Search Documents

The Committee on Papers and Publications has set June 1, 1919, as the closing date for the receipt of manuscripts intended for the Chicago meeting, which is to be held Sept. 22 to 27, 1919. Manuscripts must be received by the Secretary on or before this date. If they are sent through members of the technical committees, they must be sent to those committees long enough in advance to be forwarded and in the hands of the Secretary by the time specified.

Jan 5, 1919

By C. Richard Tinsley

SUMMARY A detailed analysis of nickel, copper, and cobalt recovery from manganese nodules shows simple rates of return of 9-15% in 1985. A sulfur dioxide roast process yields a slightly better return than an ammonia leach technique. Nodule tonnage predictions tend to be over-optimistic and more conservative forecasts show that market penetrations are only significant for cobalt and manganese. However, cobalt prices are unlikely to fall to the level of nickel. Between now and 1985, cobalt is expected to be in balanced to tight availability. INTRODUCTION Deep-ocean manganese nodules are one- to two-inch concretions which cover 2040% of large areas of the ocean bottom. Commercial targets far these black, potato-like nodules are located in the North Pacific at water depths of 5,000-6,000 m. in a belt roughly midway between Hawaii and Mexico. However, good grade nodules are not solely limited to this belt as areas southwest and northwest of Hawaii, as well as in the Indian Ocean, contain concentrations of acceptable grade manganese nodules. Some 90% of the nodules are found half-buried on the deep ocean bottom. A siliceous-ooze host soil combined with low sedimentation rates, certain ocean currents, and possible geo- thermal effects are favorable factors far nodule formation. The viewpoints and analyses in this paper are the author's own and should not be attributed in any way to Amoco Minerals Co.

Jan 1, 1976

Officials of the State Department have expressed their hope that a considerable number of technical men will take the examination for consular service. The Department recognizes that the interest of the United States will be served best if technical men are made available through these examinations for vacancies at points where their training will be of special value. Industrial engineers who have passed the con-sular examination will be assigned to industrial centers of Europe or South America. Mining engineers, chemists, electrical engineers, etc., will be assigned to industrial centers requiring special training.

Jan 11, 1919

By Fred A. Anderson, George B. Wallace, Edward J. Slebir

As the reservoir rises behind an arch dam, it presses the arch into the canyon walls and valley floor. To compute the stresses, deflections, and arch reactions, it is necessary to know how much the rock deforms under the combined loads of gravity, temperature, and water. Under sustained loading for a period of time, the rock continues to deform or "creep" slightly, causing changes in the stresses and shape of the arch. Under reduced loading, the elastic arch tends to resume its unstrained position and it is important to know that the rock will follow it and maintain tight contact along the abutment. It is, therefore, important to know the "set" characteristic of the rock. Past attempts to define load-deformation properties of rock, including creep and set, have largely l been limited to laboratory test of intact cores and in-situ jacking test utilizing bearing plates 2 to 3 ft in diam. In both cases, a uniaxial load has been applied to a volume of rock too small to fully reflect the influence of cracks, joint systems, foliation, and other inherent weaknesses within the rock mass. This chapter describes a large radial jacking test which more nearly duplicates the action of an arch dam by penetrating the load deep into the rock mass, bringing into play more of the factors which contribute to prototype deformation. Results obtained from the large radial test are compared with those from smaller uniaxial test. DESCRIPTION OF RADIAL TEST The radial jacking test described in this chapter was performed in an adit off of an exploratory tunnel driven into a proposed dam abutment

Jan 1, 1972

By W. B. Braden

This paper presents a suitable method for predicting gas-free oil viscosities at temperatures up to 500F knowing only the API gravity of the oil at 60F and the viscosity of the oil measured at any relatively low temperature. The API pravity and the one viscosity value are used as parameters to determine the slope of a straight line on the ASTM slanaord viscosity-temperature chart. Then, knowing the slope of the line and one point on the line, the vrscosities at higher temperatures can be determined. The line slope correlations were developed at I00 and 210F since viscosity data are frequently measured at these temperatures. A procedure is given for predicting line slopes from measurements at other tetnperatures. A nomogram is furnished for solving the relationship. The correlation has been evaluated at temperatures up to 5OOF for oils varyzng in gravity from 10 to 33 " API. The correiution is applicable only to Newtonian fluids. Comparison at 500F of true viscosities and those predicted from values at 100F shows an average deviation of 3.0 per cent (maximum deviation of 6.0 per cent). Predictions from the values at 21 0F for the same oils how an average deviation of 1.5 per cent (maximum deviation of 3.4 per cent). INTRODUCTION Correlations have been developed by Beal' and by Chew and Connally' for predicting viscosities of gas-saturated oils at reservoir conditions. Each of these correlations requires a knowledge of the solution gas-oil ratio and the viscosity of the gas-free oil at the reservoir temperature. For temperatures below 350F, measurements of the gas-free oil viscosities can be made easily using commercially available equipment. In thermal recovery processes, however, reservoir temperatures well in excess of 350F are encountered. Viscosity measurements at such conditions are more difficult and time consuming and require modification of existing equipment or the construction of new equipment. Measurements are further complicated by the difficulty of handling highly viscous oils associated with thermal recovery processes. Therefore, it is desirable to have a correlation which allows accurate prediction of viscosities at high temperatures. A commonly used technique for predicting viscosities at high temperatures is to measure the viscosities at two lower temperatures, plot the values on ASTM standard viscosity-temperature charts and extrapolate to the temperatures desired. If either of the values is slightly in error, the extrapolated value can be significantly in error. To justify an extrapolation, three points are actually necessary. This procedure can consume much time, particularly with heavy oils. Considering the cost of viscosity measurements, it would be desirable to eliminate the need for direct measurements by having correlations which would allow viscosity predictions from other physical or chemical properties. Beal1 investigated the possibility of correlating viscosity with oil gravity at temperatures from 100 to 220F. While showing that a general relationship exists, he also found significant deviations. It is possible that correlations will be developed based on oil composition as more information becomes available. While not eliminating the need for viscosity rneasurements, the method presented herein requires that only one viscosity measurement be made. The API gravity must also be known. The theory is based on the fact that the viscosity of paraffins (high gravity) changes less with temperature than does the viscosity of naph-thenes or aromatics (low gravity). The gravity. therefore, is used as a parameter to determine the slope of a straight line on the ASTM standard viscosity-temperature charts. The correlation is applicable only to Newtonian oils, and deviations due to thermal decomposition and nonhomo-geneity cannot be predicted. Oils containing additives have not been evaluated. PROCEDURE Fifteen oils were used in developing the correlation; eight were crudes and seven were processed oils. Oil gravities varied from 9.9" API (naphthene base) to 32.7' API (paraffin base). The temperature range studied was 81 to 516F. Each oil used had a minimum of three viscosity measurements and each plotted essentially as a straight line on the ASTM charts. In all, 91 viscosity measurements were used in the correlation. Saybolt, rolling ball and capillary tube viscometers were used for the measurements. Viscosity data for Samples 1, 2, 4, 7, 10, 11 and 14 were obtained in Texaco, Inc. laboratories. The data for Samples 3, 5, 6, 8, 9, 12 and 15 were from Fortsch and Wilson,3 and data for Sample 13 were from Dean and Lane.' All data points used in the correlation are plotted in Fig. 1. It is seen that some of the viscosity values deviated slightly from the straight-line plots at the higher temperatures. Properties of the oils after exposure to the

Jan 1, 1967

By AIME AIME

Council.* PRESIDENT OF THE COUNCIL. JOHN HAYS HAMMOND* New York, N. Y. (Term expires February, 1909.) VICE-PRESIDENTS OF THE COUNCIL. SAMUEL B. CHRISTY BERKELEY, CAL. JOHN A. CHURCH NEW YORK, N. Y. PERSIFOR FRAZER PHILADELPHIA, PA. (Term expires February, 1909.) J. PARKE CHANNING NEW YORK, N. Y. FREDERICK 1V. DENTON PAINESDALE, MICH. JOHN B. FARISH DENVER, COLO. (Term expires February, 1910.)

Mar 1, 1908

By Charles E. Packard

Many coal producers have been faced recently with the problem of arranging their production facilities to accommodate recent trends in the transportation of their product. Each operator is normally faced with a different problem requiring a system to meet his specific needs. It may be that he would be required to load a seven or eight thousand ton integral train each day which would naturally call for a large storage pile, high loading rate, accomplished in a minimum of time On the other hand, it may be that he is faced with furnishing coal to make up one-half of a unit train that is to be assembled twice a week. Whether the problem is large or small, many considerations must be given to each specific problem to be certain that the proper scheme is applied. The operator actually has several choices as to what type of storage and loading facilities he may consider. The storage pile, for instance, may be open type, conical in shape, kidney-shaped, or long and wedge-shaped. It may also be enclosed by steel or concrete

Jan 8, 1964

By S. J. Aresco, George E. Keller, J. Visman

INTRODUCTION The accurate sampling of coal, as with most minerals, is a difficult task. Coal is a very heterogeneous material made up of different types of coal and varying amounts of mineral matter. The product as mined may contain all of the layers of coal and impurities found in the seam as well as portions of the strata above and below the coal seam. The preparation plant is the device to size, crush and/or remove impurities so that the coal may be shipped as a saleable product. Sampling may be needed at many stages in the preparation process. Although this chapter is mainly concerned with sampling in connection with preparation processes, the principles will apply to all coal sampling. The main reasons for sampling in connection with coal preparation are: 1. To determine the washability characteristics of the raw coal by means of float and sink tests. These may be used for the design of a preparation plant, prediction of results to be obtained or for monitoring raw coal delivered to the plant. 2. To check the performance of various operating units in the plant, either by float and sink tests or chemical analyses. 3. To determine the analytical characteristics of the products produced, such as moisture, ash, Btu, sulfur, etc. HISTORY The earliest accepted methods of sampling coal in the United States were given in U. S. Bureau of Mines publications by J. A. Holmes,1 G. S. Pope2 and A. C. Fieldner.3 The American Society for Testing and Materials more or less adopted the methods proposed by the U.S. Bureau of Mines in their Standard D-21-1916, and it remained a standard for many years. Briefly, the standard called for a 500 pound sample for coals less than. 3/4 -in. in size and a 1,000 pound sample for all coals over ?4 -in. in size. No mention was made of increments but there was an instruction that the sample should spread over the coal to be sampled. Sample preparation was by hand crushing with the alternate shovel method for reduction to 250 pounds followed by coning and quartering below 250 pounds. Obviously, with the amount of work involved, this method of sample preparation was rarely followed. This method of preparation resulted in samples that were practically air dried because of long exposure while crushing, shoveling and quartering. In the late nineteen twenties and early nineteen thirties, studies for more practical methods were begun. Dr. E. S. Grummell4, Imperial Chemical Industries, Ltd, London, summarized the work to date at the

Jan 1, 1968

By Clement K. Chase

The ammonia leach for copper recovery is discussed from historical and current practice standpoints. The chemistry of the system is presented together with Eh-pH and copper-ammonia solubility curves. A list of metals forming ammine complexes is presented. The advantages and disadvantages of the ammonia leach as applied to copper recovery in conjuction with modern liquid ion exchange techniques are compared.

Jan 1, 1980

By Theron Wasson

The discovery of eight new oil fields, two of which may be of major importance, was the outstanding record in Michigan this year. These new fields have helped to support the declining production from old areas and place the total of 18,559,000 bbl. in line with the past six or seven years. Thus, it appears that Michigan is doing its part in maintaining the production of the country in the third year of the war. The new fields are in the central basin area where oil was first discovered in Michigan, thus tending to focus attention on the deeper part of the lower peninsula of the state. Through 1944 the state of Michigan has produced a total of 222,-641,580 bbl. of crude oil from 100 pools, many of which arc relatively small. Among the previous1y discovered fields Reed City is still the outstanding producer, with Fork, Headquarters, and Adams following in the order named. The Reed City pool produced a little over 5,000,00 bbl., which was more than one third of the state's total for the year. Almost two thirds of the year's total oil production came from fields discovered in the past five years. Maps A map of the oil and gas fields of Michigan in 1943, published in the A.I.M.E. report for 1944,* shows the main producing areas and should be referred to if information in regard to their location is desired. The producing zones are shown in the columnar section in the same publi- cation." The data in Tables I and 2 have been carefully ' checked and every effort has been made to show as complcte information as possible. New Discoveries and New Developments Eight new producing areas were discovered during 1944 which, in order of importance, are: Deep River Field.—The discovery well in the Deep River field was drilled by Don Rayburn and others, and should be listed as a chance discovery, as, from a geological standpoint, it was not considered favorable until oil was found at a depth of 2838 ft. in a dolomitic layer in the top of the Dundee limestone. The first well was completed in January 1944, with an initial production of 2500 bbl. By the end of the year 15 wells had been completed, proying an area 2 1/2 miles long and 1/2 mile wide. Coldttater Field.-The Coldwater field was discovered in August 1944, by the Sohio Oil Co. Production is from secondary dolomite at the top of the Dundee at a depth of 3703 ft. To the end of 1944 nine wells had been drilled on 40-acre spacing. Essexville Field.—Essexville field was discovered by United Drillers and Producers, Inc. Eight wells had been completed to the Dundee lime by the end of 1944, and prospects were good for further development during 1945. Hilliards Field.—Hilliards field was discovered by Cook and Fortney. Production is from the Traverse lime at an average depth of 1588 feet,

Jan 1, 1945

We are advised by Second-Lieutenant Maxwell E. Erdofy, a member of the Institute, and athletic officer of the 602d Engineers, stationed at Camp Devens, Mass., that his regiment, representing all branches of the engineering profession, is in need of athletic equipment and supplies. The regiment will highly appreciate any assistance in the way of financial contributions, or of apparatus and equipment for their athletic needs.

Jan 5, 1918

By L. C. Aycock, J. Hunter, P. M. Lyons

In view of the unfavorable discovery trend that has set in during the past few years, it seems permissible to infer that the large, more easily found crude reserves in Louisiana are now known. Without doubt, many new producing areas will be located, but in the light of development during the past few years the majority of new areas probably will be found at greater depths and from relatively poorer sands. f Although sufficient reserves exist in Louisiana to last at the present rate of production for a considerable period, additional reserves must be found in more intensive development of the presently known structures. In order to ensure the greatest ultimate recovery from such structures, the most advanced technical methods must be employed in their exploitation. Wherever possible, cycling and repressuring plants should be installed. 'here are presently in Louisiana, especially in south Louisiana, a great many fields that contain gas-condensate reservoirs. These reservoirs cannot be produced for their liquid hydrocarbon content under present conditions without wasting an enormous quantity of gas and creating underground waste. Although some of these reservoirs are being produced, such production must be considered in the nature of a salvage operation rather than as a sound economic proposition. Such reservoirs, however, can become profitable ven- tures through the use of cycling and repressuring plants. Cycling operations now operating in Louisiana have increased the ultimate recovery from gas-condensate reservoirs anywhere from 10 to 30 per cent. Cycling operations will also provide a considerable reserve of gas, without which Louisiana cannot hope to develop any program of industrialization. During the past year, Louisiana attained the rank of third among the oil-producing states of this country. With a proper program of exploitation and development, and with emphasis on conservation, Louisiana can maintain this position for a great many years. Production On Dec. 31, 1943, oil and/or gas were being. produced in 52 parishes, or 81 per cent of all the parishes in the state. Thirty-three of the parishes produced oil and gas, 14 produced oil, and 5 produced solely gas. Tensas Parish in north Louisiana and Assumption Parish in south Louisiana formerly contained no producing fields but during 1943 joined the ranks of the producing parishes. Twenty-three new fields, including one rediscovery, were found during 1943-—a rate of discovery almost comparable to that of the preceding year. Eleven of these new discoveries were either gas or gas-condensate fields. Thus, the trend of development in finding new reserves was also comparable to that of 1942. Many reasons of considerable merit have been advanced to account for the discouraging lack of crude-oil reserves found during the past year. None are, however, completely satisfactory.

Jan 1, 1944

By J. Hunter, P. M. Lyons, L. C. Aycock

In view of the unfavorable discovery trend that has set in during the past few years, it seems permissible to infer that the large, more easily found crude reserves in Louisiana are now known. Without doubt, many new producing areas will be located, but in the light of development during the past few years the majority of new areas probably will be found at greater depths and from relatively poorer sands. f Although sufficient reserves exist in Louisiana to last at the present rate of production for a considerable period, additional reserves must be found in more intensive development of the presently known structures. In order to ensure the greatest ultimate recovery from such structures, the most advanced technical methods must be employed in their exploitation. Wherever possible, cycling and repressuring plants should be installed. 'here are presently in Louisiana, especially in south Louisiana, a great many fields that contain gas-condensate reservoirs. These reservoirs cannot be produced for their liquid hydrocarbon content under present conditions without wasting an enormous quantity of gas and creating underground waste. Although some of these reservoirs are being produced, such production must be considered in the nature of a salvage operation rather than as a sound economic proposition. Such reservoirs, however, can become profitable ven- tures through the use of cycling and repressuring plants. Cycling operations now operating in Louisiana have increased the ultimate recovery from gas-condensate reservoirs anywhere from 10 to 30 per cent. Cycling operations will also provide a considerable reserve of gas, without which Louisiana cannot hope to develop any program of industrialization. During the past year, Louisiana attained the rank of third among the oil-producing states of this country. With a proper program of exploitation and development, and with emphasis on conservation, Louisiana can maintain this position for a great many years. Production On Dec. 31, 1943, oil and/or gas were being. produced in 52 parishes, or 81 per cent of all the parishes in the state. Thirty-three of the parishes produced oil and gas, 14 produced oil, and 5 produced solely gas. Tensas Parish in north Louisiana and Assumption Parish in south Louisiana formerly contained no producing fields but during 1943 joined the ranks of the producing parishes. Twenty-three new fields, including one rediscovery, were found during 1943-—a rate of discovery almost comparable to that of the preceding year. Eleven of these new discoveries were either gas or gas-condensate fields. Thus, the trend of development in finding new reserves was also comparable to that of 1942. Many reasons of considerable merit have been advanced to account for the discouraging lack of crude-oil reserves found during the past year. None are, however, completely satisfactory.

Jan 1, 1944

By A. A. Gustafson

The Freeport Sulphur Co. built a portable crusher in 1944 that solved a problem that none of the crusher manufacturing companies contacted were able to do. Two of these crushers have now been in service for 6 years, giving satisfactory service in handling a million tons per year, and having a capacity of over 2000 long tons per 8-hr shift. These machines reduce ton size blocks of sulphur to 12 in. and also feed the conveyor system at the rate of 350 long tons per hr per machine.

Jan 10, 1950

By James H. Boettcher

INTRODUCTION There are many and varied sources of finance available to the mining industry for exploration, development and/or the operation of mining projects and companies. These sources include equity from major as well as "penny" stock exchanges, precious metal mutual funds, private investor groups (from "grubstakes" to tax-oriented limited partnerships) and banks. The variety is representative of the fact that the world's capital markets are segmented and stratified according to risk-reward characteristics. This interrelationship is summarized in Exhibit I and 2 which relate (very approximately) various sources of finance to a typical mining project's life cycle and risk-return characteristics. The objective of this paper is to introduce, as it applies to the mining industry, a somewhat recent phenomenon represented by one of these capital markets segments referred to as "venture capital." Venture capital investing per se, which today is a multibillion dollars per annum investment business, goes back as far as Queen Isabela's backing of Columbus' "wild ideas." The real institutionalization of the venture capital process really began in earnest, however, after World War II. Today over 700 private venture capital sources (and more government related ones) exist providing funding to a range of industries, but typically related to the "high-tech" business. The table to the right shows industries financed by venture capital funds between 1980 and 1982. Conspicuous by its absence is, of course, mining which is not a great surprise since typical mining projects up until recently were large, required long lead times and were undertaken by established mining houses. Also, as most of you can appreciate, successful investing in the mining business requires a great deal of experience and understanding of the industry which most venture capital funds do not have. TARGETED RETURN The rate of return objective of most venture capital funds is, according to the legalized version, to realize a return which is "substantially in excess of that obtainable through conventional equity investments." One may say that a common objective of venture capital funds is to realize a 20% to 30% compound annual internal rate of return on capital over their life which is often ten years. [ ] This objective has been recently more feasible in the mining sector due to the development of smaller precious metal projects which cost less and are quicker to generate cash flow than the behemoth projects of the 1970s. In addition to precious metals, venture capitalists have invested or looked at a variety of other mining projects including ones as prosaic as a high margin "kitty litter" operation, sand-gravel and other industrial minerals operations, the leveraged buyouts of coal mines or mineral divisions of major energy or mining corporations, and even in in-situ copper or gold leaching ventures. A typical investment is in the range of $100,000 to $3,000,000 although some can go as high as 5,000,000. This implies a project size up to, say, 30,000,000 if a venture capital fund does it on its own. Larger projects can be done if the equity portion of the investment is syndicated with other investors.

Jan 1, 1985

By AIME AIME

WHEN the War Production Board issued its order which will end the use of iron and steel in more than 400 familiar civilian articles, the list of those products formed a fascinating and homeric catalogue of the things we use. Articles for which iron and steel may not be used after a 90-day "tapering-off" period are as workaday as office machinery and as frivolous as cocktail shakers. Mostly they are smaller items-the smallest probably are phonograph needles but in the aggregate they will save tremendous quantities of the metal most needed to win the war. In total war there are no trifles. Interesting proof of this lies in the fact that by eliminating manufacture of blackhead squeezers we shall save 110,000 lb. of steel a year. Out of this steel we might have made four 155-mm. field pieces. We might have made a thousand 3-in. trench mortars, 4400 0.30-caliber machine guns, 55 16-in. shells, 110 200-lb. aerial bombs, or three 15-ton tanks with something left over to arm them.

Jan 1, 1942

By Cleland N. Conwell

APPLICATION of seismic methods to the location of buried channels in placer mining is fairly common knowledge, yet some of the facets of seismic refraction surveys have remained obscure in their application to mining. This description by a member of the U. S. Bureau of Reclamation team investigating bedrock at the Oso Dam site, may offer a lead to wider application of the method for bedrock determinations in engineering of mine and mill plants, tailing disposal, and water supply. It may also offer assistance in planning geological exploration in areas covered by overburden. Pertinent, and perhaps more than passingly significant, is that the seismic survey of the Oso dam site started at noon and was completed the afternoon of the next day. Location Oso dam site is on the Navajo River, Archuleta, County, Colo., 30 miles southeast of Pagosa Springs, Colo., 10 miles northwest of Chama, N. M. Bedrock at the proposed dam site is Mesa Verde Formation, Cretaceous age sandstone. The nearest good sandstone exposure is about 5/8 of a mile upstream from the location of the seismic determinations. The material above bedrock is sand and gravel with sandy loam soil covering benches above the river. The site appeared favorable, after a geologic and topographic reconnaissance, but overburden thickness was unknown. Exploratory drilling was not contemplated in the near future so a short seismic investigation was selected as the most suitable method of determining depth to bedrock. Field Procedure Geophysically, a seismic depth investigation is simply the measurement of depth from ground surface to the top of a layer which transmits seismic waves at a higher velocity. In this case the high-velocity seismic layer tentatively correlates with the Mesa Verde sandstone. Field procedure required a seismic explorationline or "spread" with 12 geophones set at measured intervals. Explosive charges were buried at few feet in the ground and detonated at shotpoints near the ends of the spread, and at intermediate points. The time of travel of the seismic waves from the shotpoints through the ground to each of the geophones along the spread was measured and recorded photographically with equipment housed in a field truck. The seismograph on each spread provided a time-travel graph. From it were computed the speed of seismic waves in various layers below the surface and depth to each different seismic layer below the shotpoint. In the case of the Oso dam site it was possible, in addition, to determine the depths below certain geophones, because there were only two seismic layers involved. Interpretation In seismic exploration waves are refracted from the top of layers which often correspond to divisions between subsurface formations. When drill holes are available the geologic logs offer a means of correlating stratigraphic breaks with seismic layers, improving reliability of seismic interpretation in terms of depth to bedrock or other geologic terms. There were no drill holes available in the case of the work at the Oso dam site. Geologic conditions appeared favorable for seismic technique because of excellent contrast in seismic wave velocity between the overburden and the Mesa Verde formation. The upper layer had a velocity of approximately 2500 fps and was interpreted as overburden, the lower layer had a velocity of approximately 9000 fps and was assumed to be the sandstone. These velocities are of the order expected in these materials. The seismographs obtained at the Oso dam site were excellent. The energy from the shot came in strongly at each geophone, giving an easily read record. Time-travel graphs plotted from wave arrival times were uniform and made interpretation comparatively easy. In Spreads 1 and 2 near the river the lower velocity layer was 12 to 15 ft deep. For the spreads on higher ground, or the bench south of the river, it was from 15 to 29 ft deep.

Jan 1, 1952

By M. D. Banus, M. B. Bever, A. K. Jena

The heals of formation at 78", 195, and 273°K of the ternary compound h3SbTe2 based on the elements and based on the binary compounds In Sb and [inTe have been measured. The heats of formation at these temperatlcres of the binary compounds In Sb and In Te based on the elements have also been determined. Heal contents and free energies of the three compounds have been calculated from 0° lo 80I)°K. The free energies of joyrrzalion, heats of formations, and entropies of formation at 298°K have also been calculated. The results shown that the tertnary compound is metastable with vespecl to InSh and ln Te below 696 °K. bul is slable above that temperature. The weaker bonding of results in a positice entropy of formation which with incrensirzg temperature makes increasing negative conlvihtclions to the free energy and above 696°K renders the compound slable. THE ternary compound In3SbTez occurring in the quasi-binary system In Sb- In Te' forms on cooling at 829°K by a peritectic reaction.' Observations at 673" and 573 K have shown that this ternary compound decomposes slowly into the binary compounds InSb and1n~e.l'' It has not been possible to analyze the metastable behavior of the ternary compound because up to the present time data on its thermodynamic properties have been lacking. Some information on the binary compounds, however, is available. The heat of formation of InTe at 273°K and its free energy at 673°K are kn~wn.~'~ The heats of formation of InSb at 78", 273', 298", and 723°K have been measured5-' and its heat capacity between approximately 12" and 300"Kg9l0 is also known. In the investigation reported here the heats of formation at 78% 195% and 273°K of the ternary compound In3SbTez have been measured. The heats of formation of the binary compounds InSb and InTe at these temperatures have been obtained by combining new calorimetric results with previously published data. The heat contents and free energies of the three compounds at various temperatures from 0" to 800°K have been calculated. Against the background of this information, the metastability of the ternary compound will be discussed. 1) EXPERIMENTAL 1.l) Preparation of Specimens. The materials used consisted of the elements indium, antimony, and tellurium, the binary compounds InSb and InTe, and the ternary compound In3SbTez. The elements, obtained from American Smelting and Refining Co., had a nominal purity of 99.999+ pct. The compound InSb was Cominco semiconductor grade; the compound InTe was prepared from the elements by melting under a vacuum of 10-h m Hg followed by slow cooling. Three batches of specimens of the compound In3SbTez were used. One batch was prepared by melting appropriate amounts of the elements in an evacuated and sealed Vycor tube. The melt was held at approximately 100°K above the liquidus for about 8 hr, shaken repeatedly, and quenched into a mixture of ice and water. The specimen was annealed in vacuum at 760°K for 4 weeks. In preparing a second batch, a mixture of the component elements was melted and quenched in water. The resulting ingot was powdered. The powder was pressed into pellets, which were annealed in vacuum at 748" to 773°K for 4 weeks. A third batch was prepared in the same manner as the second, except that the starting materials were InSb and InTe rather than the elements. Metallographic examination of samples of the three batches and X-ray diffraction examination of a sample of the second batch did not reveal evidence of microsegregation or a second phase. The results obtained with the three batches showed no systematic differences. 1.2) Calorimetry. The calorimetric method has been described in detail." Samples of the compound In3SbTez, mechanical mixtures of InSb and InTe in the proportion of 1:2, and mechanical mixtures of indium, antimony, and tellurium in the proportion of 3:1:2 were added to a bismuth-rich bath at 623°K in a metal-solution calorimeter. These additions were made from 78°K (liquid nitrogen), 195°K (dry ice and acetone), and 273°K (ice and water). The heat effects of the additions were measured. The difference in the heat effects of the additions of a compound and the additions of the mixtures of its constituents, adjusted for differences in the concentration of the bath, is the heat of formation of the compound. In the concentration range not exceeding 1.5 at. pct solute, the heat effect of the additions was a linear function of concentration. The heat of formation refers to the temperature from which the additions were made, namely, 78", 195", or 273°K. Several calibrating additions were made in each calorimetric run. The calculated heat capacity of the calorimeter and hence the calculated heat effects of the additions of samples depend upon the values adopted for the heat contents of the calibrating substance. In this investigation bismuth at 273°K was used and a value of 4.96 kcal per g-atom was taken for (HGZ3"k . 2) RESULTS AND DISCUSSION 2.l) Heats of Formation. The heats of formation of the ternary compound In~SbTez from the component elements indium, antimony, and tellurium and from

Jan 1, 1968

TO THE BOARD OF DIRECTORS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS Gentlemen -The Institute was founded 54 years ago "with the object of promoting the arts and sciences connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained" At least once a year it is well to take stock of our assets, review our performance and determine how well we are now carrying out the purposes of our Founders There can be no question as to the work the Institute has done and is doing in promoting the arts and sciences in the fields of mining and metallurgy One needs only to contiast the methods, the labor and the costs of a half century ago with those now to visualize how far we have gone in the development of accurate technology and sound economics in mineral and metal production The great mines, mills and smelters of the present, handling individually thousands of tons per day, would have been impossible except for the accumulation of knowledge, the development of theory, and the improvement in practice that has charac¬terized the period since the foundation of the Institute The United States has prospered in the last half century greatly, and this has been due not merely to the possession of great natural resources, but to these resources being reduced to possession and put to work The absence of customs barriers and the freedom of trade across the whole width of this great continent has been an important factor in the growth of our wealth Unrestricted interchange of goods has permitted each citizen to draw on the resources of the whole country However, these are but subsidiary causes of prosperity The free interchange of scientific and technical data, by making the whole body of facts and theory available to each worker, has made this quick and unrivaled development possible In promoting this free trade in knowledge the Institute may claim a large place without fear of denial The 72 volumes of TRANSACTIONS, the special volumes, the bulletins and the other pub¬lications that have been issued, include a store of knowledge of the arts and sciences related to the pioduction and use of metals and minerals not duplicated elsewhere The large list of foreign members-1746 in number-few of whom ever have opportunity to attend meetings and all of whom derive their main benefits from membership through the pub-

Jan 1, 1923

By Karl Cohen

The question of attainment of competitive nuclear electric power is of interest to uranium producers because the rate of attainment of this goal determines the date when there will be a solid, non-political, domestic uranium market. It is a burning question to those of us in the civilian nuclear power business, because our entire business future hinges on how well, and how soon, we can make electricity from nuclear reactions at prices comparable to electricity from coal. For an idea of the magnitudes involved, consider that the first fuel load of the Dresden (Illinois) nuclear power station, plus spares, will be about 90 tons of 1.5 pct UO2. This requires about two-and- a-half times as much natural uranium oxide feed to the diffusion plant, or 225 tons. This, in turn, represents about a month's production from the nearby Uranium Reduction Co. mill. Note also that the 180,000 kw electric output of the Dresden station will be about 0.1 pct of the national electric generating capacity in 1960.

Jan 12, 1958