution quoted in full from their memoranda. Without the assistance of all these colleagues, this presentation would not have been possible. It has been a privilege to serve and work with them and to acknowledge repeatedly their loyal cooperation. The recovery of the energy inherent in coal beds throughout the world has been done through the years by methods that today may be justly regarded as primitive. While the techniques of coal mining through the application of machines and the enhancement of information and skills have advanced to an extraordinary extent, particularly during the past 20 years, the underlying means is essentially the same as when man first began to mine coal. Despite this progress in the manner of coal mining, it continues today as a hazardous, toilsome, grimy task. Coal mining per se has advanced at a greater and more rapid stride in the past 25 years than the mining of any other mineral, but the basic method is fundamentally the same as it was the first day a miner took a pick into his hands many centuries ago. This situation presents a challenge to mining engineers everywhere, from

Jan 1, 1953

By R. J. Wasilewski

Axial expansion has been determined by X-ray diffraction up to 600° to 760°C in a titanium and four high-oxygen alloys. Expansion data cannot be fitted to the usual quadratic expression and anomalies observed are believed indicative of the changes in the bonding configuration of the valence electrons. Furthermore, there is significant disagreement between data obtained on poly crystalline and single crystal powder specimens. The major disagreement occurs within the temperature range (-470°C) where both mechanical and electrical properties also show markedly anomalous behavior. X. HIS work forms part of an investigation of physical properties of pure titanium and its osolid solutiono alloys with oxygen and nitrogen. In view of the anomalies observed in both the electrical resistivity' and the susceptibility behavior it was decided accurately to determine the thermal expansion behavior of the pure and alloyed a titanium. PREVIOUS WORK The axial expansion coefficients reported for pure titanium are listed below. As can be seen, there is a marked discrepancy between the axial expansion and the experimentally determined coefficients on poly crystal line material. Thus, if we take the most recently reported axial expansivities3,4 we obtain perature interval of 25o to 700°C. The experimental value reported for polycrystalline metal is, however, of the order of 9.7 x 10o6 per OC. EXPERIMENTAL I) Pure Titanium. High purity titanium powder of -325 mesh was used throughout most of this work. The only significant impurities present were the interstitials, oxygen and nitrogen, which analyzed respectively 650 and 80 ppm. The purity of the ma-

Jan 1, 1962

By Eugene Stebinger

INTRODUCTION. A LARGE number of papers and reports dealing with the coalfields of Montana have been published + during the last 30 years, but the information is much scattered, appearing in many technical and scientific journals and in government reports, in many cases inaccessible to those most interested. In recent years, especially since 1905, ,our knowledge of the geology and coal contents of the important fields of the State has been much increased. Fairly specific and detailed information is. at hand on all of the principal coal-bearing areas. The fields for which data are not at hand are small and inaccessible, and their omission will not materially affect an estimate of the coal resources of the State, viewed as a whole. The paper here presented is a summary of existing information, all sources having been freely utilized in its preparation. The viewpoint adopted is that of the geologist, rather than that of the engineer or colliery operator, because by far the greater portion of the coal areas present have had only the most meager development, making information that, will aid in prospecting and opening the at present little used coal lands of paramount importance to those interested in the coal fields of the State.

Jan 9, 1913

By Orrin Peterson

THE decision of the Supreme Court of the United States not to review the findings of the lower courts closes an interesting chapter in the mining litigation that has arisen as a result of the extralateral feature of the mining law. The time seems opportune to record some of the important geological features, and also some of the legal features, of the controversy, in the hope that these will be permanently accessible to members of the mining profession. After many rumors of litigation, the Utah Consolidated Mining Co. sued its neighbor for the ore that had been, it was alleged, wrongfully extracted from its so-called Yampa limestone lode. This ore lay beneath Utah-Apex surface and was claimed by virtue of the extralateral rights conferred on the Utah Consolidated Co. through the ownership of certain specific mining claims, one of the principal claims being the Yampa. Previous to bringing suit, the Utah Consolidated Co. had strengthened its position by purchasing the Old Yampa mine and by making an agreement with the Utah Metal & Tunnel Co., which gave it clearer title to the outcrop of the Highland Boy limestone. Access to the workings of the Utah-Apex Co. was secured and reciprocal privileges gave Utah-Apex representatives the right to enter the properties of the Utah Consolidated Co. This resulted in the Utah-Apex immediately bringing countersuit for ore alleged to have been wrongfully extracted from under its surface in the Leadville country, see Fig. 4. Six cases came up for consideration: five related to the original suit and the countersuit, and one related to the Dana extralateral claims of the Utah-Apex Co.

Jan 6, 1924

By W. G. Woolnough

It is perhaps a little difficult for Americans fully to appreciate the slow progress in the search for oil in Australia. Conditions are so different from those in the United States that methods must also differ considerably. Australia possesses an area almost exactly equal to that of the United States, but has a population of less than 7,000,000, and this population is concentrated almost entirely around the eastern and southern coasts of the continent. There are, therefore, vast "empty spaces" entirely unpopulated or exceedingly sparsely populated. The emptiness is due not to any lack of energy or initiative on the part of Australians but to the arid and waterless character of much of the country's interior. Throughout the greater part of the area that is comparable with the Mississippi drainage area of the United States, there is not a single flowing stream, and over most of it the rainfall is less than 7 in. a year. This hinders exploration and geological survey, and also isolates from potential markets many of the regions that otherwise might be considered worth prospecting. Also, Australia consists of six independent and sovereign states. With the establishment in 1901 of the Commonwealth of Australia, the states retained complete control of lands and mineral rights. Each state has its own petroleum legislation, and the absence of a central controlling authority has tended to confusion and to the introduction of many complications in oil prospecting. There are three major "territories," administered by the Federal Government; namely, the Northern Territory, enclosed between the northern parts of Queensland and Western Australia, within Australia itself, and the Territories of Papua and New Guinea in the island of New Guinea. Land and mineral legislation in these territories is not uniform. Furthermore, during the late twenties there occurred an orgy of company flotation and indiscriminate drilling, wQch resulted in the discovery of some definite indications of oil in three of the states and two of the territories, but which failed to develop any producing oil field in the common acceptation of the term. Much money was squandered,

Jan 1, 1938

By Arthur S. Dwight

From the latest and best literature on lead-smelting, little can be learned concerning the present state of the art of mechanical feeding in the United States. H. O. Hofman, in his Metallurgy of Lead (5th ed., 1899), briefly describes the main features of the system in use at Pueblo, Colo., and later (p. 235) says " the only successful mechanical feeding, as far as the writer is aware, is that found at the works of the Pueblo Smelting and Refining Co." H. F. Collins, in his Metallurgy of Lead and Silver (London, 1899), covers American practice pretty thoroughly; but as to mechanical charging, he says: "The German plan of taking off the gases by means of a small iron pipe suspended in the center, and the plan of charging by means of cup and cone, as in iron blast-furnaces, have both been tried, but have not found favor, chiefly on account of the difficulty of obtaining free access to the furnace-shaft for barring, etc., with such devices."' . H. W. Hixon, in his Notes on Lead and Copper Smelting (3d ed., New York, 1900), gives a description and drawing of the Hixon feeding device, as originally installed at East Helena. Evidence that this system of feeding has passed its experimental stage, and deserves more serious consideration than it has heretofore received, is furnished by two large plants—the Pueblo and the East Helena—of the American Smelting and Refining Co., where mechanical feeding has been in continuous and successful operation for a considerable period; one new plant now erecting at Salt Lake City, Utah, and one old one belonging to the same company, the El Paso works, now being rebuilt after a disastrous fire, in both of which mechanical feeding is to be a prominent feature ; one new plant of an independent concern at Torreon, Mexico, which will adopt mechanical feeding; and a number of other smaller plants, among

Jan 1, 1902

By C. H. Jr. Herty

IRON oxide .(Fe0) plays an extremely important part in the manufacture of steel. In the open-hearth furnace and the Bessemer converter it is the chemically predominant compound and controls to a large extent both the operation of the furnaces and the composition and quality of their products. Almost all of the refining action is carried out through the medium of FeO, which oxidizes carbon, manganese, silicon, and phosphorus. At the end of any open-hearth or Bessemer heat the steel contains dissolved iron oxide, which must be wholly or partly eliminated. The type of deoxidation product depends on the amount of dissolved iron oxide and on the deoxidizer used. After the heat has been deoxidized and while it is being teemed, iron oxide diffuses from the ladle slag into the metal, causing losses of deoxidizer and increase in iron oxide content of the steel. It is generally believed that non-metallic inclusions are responsible for a great many failures of steel in service and for decreased yield of steel during rolling. The basis of most non-metallic inclusions is dissolved iron oxide. This investigation was undertaken in order to determine the amount of iron oxide that will dissolve in iron under various conditions. Steel-making slags are complex and it has been thought best to determine solubility under simple slags as a first step. The study is being continued under slags whose compositions approach those of operating. slags.

Jan 1, 1928

By Jack A. Simon, M. E. Hopkins

GENERAL GEOLOGY Coal is defined as a combustible rock that originated in the accumulation and physical and chemical alteration of vegetation. Coal can be ignited and burned like the wood that was man's earliest fuel, but coal gives more heat than the same amount of wood and has many industrial uses. Unlike wood, coal is not generally found on the surface of the ground but is mined from the solid rock of the earth. Before taking up the occurrence, formation, and the unique character of coal in the rock sequence, let us briefly consider the general character of all rocks in the crust of the earth. Relatively little is known about the very earliest history of the earth, although a number of logical theories have been developed. Manned exploration of the moon and the rocks returned to earth continue to provide some answers to questions concerning the earth's origin and history. The period of earth history with which we concern ourselves here begins after great areas of water had evolved on earth and substantial land areas of once molten (igneous) rock existed. Weathering and other processes that attacked the surface of the rocks reduced them to small particles. Water provided by rainfall transported this material, ultimately, to large bodies of water where it was deposited. Thus was initiated the geologic sequence of sedimentary rocks that lie above the once molten igneous rocks. The crust and upper mantle of the earth are made up of several large plates along which differential movement (primarily horizontal) takes place. Such movements, although small, are occurring today. These horizontal movements are accompanied by vertical movements causing important changes in the relative position of the continents and oceans. Low-lying coastal swamps with favorable climates are ideal locations for coal accumulation and burial by river-borne sediments, and large areas

Jan 1, 1981

By D. Swan

Industrial research may be defined as a critical and exhaustive investigation to create new and better ways of doing things. The results of industrial research are new and improved products, processes, and techniques. This broad definition, of course, covers investigation of all subjects by either individuals or groups of people, and this chapter aims to examine the purpose (what research tries to do), and methods (or how research is done) as applied in the mineral industries. Concepts and History The idea or concept of organized research probably originated in the universities of Europe. There, groups of scholars banded together for discussion and application of their particular specialty to a common problem. Publication of the conclusions drawn from such investigations gave scholars in other areas the opportunity to review and criticize the work of their colleagues, and one of the hallmarks of scientific research work is the publication and criticism of the results of the investigation. It was not until the late nineteenth century that the concept of organized research for the profit of industry was recognized. During the late nineteenth and early twentieth centuries, a large number of industrial enterprises sponsored organizations to study the application of the physical sciences with the aim of making discoveries that would result in profit to the sponsoring organization. The tangible benefits accruing from these activities were so great that they, in turn, fostered several other methods for the support of organized research activities. For the large problems involving public interest, United States Government scientific research laboratories were set up. As the demand of smaller enterprises for research activities increased, research institutes and consulting laboratories were organized. In Europe the idea of common industry sponsorship of research centers grew and many large research organizations there were sponsored by associations of manufacturers. Finally, in the United States

Jan 1, 1964