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The Library of the above-named Societies is open from 9 A.M to 10 P. M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should he made as definite as possible so that the information received may he what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 6, 1918

For a nation whose mining industry has generally been floating through history in the shadows of major mining developments elsewhere in the world, Australia has in the decade of the Sixties made a convincing bid to be one of the world's great "store- houses" of minerals. In fact, at the rate things are developing Down Under and Out Back, what with professional prospecting teams crisscrossing the continent under the direction of professional exploration management, Australia may one day find itself as the world's greatest storehouse. Whereas Necessity may be the Mother of Invention, Consumption is surely the Mother of Exploration. At least this is true in Australia of today. First, the forecasted shortage of iron ore in the world led to the fabulous discoveries in the Pilbara district of Western Australia. Now, the demand for nickel has generated even more interest among mining companies in the vast, untapped potential of Australia.

Jan 10, 1968

By R. V. Ramani, G. W. Luxbacher

Computer simulation of mine ventilation system is rapidly becoming an essential tool in mine planning and design. This Paper examines the utilization of ventilation simulation techniques to evaluate the number, shape, size and layout of mine entries in a typical coal mining system. Since the mains and sub-mains serve primarily for transportation and ventilation and the ventilation system is critically important to the health and safety of the workers, there exists a great need for optimal designs in this area. Evaluation criteria could include, among others, minimization of power costs, shaft requirements and leakage. Constraints of this optimization problem include health and safety regulations and production and mine infrastructure requirements.

Jan 1, 1980

By Harold R. Wampler, John L. Bolles, Adrian J. Broderick

Phelps Dodge's 60,000 tpd Morenci Concentrator has been in operation since 1942. The integrating of process control applications into the concentrator began in 1972. A process control system is presently on-line controlling 30 primary grinding circuits and all reagent additions. The system consists of a centralized control room process control Computer, on-stream X-ray analyzer, on-stream particle size analyzers and an operator interface. This paper describes the process control system's development, control concepts and its influence on the concentrator performance.

Jan 1, 1978

By Claudio Gutiérrez

The action of quebracho in the selective flotation of fluorite and calcite has been studied. It has been found that the unavoidable ions produced by dissolution of these minerals can precipitate calcium oleate which profoundly influences the adsorption of oleate. The depressing action of quebracho is due, at least partly, to a decrease of the oleate adsorption. The depression of flourite flotation by quebracho in the presence of calcium is due to the fact that precipitated calcium oleate can become only physisorbed, its adsorption being strongly prevented by quebracho. It is concluded that adsorption experiments with flourite must be conducted with a flotation-size mineral, which has a lower dissolution rate than when finely ground.

Jan 1, 1980

By R. E. Head

UNDER existing economic conditions, the treatment of gold ores occupies an outstanding position in metallurgical activity. The increased price of gold has automatically brought about a reclassification of old dumps and low-grade orebodies, and many that formerly were considered valueless are now being vigorously investigated and worked. This situation has developed problems that have taxed the ingenuity and ability of metallurgists to the utmost. Some gold ores give a high extraction of gold by standardized methods of treatment; other ores of apparently similar character yield but a relatively small percentage of their gold when treated by the same processes.

Jan 1, 1936

By G. W. Poling

Chemical and physical properties of thiol collectors are re-examined to compare the prospects,of heavy metal-thiolate or disulphide surface reaction products acting as actual collector species. Recent evidences for the existence and importance of each of these types of adsorbed species on sulphide minerals are also discussed. A conclusion is reached that partial coverage by chemisorbed heavy metal thiolate is often sufficient to confer practical levels of hydrophobicity and floatability. Only on a few highly conducting and "noble" sulphides does adsorbed disulphide-type collector oxidation product appear to be significant.

Jan 1, 1976

PRESIDENT BENJAMIN B. THAYER,1 NEW YORK, N. Y. PAST PRESIDENTS JAMES F. KEMP,1 NEW YORK, N. Y. CHARLES F. RAND,2 NEW YORK, N. Y. FIRST VICE-PRESIDENT SIDNEY J. JENNINGS,1 NEW YORK,. N. Y. TREASURER GEORGE C. STONE,1 NEW YORK, N. Y. SECRETARY EMERITUS ROSSITER W. RAYMOND, NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON NEW YORK, N. Y.

Jan 11, 1914

References are in all cases to the earliest known editions. In the few cases where the first edition has been unavailable for consultation, the particular one studied is indicated. English translations are included when known, but not others. [ ]

Jan 1, 1942

By Gilbert Santoro

In this study tantalum carbide filaments of various compositions in the fcc region were prepared by heating a tantalum wire in a measured amount of hydrocarbon vapor. Such properties as tensile strength, transverse-rupture strength, microhard-ness, lattice parameter, electrical resistivity, and magnetic susceptibility were measured as a function of carbon content. Some of these properties showed a maximum or a minimum between a carbon-to-tantalum molar ratio of 0.80 and 0.85, the composition range at which the color changes from metallic gray to gold. The recent literature has shown that in the large homogeneity range for the fcc phase of the Ta-C system there is a marked variation for such properties as microhardness,' electrical resistivity, ' thermodynamic properties,z'3 lattice parameter and superconductivity. In addition to the technological interest of these variations within a single phase, important theoretical benefits may ensue from a continuous investigation of properties vs stoichiometry in tantalum carbide and other refractory defect compounds, for example the effect of the metal-metal distance and crystal structure upon bond formation and electronic structure. Whether there is a similar variation of the tensile strength is of practical importance. Of theoretical interest would be the knowledge of how the magnetic susceptibility varies with carbon composition. Both of these properties, as well as the transverse-rupture strength, were determined for tantalum carbide filaments in the fcc phase region. The lattice parameter, the electrical resistivity, and the microhardness were also investigated and compared with values appearing in the literature. EXPERIMENTAL PROCEDURE Material Preparation. Tantalum carbide specimens of various carbon content were prepared by statically carburizing high-purity tantalum filaments in measured quantities of pure hydrocarbon gas. The filaments, which were 10 mil in diameter and 20 or 40 cm long, were heated by their own resistance at temperatures from 1800" to 2200°C using alternating current in some cases and direct current in others. Tantalum wire from two sources was used. One had a reported purity of 99.96 wt pct Ta. The ingot from which this wire was drawn had been electron beam-melted as the final step in its purification. The reported purity of the other wire, which was prepared by a powder metallurgical process, was 99.88 wt pct Ta. The impurities of both tantalum sources are listed in Table I. Spec-trographic-grade toluene or research-grade propane was used as the source of carbon. The apparatus for the carburization of the filaments is shown schematically in Fig. 1. The system was evacuated to 1 x l0-' mm of Hg when using the electron beam-melted tantalum and to less than 1 p when using the less-pure tantalum. Neither the difference in the base vacuum, nor in the hydrocarbon gas, nor in the tantalum filaments resulted in any detectable difference in the properties studied in this work. However, only the carbides prepared from the higher-purity tantalum were used in the magnetic-susceptibility determinations. Once the base vacuum had been reached, the system was flushed with the hydrocarbon and re-evacuated. For any desired composition of the carbide, hydrocarbon gas was allowed to leak into a constant-volume flask to a predetermined pressure. These pressures were measured by a Cartesian diver-type mercury gage with a range from 0 to 20 mm and with a scale expanded to nine times. The hydrocarbon gas was allowed into the reaction tube and the filament was quickly raised to the reaction temperature. The slack in the filament due to thermal expansion was taken up by drawing out the movable electrode with a screw mechanism. The filaments were kept at temperature from a few minutes to 200 hr. In the majority of cases the heating time was 6 hr. The reaction tube was cooled by cascading water on its outer surface. By means of an ammeter and a voltmeter the electrical resistance at the reaction

Jan 1, 1963

By Eizo Yabuuchi, Yukito Imanaga

INTRODUCTION In treatment of mine drainage, it is well known that the neutralization by calcium carbonate is far better than by slaked lime because of cheaper cost and better precipitability of its deposit. However, in case of iron ion contained in the mine drainage consists of ferrous salt, the ferrous salt must be oxidized to ferric salt before neutralization, because the ferrous salt does not react with calcium carbonate. At Yanahara Mine, during the period of 1950 through 1956, ferrous ion in the mine drainage had been oxidized to ferric ion, simultaneously neutralized by adding calcium carbonate into the aerated drainage. During the period of 1961 through 1974, after passing through many kinds of treating methods, the neutralization had been carried out by addition of calcium carbonate into the drainage after oxidized its ferrous ion to ferric by using nitrous gas as an oxidizing catalyzer. Meanwhile we had made an experiment on the oxidation of ferrous ion by utilizing iron bacteria, and developed a method which oxidized ferrous ion in large quantities briefly by cultivating and concentrating iron-oxidizing bacteria. Since 1974, we have been operating successfully for treating the drainage at Yanahara Mine by means of utilizing these bacteria.

Jan 1, 1976

By Chester O. Ensign

Results of the application of geologic knowledge to grade control have been remarkable. Grade reduction from dilution has been diminished from greater than 9% at the time of the program's beginning to about 2% at present. This has resulted in an increase of about 1.8 lb of copper per ton of ore mined and has made a substantial contribution to earnings at White Pine during the past two years. Even more improvement is expected in the future. The White Pine orebody, situated in the southwestern portion of the Keweenaw peninsula of upper Michigan, is a gently dipping stratiform or bedded deposit. Copper distribution is stratigraphically controlled with higher values being confined to specific beds in the ore column. Room-and-pillar mining is practiced. Mining technique and geologic characteristics present a special array of problems in controlling the grade of ore.

Jan 4, 1964

By I. Iwasaki, K. Adam

During wet grinding the electrochemical interactions between grinding media and pyrrhotite not only accelerate media wear but also adversely affect the suede mineral's flotation response. A possible remedy of the adverse effects on floatability by applying electric potentials to grinding media was examined. Flotation tests, Auger electron spectroscopy, and X-ray photoelectron spectroscopy were used to study pyrrhotite surface properties. Although anodic polarization of the steels increased metal loss by corrosion, pyrrhotite flotation recovery was increased. In the case of cathodic polarization, flotation recovery improved somewhat in a narrow range of overpotentials. At higher cathodic overpotentials, however, mineral floatability was progressively lowered although the corrosive wear of grinding media might be reduced.

Jan 1, 1985

By T. S. Mohibatsela, R. V. Ramani, C. V. Manula

The Mineral Engineering Department of The Pennsylvania State University has developed a suite of computer models for anthracite open pit mining (Fig. 1)1 Individual sub-systems have been developed to (a) interpolate geologic field data to obtain coal tonnages, waste volumes, and strip ratios; (b) simulate equipment performance on selected pit profiles to generate data required to choose coal and waste removal equipment; and (c) evaluate selected cost factors to determine either a rate of return for a specified selling price or vice-versa. This paper describes the application of two of these subsystems, namely, the Reserves Model (GEOL) and the Open Pit Materials Handling Simulator (OPMHS), and how these may be applied for the selection of equipment for a prime anthracite mining site.2

Jan 1, 1981

By J. Van Steveninck, A. C. Pols, R. Feenstra

In the course of time, an increasing number of investigations on jet cutting all kinds of material, such as rock,1,2,3 metal,4,5 and wood6 have been reported to serve various applications. A number of papers have been published on these subject, 7,8,9 some of which refer to jets purposely containing abrasives, termed 'jetted particle drilling'.7 Since such abrasives complicate fluid handling considerably and do not appear to be absolutely necessary for making holes, only conventional drilling fluids have been considered. A large part of our investigation has been performed with the aid of three laboratory-type drilling machines, which permit tests on both micro-bits (1 ½ in. ) and full-scale bits (6 ½ -9 5/8 in. ) . In view of the application of jets in deep holes, care has been taken to simulate hydrostatic pressures as they exist in the field on the hole bottom. These have been found to have a major effect on the bit-penetration rate for various drilling fluids.

Jan 6, 1974

By Dennis K. Mortensen

Startup of the 9000 tpd Sacaton concentrator is expected to increase Asarco's domestic copper concentrate capacity by 21%. The plant site is located due west of the mining operations, consisting of both crushing and concentrating facilities. Arthur G. McKee & Co. served as the prime contractor for the project. The Sacaton mineralization contains both sulfide and oxide ores. Primary mineral constituents are chalcocite, azurite, malachite, chrysocolla, and minor amounts of silver and occasional gold. Sulfides are distinguished from oxides when more than half the total copper content is in the form of a sulfide copper mineral. While non-sulfide copper minerals are considerably less prevalent throughout the orebody, they tend to occur quite intimately with the sulfide minerals, particularly in the upper zones of the mineralization. For this reason the decision was made to treat all the ore in a flotation circuit using existing sulfidizing methods.

Jan 11, 1974

By G. E. McElroy

MUCH attention has been directed to mine-air flow in recent years, more especially in Great Britian where there is frequent reference to a theory of fluid flow developed by English engineers. Briefly stated, this theory is that for similar passages of the same relative roughness, in which fluid flow occurs, the conditions of flow are exactly the same for equal values of the product W D V, where W = density of the fluid, D = diameter of the passage through which flow occurs, V = mean velocity of flow, and m = absolute viscosity of the fluid flowing. This, the "Reynolds Criterion" of fluid flow, had its origin in the work of Prof. Osborne Reynolds' more than 40 years ago. Later, Lord Rayleigh amplified the theory2 which has been conclusively proved for small pipes by the experiments of Stanton and Pannel3 over a large flow range, and by Lacey4 over a somewhat more limited range. Concordant results on small pipes have also been obtained by numerous other investigators with single fluids over more or less limited ranges of flow. According to this theory results in one medium, such as water, are immediately applicable to another, such as air; and experimental results on models are (theoretically, at least) applicable to full-scale designs. This is of great importance in aeronautics and can be of considerable value in mine ventilation research. Hodgson, in a recent paper,5 has outlined the application of this theory to mine-air flow and recent English experiments' on the resistance of a timbered mine airway have been expressed in this form.

Jan 10, 1926

By Z. T. Bieniawski

Tunneling in coal mines includes driving the main haulageways or roadways which serve as the development entries. Although constituting the lifelines of these mines, little attention has been paid to development entries in the United States in terms of systematic pre-construction planning and design. Coal mine tunnels, as the terminology is used in Europe and elsewhere, are understood in the United States to be the main development entries, either in room-and-pillar mining or in longwall mining. These development entries are not tunnels in the traditional sense since they usually are of a multi-entry type involving entries and cross-cuts, and their intersections. Thus, the design of coal mine tunnels is intertwined with the design of coal pillars. This paper summarizes the results of a three-year research project aimed at improving the design of development entries in U.S. coal mining. A design approach has been developed for this purpose and design procedures for roof support in main entries and for pillar sizing are proposed.

Jan 1, 1984

By H. F. Yancey

AT the annual meeting of this Institute held two years ago a new method, of estimating the grindability of coal was described, based on experimental work carried on by the Bureau of Mines at its Northwest Experiment Station. Since that time, several organizations concerned with the testing or utilization of coal as pulverized fuel have adopted and used the method in determining the grindability of several hundred samples of coal. In addition, a series of comparative tests of this method and three others has been carried out in five laboratories under the auspices of Committee D-5 of the American Society for Testing Materials. As a result the Committee has recommended that the Bureau of Mines method, designated as the "ball-mill method," and the Hardgrove method2, previously advanced, be accepted as tentative standards3. Since the ball-mill method was originally developed and published, an opportunity has been presented to apply it to a larger number of coals and to study intensively some of the principles upon which the method is based. This paper presents a resume of these further studies and includes a comparison with the Hardgrove-machine method. Trial runs were also made with another procedure recently proposed-the C.I.T. roll-test method4.

Jan 1, 1936

By R. W. Culbertson, S. Kasper

During the 1920's, approximately 11,000 small gasifiers were in operation in the United States. They converted about 15 million tons (13.6 Mt) of coal per year into low Btu gas. In some cases, hot raw gas was used for applications such as firing open hearth furnaces or brick kilns. In other cases the gases produced in the gasifiers were cooled, cleaned and desulfurized for various utility and industrial purposes. The steel industry was by far the largest user. The most important fact was that the conversion of coal to a usable fuel gas was demonstrated to be commercial. During the late 1940's and early 1950's, this form of energy was largely replaced by natural gas as the pipeline net work was expanded. Producer gas was no longer economically competitive. Over the past 25 years, government controls on the interstate price of natural gas have maintained this situation. At present only three commercial small coal gasifier plants are still in operation in the United States. These facilities are operated

Jan 1, 1980