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By Haim Chiswik

IN recent years considerable attention has been devoted to the devel-opment of new commercial uses for silver, chiefly because of lowered prices and large stocks of the metal. This has led to increased interest in the phase diagrams of silver alloys. The silver-lead diagram is reported' to be of the simple eutectic type, but no measurements of the solubility of lead in silver have been made. The solubility of silver in lead has been estimated2 from diffusion experiments and resistance measurements to vary with temperature from 0.09 to 0.18 atomic per cent (0.05 to 0.10 weight per cent). Silver-rich silver-lead alloys have recently been recommended as high-strength bearing metals.3 The silver-bismuth diagram is similar.' The solubility of bismuth in silver has been estimated to be about 5.5 weight per cent on the basis of X-ray work.4 Matthiessen5 found a solubility of silver in bismuth from 0.25 to 0.50 per cent by conductivity measurements. Silver and thallium form the same type of diagram,1 with no data on their mutual miscibilities. We have studied the first two of these diagrams by X-ray methods, verifying their main features and determining the solubilities of lead and bismuth in silver at several temperatures. We also determined the solubility of thallium in silver at one temperature. The solubilities of silver in lead and in bismuth were found to be too low to be detectable.

Jan 1, 1940

By F. V. Lenel

R. P. Seelig.*—Dr. Lenel is to be congratulated on his presentation of a particularly interesting paper describing the use of the powder metallurgy process for the production of magnetic pole pieces. The only thing that might be added is that we have been successful in producing pole . pieces with a narrow hysteresis curve by the use of considerably lower sintering temperatures than the ones used by Dr. Lenel. It is quite possible that this use of lowe- temperatures has considerably widened the field of commercial application for pole pieces made from metal powders. Development work is currently being done on an a.c. application of a sintered iron part. However, I am in full agreement with Dr. Lenel that if eddy currents are an important factor in the application, we cannot substitute sintered material for laminated sheet-metal structures. Mr. Peters' remarks concerning the limitations of machine parts were well taken. The emphasis of the limitations makes it easier to define clearly what we can do and-what the advantages are of machine parts made of metal powders. When I mention metal-powder machine parts, I mean those of relatively high density, although complete elimination of porosity is not possible at this time. The limitations of the field for this type of parts are largely economical. I believe that Mr. Langhammer has made that point very clear. The following questions are very often asked: How large a part can you make? How close can you hold the dimensions ? How fast can a part be produced? In a majority of the cases, it depends on the cost at which the part can be produced. A large variety of shapes and sizes of a number of materials can be formed. However, the main requirement in this field of endeavor is whether this can be done more economically by powder metallurgy than by other manufacturing methods. As a general indication, it may be stated that densities up to 95 per cent of that of rolled material can now be produced commercially in simpler parts. Tolerances of plus or minus 0.001 in. are common, but where special conditions justify, closer tolerances can be held; we are producing a part of which one dimension is held to 0.0003 inch. Finally, as far as maximum size is concerned, technically this would depend on the capacity of the press and furnace equipment available. Actually, we find that the economical limit of powder-metallurgy machine parts is approximately one pound. From there on, each individual case must he studied on its own merits.

Jan 1, 1945

By M. B. Standing, D. L. Katz

Equilibrium data are reported on the composition and densities of coexisting vapor and liquid phases as a function of Pressure and temperature for four hydrocarbon systems prepared from crude oil and natural gas. The data were observed over a range of pressures from 1000 to 8220 Ib. per sq. in. and at temperatures ranging from 35' to 250°F. The compositions of the hydrocarbon systems were such that the critical temperatures of the mixtures were lower than the range of the investigation. Under these conditions, it is shown that the composition of the systems has a marked effect upon both the absolute value of the equilibrium constants and the change of the constants with pressure for the several components comprising the system. From weight-balance considerations, it has been possible to construct the partial phase diagram of a mixture of a 49.9" A.P.I. crude oil and natural gas having a gas-oil ratio of 3660 cu. ft. per barrel. Descriptions of the apparatus used, the analytical procedure, the material used, and the equilibrium measurements are included. A knowledge of the physical behavior of naturally occurring hydrocarbon mixtures is fundamental to the treatment of many problems in the production, transportation and rehing of petroleum. The recent discoveries of pools having formation pressures up to 7500 lb. per sq. in. and higher, and the development of full-scale equipment to operate at pressures of 5000 lb. per sq. in. or more have greatly increased the need for knowledge of the composition, temperature, pressure and density relationships of coexisting vapor and liquid hydrocarbon phases. The following paper presents the results of investigations upon 22 mixtures of natural gas and crude oil of known com~o~itio~ that had been brought to equilibrium under controlled conditions of temperature and pressure. Data are presented upon the densities and compositions of the coexisting vapor and liquid phases for four different systems containing hydrocarbon material having boiling points from minus 2 5S°F. to well over I000 F. The data were observed Over a pressure range from Iooo Ib. per Sq. in to 8220 lb. Per sq. in. and a temperature range from 35' to 2 50°F. The accepted method of computing the physical relationship between two coexisting phases of a hydrocarbon mixture is by use of the "equilibrium constant" K as proposed by Souders, Selheimer, and Brown. definition,

Jan 1, 1944

By M. B. Standing, D. L. Katz

Equilibrium data are reported on the composition and densities of coexisting vapor and liquid phases as a function of Pressure and temperature for four hydrocarbon systems prepared from crude oil and natural gas. The data were observed over a range of pressures from 1000 to 8220 Ib. per sq. in. and at temperatures ranging from 35' to 250°F. The compositions of the hydrocarbon systems were such that the critical temperatures of the mixtures were lower than the range of the investigation. Under these conditions, it is shown that the composition of the systems has a marked effect upon both the absolute value of the equilibrium constants and the change of the constants with pressure for the several components comprising the system. From weight-balance considerations, it has been possible to construct the partial phase diagram of a mixture of a 49.9" A.P.I. crude oil and natural gas having a gas-oil ratio of 3660 cu. ft. per barrel. Descriptions of the apparatus used, the analytical procedure, the material used, and the equilibrium measurements are included. A knowledge of the physical behavior of naturally occurring hydrocarbon mixtures is fundamental to the treatment of many problems in the production, transportation and rehing of petroleum. The recent discoveries of pools having formation pressures up to 7500 lb. per sq. in. and higher, and the development of full-scale equipment to operate at pressures of 5000 lb. per sq. in. or more have greatly increased the need for knowledge of the composition, temperature, pressure and density relationships of coexisting vapor and liquid hydrocarbon phases. The following paper presents the results of investigations upon 22 mixtures of natural gas and crude oil of known com~o~itio~ that had been brought to equilibrium under controlled conditions of temperature and pressure. Data are presented upon the densities and compositions of the coexisting vapor and liquid phases for four different systems containing hydrocarbon material having boiling points from minus 2 5S°F. to well over I000 F. The data were observed Over a pressure range from Iooo Ib. per Sq. in to 8220 lb. Per sq. in. and a temperature range from 35' to 2 50°F. The accepted method of computing the physical relationship between two coexisting phases of a hydrocarbon mixture is by use of the "equilibrium constant" K as proposed by Souders, Selheimer, and Brown. definition,

Jan 1, 1944

By R. L. McCarron, G. R. Belton

The diffusivities of oxygen and sulfur in liquid iron have heen determined hy a capillary technique in which the surface concentrations of the solutes were established by means of appropriate H2/H2 and H2S/H, gas mixtures. Total diffusate and concentration profile results are shown to be in good accord, yielding for- 1560 and Supporting results at 1660°C are also presented. The conditions necessary to avoid gas transport control in this type of experiment are discussed. IN spite of their importance in understanding the kinetics and mechanisms of refining reactions, the dif-fusivities of oxygen and sulfur in liquid iron are not well established. Accordingly, as a first step in studies of rates of solute absorption from the gas phase into liquid iron, new measurements of these diffusivities have been made and are presented in this paper. The only published results for the diffusion of sulfur in pure liquid iron are those of Kawai.' He used a diffusion couple technique in which two cylindrical specimens, one containing sulfur and the other with negligible sulfur concentration, were joined together and held in a refractory capillary. After an experiment, the sample was quenched and the concentration distribution of the solute determined. Kawai recognized that significant changes in solute distribution occurred during melting and freezing and he attempted to correct the concentration profiles for these effects to give a sulfur diffusivity of 4.6 x 10-6 sq cm per sec at 1560°C. The method of correction, however, was not rigorous and the uncertainty in this result cannot be easily assessed. Koslov et a1.2 have reported the diffusivity of oxygen in iron as 7.8 x 10"3 sq cm per sec at 1660°C. This value appears to be unreasonably high but, unfortunately, details of their experiments are not available. Shurygin and Kryuk have used the rotating disc method for a study of oxygen diffusion in liquid iron. In their experiments a silica disc was rotated in liquid iron containing oxygen, and the rate of formation of liquid iron silicate was determined by measuring the decrease in weight of the disc. On the assumption that the rate of dissolution was controlled by the diffusion of oxygen in the iron, the diffusion coefficient was computed to be 5.2 x sq cm per sec at 1550°C. However, the Levich equation, which was used to interpret the rate data, was originally de- rived for the case of mass transfer between a solid disc and a single-phase liquid. The hydrodynamic and diffusion boundary layers in the iron stirred by a disc, via coupling of the silicate melt, may be appreciably different from those predicted by Levich's equations. Recently, Novokhatskiy and Ershov, using an identical experimental method to that of Shurygin and Kryuk, obtained a diffusivity for oxygen in liquid iron of 1.22 x 104 sq cm per sec at 1550°C: no reasons were offered for the disagreement. Schwerdtfeger5 has also recently studied the diffusivity of oxygen in liquid iron. He reacted shallow melts of liquid iron, 0.5 to 1.0 cm deep and contained in high-purity alumina crucibles, with appropriate H20-HZ-He mixtures. The total sample was analyzed, without sectioning, to obtain the average concentration of diffusate. A value at 1610°C of D = 12(3) x 10-5 sq cm per sec was obtained from the results of twenty experiments.= Oxygen profile measurements, which were carried out in three additional experiments using long capillaries and the semiinfinite boundary conditions, indicated a diffusivity about half that computed from the shallow bath experiments. Possible sources of error in Schwerdtfeger's study will be discussed later in this paper. EXPERIMENTAL TECHNIQUE The essential arrangement of the diffusion cell is shown in Fig. 1. The liquid iron was contained in an alumina capillary, 3 to 4 mm diam and 3 to 9 cm long, which was supported by a hollow alumina pedestal and this whole assembly was held within a movable alumina reaction tube. This tube, which was about 7 mm in bore

Jan 1, 1970

By J. E. Metcalfe

Proceedings of the Fourth Empire Mining and Metallurgical Congress, Great Britain 1949. Part II published at the Offices of the Congress in London, England, 1139 pp. The price of these proceedings is £ 2. The parts may be purchased separately at a cost of £ 1 each.-Part I of this book covers a report of the organizing committee, the inaugural meeting and presidential address, banquet at Guildhall, welcome by Sir Richard Livingstone at Oxford. and final session. Technical session and papers are also covered in Part I. Part II covers such topics as coal, present-day trends in mineral dressing and metallurgy. Mining Engineer's Survey Manual. By J. E. Metcalfe. Published for "Mine & Quarry Engineering" by Electrical Press, London, 1951. 341 pp., illus., charts, diagrs., tables, 8 ¾ x 5 1/ in., cloth, 30s., available from Percival Marshall & Co., Ltd., London, and British Book Centre, 122 East 55th St., New York 22, N. Y. Beginning with a brief treatment of surveying fundamentals and a discussion of the correlation of surface and underground surveys, this practical manual continues with descriptions of surveying practice both above and below ground including stopes, inclined shafts; etc. Space is devoted to sampling and valuation, geological considerations, and descriptions of modern surveying instruments. The organization of survey operations is covered in the last chapter.

Jan 1, 1952

FIGURES covering appropriations recommended by the Budget Bureau for the Bureau of Mines at Washington for next year are now available and are as quoted below. APPROPRIATION BUDGET APPROPRIATION 1928 1929 General Expenses $ 86,000` $ 86,000 Investigating Mine Accidents 386,470 399,470 Mining Investigations in Alaska.. 10,860 10,860 Operating Mine Rescue Cars and Stations 327,630 342,630 Testing Fuel 154,000 158,500 Mineral Mining Investigations.... 99,570 125,000 Oil, Gas and Oil-Shale Investiga- tions 198,260 198,260 Oil-Shale Investigations 5,000 80,000 Expenses Mining Experiment Sta- tions 173,000 173,000 Care, etc., Buildings and Grounds, Pittsburgh, Pa 71,360 76,360 Maintenance and Operation, Fuel Yards Balance Balance Helium Investigations :.... 75,000 75,000 Helium Production and Conserva- tion 1,063,000 462.000 Potash Investigations 100,000 100,000 Economics of Mineral Industries. . 225,000 275,000 Totals $2,975,150 $2,562,080

Jan 1, 1928

Samuel T. Wellman, Cleveland pioneer steel man, who was often referred to as the "father of the open-hearth process of the United States," died suddenly on July 11, 1919, of heart disease, at Stratton, Me. For more than half a century, he was closely identified with the improvement of equipment used in the making of steel and contributed a number of inventions that virtually revolutionized the industry. Mr. Wellman was born Feb. 5, 1847, at Wareham, Mass., his father at the time being superintendent of the Nashua Iron Co., Nashua, N. H. After attending public school and a year at Norwich University, he served in the Civil War as a corporal of the first New Hampshire Heavy Artillery. He went to Pittsburgh in 1867 and assisted in starting the first crucible steel melting furnace built in America at the works of Anderson, Cook & Co. It melted a ton of steel with an average of 1000 Ib. of nut coal, which cost less than $1, while the melting of a ton of steel in crucibles in the old fashioned coke furnace took three tons of the very best coke, costing from $2 to $3 per ton. This furnace was a great success and in a very few years had driven the coke furnace out of use. From Anderson, Cook & Co., Mr. Wellman went to the Singer, Nimick & Co. works, Pittsburgh, where he built two crucible steel melting furnaces of the same type. After that he spent some time in the office of the Siemens agents in Boston and also at steel works in different parts of the country, starting crucible steel furnaces. He then went to the Bay State Iron Works in South Boston, Mass., where he built the first open-hearth furnace that was a commercial success in the United States. It made steel of a much better quality than had previously been made in this country. The principal use to which it was put in those days was the manufacture of locomotive fire-boxes. From South Boston, he went hack to the old works in New Hampshire where his father was still superintendent, and built for it an open-hearth furnace, a plate mill, and a bar mill. In 1873, Mr. Wellman went to Cleveland to design and build the plant of the Otis Steel Co. He remained with this company for 16 years as engineer and superintendent. During this time he developed the open-hearth charging machine and introduced the electromagnet for handling pig iron and scrap steel. The first charging machine was operated by hydraulic power, and although it was not entirely satisfactory it performed the work fairly well and encouraged its inventor to build another one, which was driven by electric motors. This proved

Jan 1, 1920

By E. B. Branson

Introduction to Geology, by E. B. Branson, W. A. Tarr, and W. D. Keller, revised-by Carl C. Branson. McGraw-Hill, 1952. $5.50.-Dealing with physical and historical geology, the book has been revised from an earlier edition. An attempt has been made to eliminate unnecessary detail in discussing processes and history. Revisions bring technical and statistical data up-to-date, and follow suggestions by teachers who used earlier editions. The book carries an eye witness account of the severe earthquake in Assam, India, in 1950 and the story of Paricutin and other major examples of volcanism. Charts summarize chemical weathering, and the results of metamorphisms. The book also contains many new illustrations, including aerial photographs. A History of Phelps Dodge 1834-1950, by Robert Glass Cleland. Alfred A. Knopf, 1952. $4.00.-The book traces the growth of Phelps Dodge from the day Anson Greene Phelps opened a small saddle shop in Hartford, Conn., to the present day. As the country grew, so did Phelps Dodge. The company took part in large affairs from its very beginning. It bought and sold, exported and imported, built factories and railroads, and widened its scope of operations economically and geographically. Entrance of Phelps Dodge into copper mining and the gradual giving up of other interests in favor of the new venture is traced.

Jan 1, 1952

By Nicholas J. Grant, Hanna Ibach, Bill C. Giessen

The system Ta-Rh was investigated over the entire comnposition range using metallogvaphic and X-ray techniques as well as thermal analysis. Terminal solubility limits, solidus temperatures, and the crystal structures of two new intermediate phases were determined. There are five intermediate phases: o, tetragonal, isostructural with o(Fe-Cr); a1, orthorhomnbic : a2, orthorhombic, isostructural with CozSi; 0 3, a high -temperature phase of unknozun structure; and a TaRh3, cubic, AuCu3 structure. a, aL, a,, and a melt peritectically; and a TaRh, has a maximum melting point. Five peritectic and one eutectic reactions occur. THE Ta-Rh phase diagram has not been fully treated in the literature; however, two inter metallic phases have been described.&apos;-&apos; This study attempts to work out the diagram covering the details of phase boundaries as well as the crystallography of the intermediate phases. EXPERIMENTAL METHODS Starting materials were tantalum powder of 99.8 pct purity, supplied by National Research Corp., Cambridge, Mass., and rhodium powder of 99.9 pct purity, supplied by Bishop Co., Malvern, Pa. Analyses as given by the manufacturers are presented in Table I. In addition to the spectroscopic analysis, an oxygen analysis has been made of the tantalum powder. After preliminary trials, the standard procedure employed in making the alloys was as follows (see Ref. 4 for further details). The powders were weighed, mixed manually, compacted under 16,000 psi, and arc-melted at not more than 500 amp under thoroughly titanium gettered welding-grade argon of 400 mm Hg pressure. The gettering process was repeated after each melt. It had been shown previously5 that under these conditions no oxygen pick-up exceeding 0.001 pct in a hafnium button could be detected. The buttons, ranging from 5 to 10 g in weight, were inverted or, if possible, crushed and remelted three times. Melting presented no difficulty, except for tantalum-rich al- loys, which showed considerable spashing during melting. The average weight loss of 1 wt pct rose to 2.5 wt pct in these cases. Subsequent melting, however, resulted in losses of less than 0.1 wt pct. The melts obtained frequently showed small in-homogeneities, mostly in the tantalum-rich part of the system below 25 at. pct Rh. This was not due to insufficient blending of the elements, but to crystallization taking place from the cooled bottom. This condition was not improved by further re-melting; therefore the following precautions were taken. Cross sections of as-cast buttons were made. For the investigation only buttons were used where these inhomogeneities did not exceed 1 at. pct (estimated from the amounts of haSeS resent). In addition, only the center portions of such buttdns were utilized to minimize errors. Smaller buttons showed smaller concentration gradients and were used as a check. Finally, all alloys were homogenized to eliminate coring (see below). After this, the error in alloy composition due to inhomogeneity was cl at. pct. In order to confirm the concentrations of the alloys and to provide an impurity check, wet-chemical analyses and oxygen-fusion analyses of four key alloys were carried out. The results, together with the concentrations as calculated with the weight balance method, are presented in Table 11. It was found that for three alloys the agreement is very good (< 0.2

Jan 1, 1964

By Nicholas J. Grant, A. W. Mullendore, Paul Predecki

The Duwez technique of splat cooling in which a molten droplet of metal is accelerated and made to impact on a cold, highly conducting substrate was investigated.- An apparatus for producing "splat" was constructed employing an explosive powder charge to accelerate the molten metal. Transport of the molten metal just prior to impact with the substrate was studied by means of high-speed photography. The molten particles are small spherical droplets from about 1 to 50 µ diameter. The average cooling rates for aluminum, silver, and a gold alloy splatted on nickel substrates at room temperature were determined experimentally and were found to vary from 18 to 5 x 10&apos; C per sec. The heat-transfer coeficients for pure aluminum and pure silver splats cooled on nickel substrates at room temperature were found to be 2.7 to 6.8 and 13.6 to 54.2 cal per sec sq cm &apos;C (2 to 5 x 104 and 1 to 4 x 18 Btu per hr sq ft OF), respectively. Solidification rates in pure aluminum and silver splats were calculated. "SPLAT cooling" is a term describing a technique for extremely rapid freezing and cooling of molten metals and alloys to room temperature or below. The technique was developed by Duwez et al.&apos; in 1960, and after refinement2 consisted in transferring a few tenths of a gram of molten metal to near sonic velocity to strike a suitably placed cold copper surface. Upon impact, the metal spread into a thin nonuniform film called a splat, about 10-4 cm thick. The splat particles produced in this manner were thin enough in some areas to be suitable for transmission electron microscopy, without further treatment, and, together with X-ray data, yielded a variety of structures which would be classified as follows: 1) supersaturated solid solutions (increase in solubility limit), 2) metastable crystalline stoichiometric and non-stoichiometric intermediate phases ( in Au-20.5 at. pct Si and in Au-14 at. pct Sb, respectively), 3) amorphous alloys, 4) retained high-temperature phases, 5) alloys having equilibrium phases present, but with unusual, markedly altered structures. The crystalline phases present in splats were usually extremely fine-grained and had low dislocation densities. Present interest in splat cooling centers around a study of the unusual structures produced by the technique, their contribution to alloy theory, and the possibility of the development of new or unusual properties. In addition, the technique is being examined for the production of bulk quantities of new high-strength alloys for low- and high-temperature use. Although a number of alloy systems have already been investigated by the technique, relatively little is known about the mechanism of splat formation and the physical conditions encountered by the metal during solidification and cooling. The purpose of this work was: 1) to determine the velocity, shape, and size of the molten metal droplets just prior to impact with the cold substrate; 2) to try to estimate or measure solidification rates, heat-transfer coefficients, and cooling rates in splats. EXPERIMENTAL TECHNIQUE Splatting Apparatus and Procedure. An apparatus similar to the type originated by Duwez et a1.,2 but employing an explosive charge to accelerate the molten metal, was used. A "Ramset" fastening tool (a gun normally used for driving studs into concrete, steel, and so forth) was mounted vertically above a resistance-heated graphite crucible as shown schematically in Fig. 1. A splat product was produced by melting a few tenths of a gram of metal at the position shown in Fig. 1, and then exploding a powder charge in the breach. The shock wave thus generated traveled down the barrel into the furnace, ejecting the molten metal through the 0.06-in.-diameter hole at the bottom of the crucible. The ejected metal was impacted on a high-conductivity metallic substrate where it formed a splat. High-Speed silhouette Photography. In order to investigate the size and shape of the ejected, molten metal just prior to impact with the cold substrate, high-speed silhouette photographs were taken, and are shown in Figs. 2 and 3. These photographs were obtained with the aid of an Edger-ton, Germeshausen, and Grier microflash unit and a submicrosecond flash drive equipped with a variable time delay. Two types of triggers were

Jan 1, 1965

By John W. Cloud

IN 1877 the Pennsylvania Railroad Company removed an old bridge from its line at Duncannon, Pa., built intermediate piers and erected shorter spans of the Pratt truss type, which had previously been in use on another portion of the road. The design of this truss would not admit of diagonals larger than 1 5/8 inches diameter, and in order to stiffen the bridge somewhat steel rods were introduced for the main diagonals in the first and second panels, 1 5/8 inches and 1 3/8 inches diameter respectively. These rods were threaded without upsetting, and by the ordinary formulae the strains were of the same intensity upon both, viz., 16,000 pounds per square inch with the maximum loading. The other main diagonals in the truss are 1 5/8 inches diameter, and of iron. It was specified for the steel rods : Elastic limit, - 45,000 lbs. Tensile strength, - 80,000 lbs. Elongation, - 20 per cent. The steel was procured without difficulty, and it allowed a factor of safety of 2 3/4 at elastic limit, while a similar factor of 2 1/2 had for a long time been successfully used for iron. In the course of three years, from time to time, six of these steel rods broke, three of them being 1 3/8 inches in diameter, and three 1 5/8 inches in. diameter. The broken rods were tested, and three of them. analyzed at Altoona to ascertain the cause of failure, and what modi¬fications should be made in the steel for such service. Examination showed that all the rods were broken in detail close under the nut. The threads were well cut and properly rounded at the root. In testing the rods micrometer screws,. reading to .0001" with electric bell to signal the contact, were attached to the test pieces, and by this means the modulus of elasticity and elastic limit accurately obtained.

Jan 1, 1881

By Luis Elek

DEVELOPMENT of the cement industry in Mexico began some 40 years ago. It has gradually reached great importance in the economic life of the country and has contributed greatly to the technical and economical advances which have been so noteworthy, particularly during the last 15 years. From a modest start, the industry now comprises 18 cement-producing plants having a potential annual capacity of approximately 14 million bbl. About half the plants were built and equipped with secondhand machinery during the last world war when no new machinery could be procured. They will hardly attain full production before being modernized and reconditioned, a job now under way in several of the plants. At present, the yearly consumption is only about 8 to 9 million bbl but is steadily increasing. This is only a fraction of the cement consumed in the U.S.A., which is about 250 million bbl per year, although on the basis of consumption per capita per year, the figure is 1/3 bbl for Mexico and 1 2/3 bbl for the U.S.A. Cement consumption in Mexico is well above the average of all other Latin American countries, with the exception of the Argentine, and considering the potentialities and undeveloped riches of Mexico, the road construction and irrigation works, it is fair to assume that the Mexican cement industry will still prosper and expand in spite of temporary setbacks in the future caused by local events of economic or political nature. Portland cement is manufactured by burning a mixture of raw materials, one of which is mainly composed of calcium carbonates and the other of aluminum silicates. The most typical materials answering this description are limestone and clay, both of which occur in Mexico in many varieties. To be usable for cement manufacture limestone should contain at least 77 to 80 pct calcium carbonate. Lower grade limestone can be used for cement manufacture only if the lime content is increased by the beneficiation process, which has not yet been adopted by the Mexican cement industry. Most of the limestone used by Mexican cement plants has a calcium carbonate content of 90 to 95 pct and therefore requires addition of one or several correction materials. A typical composition of raw mix for cement manufacture is 85 pct limestone and 15 pct shale, clay or volcanic materials. Occasionally it is necessary to add a smaller amount of sand or other siliceous material to increase the silica ratio in the raw mix. Likewise, it is sometimes necessary to add 1 or 2 pct iron ore to facilitate fusion in the kiln and to obtain proper relation between alumina and iron oxide. After calcining and

Jan 1, 1953

By Luis Elek

DEVELOPMENT of the cement industry in Mexico began some 40 years ago. It has gradually reached great importance in the economic life of the country and has contributed greatly to the technical and economical advances which have been so noteworthy, particularly during the last 15 years. From a modest start, the industry now comprises 18 cement-producing plants having a potential annual capacity of approximately 14 million bbl. About half the plants were built and equipped with secondhand machinery during the last world war when no new machinery could be procured. They will hardly attain full production before being modernized and reconditioned, a job now under way in several of the plants. At present, the yearly consumption is only about 8 to 9 million bbl but is steadily increasing. This is only a fraction of the cement consumed in the U.S.A., which is about 250 million bbl per year, although on the basis of consumption per capita per year, the figure is 1/3 bbl for Mexico and 1 2/3 bbl for the U.S.A. Cement consumption in Mexico is well above the average of all other Latin American countries, with the exception of the Argentine, and considering the potentialities and undeveloped riches of Mexico, the road construction and irrigation works, it is fair to assume that the Mexican cement industry will still prosper and expand in spite of temporary setbacks in the future caused by local events of economic or political nature. Portland cement is manufactured by burning a mixture of raw materials, one of which is mainly composed of calcium carbonates and the other of aluminum silicates. The most typical materials answering this description are limestone and clay, both of which occur in Mexico in many varieties. To be usable for cement manufacture limestone should contain at least 77 to 80 pct calcium carbonate. Lower grade limestone can be used for cement manufacture only if the lime content is increased by the beneficiation process, which has not yet been adopted by the Mexican cement industry. Most of the limestone used by Mexican cement plants has a calcium carbonate content of 90 to 95 pct and therefore requires addition of one or several correction materials. A typical composition of raw mix for cement manufacture is 85 pct limestone and 15 pct shale, clay or volcanic materials. Occasionally it is necessary to add a smaller amount of sand or other siliceous material to increase the silica ratio in the raw mix. Likewise, it is sometimes necessary to add 1 or 2 pct iron ore to facilitate fusion in the kiln and to obtain proper relation between alumina and iron oxide. After calcining and

Jan 1, 1953

By Eugene Rabinowitch

The Chemistry of Uranium. By Joseph J, Katz and Eugene Rabinowitch. Published by McGraw-Hill, Book Co. of New York, 1951. 609 P. $7.15.--This volume is the first half of a comprehensive treatise on uranium chemistry. It contains a detailed summary of the properties of the element uranium, including its occurrence in nature, extraction from ores, and the physical and chemical properties of uranium metal. Binary compounds of uranium with hydrogen, oxygen, nitrogen, and the halogens, among others, receive extensive discussion, including methods of preparation and physical properties such as crystal structure, thermochemistry and volatility. A very large proportion of the material in this volume is based on the results obtained in the laboratories of the Atomic Energy Project, much of it not published before. In addition, all of the open literature has been critically surveyed and integrated with the results of the Atomic Energy Project studies. Principles of Geology. By James Gilluly, Aaron C. Waters and A. O. Woodford. Published by W. H. Freeman & Co., San Francisco, Calif., 1951.640 P. $5.75.-This book attempts to summarize some of the knowledge that geologists have won from the study of the earth. It covers such subjects as movements of the earth&apos;s crust, records of earth movement, stream erosion and deposition, deserts, the ocean and mineral resources of the earth. The authors have concentrated on the analysis of processes that are at work upon and within the earth. rather than to present a catalog of descriptive facts and terms. The development of stratigraphy is also outlined. Pictures, maps, and tables are used to illustrate the major points of each chapter.

Jan 9, 1951

By L. P. Teas

ALTHOUGH 1927 in the Arkansas-Louisiana territory will probably pass into history as a year of small profits and little new production, nevertheless during this period two large gas fields were developed; two new oil fields were discovered, and two new oil horizons, hitherto of minor Annual Production in Millions of Barrels FIG. 1.-PRODUCTION OF NORTH LOUISIANA AND ARKANSAS BY FIELDS FOR 1926 AND 1927. importance, were developed; In spite of the "hard times" some of the leading, supply houses did more business this year in this. district than in any year since 1920.

Jan 1, 1928

By M. van Swaay, C. E. Birchenall

A. S. lBrling (Johnson, Matthey & Co. Ltd., Laboratories)— Because of its initial emphasis upon the production of membranes by powder metallurgy and by normal casting and rolling techniques, this paper is of considerable interest to those concerned with the design and application of industrial diffusion units. As the subsequent performances of the three grades of palladium were not compared in detail, it can perhaps be concluded that specific permeabilities were very similar. A short table in which the absolute diffusion rates obtained by the Authors with their three grades of palladium were compared with those of other investigators18-25 would, however, have been of particular value in view of the very variable results obtained with this membrane material. The Authors state early in the paper that the permeability of the thoriated samples decreased in much the same way as that of the nonthoriated samples. Later, they emphasize that sintered palladium without thoria was very susceptible to poisoning and did not respond as well as the other materials to the decontamination treatment. These results, which suggest that sintered membranes are less effective than those produced by normal methods, have considerable industrial implications, and amplified experimental details would be very welcome. The results of the Authors differ in one important respect from those of other investigators. Thus, no "bleeding" was required to maintain a constant rate of diffusion, although Davis, Darling, and De Rosset found this to be necessary. Davisz3 found that "bleeding" was necessary even when the hydrogen had already been purified by diffusion through a palladium tube, and it would be of value to know the purity of the gas stream emerging from the purification train shown on Fig. 1 of the Authors&apos; paper. The Authors show that diffusion rates varied according to the square root of the pressure difference providing that the palladium membrane was not contaminated in any way. This finding is in agreement with the results of those workers2,18,19,23,24 who diffused their hydrogen through the membrane into a partly or completely evacuated system.Those workers who did not find this square-root law dependence did not have a partial vacuum on the downstream-side of the membrane.&apos;&apos; The difference between the two experimental con- ditions appears to be significant, as the absolute diffusion rates per sq cm of diffusion area are lower when the square-root law dependence is not observed. While the effect could be attributable to poisoning of the membrane it is conceivable that a positive pressure on the downstream side of the membrane might influence the mechanism of diffusion. In view of the capricious behavior of palladium, factors of this type, which are likely to influence its industrial significance, should be carefully considered. M. van Swaay and C. E. Birchenall (authors&apos; 9-eply) — Our Eq. 191 may be compared with several others for hydrogen diffusion in palladium: D = 5.95 x exp (-5770/1)&apos; D = 3.55 x 10"3 exp (-5550/)&apos; D = 4.3 x 10"3 exp (-5620/1&apos;)&apos; Other values are given in the literature, but in many cases surface poisoning may have affected the results. No analysis was performed on the hydrogen gas stream after purification. It should be noted that the presence of liquid nitrogen traps near the heated membranes may have set up convection currents and provided the equivalent of "bleeding." The question of whether a partial vacuum existed on the downstream side of the membrane is not clear. Does it imply that there is something unique about the permeability measured near one atmosphere pressure? We do not believe that there is. When square root pressure dependence is not observed, diffusion rates are not measured. Is "absolute diffusion rate per sq. cm. of diffusion area" equivalent to permeability? The terminology is new to us. In any case we doubt very much that pressures of the order of several atmospheres can affect the mechanism of diffusion.

Jan 1, 1962

By J. C. McHardy

During 1980-2000, the Florida phosphate industry will deplete its central Florida Polk County reserves. As a result, new mines will be built in the so-called southern Florida reserve areas. These mines will require new mining, beneficiation, and tailings disposal technologies since southern reserves have different characteristics than have been encountered in the central Florida deposits. Furthermore, government regulations will necessitate development of new tailings and clay disposal methods. This paper reviews these challenges for the Phosphate industry and how these opportunities can be expected to effect plant design and plant operating practices.

Jan 1, 1984

By J. R. Thoenen, M. C. Malamphy, G. K. Dale

THE beginning of the war and the events leading up to it precipitated a near crisis in the aluminum industry. Demands for the metal reached proportions far beyond the prewar production capacities and, in addition, the submarine menace seriously curtailed the importation of bauxite from South America, hitherto a chief source of high-grade ore. The situation required an intensive search for domestic ore to augment the reserves and in October 1941 Congress directed the Department of the Interior to investigate the extent, mode of occurrence, and quality of bauxite in the United States. In December of that year the Bureau of Mines and the Geological Survey began the search for bauxite in Arkansas, where more than 90 per cent of the domestic ore had been produced and where the greatest amount of bauxite was known to occur. The program involves the geophysical and geological investigation of the Arkansas bauxite region and the core drilling of areas considered favorable for the occurrence of bauxite deposits. Cores taken from the bauxite-kaolin zone are sampled and analyzed in the Bureau of Mines laboratory in Little Rock. The information from each of the deposits discovered is then assembled, the bauxite is graded with respect to its possible utility, tonnage estimates are made, and the whole is presented in the form of a war minerals report. Thirty-eight new bauxite deposits had been discovered and investigated at the end of the calendar year 1944, and the presence of several others had been indicated by the drilling. More than 5000 holes had been drilled throughout the bauxite region, and more than 60,000 chemical analyses had been made of samples taken from the bauxite-kaolin zone. A study of the chemical analyses led to certain general conclusions not only with regard to the chemical composition of Arkansas bauxite, but also with regard to its component minerals. Charts and diagrams based on these conclusions have been developed for practical use by the Bureau of Mines: (I) to serve as a check against laboratory analyses, (2) to present tonnage estimates of ore bodies based on mineral composition, (3) to illustrate the relationship of tonnages of bauxite to the alumina, silica, and iron content, and (4) to serve as a control for mining operations by providing a means for quick estimates of the value of the ore from a partial analysis of its chemical constituents. The use of charts and diagrams similar to those discussed in this paper is not new. The use of the trilinear diagram for studying the ultimate analyses of coals as originally proposed by Ralston in Bureau of Mines Technical Paper 93 (1915) showed that the various ranks of coal fell in different areas on the diagram and that volatile matter, calorific value and other properties could also be plotted by the use of contours. A considerable subsequent literature, largely on classification of coals, has accumulated since then, showing the utility

Jan 1, 1945

By J. R. Thoenen, M. C. Malamphy, G. K. Dale

The beginning of the war and the events leading up to it precipitated a near crisis in the aluminum industry. Demands for the metal reached proportions far beyond the prewar production capacities and, in addition, the submarine menace seriously curtailed the importation of bauxite from South America, hitherto a chief source of high-grade ore. The situation required an intensive search for domestic ore to augment the reserves and in October 1941 Congress directed the Department of the Interior to investigate the extent, mode of occurrence, and quality of bauxite in the United States. In December of that year the Bureau of Mines and the Geological Survey began the search for bauxite in Arkansas, where more than go per cent of the domestic ore had been produced and where the greatest amount of bauxite was known to occur. The program involves the geophysical and geological investigation of the Arkansas bauxite region and the core drilling of areas considered favorable for the occurrence of bauxite deposits. Cores taken from the bauxite-kaolin zone are sampled and analyzed in the Bureau of Mines laboratory in Little Rock. The information from each of the deposits discovered is then assembled, the bauxite is graded with respect to its possible utility, tonnage estimates are made, and the whole is presented in the form of a war minerals report. Thirty-eight new bauxite deposits had been discovered and investigated at the end of the calendar year 1944, and the presence of several others had been indicated by the drilling. More than 5000 holes had been drilled throughout the bauxite region, and more than 60,000 chemical analyses had been made of samples taken from the bauxite-kaolin zone. A study of the chemical analyses led to certain general conclusions not only with regard to the chemical composition of Arkansas bauxite, but also with regard to its component minerals. Charts and diagrams based on these conclusions have been developed for practical use by the Bureau of Mines: (I) to serve as a check against laboratory analyses, (2) to present tonnage estimates of ore bodies based on mineral composition, (3) to illustrate the relationship of tonnages of bauxite to the alumina, silica, and iron content, and (4) to serve as a control for mining operations by providing a means for quick estimates of the value of the ore from a partial analysis of its chemical constituents. The use of charts and diagrams similar to those discussed in this paper-- is not new. The use of the trilinear diagram for studying the ultimate analyses of coals as of proposed by Ralston in Bureau of Mines Technical Paper 93 (1915) showed that the various ranks of coal fell in different areas on the diagram and that volatile matter, calorific value and other properties could also be plotted by the use of contours. A considerable subsequent literature, largely on classification of coals, has accurnulated since then, showing the utility

Jan 1, 1948