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By K. C. Li

TITANIUM, because of its high strength, weight ratio, and high melting point, became the metal of the jet age. Zirconium, because of its low neutron cross section and high corrosion resistance to hot water, became an integral part of the nuclear era. Since both metals are very similar chemically, more or less the same process is used for their production. The sudden rise of this new industry of titanium and zirconium seems to have caused some uncertainty as to the future development of processes for making these metals. Although zirconium was discovered in 1789 and titanium in 1790, it was not until 1945, six years after W. J. Kroll patented his process, that F, S. Wartman of the U. S. Bureau of Mines perfected the technique of producing ductile titanium, and it was not until 1946 that Kroll perfected the technique of producing ductile zirconium in commercial quantities. Since then the Government and private industry have spent millions of dollars each year constantly searching for new methods, with the hope that some day titanium can be produced as economically as aluminum and magnesium or as cheaply as stainless steel.

Jan 11, 1957

By James J. Norton, Lincoln R. Page

Effective methods for determining grade and reserves of pegmatites in advance of mining have been developed in recent years. When intensive work began on the economic geology of pegmatites during the early years of World War II, it was widely believed that grade and reserves could be estimated only in a most general way. The literature indicated that not all pegmatite deposits are unpredictable, but statements emphasizing unpredictability and irregularity seem to have been more widely accepted. Many standard references reflect the prevailing opinion that minerals are unsystematic in their occurrence in pegmatites. Pegmatites have been de- scribed as "notorious for their irregular structure," and minerals within pegmatites as "irregularly distributed," "irregularly disseminated,'' of "erratic occurrence," "proverbially erratic in distribution," "characterized by extreme irregularity in size and distribution of the essential minerals, and variety and proportion of the accessory minerals, and "spotty."

Apr 1, 1956

By H. N. Eavenson

In a discussion in the Transactions of the Institute (vol. Xl, page 835 et seq.) the writer gave some data about the explosions of gas and dust in the coal mines of the United States, Canada, and Mexico…

Jan 1, 1915

By C. B. Gillson, Henry Fay

For several years past, investigations on the chemistry of tellurium have been carried on in the laboratory of this institution. The methods of preparation of pure telluriumf and the estimation of tellurium‡ have been studied, and an attempt to determine the atomic weight of tellurium is now in progress. All these problems had been investigated, however, along purely theoretical lines; and it was thought desirable to study the more practical application of the metal, which can now be had in considerable quantities as a waste product in the refining of copper-ores. In its physical and chemical properties tellurium is very similar to antimony, and it was thought

Jan 1, 1902

By W. A. Thatcher

Nearly three years of experience in Spanish Honduras has placed the writer in possession of many facts concerning its resources which may be of interest to the Institute. According to the most trustworthy surveys, Honduras is bounded on the north and east by the Caribbean Sea; southeasterly by the river Segovia (or Wanks), which flows into the Caribbean at a point called Cabo Gracias a Dios (Cape Thanks be to God), long famous as the favorite hiding-place of the celebrated pirate, Morgan ; southwardly by a corner of San Salvador, the Bay of Fonseca, and the Republic of Nicaragua; Guatemala and San Salvador form tile western boundary. It is one of the five republics composing Central America, has a population of about 310,000 and an area of 150,000 square miles, lying between the 13th and 16th degrees of N. latitude, extending from north to south 200 miles, between the Atlantic and Pacific, and 400 miles from east to west, between Guatemala and Cape Gracias a Dios. It is composed of 13 States or Departments, under one common law. The principal resources are valuable woods, hides, rubber, tobacco, coffee, fruit, cattle, silver and gold. It is of the mineral resources of the country that I will speak, calling attention to the most noted mines, and their relative position to Tegucigalpa, the capital. The introduction of foreign capital into the country dates back about eleven years, and to-day there are at least twenty-five well organized companies.

Jan 1, 1892

By E. G. Leonardon

THE first to appreciate and foresee the value of applying electrical measurements to structural studies was Prof. Conrad Schlumberger, Professor of Physics at the School of Mines in Paris. One of his earliest practical undertakings in this line was carried out, in the field, at Fierville-la-Campagne, Normandy, in 1912. His book, published in 1920,1 still stands as an authoritative, fundamental treatise on the use of the electric current in geological studies, in spite of the rapid evolution of geophysics during the last seven years. A remarkable feature of this book is that, even then, it stressed the role of electricity in structural investigations and made public the first successful results obtained therewith. Stratigraphic studies have been pursued continuously by Conrad Schlumberger and his associates since 1912, the only interruption being the World War. The results attained demonstrate the wide possibilities of electrical exploration in structural work. This field of activity is, at the least, as varied and valuable as the search for ore. It is curious that until very recently it has so slightly attracted the attention of geophysicists and geologists on this continent. The purpose of this paper is to present briefly some examples of the practical application of the potential methods to geological studies. These examples are chosen from a number of problems solved in the field by our firm, in the course of its consulting practice. Certain fundamental points are briefly stated before the field operations and interpretations are described.

Jan 1, 1928

Jan 1, 1899

Jan 2, 1950

By J. L. Shafer, Christopher L. Caenepeel, Martha L. White

Often an in situ leach is the only practical economic method for copper recovery from small low grade oxide deposits. The decision to develop a copper property by an in situ blast and leach is strongly dependent on ore grade, tonnage, hydrology, and the copper extraction and acid consumption rates. The inherent leachability of the ore will in part determine the desired amount of fracturing of the ore deposit by the blast in order to obtain a copper extraction rate that is economical. For the last several years Occidental Research Corp. (ORC), has undertaken a modest effort to address the question of how to best identify and determine the information necessary to predict and control the operation of an in situ leach for the economic recovery of copper. Modelling of the Leaching Process During the past 10 years the activity in the mathematical modelling of the leaching of copper sulfides in copper dumps and heaps has increased dramatically. The modelling of copper oxide leaching has not received as much attention. The acid leaching of non-sulfide copper minerals while chemically less complex, compared to sulfides, does generate a vertical acid concentration gradient in the ore heap being leached due to the acid-base nature of the reaction. This is generally not observed in sulfide deposits that are biologically active, due to the buffering action of opposing reactions involving the generation of sulfuric acid from sulfide minerals and acid consuming host rock. Thus, the objective of ORC 's copper oxide modelling efforts is to determine the leaching parameters which will account for this vertical acid concentration gradient. Knowledge of this gradient will result in the correct choice of the feed acid concentration to the top of the ore dump or heap, such that the effluent will have the desired pH.

Jan 1, 1980

By Shawn T. Sorrell, Carl Hrovatic

Original by Carl Hrovatic and Shawn T. Sorrell Revised by Carl Hrovatic Land is a precious resource and should be treated as such by all members of our society. The soil covering this earth is only a very thin outer layer, varying in thickness from a few inches to a few feet and covering the rocks and minerals lying beneath the surface. The wise use of this valuable commodity is the responsibility of everyone. Many everyday activities disturb the earth's surface. Examples are highway construction, housing and commercial developments, agriculture, and various types of mining. This chapter discusses the relationships of the environment to land as it applies to surface operations in the coal industry. Mining by surface methods disturbs, for a brief period of time, thousands of acres of land annually. In addition, refuse piles, slurry ponds, abandoned mine structures, unprotected mine openings, and unsightly cleaning plants can also adversely affect land unless properly handled. ACTIVE SURFACE MINING OPERATIONS Mining by surface methods includes rock quarries; sand and gravel pits; huge open pits to extract iron, copper, phosphate, and other ores; and coal mining. Production of coal by surface methods is now approaching 408.2 Mt/a (450 million stpy), amounting to almost 60% of the total coal output. Surface coal mining can be classified into the following five broad categories : Open-pit mining is practiced where coalbeds are extremely thick, as in some western states, or where coalbeds are sharply pitching, as in the anthracite region of the eastern United States. A typical open-pit mine, with coalbeds of 3.05 to 30.5 m (10 to 100 ft) or more thickness and a

Jan 1, 1981

By Jos. J. Walsh

Ventilation within a coal mine is essential to the welfare of those employed therein, from the standpoint of health, safety, and efficiency. While the saving of life and the preserving of health are the chief reasons for ventilation, efficiency and production are increased. In spite of the fact that we speak of air as having a certain composition, the proportions of oxygen, nitrogen, and carbon dioxide are not fixed, but vary between small limits. The different elements are not chemically united, they are merely mixed and each is free and can be separated with little energy. For this reason air in the mine workings is seldom found in a pure state. Factors that necessitate ventilation in coal mines are those that change the composition of pure air. Contamination of mine air results from the burning of oil-fed flames, the use of explosives, the oxidation of coal, and the liberation of gases by the coal. The extent to which these factors exist governs the size and general plan of the ventilating applianccs required. An efficient ventilating system is one that will furnish air at the working faces in sufficient volume to dilute and render harmless noxious gases and at the same time maintain an oxygen content closely approaching that of pure air. In a well-ventilated mine, the oxygen seldom falls more than 0.5 per cent. below normal. The carbon-dioxide content of the air in the average coal mine will vary from 0.1 to about 0.8 per cent., which amounts are not harmful. Three per cent. of carbon dioxide in air doubles the frequency and the depth of breathing; it is plainly noticeable and if breathed continuously for several hours its effect would probably be harmful. Slight reductions in the oxygen content of the air, such as occur in well-ventilated mines, have no debilitating effect on the worker. A person not exerting himself would fail to observe any unusual physical effect in an atmosphere: containing 17 per cent. of oxygen. This condition, however, or even a condition showing an oxygen content below 20 per cent., would indicate poor ventilation and that the elements which tend to reduce the efficiency of the worker are present, namely water vapor and a high wet-bulb temperature.

Jan 1, 1923

By D. T. Jones

In view of the importance of the application of scientific principles to the production of oil from the reservoir, the Production Staff of the Anglo-Iranian Oil Co. (late Anglo-Persian Oil Co.) has been engaged for some years on an intensive program of research on the physical properties of crude oil. Problems involving the retention of crude oil in capillaries and fine fissures demanded for their solution a knowledge of the surface tension and specific gravity of the crude under reservoir conditions, and it is the purpose of this paper to describe briefly the methods adopted for the determination of these properties, and to present the more important results. A detailed article was published in volume 1 of the World Congress Proceedings (1933). Surface-tension observations on crude oil regassed at high pressures with natural gases have been made in the past by Beecher and Park-hurstl and Swartz2, but up to the time of the investigations in Iran no one seems to have carried out experiments with gas-saturated crude direct from the reservoir and kept at its original pressure. Results obtained in this manner are obviously of greater practical value for solving problems connected with the reservoir. Method of Measurement No apparatus for the measurements, under the pressure conditions involved, was available, and a suitable instrument had to be designed and constructed in the Fields workshops. Careful consideration of the matter led to the adoption of a method for measuring the surface tension which did not involve a knowledge of the specific gravity of the oils under the working conditions: the main reason for this being that up to that time no accurate determination of the specific gravity had been made under these conditions. The method adopted involves the measurement of the actual tension in an oil film, and is effected by means of

Jan 1, 1936

By Francisco Cadena

The construction of Norris Dam, built by the Tennessee Valley Authority on the Clinch River, a tributary of the Tennessee River, involved the production of coarse and fine aggregate for approximately 1,000,000 cu. yd. of concrete. A hammer-mill plant for the manufacture of sand from quarried rock was indicated as the most economical method of providing this material. The abrasive character of the feed as compared to the average hammer-mill feed made it necessary to control operations rather closely, and this resulted in the accumulation of many data hearing on production and maintenance. This paper will deal only with three specific sets of data, accompanied by such general information as may be necessary to explain the conditions under which they were obtained and followed by discussions on the relation of silica content to hammer wear, comparative costs of slugger and stirrup hammers, and comparative costs of tool-steel and manganese-steel grate bars. Coarse Aggregate Aggregate for the concrete poured at Norris Dam came from a dolomite quarry within 2000 ft. of the west abutment of the dam. Geologically this rock is known as a Knox dolomite. A typical chemical analysis is given in Table 1. Table 1.—Typical Chemical Analysis Per Cent H2O, 110° F............................................. 0.02 lgnition loss.............................................. 43.56 MgO.................................................... 19.19 CaO ................................................... 29.07 Fe²O³.................................................... 0.39 Al2O³ .................................................. 1.94 SiO2..................................................... 5.75 SO2...................................................... Tr. Rock was carried by 12-yd, dump trucks to a 42-in. gyratory crusher set at 6 1/2in. The product of the primary crusher was taken by a belt conveyor to a double.-deck vibrating screen followed by a 5 1/2-ft. cone

Jan 1, 1938

By Lincoln F. Elkins, John T. Cooke

Injection of gas to increase oil recovery has been considered for almost all important discoveries during the past ten or fifteen years. However, the number of gas injection projects having sufficient history and data is too limited to permit valid generalities of effectiveness of gas injection. Management and engineers are faced with a difficult problem of selecting those reservoirs which are susceptible to profitable application of gas injection. Injection of gas to maintain high pressure favors some factors affecting reservoir performance such as viscosity, surface tension, and formation volume factor of oil by keeping gas in solution and favors some operating features such as extending flowing life of wells and storing part of the produced gas for future use or sales. Injection of gas at low pressure involves lower compression ratio, or at least a single gas-gathering system, larger displacement volume in the reservoir per unit of gas handled, and permits effective utilization of the naturally existing energy and agent for oil displacement that is gas dissolved in oil. Each program is thus a compromise to meet optimum economic conditions while striving to attain maximum recovery of this important nautral resource. The statement has often been made that pressure maintenance would greatly increase oil recovery by permitting abandonment of formation oil inflated with gas in solution rather than abandonment of the same liquid volume of tank oil, if the same terminal oil saturation could be attained. Simple calculations indicate increases in oil recov- ery as high as one hundred per cent on this basis for high formation volume factor oil encountered in current deep drilling. Important in this statement is "if the same terminal oil saturation could be attained." Implicit in this statement are the requirement of physical

Jan 1, 1949

By Donald L. Katz, Michael J. Rzasa

With greater effort being devoted to the discovery of new oil and gas reserves and a consequent increase in bottom hole pressures due to greater drilling depths, the phase relationships of hydrocarbon fluids at pressures above 10,000 lb psi are becoming increasingly important. The present paper discusses the results of research with a windowed cell on a methane-Kensol 16 system to pressures of 25,000 Ib psi and temperatures to 260°F. Kensol 16 is a commercial high narrow-boiling-range oil. It is shown that for the temperature range of 60 °F to 260 °F, this particular system exists in two phases to pressures of approximately 14,000 lb psi, and data are presented giving the relative amounts of liquid and vapor phase? coexisting under these conditions. Partial phase diagrams are shown for six different mixtures of methane and Kensol 16, three of which include the critical region. In contrast to mixtures composed of substances of fairly close volatility. critical opalescence was noted for as much as 200°F of the critical temperature. The critical locus of the methane-Kensol 16 system was estimated and the conventional pressure-composition and temperature-composition diagrams were prepared. From these, the equilibrium vaporization factors for methane and Kensol 16 were estimated for temperatures from 60 °F to 700 °F and to pressures above 12,000 lb psi. The relations of this study to petroleum production problems and other phase equilibria research are discussed. INTRODUCTION A knowledge of the physical behavior of naturally-occurring hydrocarbon mixtures is fundamental to a thorough treatment of nearly all operations involved in the recovery, refining, and transportation of petroleum. The operations may involve the applications of phase relationships, and the relative

Jan 1, 1950

By John T. Cooke, Lincoln F. Elkins

Injection of gas to increase oil recovery has been considered for almost all important discoveries during the past ten or fifteen years. However, the number of gas injection projects having sufficient history and data is too limited to permit valid generalities of effectiveness of gas injection. Management and engineers are faced with a difficult problem of selecting those reservoirs which are susceptible to profitable application of gas injection. Injection of gas to maintain high pressure favors some factors affecting reservoir performance such as viscosity, surface tension, and formation volume factor of oil by keeping gas in solution and favors some operating features such as extending flowing life of wells and storing part of the produced gas for future use or sales. Injection of gas at low pressure involves lower compression ratio, or at least a single gas-gathering system, larger displacement volume in the reservoir per unit of gas handled, and permits effective utilization of the naturally existing energy and agent for oil displacement that is gas dissolved in oil. Each program is thus a compromise to meet optimum economic conditions while striving to attain maximum recovery of this important nautral resource. The statement has often been made that pressure maintenance would greatly increase oil recovery by permitting abandonment of formation oil inflated with gas in solution rather than abandonment of the same liquid volume of tank oil, if the same terminal oil saturation could be attained. Simple calculations indicate increases in oil recov- ery as high as one hundred per cent on this basis for high formation volume factor oil encountered in current deep drilling. Important in this statement is "if the same terminal oil saturation could be attained." Implicit in this statement are the requirement of physical

Jan 1, 1949

By J. W. Spretnak

It is well-established that decohesions occurring at the interface of the matrix and rigid inclusions and second-phase particles are prime causes of ductile fracture initiation. It is not clear, however, how these decohesions occur. The idea that the interface bond is broken in tension is not particularly attractive when one considers the strength of such interfaces and the fact that plastic flow is not restricted under conditions of continuing flow required to initiate and propagate ductile fracture. A suggestion as to the mechanism of decohesion arises if one takes the position that, as the dislocation density increases with plastic flow and reaches some critical range of density, the phenomenon of flow can be regarded as fluidlike instead of the crystallographic motion of dislocations. As the spacing between dislocations decreases, the matrix becomes increasingly disordered in terms of loss of periodicity. At some critical degree of reduction of the periodicity, it is suggested that flow can be regarded as hydrodynamic, rather than crystallographic. Such a state has been referred to by rheologists as the "plasticized state", or the "fourth state of matter", between the liquid and solid state. A similar argument pertains qualitatively with the increase in equilibrium vacancy concentration as the temperature approaches the melting point. Taking the viewpoint that at larger strains the flow may become hydrodynamic in nature, a mechanism of decohesion is suggested. A well-known phenomenon in boundary-layer flow is that of "separation" locally of the boundary layer from the substrate.' Under certain conditions, the flow in the immediate neighborhood of the substrate becomes reversed, causing the boundary layer to separate from it. The exact condition for separation is that the velocity gradient normal to the substrate vanishes there, or It is of interest that blunt particles such as spheres and circular cylinders are most likely to give rise to separations because of unfavorable pressure distributions behind them. The source cited gives solutions for positions of separations for various geometries. In principle, such separations can also take place when metal is flowing over a "dead zone" of stagnant metal. This may explain the initiation of fracture at the elastic-plastic boundaries of plastic enclaves under a notch.

Jan 1, 1967

By Jean A. Andre

In 1969 "Société des Mines et Fonderies de Zinc de la Vieille-Montagne" produced 221,000 tons zinc ingots and 22,000 tons zinc dust, thus rating highest on the world's zinc producer list. The Company's plant at Balen, Belgium, with an output of 135,000 tons electrolytic zinc is the most important one of this group; it is an integrated metallurgical zinc and lead unit with recovery of most by-products. The present paper describes the zinc production facilities. The roasting section includes four fluid bed roasters (total concentrates charged: 740 tpd) and two sulfuric acid having a corresponding capacity. Calcine is leached in a fully automated plant by a two-step continuous process. Leaching residues, mixed with lead furnace slag, are treated in a shaft furnace. The recovered zinc fume is leached separately. In the near future, the leaching residues are to be treated by a wet process, developed in the Company's own laboratories. Purification of solutions is accomplished in two steps: antimony and zinc dust are added in the first one, only zinc dust in the second one for removal of cadmium. Electrolysis cells are partly of a conventional type. A new type of cell configuration was put onstream in October, 1969, planned output 60,000 tpy. Main features of the new cell rooms are the fully automatic pulling, stripping and replacing of the jumbo-size cathodes (immersed area 2.6 m2). Zinc cathodes are remelted in induction furnaces followed by in-line automatic casting and stacking machines.

Jan 1, 1970

By Edward Wisser

The environment of an ore body is taken to mean not only its physical surroundings but every factor, passive or active, that conditioned the ore shoot, saving only the original composition of the solutions that formed the shoot. Collection of data related to the shape and characteristics of veins should be followed by correlation of the data and the formulation of generalizations regarding ore formation. The nature of the criteria used in arriving at these generalizations is discussed. Certain of the criteria, when used with an understanding of their underlying causes, become "ore-guides." In the course of his study the geologist must not confine himself to the immediate surroundings of the veins, but should attempt to work out the geologic history of events culminating in the crucial epoch for any mining district, the period of mineralization. The work may involve study of features far removed from the veins and related to them only indirectly. It commonly means thorough study of the geology of the entire region surrounding the ore deposits. THE following question has been suggested for discussion: ? "Are there any criteria by which one can determine when mining operations have reached the roots of an ore deposit?" The question deals less with the roots of a particular ore body than with the lower limit of the vertical range within which ore bodies may be expected. It concerns a critical line upon the longitudinal vertical projection of a vein. ? Below this line it is useless to look for ore shoots; above the line exploration below the bottoms of individual ore shoots may be justified. Can we learn to determine the position of such a line?

Jan 1, 1939

By D. T. Jones

In view of the importance of the application of scientific principles to the production of oil from the reservoir, the Production Staff of the Anglo-Iranian Oil Co. (late Anglo-Persian Oil Co.) has been engaged for some years on an intensive program of research on the physical properties of crude oil. Problems involving the retention of crude oil in capillaries and fine fissures demanded for their solution a knowledge of the surface tension and specific gravity of the crude under reservoir conditions, and it is the purpose of this paper to describe briefly the methods adopted for the determination of these properties, and to present the more important results. A detailed article was published in volume 1 of the World Congress Proceedings (1933). Surface-tension observations on crude oil regassed at high pressures with natural gases have been made in the past by Beecher and Park-hurstl and Swartz2, but up to the time of the investigations in Iran no one seems to have carried out experiments with gas-saturated crude direct from the reservoir and kept at its original pressure. Results obtained in this manner are obviously of greater practical value for solving problems connected with the reservoir. Method of Measurement No apparatus for the measurements, under the pressure conditions involved, was available, and a suitable instrument had to be designed and constructed in the Fields workshops. Careful consideration of the matter led to the adoption of a method for measuring the surface tension which did not involve a knowledge of the specific gravity of the oils under the working conditions: the main reason for this being that up to that time no accurate determination of the specific gravity had been made under these conditions. The method adopted involves the measurement of the actual tension in an oil film, and is effected by means of

Jan 1, 1936