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By J. C. De Haven, Harry Seltz

INTERMETALLIC compounds are formed in many binary metal systems. Some compounds are stable to their melting points, and others decompose at lower transition temperatures. Even those of the first class are dissociated in the liquid state, as indicated by the continuous form of their solubility curves at their melting points'. While the lattice structures of some of these compounds' have been determined, their thermodynamic properties have not been investigated. In this paper is described the determination of the free energy and heat of formation of the compound CdSb, which is of the first class mentioned above, melting congruently at 455° C. This compound shows a rhombic structure, and the lengths of the edges of the elementary cell containing four molecules are: a = 6.52,b=8.60,c=4.16Å2 There are three possible methods of determining the free energy of formation of a compound of this type. The first method, applying the third law of thermodynamics, requires the measurement of its heat capacity preferably to liquid hydrogen temperatures, and a calorimetric determination of its heat of formation. The second method involves the study of the equilibrium of the compound in some gas reaction, such as: CdSb + CO2 = CdO + CO + Sb. From the known free energies of formation of, CdO, CO2 and CO the free energy of formation of CdSb could be calculated. The third method measures the electromotive force of a galvanic cell in which the cell

Jan 1, 1935

By GEORGE A. KIERSCH

The awesome destructive power of known and projected weapons of war presages a new need for geologists and engineers, who may be called upon to locate vital industry underground, thereby protecting it from sky-borne destruction. The Corps of Engineers is now conducting special tests to establish design standards covering the general field of underground installations as well as surveys a of construction methods and the operational hazards connected with such plants. National planning must dictate a policy that is either tactical, where surface manufactured parts; are stored underground and during art emergency assembled, or operational with both the manufacturing and assemblage completed in subsurface plants. Both plans of operation require the use of subterranean plants. Relocation of vital plants underground will probably involve only a small percentage of the production capacity of this nation. The cost of rebuilding in new location will obviously limit its adoption

Jan 1, 1949

By TRUMAN S. FULLER

THE GREAT INTEREST in decomposition and trans- formation, so evident in the study of alloys during the last two years, was reflected in the many papers on this subject, presented at the first session of the Institute of Metals, Tuesday morning. Dr. F. A. Thomson, of Montana State School of Mines, presented the first paper by C. Wilson, H. F. Silliman, and E. C. Little, "Rate of Precipitation of Nickel Silicide and Cobalt Silicide in the Hardenable Copper-nickel-silicon and Copper- cobalt-silicon Alloys." Dr. R. F. Mehl, in discussing this paper, stated that the title was somewhat deceptive, as it indicated that the rate of precipitation is determined; the method used is a measurement of electrical conductivity and hardness, neither of which is suitable for a quantitative measurement of rates of reaction or precipitation in the solid state. Hardness is also uncertain because it depends so much upon particle size. Of the various methods proposed for the study of rate of reaction and precipitation the evaluation of volume of reaction produced from the area of photomicrograph is the best.

Jan 1, 1933

The Palabora ore consists of two types, a carbonatite containing a low titanium magnetite, and a foskorite containing high titanium magnetite. The latter type also contains substantial quantities of phosphate. These two ore types are separately crushed and are kept separate through copper flotation and magnetic separation, for recovery of magnetite, with the low Ti magnetite being shipped as iron ore. High phosphate tailings are pumped to Foskor, a government-owned phosphate plant nearby. The Palabora plant was originally designed in 1966 for 33, 000 tpd using two 54 in. by 74 in. Allis -Chalmers gyratories; two 7 ft (2. 13 m) standards; four 7 ft shortheads; and six grinding lines, each using one 1,200 hp rod mill and two 1,200 hp ball mills. A fifth short- head and one more grinding line were added later; and with flowsheet improvements, the capacity of the plant was increased to 59, 500 stpd. A further plant expansion involving a third 54 in. primary and two 32 ft by 15 ft (9.75 by 4.6 m) 9,000 hp autogenous mills and another flotation section will bring its capacity to 87,500 stpd in 1977. These two fully autogenous mills are constructed entirely out of doors near the primary crusher, and the ground ore will be pumped a mile to the concentrator by a five-stage pumping system. The Palabora ore is mined with 6, 10, and 12 7d (4.6, 7.6, and 9. 2 cu m) shovels and hauled to the crushers in 110 and 165 st trucks. Sixty-five ton trucks were originally used, but the crusher dump pockets were designed for larger units. Dump pockets, crushers, feeders, and take- away belts are offset in order to keep the two ore types separate. Centerlines of the crushers are only 43 ft (13. 1 m) apart; but, because of their being offset, maintenance room is ample. Initially, more carbonatite ore than foskorite was mined; but as the pit has deepened, this ratio has been reversed. The Palabora ore breaks in the pit with a large amount of oversize boulders; and, with the use of larger trucks, a splitter has been installed on one side of each dump pocket to protect the crusher spider. Smaller trucks dump on the opposite side. To accomodate the splitter, the pocket edge has been raised one meter and moved back one meter. Dust is collected through a special vent shaft between the crushers and the mantle relining area; but even so, two high-pressure water spray headers with nozzles are installed under the edge of the pocket at each dumping position. While only one truck dumps at a time, sprays from all four headers are used to suppress dust. Any leakage of water through the seal around the upper bowl of the crusher is caught by a circular trough under the seal and directed to a sump pump. At this point, there

Jan 1, 1978

By AIME AIME

WITHOUT frills, but with an admirable program of technical papers and discussion, many opportunities for social contact, and all New York for a playground, the 142d Meeting of the Institute will make the Engineering Societies Building a lively place from Feb. 20 to 23. Prices are down, even in New York. Come and forget the depression listening to the stories of old friends. Hear at first hand what is going on in your professional world. The fare is varied, of wide appeal. The program on the opposite page has been arranged carefully to minimize conflicts between the subjects in which you are interested. If it is not possible to come for all four days, check over the sessions that are most important to you. No changes in the scheduling are likely.

Jan 1, 1933

By Leonard Larson

Before direct or wet smelting of copper concentrate was adopted at the McGill smelter, in November 1932, actual furnace smelting tests had indicated the possibility of smelting between 400 and 500 dry tons of wet concentrate per furnace day. Under calcine smelting practice, solid charge up to 116; tons per furnace day had been smelted. It was realized that in order to smelt wet tonnage in equivalent amount per furnace day, a higher combustion rate and higher temperatures would be necessary within the furnace. The reverberatory furnace considered in the following history of wet-smelting developments is a unit rz7 ft. long and 28 ft. 8 in. wide, inside dimensions (Fig. I). This furnace was in operation through all the years from 1934 to date. During 1933, the first complete year of direct or wet smelting, the plant was on a curtailed copper-production basis and the available concentrate tonnage to be smelted was limited. The average coal-firing rate in the reverberatory for that year was 124 tons per furnace day. This rate was lower than the average for years immediately preceding under calcine smelting practice. With this coal-firing rate, an average of 391 tons of new metal-bearing material (N.M.B.M.) was smelted per furnace day. The following year, 1934, the coal-firing rate was increased to 139 tons and the smelting rate increased to 448 tons N.M.B.M. per fur- nace day. In succeeding years production required that either more tonnage be smelted in the one furnace or an additional furnace be placed in operation. With this situation confronting the smelting department, it was determined to continue the program of increasing the coal-firing rate and also to intensify the temperature in the smelting zone of the furnace. In order to accoinplish this, various improvements were made to aid combustion within the furnace. The burners were enlarged, increased primary air was supplied to the burners, and changes were made in the furnace to enlarge and streamline the outlet, thus increasing the furnace draft. The coal-firing rate was increased yearly until 1937 when the firing rate averaged 210 tons per furnace day. Thereafter the firing rate fluctuated according to character of charge and production requirements. In general, however, with the same character of charge the smelting rate increased in almost direct proportion to the increases in firing rate. Table I shows the average coal-firing rate, smelting rate, and other pertinent data for the direct-smelting years of 1933 to 1939 inclusive, the first fivc months of 1940 and May 1940. These figures show that the water evaporated in the waste-heat boilers was in almost direct proportion to the coal-firing rate. In making comparisons in the table, it should be borne in mind that the figures, except for May 1940, are yearly averages. Because of changes in character of charge or operating conditions, records for individual days or even months

Jan 1, 1944

THE Nominating Committee appointed at the Division meeting in October and consisting of Frank A. Herald, A. W. Peake, C. R. McCollom, Joseph Jensen, H. W. Camp, C. P. Watson, F. Julius Fohs, George Otis Smith, J. B. Umpleby, J. M. Lovejoy and A. W. Ambrose, have presented the following ticket for the year 1929: Chairman, Joseph B. Umpleby; associate chairman, A. C. Rubel; secretary-treasurer, R. Van A. Mills; vice-chairman for Economics, Warren A.. Sinshein~er; vice-chairman for Engineering Education, H. C. George; vice-chairman for Engineering Research, Harry H. Hill; vice-chairman for Production, C. P. Watson;vice-chairman for Refinery Engineering, A. D. David. For Production Engineering Charles V. Millikan. is named vicechairman, with ,Charles E. Beecher, Glenn D. Robertson and W. W. Scott as associate vice-chairmen. The Executive Committee named is to consist of Joseph B. Umpleby, chairman with A. W. Ambrose, Charles E. Beecher, A. D. David, Glenn D. Robertson, H. C. George, Harry H. Hill, John M. Lovejoy, Charles V. Millikan, R. Van A. Mills, Earl Oliver, A. W. Peake, A. C. Rubel, W. W. Scott, Warren A. Sinsheimer and .C. P. Watson, members. Ballots will be mailed to members of the Division.

Jan 1, 1928

By Edward W. Parker

IF one is to place any credence at all in the reports published in the daily press, the subject of conservation has been a very lively topic of conversation during the past 60 days, and it does not appear that the temperature of the summer months has been in any way moderated by the discussion. It is a subject in which we are all vitally interested and to which, so far as our mineral resources are concerned, both the Institute and the Geological Survey have liberally contributed. The report of the National Conservation Commission, appointed by President Roosevelt, contains a series of papers on the conservation of mineral resources, all of which were prepared by members of the Geological Survey and were compiled largely from information previously collected by that Federal bureau in the performance of its regular duties. It is not the purpose of this paper to reiterate in extenso any of the material already published. The contributions of the Survey officials to the Commission's report have been published in a separate document as Bulletin No. 394. This docunient is for free distribution and may be obtained upon application to the Director of the Survey. In the preparation of this paper I desire merely to make a few suggestions regarding the possible necessity of some restraint upon or control of one branch of the mining industry with which I have been somewhat closely associated for the past 20 years-that of coal. Most of the members of the Institute are cognizant of the suits brought by the government against the anthracite-operators in Pennsylvania, or the combination of interests commonly known as the ? hard-coal trust." No defense of any illegal combination in restraint of trade is intended, but there are some facts which should not be lost sight of, and unfortu-\

Nov 1, 1909

BECAUSE of the impetus given to placer mining since the price of gold was advanced to $35, several types of small dredges have made their appearance, especially in the Lincoln and Oroville areas of California. Some of these are known as "doodle bugs," and have been given considerable publicity, though many believe their performance has been overrated and that complete costs of construction and operation, if known would not put them in so favorable a light. Fig. 1 is a doodle bug owned by E. M. Clark and operated near Lincoln, Calif. It is understood that it was abandoned because of inability to handle deep ground. A similar machine that has been operated-profitably by Comstock Placers is shown in Fig. 2.

Jan 1, 1938

By Arthur F. TQggQrt

THE approximate status of education in ore dressing in 1871 is reflected by Rossiter W. Raymond in an article written at that time presenting the curricula and descriptions of the laboratories at the various mining schools in the United States. For the most part, the curricula in which ore dressing was taught were for mining engineering. They comprised courses in geology, mining, and pyrometallurgy about equal in point or credit weights; a short course in ore dressing, and a somewhat longer course in assaying; and courses in surveying, hydraulics, power, and strength of materials-all superimposed on a broad foundation of physics, chemistry, and mathematics. Some curricula contained a fair content of the humanities. Then, as now, the emphasis on fundamentals was greater in the older colleges and universities. The report on the Columbia School of Mines, then relatively young, emphasized that a large percentage of its students were college graduates. As technical and scientific knowledge grew, first metallurgy and then geology were set up as separate curricula. So far as curriculum designation is con-

Jan 1, 1947

By Charles F. King

THE only investigations on record of the reactions occurring during the Bessemer blow are of charges containing a large percentage of manganese, with the exception of two partial analyses by Snelus and Barker of the. English method, where a low percentage of manganese was used. They do not give the analysis of the spiegel, nor do they report any graphitic carbon after the first stage of the process. Both report only traces of manganese after the first stage until the addition of spiegel. The slags corresponding to the samples of metal were not analyzed.

Jan 1, 1881

By W. E. Wrather

SERIOUS consideration was given by the Petroleum Division to a wide variety of subjects, during six busy sessions at the Annual Meeting. Beginning with a joint session on engineering research and production engineering, Tuesday afternoon, conducted by E. A. Stephenson and H. C. Fowler, problems of petroleum technology, domestic and foreign production, proved oil re- serves, economics, and stabilization were mooied almost without interruption until nearly everyone was "talked out,' and the meeting was adjourned at the end of the annual Petroleum Division dinner, late Thursday night.

Jan 1, 1933

By AIME AIME

IN ORDER to carry on its work most effectively, the Committee on Industrial Organization (now known as the Committee on Industrial Relations) consists, of .a number of sub-committees, each composed of a chairman and members who are especially fitted to carry out the work designated by its title. With only one or two exceptions, all of these committees made reports at the New York meeting of the Institute, in February of this year, abstracts of which follow.

Jan 1, 1920

By W. H. Geis

The following pages summarize the causes that led to the suggestion of unit operation of the paloma field, the organization of com-mittees, preparation of the Paloma Operators Agreement and the reasons for rejection of the plan. Introduction Long ago an Austrian physicist observed that under certain conditions the condensation of a liquid from gaseous mixtures resulted from pressure reduction. Some 50 years later he would have known that his research was not in vain. He would have seen a group of serious operators and engineers seeking to apply that principle to a conservation . program for unitized production in the Paloma gas field—but he would also have been saddened to see that forces unsympathetic to the application of science in oil production, with little or no appreciation of modern methods and the advantages of cooperation, so far have prevented the adoption of that program. Soon after the Paloma field was discovered it was realized that all the hydrocarbons in the reservoir existed in the gaseous phase. This condition was confirmed over a large area. Therefore, if the field was to be properly exploited with the greatest ultimate recovery of condensate, the hydrocarbons in the reservoir must be produced in the single or gas phase. They must be cautiously extracted with the least possible reduction of the natural pressure. If this could be accomplished, or if artificial pressure control were utilized, the condensation and underground loss of the valuable distillate would be preventable—otherwise it would not be. Wholehearted cooperation of all oper-ators was required in order to accomplish the conservation purposes of the program. To this end the production engineers of the several companies concerned lent their time and talents. They fully investigated the physical relationships of the products within the complicated gaseous mixture, prepared extensive reports on the subject and drew up a reasonably efficient plan of operations, which now is commonly called the "Paloma Unit Plan" but actually was entitled "The Paloma Operators Agreement." All of the engineers were not in perfect agreement on all the features of the plan, or even on all the engineering principles. However, it is safe to say that on all the important or essential factors there was a unanimity of opinion, particularly as to the objectives. These were fairly simple and reduce to one controlling item, "pressure control" by cycling or recycling. Organization The principal operators initiated the program by calling a meeting of all the lessees in the area, at which an organization was perfected, known as the "Paloma Operators Committee." Various subcommittees were appointed to expedite the work, including an "Engineering Committee." These func-tioned in a businesslike manner, frequently reported to the superior committee and

Jan 1, 1942

By W. H. Geis

The following pages summarize the causes that led to the suggestion of unit operation of the paloma field, the organization of com-mittees, preparation of the Paloma Operators Agreement and the reasons for rejection of the plan. Introduction Long ago an Austrian physicist observed that under certain conditions the condensation of a liquid from gaseous mixtures resulted from pressure reduction. Some 50 years later he would have known that his research was not in vain. He would have seen a group of serious operators and engineers seeking to apply that principle to a conservation . program for unitized production in the Paloma gas field—but he would also have been saddened to see that forces unsympathetic to the application of science in oil production, with little or no appreciation of modern methods and the advantages of cooperation, so far have prevented the adoption of that program. Soon after the Paloma field was discovered it was realized that all the hydrocarbons in the reservoir existed in the gaseous phase. This condition was confirmed over a large area. Therefore, if the field was to be properly exploited with the greatest ultimate recovery of condensate, the hydrocarbons in the reservoir must be produced in the single or gas phase. They must be cautiously extracted with the least possible reduction of the natural pressure. If this could be accomplished, or if artificial pressure control were utilized, the condensation and underground loss of the valuable distillate would be preventable—otherwise it would not be. Wholehearted cooperation of all oper-ators was required in order to accomplish the conservation purposes of the program. To this end the production engineers of the several companies concerned lent their time and talents. They fully investigated the physical relationships of the products within the complicated gaseous mixture, prepared extensive reports on the subject and drew up a reasonably efficient plan of operations, which now is commonly called the "Paloma Unit Plan" but actually was entitled "The Paloma Operators Agreement." All of the engineers were not in perfect agreement on all the features of the plan, or even on all the engineering principles. However, it is safe to say that on all the important or essential factors there was a unanimity of opinion, particularly as to the objectives. These were fairly simple and reduce to one controlling item, "pressure control" by cycling or recycling. Organization The principal operators initiated the program by calling a meeting of all the lessees in the area, at which an organization was perfected, known as the "Paloma Operators Committee." Various subcommittees were appointed to expedite the work, including an "Engineering Committee." These func-tioned in a businesslike manner, frequently reported to the superior committee and

Jan 1, 1942

By T. L. Johnston

MUCH has been said and written about deep mine shafts and deep drill holes as man in his search for mineral wealth digs deeper into the earth's crust. Each year some new extra depth is heralded as a record, but with unlimited possibilities of going still deeper. In contrast to "digging deep," "mining high" is limited by the height of the mountains (Mt. Everest being the maximum with its 29,000-ft. elevation) and also by the extent of human endurance. An ex- ample of what might be called near- stratosphere mining in what is probably the highest mine worked by compressed air in the world is seen in a recent project in the Andes mountains of southwestern Bolivia.

Jan 1, 1939

By Edward H. Robie

THE registration badges gave out, there were not enough programs, the Pioneer Hotel's rooms were insufficient, and some hundred applicants for banquet tickets had to be turned down at the Institute's Regional Meeting in Tucson, Nov. 1-5. Minor inconveniences these, however, occasioned by the fact that, optimistic as they are in Arizona, about half again as many partook of the week's activities as were expected. For this, the local program committee can be blamed-both the technical and social features were too attractive in quantity and quality. Seriously speaking, though, the Institute has probably never had a more successful Regional Meeting than this one. It being the first that has been held in Arizona in 22 years, no effort was spared to make it the distinctive gathering that it was.

Jan 1, 1938

By H. M. Chance

Discussion of the paper of H. M. Chance, Bi-Monthly Bulletin, No. 23, September, 190S, pp. 791-808. CHARLES CATLETT, Staunton,Va. (communication to the Secretary *):-Mr. Chance's suggestions that the brown hematite ores of the Potsdam formation are due to the alteration in place of iron sulphide, and that their extension may reasonably be expected to contain valuable deposits of unaltered sulphide, are interesting; but the facts marshaled by him are too limited to justify more than the hope that they may serve as a commercial source of sulphur. It is true that these deposits have been the source of large amounts of iron-ore; and it. is common, as stated by him, for the mining operations to extend to a shallow depth only; but this is largely due to the fact that the surface-material represents an accumulation from the breaking down and collection of the ore which formerly reached a much higher level. With, increasing depth comes a decreasing thickness of valuable material. This is especially appreciated by a glance at Mr. Chance's drawings. This is the reason why so many disappointments have resulted when these ores have been followed to greater depths. Even if the ore is largely derived from oxidation in place, it is impossible to ignore the great number of concretionary forms, as well as those showing the evidence of secondary solution and deposition now taking place, such, for instance, as the part replacements of fragments of quartzite derived from the underlying beds. Concretionary form does not necessarily mean long transportation, and may be a variation of material in place; but commonly it is an evidence of collection, and tends to imply that more or less concentration has taken place. This fact would also argue against an equally extensive develop¬-

Nov 1, 1908

By J. Koskinen, P. Vanninen, T. Leskinen, A. Leppala

Continuous and accurate analysis of slurries has become a critical requirement in mineral processing. With on-stream assay data, automation procedures can be employed to obtain higher recovery and improved control of production. The Courier system was developed by Outokumpu Oy, taking advantage of mineral processing know-how, to provide means for achieving these objectives in the company's ore concentrator operations. It became evident, based on early experience with on-stream analysis, that the Courier should be a complete system to fulfill all functions of the analysis operation. The system includes equipment and techniques for primary sampling, sample preparation for assaying, and processing of data for final assay results. In addition, the on-line X-ray spectrometer unit was developed specifically for industrial use, incorporating a number of technical advances. A new system for converting spectrometric data to assays is based on a physical model programmed on a digital computer. The Courier system is furnished on a turn-key installation basis incorporating all elements needed for operation including calibration. The experience to date with the Courier system at the Pyhäsalmi concentrator is summarized. Reference is also made to recent results with installations at the Outokumpu and Vihanti concentrators.

Jan 1, 1972

By H. P. Leighly, F. C. Perkins

THERE have been several statements in the literature about the difficulty of producing single crystals of high-purity (99.99pct) by the strain-anneal method. Consequently, investigators tend to employ low-purity aluminum for their single-crystal experiments, or else resort to the Bridgman or other techniques which depend on solidification for the production of single crystals. The following paragraphs describe a solid-state method for the manufacture of single crystals of high-purity aluminum which should provide crystals with greater perfection than those formed by solidification. The starting material for this method of producing single crystals was secured from the Aluminum Corp. of America and has a purity of 99.99 pct, the balance being trace amounts of impurities. Specimens approximately 1 by 4 in. are sheared from sheet having a nominal 0.050 in. thickness. The specimens are given a preliminary anneal at 640°C for approximately 3 hr in order to remove fabrication strains and to produce an average grain size of about 1/4-in. diam. The specimens are then etched in Tucker's etchant (45 pct HC1, 15 pct HNO3, 15 pct HF and 25 pct H2O) to remove the oxide film. Critical strain is applied by wrapping each specimen about a 1 3/4 in. round and subsequently straightening it against a flat surface. The high-purity aluminum sheet is sufficiently soft that this operation can be accomplished by ordinary finger pressure. The specimens are immediately annealed again at 640°C for 3 hr and reetched for examination. Ordinarily, considerable growth of certain of the grains will have occurred, and occasionally a single crystal will be produced on the first attempt. The procedure of alternately straining, annealing and etching is repeated until the majority of a batch of specimens contains usable crystal sizes. Typical examples are illustrated in Fig. 1. The greatest changes in crystal sizes are produced in the initial treatments. As the average crystal sizes get coarser in the later treatments, the sever- ity of the strain must be increased in order to produce grain boundary- migration. This increase in severity is effected by decreasing the diameter of the round used for straining (to 1 1/2 in., for example) and/or wrapping the specimens about the round twice, with opposite faces in contact with the round, before flattening. Usually the strain treatments described are not severe enough to produce nucleation in coarse grain high-purity aluminum. The growth of grains occurs by strain-induced grain-boundary migration. It has been observed that the grain boundaries move most readily during the first hour or so of each annealing treatment and that the rate of movement decreases with extended holding times at temperature. Prolonged annealing treatments are therefore not usually beneficial. Similarly, the rate of growth of each crystal appears to depend upon the orientation of the crystal with relation to those of its neighbors. Frequently island grains are formed after the initial heat treatment as the result of slow grain-boundary migration. These sometime become stationary during later heat treatments. Twin orientation interfaces are frequently developed during annealing. These imperfections can usually be removed by increasing the severity of strain to produce actual nucleation of new grains of more favorable orientation at the imperfection interfaces. The largest single crystals produced in our laboratory by the above method measured 4 by 1 by 0.050 in. Examination of Laue back-reflection patterns from a limited area of the specimens, gave no evidence of polygonization. Probably there is some indication of polygonization in the original grain area provided a more sensitive technique is used for detection. Experiments to produce wider specimens were less successful, possibly because wider sheets increase the complexity of the strains induced by deformation and promote widespread nucleation. Grain boundary migration occurs preferentially in a direction parallel to the longitudinal axis of the specimen. The choice of specimen geometry with respect to the rolling direction of the sheet appears to be immaterial in regard to the production of single crystals.

Jan 1, 1961