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By W. W. Harvey, F. O. Dudas

Toward hot hydrochloric acid, the usual order of reactivities of the common copper sulfide and associated minerals is reversed, and the rates of H2S formation vary as [ ]. The iron component of chalcopyrite and bornite reports to the solution as ferrous chloride, while pyrite remains essentially unreacted. If a pressure of H2S is maintained in the reactor, copper solubilization is suppressed, and the primary copper sulfides are converted to finely divided secondary sulfides (principally covellite). The HCl leach reside then consists mainly of covellite, pyrite and acid-insoluble gangue. Copper can be selectively leached from this upgraded concentrate to yield a clean, strong copper sulfate solution for direct electrowinning. Preliminary analysis indicates competitive economics with respect to established hydrometallurgical processes. Other concentrate treatments based on an initial HC1 leach are proposed and relative advantages compared. The common denominator of the major process routes considered is the requirement to regenerate HC1 from an FeC12 solution. Five distinct concentrate compositions were employed in the experimental study, which included some attention to the fates of selected minor constituents of the copper concentrate, especially gold, silver, molybdenum, arsenic and selenium. Significant mineralogical features of reactants and products are described.

Jan 1, 1978

By Potts N. L., Eilerts C. K., Summer E. F.

The second-order, nonlinear, partial- dillerential equation representing the transient radial flow of gas - condensate fluids in reservoirs has been integmted by using finite -dillerence equations and electronic computers. Effect was given to pressure -dependent permeability, viscosity, and compressibility and to distance-dependent permeability. The influence of a second-degree velocity term in the Darcy equation was investigated. Implicit methods were used and practical, convergent solutions were obtained with material balance to less than 6 x 10-4 for recovery of one- hall the reserve at constant flow rate. Integration results provide the productive period of a reservoir for a given constant rate and the fraction of the fluid initially in place that can be recovered in that period. The properties of a lean and a rich fluid are represented in a set of integrations designed to demonstrate the effect of different constant-recovery rates and significant variables emphasized one at a time. INTRODUCTION A method is needed for computing the availability or reserve of a gas in a formation, making use of all technical and engineering information that is pertinent. As a step in this direction, a program for computing transient linear flow1 was developed that utilizes principles of earlier finite-difference computing for a similar purpose2-4 and gives effect to significant pressure- and distance-dependent properties of reservoirs and their contents. The present paper pertains to transient, radial flow of gas-condensate fluids. In the partial-differential equation of flow, effect is given to the variables viscosity and compressibility,5 and also to permeability. Included in the study is the quadratic form of the Darcy equation of flow that has been the subject of field tests6 and that has been applied to a gas with constant properties in transient flow computing. 7 Inclusion in the differential equation of variable coefficients to represent properties greatly complicates the higher derivatives of the equation. Because it was impractical to make a required improvement in certain of the finite-difference derivatives by Taylor-series expansion, five-term derivatives were used in the implicit computing. Related methods were developed that can improve general facility in manipulating finite-difference equations. BASIC EQUATIONS PARTIAL DIFFERENTIAL EQUATION The basic partial differential equation for transient radial flow in the direction of decreasing radius is l_ a(vpr) _? .......(1) r gr at where r = radius, L v = apparent velocity aIong radius, L/t p = density, M/L3 t = time, t Ø = porosity, dimensionless. In this equation, only the porosity is regarded constant. The density is where p = pressure, m/Lt2 M = molecular weight of fluid, m T = constant temperature of fluid, T z(p) = pressure-dependent compressibility factor, dimensionless R = gas Constant, mL2/t2t. The physical boundary of the reservoir is at re, and the producing boundary is defined to be at tq with rq = re /200. By definition,

Jan 1, 1966

By J. E. Hilliard, H. E. Cook

It is shown that for systems having a miscibility gap the spinodal composition (c,) in the vicinity of the critical temperature (Tc) is related to the equilibrium composition (c,) by where cc is the critical composition. This expression is exart for the limit T — Tc and is a good approximation down to (T/Tc) - 0.9. If the miscibility gap meets the composition of the pure components THE recent theoretical treatment by cahn1,2 on spinodal decomposition of solid solutions has revived interest in methods of estimating the chemical spinodal, * i.e., the locus on a binary phase By use of the appropriate expression, the spinodal can be drawn on the Phase diagram almost by inspection with an accuracy comparable to that of lengthy calculations in which a free-energy function is fitted to the phase diagram. Satisfactory agveemenf is also obtained with spinodals comPuted from experimental free-energy curves. where G is the Gibbs free energy of the homogeneous solution and c the atomic fraction of component 2, the derivative being evaluated at constant temperature (T) and pressure (P). (These subscripts will hereafter be omitted from the partial derivatives.) If experimental measurements of G as a function of c and T are available in a single-phase region above the spinodal, then these can be extrapolated to obtain a series of metastable free-energy isotherms in the two-phase region, and from these isotherms a series of spinodal compositions can be calculated. Because the value of is very sensitive to experimental errors, an elaborate analytic procedure is required for

Jan 1, 1965

[FUQUA, H. B. and Thompson, B. E.: Oil and Gas Development and Production in North Texas for 1933, 107, 320; for 1934, 114, 417 Oil and Gas Development in West Texas 114, 438 FURMAN, W. F.: Heat and Corrosion-resisting Alloys. Printed in Oil & Gas Jnl., June 13, 1935 Furnace-bottom sand, uniformity, 73, 390 Furnace control, Isley apparatus, M27, 502 Furnaces (See also Holt-Dern; Blast Furnaces; Roasters; Wirebar, etc.): annealing: electric, 89, 424 gas-fired, 89, 425 gas vs. wood for nonferrous metals, 89, 422]

Jan 1, 1936

By F. N. Rhines

Despite the large amount of study which has been devoted to the subject our present knowledge of the copper-oxygen system remains incomplete and unsatisfactory .in many respects. This applies particularly to those regions in which solid metallic copper exists. The primary object of the present paper is the contribution of new information relative to the solid solubility of oxygen (or cuprous oxide) in copper at atmospheric pressure, together with certain observations in the low-pressure regions of the system. It seems appropriate also to present a brief summary of the outstanding previous work on the constitution of mixtures of copper with its lowest oxide in order. to show the relation between the new facts and the system as a whole. The earliest recorded investigations of the copper-oxygen system are those of M. S. Lucas(l) $ and of M. Chevillot(2) in 1819 and 1820. Lucas believed that liquid copper is capable of dissolving its oxide, but neither he nor Chevillot was able to furnish convincing proof of this property. It was not until 1866 that T. Graham(3) definitely established the existence of such a solubility. Nine years later W. Hampe(4) measured its extent and roughly outlined the copper-rich portion of the system. The first really precise examination of the constitutional relationship between copper and cuprous oxide, however, was that of E. Heyn(5) who in 1900 published a temperature-concentration diagram covering the range from 0 to 10 per cent of cuprous oxide at atmospheric pressure. Within these limits of composition cuprous oxide was found to dissolve in liquid copper, forming at 3.4 to 3.5 per cent a eutectic which melted at 1065" C. R. E. Slade and F. D. Farrow(6) extended these studies to mixtures of higher oxygen content. They discovered that between 20 and 95 per cent of cuprous oxide the metal and oxide form two liquid phases at a monotectic reaction of 1195" C. The span of the biliquidal region diminishes slightly

Jan 1, 1934

By J. Parke Channing

ALTHOUGH the original thought of investigating waste in industry came from a mining engineer, Herbert Hoover, and although the chairman of that committee was a mining engineer (although the real work was done by the vice-chairman, L. W. Wallace), it is an interesting commentary that when the report first saw light, at St. Louis, on the first of June, 1921, some people most violently went up in the air when it was submitted by the representatives of the mining engineers. At the time they resented most markedly the report of the committee that 50 per cent. of the waste in industry, or as Mr. Ingalls in his paper has properly said, inefficiency in industry, was to be laid upon management. The reason for that seems to have been that, as a whole, the mining industry is pretty well organized and is superior to a large number of manufacturing industries including those studied by the Report. However, this very meeting shows that even the min-ing engineers have finally realized that there is waste or inefficiency in mining and that a large proportion of it can, with propriety, be assessed against management.

Jan 3, 1922

By W. G. Pfann

WHEN a molten zone traverses a long, solid ingot in a level, open boat the ingot becomes tapered. While the taper may be slight after one zone pass, it can be appreciable after repeated zone passes, even to the extent of causing an overflow of matter at the end of the boat. It will be shown here that such matter transport by a molten zone arises from the volume change on melting and that it corresponds in magnitude and direction to the magnitude and sign of the volume change. It will be shown also that the mechanism of matter transport is basically similar to that of solute transport by a molten zone, which has been discussed elsewhere,1,2 and that the two processes can be described by similar equations. Finally it will be shown that matter transport can be prevented by inclining the ingot at a critical angle. Contraction on melting results in forward transport, that is, transport in the direction of zone travel; expansion on melting results in reverse transport. The way in which forward transport arises from the contraction on melting may be seen as follows: At the starting end of a solid horizontal ingot of uniform rectangular cross section of height h., form a molten zone of length 1, as shown in Fig. 1. The height h of the liquid will be h. where a is the ratio of density of solid to that of liquid. Advance the molten zone, at constant length, a distance dx. The volume of solid melted will be hdx; the volume of solid frozen will be Izdx, because the height of the freezing solid will tend to be equal to that of the liquid. The resultant change, dv, in liquid volume will be the difference in these quantities multiplied by the density ratio. Hence the following equation may be used for a zone at any distance x from the origin: which is valid in all but the last zone length in the

Jan 1, 1954

By Clyde Williams

IF you would allow me some liberties, I would restate the title of this talk as "Scientific Research, Our Greatest Resource," because that title would represent more clearly a present-day conception of the metals and minerals situation. It is a subject worthy of careful consideration. Canada and the United States are so similar and interdependent in their national economies that, in the following discussion, examples of conditions in the United States may be interpreted to apply to Canada as well. Moreover, it is a striking fact that the per capita value of mineral production in Canada and the United States in 1940 was almost the same. Therefore, in the consideration of this subject, I have made no attempt to differentiate between the two countries. Consumption of the world's mineral resources in the last few decades. and particularly during World War II, has been so enormous as to require some form of magic to ensure the continued progress of civilization in the face of a diminishing supply of these resources which are so critically essential. As C. K. Leith pointed out, in 1941, indus-

Jan 1, 1947

By Marston G. Fleming

E. C. Peterson (Anaconda Copper Mining CO., Darwin, Calif.)—A study of this quite comprehensible and interesting paper by Dr. Fleming brings to mind several observations in the practical application of alkalinity and related factors to the actual practice of lead mineral flotation. Soda ash has long been a widely used and a very helpful alkaline conditioning agent in the flotation of galena from the usual run of lead-zinc ores. Soda ash is one of the common "standard" conditioning agents tried in any laboratory investigation of lead-zinc ores because it has so often proved helpful to galena flotation. However, the use of soda ash in the actual flotation of oxidized lead ores is certainly not widespread. In the flotation of certain lead-zinc ores from the Park City district of Utah, it was found in the usual cyanide-zinc sulphate-xanthate circuit that soda ash had an effect of producing a very condensed and flat froth regardless of the many frothers tried and that substitution of lime for soda ash to produce the same pH (8.0 to 8.4) improved the froth condition. However, the flotation of coarse particles of galena became so critical that some would pass through into the tailing, but caustic soda as a substitute for either soda ash or lime produced a very desirable froth condition in the same pH range and greatly improved the metallurgical outcome. Milling was carried out in typically "hard water" from watersheds of limestone and other calcareous rocks and the ore also apparently contributed magnesium and calcium salts to the pulp. Certain lead-zinc ores of Mexico have shown their greatest flotation response in circuits conditioned with sodium bicarbonate, and such actual mill use was also believed to be related to the water necessarily used in milling. On other lead-zinc ores the optimum has been obtained in actual milling treatment by use of caustic soda in both circuits of the operation. In flotation of oxidized lead ores in which sulphidi-zation is employed by addition of sodium sulphide, very high pH's exist in the flotation circuit. With the usual oxide lead ores, demanding 5 to 15 lb of sodium sulphide per ton of ore, pH's in the circuit (closed and open water-circuits) may range from 9.5 to 12, and for ores that contain much anglesite or a high percentage of iron oxide minerals, sodium sulphide consumption may reach as much as 30 lb per ton of ore and the resultant pH will be correspondingly higher. Yet in such flotation treatment employing either xanthate or oil (high-sulphur crude oil or diesel oils) as the collector, satisfactory to excellent grades of concentrate and lead recovery are obtained. Although there have been great studies and accomplishments in the investigations of flotation fundamentals and flotation theory, and although an investigation to determine the effect of all factors entering into the actual plant flotation of sulphide and oxide ores must become very complicated, as Mr. Fleming has mentioned in his caution regarding the drawing of general conclusions for other ores, it seems that it would be of greater interest if the techniques and investigations could, with time, approach the conditions of actual practice and lead the way to improved and more efficient flotation plant performance. Marston G. Fleming (author's reply)—The gulf between fundamental flotation research and plant operation is, perhaps, less wide than Mr. Peterson suggests. For example, the work described in my paper developed from an extensive investigation of a complex lead-vanadium ore from southwest Africa. This investigation started as a standard ore-testing problem but, at almost every stage, results were obtained which could not be interpreted in terms of previous experience. A program of fundamental research was therefore undertaken and was closely interlocked with the ore testing. This coordinated investigation resulted in a flotation process which has now been proved by two years of successful plant operation, and although the grade and mineralogical constitution of ore as well as smelter requirements have altered more than could have been anticipated, our knowledge of the fundamental character of the problem has made it possible to meet each change in conditions with much more confidence than would have been the case had we neglected this aspect of the investigation.

Jan 1, 1954

PHILIP D. BLOCK, JR., vice president of Inland Steel Co., visualizes a fine future for the Menominee Range of the Upper Peninsula of Michigan. He sees a future unclouded by threat from foreign ore imports or the development of low grade ore processing in Minnesota. The statement was made during the opening of Inland's new Cayia mine near Crystal Falls. Inland, according to the vice president, is planning to use an increased amount of the high phosphorous ores found on the Menominee Range. He said that other steel companies will probably do the same, because the steel industry has learned how to use ores of high phosphorous content. He said: "I do not mean to imply that we can use an unlimited amount of high phosphorous ores or that we can burden our blast, furnaces with 100 pct high phosphorous ores, but we have reached the point where we can absorb a much larger percentage of these ores without any detrimental effects. Foreign ores and lowgrade Minnesota ores cost too much to offer real competition, Block said. Transportation costs from the Menominee range to steel producing centers in Chicago and on Lake Erie are less than for any other range in this country. In the meantime, the American operators of the Bomi Hills iron ore mine in Liberia, have reportedly signed a new agreement with the Government. Several months ago, President Tubman of Liberia expressed a definite dissatisfaction with the original contract. Informants state that the agreement only needs the approval of the Export-Import Bank, which loaned Liberian Mining Co. $4 million to develop the iron ore properties. Majority stockholder of the Liberian Mining is Republic steel, with 61.57 pct of the stock. Under the new contract, the Liberian Government will start to share in the profits when the indebtedness is liquidated and the return of invested capital accomplished, or April 1, 1957, whichever is earlier. Under the old agreement the Liberian Government received a 5 cent per ton royalty and an additional sum based on the price of pig iron. The royalty rate reached more than 17 cents per ton this year. After debt liquidation the Liberian Government will receive 25 pct of net profits for the first five years; 35 pct for the next ten years; and 50 pct thereafter. Until the Government starts to share in profits it will receive a royalty of $1.50 per ton in U. S. currency, in addition to royalties provided for in the old agreement.

Jan 1, 1952

By E. W. Johnson, M. L. Hill

Equilibrium concentrations of hydrogen in iron were measured at H2 pressures up to 136 atm and temperatures down to 145°C. Residual hydrogen was prominent near 600°C in air-melted but not in vacuum-melted iron. The diffusible hydrogen solubility is abnormally high below 390°C, confirming the hypothesis of hydrogen trapping.' It appears that the traps for hydrogen in iron form suddenly on cooling. The estimated H2 pressure in equilibrium with 5 ppm hydrogen in steel at room temperature is less than 1000 atm. It was shown previously1 that the diffusivity of hydrogen in a-Fe below 200°C is anomalously low, a behavior attributed to the presence in the metal structure of hydrogen "traps." The energy of the trapped hydrogen was computed as 4.8 kcal Per g-atom below that of the interstitially dissolved hydrogen. The strongest confirmation of the trap hypothesis should be obtainable from measurements of the hydrogen solubility at low temperatures. such measurements have been performed and are reported in this paper. The "residual hydrogen" effect1'' must be carefully controlled if valid measurements of the solubility are to be obtained, and such an effort was made in the present work. Previous data for the solubility of hydrogen in iron have been summarized by Geller and Sun.3 Their equation for the most probable solubility at 1 atm in a-Fe above 400°C is

Jan 1, 1962

By E. W. Davis

DURING late years, the proportion of beileficiated iron ore shipped from the Lake Superior District has increased very rapidly. By benefication is meant washing, screening, drying, sintering or any process by which the grade or structure of the crude ore is improved before shipment. In 1915, only 3,000,- 000 tons, or 9 per cent, of t6e total Minnesota shipment was beneficiated ore, compared with 13,500,000 tons, or 35 per cent, of the total Minnesota shipment in 1925. This increase is, of course, due to the fact that iron and steel can be made more cheaply after beneficiating these ores than they could have been had these ores not been so treated. Fundamentally, however, several causes contribute to the necessity for beneficiating iron ores, such as depletion of the reserves of high-grade ores, the iron ore leasing systems and taxation methods and, at the smelting plants, a better understanding of blast-furnace operations, increased operating costs and increased sulfur content of blast-furnace coke. As economic conditions change, it is by no means certain that the proportion of beneficiated ore shipped each year is going to continue to increase. Undoubtedly some of the beneficiation operations are not economically sound at the present time and what the future has in store for the iron ore industry is problematical. Generally speaking, the cost of fuel for blast-furnace operations will increase as time goes on and in order to continue to produce cheap iron and steel, some of the other costs must be lowered. Freight and labor rates probably can- not be reduced. The cost of producing iron ore cannot be reduced much below the present price. It therefore appears that the best opportunity for maintaining iron and steel prices at their present level in spite of in- creased costs of labor and raw materials is to use. less or cheaper raw materials. This, of course, contemplates an improvement in metallurgical processes all along the line and, as a matter of fact, we can confidently expect these improvements because scientific investigations will undoubtedly be even more productive in the future than they have been in the past.

Jan 1, 1926

By Alfonso W. Ovalle

INTRODUCTION The block-caving mining method is one of the most economical ways existing today to extract ore from nature. It is undoubtedly the least costly of the underground systems and moreover it compares favorably to open-pit mining. In addition to its low cost characteristic, the block-caving mining method permits a great extraction volume as can be exemplified by El Teniente's output capacity of over 22 million tons of ore per year. These characteristics of block-caving give assurance that, even though it is a very old mining system, it will be a good answer to the many future large massive low ore grade deposits to come and a1 so to rep1 ace open-pi t mining as such operations get deeper with higher stripping ratios. These are the reasons that induce further study of block-caving. In this paper block-caving at El Teniente is analyzed with due consideration to the major problems that this mine will encounter. Emphasis is given to the factors influencing the mining of soft ore which accounts for most of the ore to be extracted in the next ten years. A separate paper is devoted to a major modification introduced to block-caving hard primary ore at El Teniente by means of LHD equipment extraction. DESCRIPTION OF THE PRESENT MINING Ore Production and Flow Over 62.000 tons per day of ore are extracted 359 days per year at the El Teniente Mine. The Teniente 8 train haulage level at 1.983 m takes 29.000 tons daily to the Col6n Concentrator. Two trains make the 8 km haul with 16 cars per train. Car capacity is 90 tons. The Teniente 5 train haulage level 298 m above takes 33.000 t per day to the old Sewell Concentrator. Ore is produced from three production areas in two different levels. The so called North Mine produces 42.000 tons daily from the Teniente 4 level 65 m above the Teniente 5 haulage level. The Central Mine produces 1.000 tons from the first hard rock block caved at the Te- niente 4 level. The combined 43.000 tons per day production is sent through inclined 2 m dia- meter raises to the Teniente 5 haul age level , where 33.000 tons are taken 2.5 km to the Sewell Concentrator and 9.000 tons are hauled 0.5 km to a 5 m diameter vertical ore pass which sends ore to Teniente 8. The haulage is by 7 trains, 15 gabble-bottom cars per train. Car capacity is 20 tons. The so called South Mine produces 19.000 tons per day from the Teniente 1 level 645 m above the Teniente 8 haulage level. Ore is transferred by 2 m diameter inclined raises to the Ten 1 Retram level 22 m below, where 5 trains with 20 Sandfor Day cars per train, 8 tons capacity per car, haul the ore 1.5 km to two vertical 5 m diameter ore passes which connect to Ten 8. Starting in 1982 the Central Mine will in- crease production to 6.000 tons per day. An in- dependent loop haulage system will start operat- ing at the Teniente 5 level to feed a new under- ground 1.372 mm (54 in.) gyratory crusher which will send minus 152 mm ore (9 in.) to Teniente 8. In two or three years time the North Mine will only feed the 33.000 tons to the Sewel 1 Concentrator with its old Teniente 5 haulage system. The Col6n Concentrator will be fed from the Central and South Mines. Figure 1 shows the transfer systems and ore flows. The Ore Body In plan view at the Teniente 4 level the ore body has a kidney shape 1.800 m long and between 400 to 700 m wide. The north-eastern section of the ore body was washed away by the Teniente River. At the Sub 5 Level, 125 m below Teniente 4, the mineralization completely surrounds the circular 1.000 m diameter steep-sided barren breccia pipe (Braden pipe) . The ore body rock is 73% andesite, 14% diori te, 13% dacite and 6% mineralized breccia. Most of this ore is secondary enrichment sulfides which apart from the dacite is strongly fractured being chal cocite, cove1ine , bornite and

Jan 1, 1981

By Frank Firmstone

The piece of spiegeleisen, the analysis of which is given below, was collected by my father, together with various other specimens, while he was manager of the Glendon Iron Works. It bears a label stating that it was taken from a building in the town of Newton, New Jersey, erected in 1765 and torn down in 1863. The building belonged, in 1863, to T. N. McCarter, Esq. The label is in the hand-writing of Mr. McCarter, now deceased, well known as a member of the bar of northern New Jersey. The specimen was, no doubt, given by him to illy father, with whom he had business in 1863 and 1864. It is now in the metallurgical collection of Lehigh University. I know nothing further as to the history of the specimen, but there is no reasonable doubt that it was made from ore from the Andover mine, at the old charcoal-furnace which once stood at the village of Andover, about 5 miles south of Newton, on the Sussex railroad. It was probably broken from one end of a bearer over an open fire-place, is about 6 in. wide by 2.5 in. thick, has been cast in open sand and shows the charcteristic fracture of spiegeleisen rather low in manganese, as shown in Table I. One edge has been white-washed. Table I.—Analyses of Spiegeleisen Made from Andover Ore. 1. 11. Per Cent. Per Cent Graphite,.0.101 0.005 Combined carbon,... 4.529 4.212 Silicon,..0.037 0.294 Manganese,..... 5.760 3.750 Sulphur,.0.003 0.031 Phosphorus,.0.060 0.072 Iron,........ 89.440 91.570 99.920 99.934 I. Spiegeleisen made at Andorer (charcoal) furnace not later than 1765. IT. Spiegeleisen made from Andover ore at Phillipsburg, N. J., anthracire-furnwe, 185-. Both analyses were made by Dr. P. W. Shimer.

Jan 1, 1907

By H. B. Kinnear

THE first copper stool used under an ingot mold to receive molten steel has recently been taken out of service after it had received ingots amounting to 6012 gross tons. This stool, weighing 8330 lb. had been in continuous service for 1822 heats since its installation. From this modest beginning the use of copper for ingot-mold stools grew to 425,000 lb. in 1934, with an additional 50,000 lb. of copper used in the form of inserts in cast-iron stools. During 1935 the quantity of copper used for stools increased by about 350,000 lb., making a total of 775,000 lb. now in use for that purpose. Copper used for inserts has increased during this time 180,000 lb., or over 350 per cent, to a total of 230,000 lb. The total of copper, therefore, in use at present under ingot molds is slightly over 1.000,000 lb.

Jan 1, 1936

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'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

Impact Transition Temperatures of Some Pearlite-Free Mild Steels As Affected by Heat Treatments in the Alpha Range H. P. Tardif (Canadian Armament Research and Development Establishment, Quebec)—Mr. Josefsson is to be congratulated for his study of a most difficult subject and for the theories proposed to explain the re- sults. One point which, however, might not have received proper attention is that of the shape of the stress-strain curve at the yield point of quenched and furnace-cooled specimens and of specimens strain aged

Jan 1, 1956

By J. A. Hutcheson

NO one questions that it is technically possible to achieve the controlled release of atomic energy in a form that can be converted into heat or electricity. However, before this is actually an accomplished fact a great amount of work must .be done. This work falls into two general classifications: research and engineering development. At present a research program is under way in this country, co-ordinated and directed by the Atomic Energy Commission, which, as time goes on, will uncover fundamental knowledge of this new science that is essential before industrial applications of atomic energy are practical. Undoubtedly therefore, as the store of available knowledge increases, a time will come when answers to the many questions relating to practicality of atomic energy in industry can be determined with reasonable certainty. That the application of atomic energy in industry will eventually be proved practical is assumed. What then are the engineering problems that must be solved before the first practical electric power generating station can be built?

Jan 1, 1948

By H. Cecil Spicer

The results described in this article are based on field work conducted during the periods APril-May, 1939, and MaY-JulY, 1940. The United States Potash CO. is mining potash on Government land under a permit from the Department of the Interior and the geophysical investigation mas completed under a cooperative arrangemerit made between that company and the Conservation Branch of the Geological Survey. The writer, a member of the Section of Chemistry and Physics of the Geologic Branch, was assigned to this investigation. Four definite objectives were in mind for the geophysical work in the studies over the salt deposits. The first was to determine the measure of success that could be attained in this type of work with the resistivity methods that were to be employed. These methods had been introduced into the work of the Conservation Branch by Benjamin E. Jones for the investigation of dam sites, and have been used under his direction by the author for such work. If the method proved to be applicable, an l was to be made to contour the top of the salt beds and also the other formation boundaries known to be present in this area. Salt-water aquifers were to be studied in an effort to determine their boundaries, and an attempt was to be made to delineate the potash-bearing beds. Others have made, and reported, resistivity studies over saliferous deposits in different areas. Friedell and Messrs. Schlumberger2 reported geophysical work performed in the disrovery of the salt domes of Alsace; Carrette and Kelly3 described the geology of the same area. Leonardon and Kelly4 published a resistivity curve obtained over the Hettenschlag dome, and a further discussion of this same area was given by the Messrs. Schlum-berger5 in a communication. Messrs. Alty6 described studies 0" salt deposits in which the sing[e-probe method was used. Sinerez7 mentions that electrical methods were tried over salt deposits in Spain. Geoffrey and Charrin8 show a resistivity curve obtained over marl, gypsiferous marl and salt which is similar to that obtained over the New Mexico salt deposits. Kelly9 reported resistivity work performetl with the ground comparator of Zuschlag over the salt deposits near Syracuse, N. Y., where the Salina formation is at a depth of 700 to 800 ft. Some structural studies on the potash basin of Alsace are described by Poldini.10 Another single-probe resistivity study, made over salt deposits in New Mexico, is briefly described by Heiland,ll through the courtesy of Harry Aurand, of the Midwest Refining CO.

Jan 1, 1942

By H. Cecil Spicer

The results described in this article are based on field work conducted during the periods APril-May, 1939, and MaY-JulY, 1940. The United States Potash CO. is mining potash on Government land under a permit from the Department of the Interior and the geophysical investigation mas completed under a cooperative arrangemerit made between that company and the Conservation Branch of the Geological Survey. The writer, a member of the Section of Chemistry and Physics of the Geologic Branch, was assigned to this investigation. Four definite objectives were in mind for the geophysical work in the studies over the salt deposits. The first was to determine the measure of success that could be attained in this type of work with the resistivity methods that were to be employed. These methods had been introduced into the work of the Conservation Branch by Benjamin E. Jones for the investigation of dam sites, and have been used under his direction by the author for such work. If the method proved to be applicable, an l was to be made to contour the top of the salt beds and also the other formation boundaries known to be present in this area. Salt-water aquifers were to be studied in an effort to determine their boundaries, and an attempt was to be made to delineate the potash-bearing beds. Others have made, and reported, resistivity studies over saliferous deposits in different areas. Friedell and Messrs. Schlumberger2 reported geophysical work performed in the disrovery of the salt domes of Alsace; Carrette and Kelly3 described the geology of the same area. Leonardon and Kelly4 published a resistivity curve obtained over the Hettenschlag dome, and a further discussion of this same area was given by the Messrs. Schlum-berger5 in a communication. Messrs. Alty6 described studies 0" salt deposits in which the sing[e-probe method was used. Sinerez7 mentions that electrical methods were tried over salt deposits in Spain. Geoffrey and Charrin8 show a resistivity curve obtained over marl, gypsiferous marl and salt which is similar to that obtained over the New Mexico salt deposits. Kelly9 reported resistivity work performetl with the ground comparator of Zuschlag over the salt deposits near Syracuse, N. Y., where the Salina formation is at a depth of 700 to 800 ft. Some structural studies on the potash basin of Alsace are described by Poldini.10 Another single-probe resistivity study, made over salt deposits in New Mexico, is briefly described by Heiland,ll through the courtesy of Harry Aurand, of the Midwest Refining CO.

Jan 1, 1942