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By Harry H. Angst

The history and efficiency of 40-ton capacity dump trucks for surface waste removal at the New Cornelia opencut copper mine, at Ajo, Ariz., are summed up in this paper. Tabulations of truck performance, together with detailed cost figures, prove the value of truck transportation for certain special operations at a large mine. Emphasis is given to the fact that truck transportation not only reduces the haulage costs but also reduces the breaking ground and shovel-loading costs per ton. The New Cornelia opencut copper mine is in the desert. The climate is ideal for seven months of the year, but the five summer months are uncomfortably hot. 'She elevation is 1820 ft. above sea level and the annual rainfall is approximately 6 inches. The ore body is a monzonite-porphyry deposit. The waste-rock capping consists of hard rhyolite, conglomerate and porphyry. All the material is hard and cannot be excavated without blasting. The rhyolite and conglomerate waste is very blocky. The weight of the rock in place is 2.16 tons per cubic yard. The average mine production per day is 22,090 tons of 012 and 18,000 tons Of waste rock, the latter consisting of surface rock and material within the ore body too low in grade to send to the concentrator. The rock is loaded by electric shovels with 4½-cu. yd. dippers. The primary transportation of ore to the concentrator and waste to the dumps is by 30-yd. dump cars and oil-burning steam locomotives; therefore truck haulage of waste is a minor factor of the New Cornelia operation. However, as New Cornelia was one of the first mines to use large-capacity dump trucks for haulage, the results obtained are of interest. Equipment On the south side of the New Cornelia is a hill rising about 500 ft. above the normal surface elevation, roughly 1000 ft. in diameter at its base, called locally Arkansas Mountain peak. Exploratory drilling in this area developed additional ore that could be made accessible for open pit operation only by moving the mountain face a maximum distance of 400 ft. to the south. The slope of the mountain adjacent to the pit averaged 35°, and the small area involved precluded the use of train haulage for the removal of the 4,000,000 tons of waste estimated above the normal pit elevation. A study of dump-truck haulage at Boulder Dam and San Gabriel Dam led to the decision to use large-capacity end-diii~lp trucks rather than smaller trucks, for the following reasons: I. The truck would have to withstand the impact of hard, heavy chunks, some of them weighing as much as 10 tons, which would be dumped from the 4½-cu. yd. dipper. 2. The coarse, rocky, abrasive material would soon damage a light truck body. 3. The body of a small truck could not be efficiently loaded with coarse rock.

Jan 1, 1943

By F. Rosenblum, P. Spira, F. Kitzinger

The possibility of increasing the efficiency of mineral processing plants by means of computer control has prompted metallurgists to examine their flowsheets more critically in order to develop practical control strategies. Control schemes in use to date generally rely on the automation of traditional and previously manually regulated control loops, e.g., the addition of reagents to maintain a constant assay or a constant pH. This approach is predicated on the availability of well established primary sensors such as pH electrodes or on-stream analyzers. Noranda Research Center, in cooperation with Noranda Group concentrators, has developed a froth level monitor and a pulp density meter adaptable to this type of control. Although some of the basic principles on which they are based have been known for some time, their incorporation into the design of reliable, direct-reading instruments which can be interfaced with a computer is believed to be novel.

Jan 1, 1980

By J. L. Gillson

Historically, rock deposits and sand deposits of titanium minerals came into production about the same time, although there may be some argument as to what is meant by production. Beach deposits of heavy minerals in India (Figs. 1-4) and Brazil (Figs. 5) were worked for monazite about the turn of century, but as there was then no market for titanium minerals, these were thrown away. The rock rutile deposits at Roseland, Va., Fig. 6, were worked to supply rutile for titanium chemicals and for coloring ceramics long before there was a titanium pigment business. The pigment industry started about the middle twenties, both in Europe and the U. S., and almost simultaneously the rock deposits at Ponte Vedra Beach near Jacksonville, Fla., were worked for titanium content. Since those days, production from both types of deposits has continued to grow at a rapid rate; many deposits of both types have been found, and reserves have grown to very large figures. In total tonnage of reserves, there is no doubt that the rock deposits are far ahead of the sand deposits; nevertheless there is a very large tonnage of commercial sands available. It is the quality of titanium mineral in the sand and the relatively lower costs of operating sand deposits that have kept them abreast, at least in annual tonnage produced, with the rock deposits. The principal titanium mineral used is ilmenite, but as soon as that mineral began to be sought as a titanium ore, it was obvious that there are ilmenites and ilmenites. Textbook ilmenite should have the composition FeOTiO2 and should analyze 52.6 pct TiO2 and 36.8 pct iron as Fe. The Indian ilmenite, for almost a generation the standard ore for manufacturing pigment in the U. S., was found to analyze about 60 pct TiO, and only 24 pct. Fe, and most of the iron is in the ferric condition. The whole process of pigment manufacture in the U. S. was built up on the use of a raw material of that grade, and the American chemical engineers who operate the pigment plants shuddered at the thought of using a rock ilmenite with 45 pct or so of TiO, and nearly 40 pct Fe. Intensive search was made around the world to find other deposits of rich black sand, like the Indian beaches, but although a few were found, there was some objectionable feature about each. A deposit in Senegal, south of Dakar (Fig. 7), was worked for a while, but an organic coating on the grains made attack by acid difficult. Modern practice would have included a scrubbing operation, in a caustic soda bath, to eliminate the organic coating. Brazilian deposits were numerous, but individually small, and shipping from them difficult. Deposits on the east coast of Ceylon had many attractive features, but the ilmenite analyzed only 54 pct TiO2 and could have been used only with a penalty. Sand deposits with 2 pct ilmenite, like those now worked in Florida, would not have been considered commercial ore, even if they had been known at that time. Most rock ilmenites are associated or mixed with hematite or magnetite, which accounts for the lower titanium and higher iron values than in the sand ilmenites. The Norwegians, English, and Germans, with cheap Norwegian rock ore at hand, learned to install in their pigment plants adequate capacity on the black side, as it is calltd, and counterbalanced the extra cost of plant, and larger amount of acid used, by the lower cost of ore. When World War II arrived, two of the largest pigment manufacturers in the U. S. had to learn how to use the Adirondack ilmenite, but one of them very gladly went back to sand ores when the Florida deposits came into large-scale production after the war. The other continues to use Adirondack ilmenite and finds it commercially attractive to do so. Rutile is not a raw material for titanium pigment manufacture by the sulfate process, since it is insoluble in sulfuric acid. In addition to its small consumption in chemicals and ceramics it began to be used in quantity in welding rod coatings. With the outbreak of World War 11, and the tremendous need for welding rods in shipbuilding and other structural steel construction, rutile suddenly became in heavy demand. The sand deposits on the eastern shore of Australia (Fig. 8A) which had been worked in a small way since 1934 were brought into production, and some stream placers in Brazil were worked and rutile concentrates shipped to American

Jan 1, 1960

By F. Rosenblum, P. Spira, F. Kitzinger

The possibility of increasing the efficiency of mineral processing plants by means of computer control has prompted metallurgists to examine their flowsheets more critically in order to develop practical control strategies. Control schemes in use to date generally rely on the automation of traditional and previously manually regulated control loops, e.g., the addition of reagents to maintain a constant assay or a constant pH. This approach is predicated on the availability of well established primary sensors such as pH electrodes or on-stream analyzers. Noranda Research Center, in cooperation with Noranda Group concentrators, has developed a froth level monitor and a pulp density meter adaptable to this type of control. Although some of the basic principles on which they are based have been known for some time, their incorporation into the design of reliable, direct-reading instruments which can be interfaced with a computer is believed to be novel.

Jan 4, 1979

The opening session* was held in the hall of the Franklin Institute, on Tuesday evening, June 20th, President Holley in the chair. The President introduced Mr. Franklin B. Gowen, who addressed the Institute as follows: Mr. President and Gentlemen : It has been made my pleasant duty to welcome you to the city of Philadelphia, but in so doing I shrink, with some natural reluctance, from appearing before an audience so much better fitted than I am to cope with the subjects which are usually presented to your association, and I can assure you that no trembling neophyte, first venturing within the groves of the Academy, or walking, with sacred reverence, in the gardens of Plato, felt more natural dread at the consequence of his own temerity than I do in appearing before an audience composed of geutlenlen belonging to a scientific society of which I am but too sensible that until now I have been a member only in name. In olden times, upon entering a temple sacred to the worship of any deity, it was customary to lay some offering upon the altar, and, in following this custom, it will be my duty, before entering upon the more pleasant part of the task which is assigned me, to call your attention to a subject with which I have been somewhat familiar, and which is entirely within the scope of your investigations, in the belief that I may throw out some hints or some suggestions of a process that may be fully developed by some of you, and eventually lead to the introduction of that which may be of service to the human race. The satirist who described the philosopher whom he met, as engaged in the process of extracting sunbeams from cucumbers,

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) The position of converter blower at a side-blow Bessemer steel casting plant is vacant. The State Legislature of Utah has provided for the establishment of a metallurgical research department at the State School of Mines, Salt Lake City. Applications will be received for, the position of head of this laboratory, and further details may be obtained by applying to Prof. Joseph F. Merrill, Director, University of Utah, Salt Lake City. An engineering company owning patents for improvements in steel manufacture which have been adopted at many works in America, desires. to secure the services of a technical iron and steel metallurgist as assistant to its chief metallurgical engineer.

Jan 6, 1913

By AIME AIME

The following financial report of the Treasurer of the United Engineering Society is published for the information of members NEW YORK, February 15, 190S. To the Board of' Trustees, United Engineering Society I beg to submit herewith the report of the Treasurer as of December 31, 1907. Your attention is called to the fact that the resources and liabilities, receipts and disbursements statements cover all the financial transactions of the United Engineering Society from its organization up to December 31, 1907. The income and expenses of operating the building during the whole operating period from December 1 to December 31, 1907, somewhat in excess of twelve months, are given. Included in the expenses, amounting in all to $52,647.11, will be found an item entitled "Building Equipment (construction account)." The expenditures under this item were not made for the operating expenses of the building, they represent a construction account, properly speaking, covering expenditures for furnishings and equipment of the building. The Founders' Agreement specifically provides for this class of expenditure under the provision that the Founder Societies shall each be liable for a charge not to exceed $200,000 of principal, which shall include the land and building completed and ready for occupancy, together with the " furnishings, equipment and personal property therein." Certain details of equipment are yet to be supplied, and it. is proposed in the near future to call upon the Founder Societies for an assessment on their respective land and building funds to cover this item of building equipment. Such action would enable the item of $10,039.85 to be transferred to the income account and reduce correspondingly the assessment

Mar 1, 1908

By S. Katz, M. E. Nicholson, J. J. Kelly, D. R. Curran

A series of wedges of 1020 steel (2 1/2 by 6 by 8 in.) were explosively loaded, as shown in Fig. 1. A slab of explosive on the surface of the steel wedge was initiated simultaneously along one edge, producing an essentially two-dimensional oblique shock in the metal. Pressure and density in the metal were measured as a function of distance from the explosive-metal interface by a method described elsewhere.' While for pressures below 130 .kbars the technique produces accurate results, for greater pressures the presence of two shock waves in the metalzy3 makes interpretation of the data uncertain. However, the location of the transition in pressure at 130 kbars can be readily identified from the data. The assumption of a single shock in the region above 130 kbars overestimates the pressure computed on a multiple-shock model. After firing, the wedges were sectioned, lapped, and etched with 2 pct Nital. A photograph of an etched specimen is shown in Fig. 2. The specimens were examined metallographically. The dark region, at the top of the specimen, was heavily banded, Fig. 3, while the lighter area was comparatively free from banding, Fig. 4, the boundary between the two regions being quite abrupt. The very light regions at an angle of about 45 deg to the explosive-metal interface show virtually no banding. The origin of these light regions, which are not Luder's bands, is not yet explained. The thickness of the heavily banded area was measured and compared with the pressure at the boundary between the heavily and lightly banded regions. The results of these measurements and calculations are given in Table I. For all shots, the pressure at the boundary is approximately the same

Jan 1, 1960

By Robert B. McCormick

WORLD WAR II has developed a use for the nonmetal mineral quartz crystal that was unknown in World War I. During the interim period of peace, experimental work in the radio field with the piezoelectric properties of quartz crystal resulted in the almost universal adoption of quartz-crystal radio oscillator plates to control frequency in radio broadcasting, police, commercial and amateur communications equipment. Telephone resonators and filters made from quartz crystal also were developed, which vastly improved the frequency control of long distance telephone circuits. EXPANSION OF THE INDUSTRY The sudden war demands of the armed services for radio equipment using quartz crystal for frequency control led to an unprecedented expansion of the manufacturing industry. It is estimated that the 1940 peacetime volume amounted to approximately $1,500,000, while today a vast new quartz-crystal industry supplies more than $150,000,000 worth of quartz oscillator plates to the Army and Navy each year. This demand has caused an enormous expansion not only of American manufacturing facilities but also of Brazilian mining output, virtually our only source of raw quartz crystal. Actual figures of imports and consumption cannot be cited, for security reasons, but certain comparisons have been made, which indicate the transformation of quartz crystal from a minor to a major nonmetal. Lends has shown that the value of quartz-crystal exports from Brazil is now about equal to that of phosphate rock produced domestically in 1941 and actually exceeds the combined value of crude feldspar, gypsum and fluorspar production in the United States in the same year. This great expansion under wartime pressure was not accomplished without some anxious moments, but all the demands of industry have been met and the Government has been able also to accumulate a substantial stock pile of material against future contingencies. INSPECTION AND GRADING OF QUARTZ CRYSTAL The swift growth of the quartz-oscillator industry necessitated the simultaneous evolution of methods and criteria for inspecting and grading quartz crystal. It has been found that, generally speaking, it is economically feasible to cut only crystals that are at least 30 per cent by volume free from major defects such as optical and electrical twinning, cracks and fractures. Blue needles, bubbles, "chuva" and other minor imperfections can be tolerated in the usable portion unless present in great excess. The present marketing system in use in both Brazil and the United States, as far as quality is concerned, depends solely on the "usability" of a crystal, which is defined in the Brazilian-American agreement2

Jan 1, 1945

By AIME AIME

THE accompanying photograph: submitted by C. L. Bransford, assistant district manager of the Republic Steel Corp., in Birmingham. Ala., shows the remains of the old Tannehill blast furnaces, one of the first furnace plants in the South. They were built by Moses Stroup and operated during the Civil War period, when cannon balls were cast there. The record day's run of this furnace plant was said to be 30 tons of iron. The furnaces were fed by a water-wheel-operated bellows and used charcoal, a product of the neighboring forest. They were first owned and operated by the Pioneer Mining & Manufacturing Co., that later became the Republic Iron & Steel Cu., and subsequently the Republic Steel Corp. in that district.

Jan 1, 1936

By J. H. Schulman, M. H. Buckenham

Although much interest has been taken in the use of mixed collectors in flotation, this investigation is probably the first in which oppositely charged collectors have been considered. The results obtained and the techniques used could well be applied in the behavior of other mixe the behavior of other mixed collector systems and could possibly explain the effective flotation results which have been reported when various collector combinations have been used. Collectors conventionally employed in flotation systems are soluble in water, but many of their homologs of longer hydrocarbon chain length are insoluble. The properties and behavior of these insoluble compounds may be conveniently studied when they are spread as monolayers at the air/water interface on the Langmuir-Adam trough. Although some extrapolation is involved in applying effects observed at this interface to the solid/liquid interface where the action of collectors is most important in flotation, the technique nevertheless is most useful for the study and interpretation of flotation phenomena. Of particular interest in this field are investigations on the insoluble monolayers of the fatty acids, alkyl sulfates and alkyl amines; the penetration of these insoluble monolayers by soluble surface active components and their interaction with metal ions from the underlying solution.'-' Unfortunately, the insoluble xanthates and related compounds do not exhibit stable monolayer properties due to rapid oxidation at the air/water interface and, therefore, cannot be studied directly in this way. These approaches have enabled Leja and Schulman8 to suggest mechanisms explaining dynamic attachment of mineral particles to air bubbles involving collector-frother interaction and the adsorption of collectors onto mineral surfaces. In this and other papers 9-12 considerable evidence is presented to support the concept of collector-frother and metal ion-monolayer interaction and to emphasize the value of monolayer techniques in elucidating the flotation system. Molecular interactions resulting from monolayer penetration are determined by the nature of and the association between both the polar and nonpolar groups of the two molecules concerned. Stable complexes are formed on penetration when interaction takes place between both the polar and nonpolar groups, and although the resultant complexes are not necessarily true chemical compounds, the properties of the molecularly associated complexes are very different from those of the individual components. Shortening of, or changes from, a straight hydrocarbon chain in one of the reacting molecules reduces considerably the stability of the associated complex as do changes in temperature, pH and substrate composition. The effect of hydrocarbon chain length becomes most important when observed effects are to be applied in flotation studies where soluble homo-logs and, therefore, much shorter hydrocarbon chain lengths are used. The present investigation is based on Langmuir trough work carried out by Bowcott,l3 who studied the penetration of insoluble amine monolayers by potassium lauryl xanthate. Bowcott observed that cetyl amine monolayers were readily penetrated by xanthate, but found that with time the high film pressures resulting from penetration and association fell off, indicating decomposition and ejection of xanthate from the film. This decomposition was pH dependent. Of particular interest in this work were studies on an equimolecular mixed monolayer of the fully N-substituted ammonium compound, for example, cetyl trimethyl ammonium iodide (CTAI) and potassium cetyl xanthate. Despite the fact that the CTAI is water soluble and the xanthate on its own is incapable of forming a monolayer, the mixed film was stable up to a surface pressure of 67 dynes per cm. In this condensed state the xanthate was stabilized against atmospheric oxidation, although iodine injected beneath the film caused an immediate collapse. The stabilizing of xanthate against oxidation by association with an alkyl trimethyl ammonium bromide (TAB) could be important in flotation, and a study of the performance and behavior of mixed collectors therefore was undertaken. A modified Hallimond tube operated under controlled conditions was used to evaluate flotation. Surface tension measurements were made to investigate the properties of the soluble

Jan 1, 1963

By M. Van Siclen

THE outstanding fact in connection with dust disease in. the United States at present is the growing recognition of its seriousness by state officials and by the more progressive operators of mining, metallurgical and allied industrial plants. The same may perhaps be said of labor in some. of its better organized centers, but the average independent non-. union workman continues, as of yore, to suffer the toll of disability and. even of death from dust inhalation without realization of the source of his ill-being. Progress in the betterment of the handling of sufferers from dust disease and of the conditions creating dust hazards in mining and allied industries is pursuing a course similar to that of the now widespread campaign against accidents, in which the risk is more obvious, more severe, and was naturally recognized sooner. The coming on of dust disease is generally relatively slow and its immediate effects not infre-quently masked by or attributed to other diseases. Marked exceptions to this general rule have occurred in districts where the dust is particularly pernicious, such as the Rand and Joplin; yet such exceptions, unhappy in themselves, opened the eyes of medical men, and of those in other localities charged with the responsibility for the welfare of industry, to the much more widespread if less spectacular hazard existing from the inhalation of. dust in all rock-excavating operations and all industrial operations creating inorganic dust, whether it be crushing and grinding, sand-blast-ing, granite-cutting, or what not. Advancement to date in the United States in prevention and treat-ment has been slow, yet the record shows that quantitative methods for determining the degree of hazard and means for decreasing it were being developed as far back as 25 years ago; and that more rapid progress may be looked for from now on. In 1908, in this country; F. L Hoffman?(1) discussed the mortality from consumption in dusty trades, especially brass foundries; and in 1913.E. R. Hayhurst(2) described the effects of inhalation

Jan 1, 1933

By Robert S. Archer, Zay Jeffries

It is about fifteen years since the development in Germany, largely by Alfred Wilm, of the aluminum alloy called duralumin. In this alloy, combining as it does the tensile strength of mild steel with the lightness and corrosion resistance of aluminum, a distinctly new material was presented to the engineering world. Despite the evident usefulness of this material, however, its commercial development has been slow, due in part to the difficulties involved in its fabrication. In view of the potentially great utility of strong aluminum alloys, it seemed desirable to find means of producing such alloys with better fabricating properties, and work was undertaken with this object in the laboratories of the Aluminum Company of America several years ago. This work has resulted in the production of two new types of aluminum alloy of the "strong alloy" class, having distinctly improved fabricating qualities. The knowledge gained has also made it possible to produce alloys of the duralumin type with greater strength and hardness than previously obtained. There have thus been made available some new engineering materials which it is the object of this paper to describe. These alloys, induding duralumin, are fundamentally wrought alloys. Castings of the same compositions heat treated in the same manner give inferior physical properties, particularly as to ductility. The statements made subsequently concerning properties and heat treatment apply to material that has received sufficient working to thoroughly break down the cast structure. The material referred to has, in general, undergone a reduction in section of at least 80 per cent, by mechanical working. It may be mentioned in passing that other compositions have been found that are suitable for the production of the maximum physical properties in heat-treated castings.

Jan 1, 1925

By C. F. Smart

SINCE their comparatively recent development, the alloys of cadmium with silver and copper or nickel, and of cadmium with nickel alone, have been used somewhat extensively as liners for connecting rod bearings and main bearings of internal-combustion engines. In applications where, owing to high hearing loads and elevated operating temperatures, the life of hearings made from tin-hale or lead-base alloys has been undesirably short, cadmium alloys have demonstrated considerable advantage. In applications where, because of deflection of the crankshaft or bearing supports, copper-lead bearing metals have resulted in scored shafts, cadmium alloys have been operated successfully. The somewhat serious drawback to these alloys in hearing service has been that they, in common with copper-lead and certain lead alloys, are susceptible to corrosion in the presence of lubricants containing organic acids. These acids may be fatty acids (such as oleic acid) derived from animal or vegetable oils that sometimes have been compounded with engine lubricants, or they may be compounds of an acid nature developed by the oxidation of some petroleum oils under operating conditions. The result of such acid attack on hearings is illustrated by the photograph, Fig. 1. The petroleum oils that are most readily oxidized to a corrosive condition, and the operating conditions under which such oxidation most readily occurs, are now rather well known among the technical organizations of both the petroleum and automotive industries. While means have been developed for inhibiting petroleum oils against such acid formation, the knowledge that this condition may be encountered has been a factor in restricting the wider use of cadmium alloys as engine bearings. It has appeared, therefore, that their value and use would be enhanced if they could be made corrosion-resistant to a degree compatible with the most severe operating requirements. Investigation, undertaken with this in view, indicated that the addition of fractional percentages of the metal indium to the cadmium bearing

Jan 1, 1938

By Robert B. McCormick

World War II has developed a use for the nonmetal mineral quartz crystal that was unknown in World War I. During the interim period of peace, experimental work in the radio field with the piezoelectric properties of quartz crystal resulted in the almost universal adoption of quartz-crystal radio oscillator plates to control frequency in radio broadcasting, police, commercial and amateur communications equipment. Telephone resonators and filters made from quartz crystal also were developed, which vastly improved the frequency control of long distance telephone circuits. Expansion of the Industry The sudden war demands of the armed services for radio equipment using quartz crystal for frequency control led to an unprecedented expansion of the manufacturing industry. It is estimated that the 1940 peacetime volume amounted to approximately $1,500,000, while today a vast new quartz-crystal industry supplies more than $150,000,000 worth of quartz oscillator plates to the Army and Navy each year. This demand has caused an enormous expansion not only of American manufacturing facilities but also of Brazilian mining output, virtually our only source of raw quartz crystal. Actual figures of imports and consumption cannot be cited, for security reasons, but certain comparisons have been made, which indicate the transformation of quartz crystal from a minor to a major nonmetal. Lundl has shown that the value of quartz-crystal exports from Brazil is now about equal to that of phosphate rock produced domestically in 1941 and actually exceeds the combined value of crude feldspar, gypsum and fluorspar production in the United States in the same year. This great expansion under wartime pressure was not accomplished without some anxious moments, but all the demands of industry have been met and the Government has been able also to accumulate a substantial stock pile of material against future contingencies. Inspection and Grading of Quartz Crystal The swift growth of the quartz-oscillator industry necessitated the simultaneous evolution of methods and criteria for inspecting and grading quartz crystal. It has been found that, generally speaking, it is economically feasible to cut only crystals that are at least 30 per cent by volume free from major defects such as optical and electrical twinning, cracks and fractures. Blue needles, bubbles, "chuva" and other minor imperfections can be tolerated in the usable portion unless present in great excess. The present marketing system in use in both Brazil and the United States, as far as quality is concerned, depends solely on the "usability" of a crystal, which is defined in the Brazilian-American agreement2

Jan 1, 1948

By Robert B. McCormick

World War II has developed a use for the nonmetal mineral quartz crystal that was unknown in World War I. During the interim period of peace, experimental work in the radio field with the piezoelectric properties of quartz crystal resulted in the almost universal adoption of quartz-crystal radio oscillator plates to control frequency in radio broadcasting, police, commercial and amateur communications equipment. Telephone resonators and filters made from quartz crystal also were developed, which vastly improved the frequency control of long distance telephone circuits. Expansion of the Industry The sudden war demands of the armed services for radio equipment using quartz crystal for frequency control led to an unprecedented expansion of the manufacturing industry. It is estimated that the 1940 peacetime volume amounted to approximately $1,500,000, while today a vast new quartz-crystal industry supplies more than $150,000,000 worth of quartz oscillator plates to the Army and Navy each year. This demand has caused an enormous expansion not only of American manufacturing facilities but also of Brazilian mining output, virtually our only source of raw quartz crystal. Actual figures of imports and consumption cannot be cited, for security reasons, but certain comparisons have been made, which indicate the transformation of quartz crystal from a minor to a major nonmetal. Lundl has shown that the value of quartz-crystal exports from Brazil is now about equal to that of phosphate rock produced domestically in 1941 and actually exceeds the combined value of crude feldspar, gypsum and fluorspar production in the United States in the same year. This great expansion under wartime pressure was not accomplished without some anxious moments, but all the demands of industry have been met and the Government has been able also to accumulate a substantial stock pile of material against future contingencies. Inspection and Grading of Quartz Crystal The swift growth of the quartz-oscillator industry necessitated the simultaneous evolution of methods and criteria for inspecting and grading quartz crystal. It has been found that, generally speaking, it is economically feasible to cut only crystals that are at least 30 per cent by volume free from major defects such as optical and electrical twinning, cracks and fractures. Blue needles, bubbles, "chuva" and other minor imperfections can be tolerated in the usable portion unless present in great excess. The present marketing system in use in both Brazil and the United States, as far as quality is concerned, depends solely on the "usability" of a crystal, which is defined in the Brazilian-American agreement2

Jan 1, 1948

By T. A. Read, M. W. Burkart

The crystal geometry of the cubic-tetragonal interface after partial transformation of an indium-thallium alloy single crystal is described and a general theory is presented. The effects of applied stresses on this transformation are interpreted and the latent heat of transformation is obtained from observations of transformation under stress. A DIFFUSIONLESS phase transformation between face-centered cubic and face-centered tetragonal structures has been reported for the indium-thallium system by Bowles, Barrett, and Guttman1, 2 The transformation takes place at approximately 105 "C at 18 atomic pct Tl and 25°C at 23 pct Tl. In their study, Bowles, Barrett, and Guttman used poly-crystalline samples whereas in the present study single crystals were used to eliminate the transformation constraints imposed by adjoining grains. The use of single crystals made possible a comprehensive study of the effect of stress on the transformation. In the course of the work, it was possible to formulate a new method of analyzing dif-fusionless transformations (presented in this paper) which permits calculation of the geometry of the interphase interface from a knowledge of the crystal structures of the initial and final phases. The specimens were prepared from chemically pure thallium and 99.97 pct In which were weighed out to produce 3 to 4 grams of alloy of the desired concentration. The metal was placed in clean fused silica tubing, then melted, degassed and sealed under vacuum. (To obtain single crystals, it was found that both degassing and extreme cleanliness were essential.) Single-crystal specimens were grown by a modified Bridgman technique.8 pecimens were removed from the tube by dissolving the quartz in concentrated hydrofluoric acid which attacks the specimen very slowly. The specimen then was polished mechanically to produce four flat surfaces, electropolished, and annealed at 140°C for 48 hr. The electropolishing solution used was that described by Bowles, Barrett, and Guttman and the polishing was carried out on both the high and low temperature phases of the alloy. The high temperature polishing was done at 110°C with a stainless steel cathode. Visual Observation of the Transformation in Single Crystals A visual study of the transformation was made on specimens which had been electropolished in the high temperature phase. The specimens were supported on the stage of a metallograph by an electrically heated holder which contained an opening for observing the specimen. Visual evidence of transformation was found in the presence of an interface which separated the two phases. The interface plane defines the boundary of the phase undergoing transformation and manifests itself by the sharp change in angle between the surface of the specimen and the incident light at the juncture of the two phases. On slow cooling, well-annealed specimens transformed from the face-centered cubic structure to the face-centered tetragonal structure by the motion of a single plane interface which traversed the specimen from one end to the other. Upon heating, the interface moved back in the reverse direction. The interface could be started, stopped, or reversed at will. A temperature hysteresis of about 31/2oC was observed in the reversal of the interface. Holding an interface stationary caused it to disappear completely in most cases, whereas in other instances the interface became less distinct depending upon its orientation. The interface could be made to reappear by changing the temperature of the specimen. The low temperature tetragonal structure exhibits only the fine markings or subbands reported by Bowles, Barrett, and Guttman and is illustrated in Fig. 1. These subbands are twin-related. Back-reflection Laue patterns show the breakup of the cubic spots into pairs of spots corresponding to the twin orientations of the tetragonal phase.

Jan 1, 1954

By R. Schuhmann, E. J. Michal

Experimental measurements are reported for the oxygen pressures of iron-silicate slags in equilibrium with solid silica. CO2-CO mixtures were bubbled through the slags in silica crucibles to find equilibrium values of p co2/p co over the entire composition range of silica-saturated slags at 1250°, 1300°, and 1350°C. From the data, the activity vs. composition relationships were calculated for O, FeO, and Fe. SLAGS composed primarily of silica and iron oxides have particular practical importance in copper smelting,' in acid steelmaking, and in accounting for the service behavior of silica refractories. These slags all contain both ferrous and ferric iron, so that, strictly speaking, they are ternary or three-component liquid solutions. For convenience, the components may be taken as the three oxides, FeO, Fe2O3, and SiO2. The constitution of the FeO-Fe,O,-SiO, system at slagmaking temperatures has been studied in a recent investigation described in a separate paper.' This work showed the compositional ranges of iron-silicate melts at temperatures up to 1450°C and also the temperature-composition relationships for melts in equilibrium with various solid phases, including iron, wüstite, magnetite, and silica. Broadly speaking, the compositions of iron-silicate melts at a given temperature should be thought of as varying over a two-dimensional field. In the first place, the silica/total iron oxide relationship varies from maximum silica for silica-saturated melts to minimum silica for wüstite-saturated melts or, at higher temperatures, to zero silica for straight iron oxide melts. In copper smelting, for example, the converter slags approach the low silica limits while the reverberatory-furnace slags have intermediate silica contents, perhaps approaching silica saturation in some circumstances. Liquids formed in the pores of silica refractories presumably are close to silica saturation. The second type of composition variation is in the ferric/ferrous relationship, which depends on how oxidizing or how reducing the process conditions are. Relatively reducing slags, such as acid-steelmaking slags, are lower in ferric oxide and ap- proach saturation with metallic iron. Oxidized slags, such as copper-smelting slags, contain larger percentages of ferric oxides and approach or reach saturation with magnetite. Since these two kinds of compositional variations are closely related to two general properties of interest for all metallurgical slags, basicity, and oxidizing power, it is hoped that the thermodynamic study of iron-silicate slags eventually will throw further light on the significance and nature of these long-recognized but as yet poorly understood slag properties. Measurements of oxygen activity as a function of slag composition, using CO-CO2 gas mixture to fix oxygen activities, afford an experimentally convenient approach to the study of the thermodynamic properties of iron-silicate slags. In a preceding investigation,³ his approach was used in a systematic study of iron-silicate slags in equilibrium with solid iron. The present paper gives the results of a similar study of the iron-silicate slags in equilibrium with solid silica. The experimental work consisted in the determination of CO2: CO ratios in gas mixtures at equilibrium in the system: gas: liquid slag: silica Determinations were made at temperatures from 1250° to 1350°C for slags ranging in composition from iron saturation to magnetite saturation. Also, equilibrium CO,: CO ratios and slag compositions were determined for the univariant systems: gas: liquid slag: silica: iron gas: liquid slag: silica: magnetite Experimental Methods The experimental procedure was essentially the same as that used in the previous study of iron-silicate slags saturated with solid iron," but in order to work with the silica-saturated slags an all-silica crucible assembly was used. A liquid slag was prepared from pure prefused stock materials and brought to equilibrium with the silica crucible at the desired temperature. Then a mixture of CO2 and CO was continuously bubbled through the melt

Jan 1, 1953

By J. D. Rice, P. L. Wearden, W. L. Hensou

Solutions to the unsteady-state partial water-drive reservoir performance problem can be obtained through the use of analogue computers or high-speed electronic digital computers. The solutions that have previously been resolved for use on digital computers, however, demand a knowledge of the aquifer parameters. Generally, the analogue computers now in use do not require this knowledge. A solution is presented herein where the aquifer performance, expressed in terms of difference equations, is related to the reservoir performance as expressed by the modified Scbiltbuis material-balance equation. A numerical procedure for a medium-sized digital computer also is presented in which a solution to the set of equations defining the aquifer and reservoir performance is obtained and the aquifer parameters (permeability and sand thickness) are automatically optimized while simultaneously matching the known pressure behavior. Predicted pressure behavior can be calculated using rates from any assumed future production practice. The procedure provides an output format which presents the cumulative, incremental and average rate of natural water influx, the per cent gas-cap expansion, the calculated reservoir pressure, the measured reservoir pressure, and the difference between the measured and calculated pressures. Results of a test problem are presented in comparison with results obtained by the Bruce Analyzer, Ohio Oil Co. 's Pace General Purpose Analogue Computer, and Sun Oil Co.'s Single-Pool Electronic Reservoir Analyzer. These results indicate that unsteady-state reservoir perlormance for a single-pool system can be adequately simulated by a numerical method employing a digital computer and that the special-purpose analogue computer can be supplanted by this method. INTRODUCTION The numerical approach to the unsteady-state partial water-drive reservoir performance problem heretofore has been limited in that solutions have been resolved only for certain fixed parameters. Also, prior to the advent of high-speed electronic digital computers in the last few years, calculations were so tedious and time-consuming that they ordinarily were neglected, or some other means of obtaining the solutions were used. The analogue approach had been used for obtaining solutions to the transmission-of-heat problem and, consequently, means were developed for applying the electrical analogue to the unsteady-state reservoir performance problem. Bruce submitted a paper for AIME publication in Sept. 1942, in which he described an electronic device (now called the Bruce Analyzer) for analyzing the water-drive performance of any reservoir, based on either steady or unsteady-state flow characteristics. 1 Sun Oil Co. adopted the analogue approach in 1949 and now has two special-purpose high-speed electronic reservoir analyzers in use.2,3 Two main features of Sun's analyzers are (1) the high repetitive rate of reproducing the entire history of reservoir performance cyclically a number of times per second, and (2) the elimination of the necessity of knowing the properties of the associated aquifer. Since the advent of larger and faster digital computers, the possibility of incorporating this second feature into a numerical approach appeared feasible. Previous work has been done and material published covering the application of numerical methods to the behavior of the pressure with respect to time at any point in an associated aquifer? However, the aquifer parameters must be known from some source. The material presented in Ref. 4 has been used to a great degree in developing the numerical method described herein. DIFFERENTIAL EQUATION AND BOUNDARY CONDITIONS The problem of simulating the performance of a reservoir and the associated aquifer is to determine the characteristics of the aquifer such that the

By Beeby Thompson

ALTHOUGH the exclusion of foreigners and private owners from participation in the development of the. Russian oil fields prevents first-hand information being obtained, both official and private news indicate a growing appreciation of the value of the country's oil resources. Notwithstanding the suppression of that initiative and energy which only ambition can adequately stimulate, the industry is progressing and exports of products are assuming an importance that cannot be disregarded as an economic factor in the world's oil business. The following notes and observations must be regarded mainly as the views of one who has closely followed the fortunes of Russian oil, when considering the changes that have taken place in geological knowledge and oil-field technique, which have so profoundly modified oil-fields methods. Russia is fortunate in having retained the services of. a few scientists and technologists whose devotion to science has superseded their personal inclinations, and to these few men must be attributed the slow, but nevertheless striking, progress that has been made. The productive oil fields of Russia are centered around the Caspian Sea which, with its connected river system, constitutes such an ideal means of internal distribution for products. From the group of oilfields of which the. city of Baku forms a center, oil is pumped to Black-town, a suburb of Baku, where all the refineries are situated. The next important group of oil fields is located in the Terek district near Grosny, where refineries are erected and the products are piped or carried by tank cars to Petrovsk for the internal Russian market, or sent to the Black Sea by rail. A third oil field is spread over the province of Uralsk, north of the Caspian, Sea, the main port of outlet being Gourief, at the mouth of the River Ural. In Trans-Caspia there are two oil-field centers, one near Krasnovodsk on Chelekan Island, and one in Central Asia at Ferghana. The product of the former fields is transported to Baku for treatment, while the output of the Turkestan field is refined and consumed locally, mainly by the railway.

Jan 3, 1925