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By Ta M. Li, Russell A. Carter

The first century of mining in northern Idaho's Couer d'Alene District will soon he drawing to a close. Like so many other great raining districts, it has been a period accompanied by a rich and colorful history. From its early days as a gold rush camp, the district has evolved into the leading silver producer in the US, but the going has not been easy: early-day labor disputes, the challenge of mining for profit in some of the deepest mines in the Western hemisphere, and the constant search for new reserves at great depths have taken their toll of mines-and miners-along the way. To these traditional mining problems have of late been added the burden of inflationary cost increases, pollution control, and reclamation. A recent visit to the district by MINING ENGINEERING, how ever, revealed that the deep commitment of the operating companies and the quiet competence and vitality of their engineering personnel are key factors in the continued prosperity of the district.

Jan 7, 1976

By AIME AIME

T HE 121st meeting of the Institute held in New York City, February 16 to 19, 1920, was a great success despite vicissitudes of weather of unusual severity. On account of tremendous snowstorms, only two members of the Canadian contingent arrived, and several of our members from the west arrived thirty hours late. Two weeks prior to the meeting, the heaviest snowstorm in 34 years wrecked the surface transportation in New York; and it was only by special dispensation that arrangements were effected, with the New York Street Cleaning Department to clear away 39th street in front of this building so that vehicles could reach the curb. The total registration of members and guests was 1138.

Jan 1, 1920

By D. K. Crampton

ON giving thought to the subject of this paper, my first reaction was that many and striking changes have come about as a direct result of the war. However, more careful analysis indicates that few, if any, of these changes can be wholly attributed to it. The actual situation is that all these changes were conceived and most of them at least partially executed in re- cent prewar years, it remaining the role of war to achieve results in a fraction of the time that might normally have been taken, lacking its driving impulse. The further discussion will therefore be with the premise that the individual changes have been greatly hastened rather than directly and primarily caused by any war conditions. Co-operation among copper alloy producers on production problems is agreed to be much worth while. The industry was too long noted for jealousy and secrecy as to equipment, methods, and even materials produced. Gradually, a more open and co-operative policy evolved but even just prior to the war the interchange of ideas was relatively cautious and limited. The need for a great increase in production in record time fostered a more co- operative attitude; exchange of ideas and experience concerning all phases of production increased tremendously to the benefit of the individual participants and thus the war effort, too. This more united effort has undoubtedly led to many specific improvements in process or equipment and these in turn to more rapid and economical operation than could have taken place on an each-for-himself basis.

Jan 1, 1944

Jan 1, 1925

By K. M. Myles

The vapor pressure of palladium over a series of Rlz-Pd alloys has been measured by the torsion-effusion method. The thermodynamic properties of the alloy system at 1575=K have been calculated from the vapor pressure data. The activities and the free energies of formation exhibit large positive deviations from ideal behavior. The enthalpies of formation are endother-mic. The entropies of formation are positive and larger than the ideal entropy of mixing. All of the thermodynamic properties suggest that a strong tendency toward phase separation exists in the solid solutions. The possible origin of the phase instability and the various factors that influence the thermodynamic properties are discussed. RECENT studies of the thermodynamic properties of alloys of palladium with nontransition elements have indicated that a significant contribution to the enthalpy of formation is related to the redistribution of the conduction electrons upon alloy formation.'-' The present work was undertaken to ascertain the importance of this contribution in Pd/transition-metal alloys. The Rh-Pd system was chosen for this investigation for several reasons: 1) The thermodynamics of the system were unknown. 2) Rhodium and palladium are completely soluble at high temperatures; below 1118OK the solid solution becomes immiscible.', 3) The difference in magnitude between the vapor pressures of rhodium and palladium permitted the use of an existing effusion apparatus. 4) Additional information was known about the alloy system that would facilitate the interpretation of the thermodynamic results. EXPERIMENTAL PROCEDURE The thermodynamic properties of the Rh-Pd alloy system were calculated from the vapor pressure of palladium over solid palladium and over several solid Rh-Pd alloys. The vapor pressure was measured by means of the torsion-effusion apparatus that has been described previously. In this method, an effusion cell is suspended from a tungsten filament inside a high-temperature furnace. Two orifices are located eccentrically such that the effusion of the vapor creates a rotational torque in the filament. The angle of rotation is directly related to the total vapor pressure within the cell. As the vapor pressures of rhodium and palladium are approximately five orders of magnitude apart," the total vapor pressure was considered to be effectively equal to the equilibrium vapor pressure of palladium. The effusion cells were made from high-purity alumina since auxiliary experiments indicated that essentially no reaction occurs between alumina and solid Rh-Pd alloys. Unfortunately, because the orifices were irregular, an accurate calculation of the Free- man-Searcy correction factors" could not be made. The constants were determined in an independent experiment where the vapor pressure of copper, as measured in the alumina cell, was compared with an accurate value of the vapor pressure, which had been determined previously.4 Depletion of palladium from the surfaces of the specimens was minimal as the deflection of the cell remained constant, for at least 15 minutes, at each of the experimental temperatures. Lattice parameter measurements of the postrun alloys also indicated that no changes in the composition of the surfaces had occurred. The alloys were prepared by arc melting the requisite amounts of the 99.99 pct pure elements. The four most palladium-rich alloys were remelted in a levita-tion furnace since complete melting of the components had not occurred in the arc furnace. All of the alloys were subsequently homogenized at elevated temperatures in sealed alumina thimbles. After heat treatment, the alloys were analyzed chemically and were in essential agreement with the nominal compositions. The thermal histories and nominal compositions of the alloys are given in Table I. Lattice parameters of the heat-treated alloys were computed, by means of the method described by Mueller et a1. ,I2 from X-ray diffraction powder patterns obtained with filtered copper radiation in a 114.6-mm-diam Straumanis-type Debye-Scherrer camera. The results, which are tabulated in Table I, exhibit a slightly greater negative deviation from Vegards' law than the values reported by Raub et al.13 The diffraction lines were sharp and well-resolved and thus indicated that the alloys were homogenous. RESULTS The logarithms of the individual values of the vapor pressure of palladium were fit, by the least-squares method, as a linear function of the reciprocal of the absolute temperatures. The constants of the equations are given in Table I along with the temperature range over which the data was accumulated. The latent heat of vaporization at 298.15"K for pure palladium, calculated by the third-law method,14 showed no systematic temperature dependence. The average value of 88,920 * 20 cal per g-atom agrees favorably with the average of the results obtained in the most reliable previous investigations.15"19 The activities of palladium were computed from the vapor pressure data at 1525', 1575", and 1625OK. Consistent with the mass spectrometric study of the atomicity of palladium vapor,lg the vapor was assumed to be monoatomic. The activities of rhodium were determined by integrating the Gibbs-Duhem equation with the aid of the a function.20 In the calculations, the activities of the pure solid metals were assigned the value of unity. From the activities, the partial and integral free energies, entropies, and enthalpies of formation at 1575° K were computed; they are assembled in Table 11.

Jan 1, 1969

By E. J. KENNEDY

FEBRUARY 15-18 will be the outstanding dates of the month for members of the A. I. M. E., for then the 141st Meeting of the Institute is to be held in the Engineering Societies Building, at New York. What with 41 technical sessions, the Annual Business Meeting at 4 o'clock Tuesday afternoon,, two sessions of the Section and Division delegates, minor committee meetings, and the many luncheons and dinners, the Dinner-Smoker, Informal Dance, President's Reception and the Dinner-Dance, the opportunity will be limited to do- more-than cast sheep's eyes at New York's other multitudinous attrac¬tions until the meeting is over. The technical program is diverse but well organized. The sessions are almost equally divided among the four days, with ten on Monday, Tuesday, and Wednesday, and 11 on Thursday. The meeting opens Monday morning with registration. Be sure to attend to this detail. Failure to do so may have its repercussions at the meeting and throughout the year.

Jan 1, 1932

By THOMAS J. CLIFFORD

IN 1926, finer grinding began to be a feature of the milling practice of the Southeast Missouri lead district. Nothing since the adoption of flotation has caused greater changes and greater improvement in results. The trend toward finer grinding, with the consequent discarding of tailing at finer sizes, and consequent lower assays in lead, continued to progress until 1931, when the abnormally low price of lead brought a halt: that is, the better metallurgical results obtained would not offset the increased costs due to higher power and necessary maintenance. Since 1931 a slight tendency toward the discard of coarser tailing has taken place. , In 1926, larger rod mills i.12 ft. 1 in. by 6 ft. 6 in.) than any previously used in the district were installed in cue plant, and a new primary crushing plant, of greater capacity was built. This combination demonstrated immediately the better metallurgical results obtainable by finer grinding and all the mills now running have adopted the practice.

Jan 1, 1934

By W. B. Lewis, M. E. True, M. C. Leverett

Tars paper states the theory underlying the design of two kinds of dimensionally scaled models of parts of idealized oil fields. One of these simulates an oil well and its surrounding sand for a distance of 16 ft. radially from the well. The other model simulates linear flow through layered sands. Construction and operation of the models are described and typical data are given. The unique features in the design of the models are: (I) the treatment of the permeability-viscosity quotient as a single variable and (2) the use of previously reported experimentally developed relations between relative permeability and saturation and capillary pressure, saturation, porosity, perm ability and interfacial tension. The models at present simulate flow of oil and water only, through unconsolidated sands. They are superior to unscaled models, which may give rise to erroneous conclusions. The models are designed to study the desirability of various methods of sell completion and the effects of various factors on recovery of oil from layered sands.

Jan 1, 1942

By G. H. BUCHANAN

ALTHOUGH the nomenclature of the chemical tools of flotation is probably familiar to you, it will do no harm to review it; . In order to make the terms more real I have employed an illustration which likens flotation to an old-fashioned balloon ascension, such as we witnessed in boyhood at the county fair. The mineral to be floated is the aeronaut, conspicuous in his gilt-spangled tights, who is to be separated from you and me and the other small boys who are standing about, said boys being the g-a-n-g-u-e, or g-a-n-g, as we would have spelled it. The oil film surrounding the bubble is the counterpart of the silken fabric of the balloon, and bubble and balloon will rise for. the same reason, namely. that the fluid outside it is heavier than the fluid within. In flotation reagent nomenclature the material of which the bubble is made is called the "frother.",

Jan 1, 1930

NEW MEMBERS The following list comprises the names of those persons who became members during the period of Oct. 10, 1917, to Nov. 10, 1917. ABEY, HIROSHI Min. & Met. Engr.. Mitsubishi Co., Tokio, Japan. BARNETT, WALTER W., Assayer & Chem., Seoul Min. Co., Tul Mi Chung, Chosen, Korea. BATES, WILLIAM S Min. Engr., Anaconda Copper Min. Co., Butte, Mont. BENDELARI, ARTHUR E Mgr. of Mines, Eagle Picher Lead Co., Picher, Okla. BERKEFELD, PAUL C Mining Engr., 2901 Piedmont Ave., Berkeley, Cal. BILLINGS, It. S Mgr., Sheep Trail Pyramid Mines Co., Kingman, Ariz. BILLWILLER, C. J., JR Mgr. Nitrate Agencies, Ltd., Iquique, Chile. BLUM, EDWARD H., Engr., Asst., to Pres., The Atlantic Refining Co., 3144 Passyunk Ave., Philadelphia, Pa. BORDEN, GAIL, Vice-Pres. & Treas., American Safety Explosive Co., 50 East 42d St., New York, N. Y. BRESLIN, THOMAS F Min. Engr., Cebu, Cebu, P. I. BURKE, JAMES M., Efficiency Engr., Calumet & Hecla Mining Co., Calumet, Mich. CANTON, WILLIAM R Met., Nevada Consolidated Copper Co., McGill, Nev.

Jan 12, 1917

By E. J. Schmitz

The following abstract of an unpublished treatise, prepared by me, on the geological formations and minerals of the State of Alabama, is deemed of interest to the Institute. This State, called after the river of the same name (which, formed by the junction of the Coosa and the Tallapoosa, waters, with its tributaries, more than half the State), is divided by its main watershed into a larger southern district, sloping south and southwest, and drained into the Gulf of Mexico, and a smaller northern district, sloping generally north and west, and drained into the Tennessee. Geologically the State may be divided (according to historical geology) according to the different formations it exhibits, among which I include the Azoic, the existence of which in Alabama has been doubted by some; or it may be divided (according to structural geology, as closely related to topography) into a north and northwestern, a middle, and a southern zone.

Jan 1, 1884

By F. O. Garrabrant

Power is furnished to the Climax Molybdenum Co. by the Public Service Co. of Colorado over two 100,000-volt lines to a bank of three 3333-kva. transformers 100/13.8 kv. These transformers are so designed that with the addition of forced cooling their capacity may be increased 331/3 Per cent at 12,000-ft. altitude. Under present conditions, these transformers are operated at 140 per cent of their rating with forced air cooling. On the secondary side of this bank there is a 15-kv., 1200-amp. Westinghouse oil circuit breaker provided with automatic reclosing relays allowing three successive short circuits before lockout. From this breaker 13.8-kv. power is transmitted to a central switching station (Fig. I) where all circuits radiate to the different operations of the property. Each circuit is protected by a 23-kv., 600-amp. oil circuit breaker with by-pass and isolating disconnecting switches.

Jan 1, 1947

By J. W. Stewart

ONE of the postwar problems posed for mineral engineering educators is the desire of some mature student veterans to finish their college education under the G. I. Bill of Rights as quickly as possible, a desire that is quite understandable. Not only have they lost several years of education, which they wish to make up as quickly as possible, but many are married and have families and want to become productive as soon as possible in order to support their families properly. The obvious solution to this problem, if it really is serious, would appear to be a continuation of the wartime Accelerated Program, as it was carried on in most colleges and universities. As a matter of fact some schools are known to have continued their wartime programs in one or another form. To ascertain just what our mineral engineering schools generally are doing to meet this postwar problem, last April a questionnaire was sent to administrative officers at colleges and universities

Jan 1, 1946

By A. D. Hodges

The process to be described, whatever other merits (or demerits) it may have possessed, certainly proved a financial success under the conditions of the locality where it was introduced and where a refining process had been sought previously in vain. I have ventured to bring it to the notice of the Institute in the hope that it may prove of some interest as a solution of a practical problem, such as is often presented to the metallurgist in the remote mining regions of the West. The method was used first at the Lyon Mill at Dayton, Nevada, and has been adopted at other tailings-mills on the Cornstock. These mills treat two classes of tailings: "sand," or; material which has passed previously through the pans of the ore-mills; and " slimes," or the fine clayey material which, coming from the battery, is too light to settle in the tanks inside of the mills but is

Jan 1, 1886

By R. Schuhmann, A. M. Gaudin, J. Dasher

Occurrrences of South African uranium have been known qualitatively for over twenty years, but no account was taken of them because of their low grade. In 1945, known uranium deposits were few, but their grades were 20 to 100 times higher than South African ores. Viewed in this light, the exploitation of South Africa's uranium is revolutionary indeed. Development of various analytical procedures capable of dealing with the needs of the project accounted for one-half of the cost and included: a) simple and automatic radiometric analytical procedures, b) sampling procedures appropriate to prevent sample contamination, c) procedures for sample and record-storing to accommodate many thousands of analyses per month, d) chemical methods giving high accuracy analyses for high grade samples not at radioactive equilibrium, and e) development of rapid procedures having moderate accuracy for low grade samples i.e., mill tailings and barren liquors. This task is continuing today with major improvements coming from time to time.

Aug 1, 1956

By Richard P. Rothwell

A REFERENCE to the geological map of Alabama shows the coal- measures of that State to form three distinct fields. The Coosu, or most easterly, contains about one hundred square miles ; the Cahaba, or middle field, which is also the most southern true coal in the United States, contains about 230 square miles ; and the Warrior field, which contains in the State of Alabama some 5000 square miles, is the southern extremity of the great carboniferous deposit, which extends through Pennsylvania, West Virginia, Kentucky, Tennessee, and Georgia. But very little has yet been done towards developing those coal- fields, partly owing to the absence of all commercial manufacturing enterprise in the South under slavery, and partly owing to the want of capital and the disturbed condition of the South since the war. During the past three or four years I have devoted a large part of my time to the examination of the coal and iron ores of this range,

Jan 1, 1874

By F. O. Garrabrant

Power is furnished to the Climax Molybdenum Co. by the Public Service Co. of Colorado over two 100,000-volt lines to a bank of three 3333-kva. transformers 100/13.8 kv. These transformers are so designed that with the addition of forced cooling their capacity may be increased 331/3 Per cent at 12,000-ft. altitude. Under present conditions, these transformers are operated at 140 per cent of their rating with forced air cooling. On the secondary side of this bank there is a 15-kv., 1200-amp. Westinghouse oil circuit breaker provided with automatic reclosing relays allowing three successive short circuits before lockout. From this breaker 13.8-kv. power is transmitted to a central switching station (Fig. I) where all circuits radiate to the different operations of the property. Each circuit is protected by a 23-kv., 600-amp. oil circuit breaker with by-pass and isolating disconnecting switches.

Jan 1, 1947

By V. V. Clark

WHEN a district is more or less primitive, and a trained mining engineer attempts single- handed to prospect it according to old standards, he generally fails. He has not the ability to live out in the open alone for months at a time and carry on with enthusiasm and determination like the old-time prospector. But the same engineer, placed in an organized group where modern prospecting methods are employed, is immediately put on his mettle and his chances of winning are greatly increased. Marsman Investments, Ltd., with headquarters in Manila, has at the present time, Sept. 4, 1937, six prospecting parties in the Netherland East Indies. Three of these groups are combing their assignments for lode mines, studying structures, developing and reaching out into veins and zones with diamond drills. The other three are searching for placer mines with pans, pits, and Empire drills. I am in charge of one group seeking commercial gold placers on the Island of

Jan 1, 1937

By T. M. Gurr

The United States is the world's leading producer of phosphate rock. In 1975 according to the US Bureau of Mines' statistics, 44.3 million tonnes (48.8 million st) of phosphate rock were produced in the United States, l which is 40.6% of the world's production.2 The major phosphate producing areas of the United States are located in [Fig. 1] and the production for 1975 is listed as follows: [ ] All of these areas produce phosphate from deposits which are of marine sedimentary origin. Occurrences of phosphate exist throughout the United States in numerous locations that are of both igneous and sedimentary origins. However, these other phosphate occurrences vary greatly in extent and economic significance. Georgia, South Carolina, California, Texas, Arkansas, Kansas, Iowa, Alabama, Kentucky, and Virginia are but a few of the states in which phosphate is thought or known to exist. The near future expansion will probably continue to be in, or near, existing producing areas, (i.e., Florida and North Carolina).

Jan 1, 1980

By George Rice

SINCE my earliest recollection, the coal business has been in a state of unrest. It has always been a matter of bewilderment to the serious thinking, the instability of this most important industry; second only to agriculture in its effect on the great development of this country, and even more important in certain aspects, because without fuel railroads could not run, agriculture could not get its products to market, nor would the great manufacturing enterprises have been possible. I will not attempt to discuss the present serious -labor dispute or similar disagreements of the past; in the settlement of which more or less successful attempts have been made to equalize, temporarily at least, natural conditions through "joint agreement" as to prices paid labor; but will confine my views to the general underlying conditions of which the disputes are symptoms, and try to show how these must be remedied before there can be any hope of stabilizing conditions.

Jan 5, 1922