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NEW MEMBERS The following list comprises the names of those persons Who became members during the period Dec. 10, 1914, to Jan. 10, 1915: Members AGUILAR-REVOREDO, J. F., Min. Engr -Casilla 146, Oruro, Bolivia. BAKER, JOHN M., Min. Engr Baker Mines Co., Cornucopia, Ore. BETTS, ROBERT M., Mgr Cornucopia Mines Co., Cornucopia, Ore. BILLINGS, THOMAS PARRY, Min. Engr., 404 Dooley Block, Salt Lake City, Utah. BLAIR, GEORGE SHEPPARD, Engr. and Assayer, Mariposa Min. & Mill. Co., Hornitos, Cal. BOLE, JOHN W., Supt ...Siskiyou Dredging Co., Fort Jones, Siskiyou Co., Cal. BOWMAN, REGINALD G., Statistician, International Smelting Co., 621 Kearns Bldg., Salt Lake City, Utah.

Jan 2, 1915

By H. M. Howe

The chief purpose of this note is to call attention to the triaxial diagram as a convenient means of illustrating the properties of slags, and by this example of its use to commend it to those inclined to graphical studies having other possible applications. Explanation.—In the common or di-axial diagram, the properties corresponding to any point are determined by its perpendicular distance from each of two axes. For example, in an ordinary stress-strain diagram the properties of a given point in the curve are, first, a stress cd so many pounds per square inch, because its perpendicular distance from the horizontal axis of the diagram corresponds by the vertical scale to that stress; and second, a strain or elongation of so many per cent., because its perpendicular distance from the vertical axis corresponds by the horizontal scale to that elongation. It happens that, as a matter of convenience, we habitually place these two axes at right angles to each other; so that our measurenieilts happen to be made not only at right-angles to

Jan 1, 1899

By Richard D. Call

Predicting the performance of a waste embankment requires an estimate of the properties of the waste and foundation materials. The performance characteristics and the associated material properties are: [ ] Methods for obtaining estimates of the material properties include: laboratory and field testing, back analysis, and indirect estimates from other material properties. The most critical technical need is the development of indirect methods for use in feasibility studies and mine planning, prior to production when actual samples of waste material are not available. Material properties are not unique, single values; they are probability distributions. There are two components to these distributions: the uncertainties in testing and the inherent variability of the material. The objectives of a material properties evaluation should be to obtain an unbiased estimate of the property distributions rather than the average or the minimum value. Whether the current trend to a probability design analysis is followed or a simple sensitivity analysis is conducted, the unbiased probability distribution is preferable to single values.

Jan 1, 1985

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

By M. E. Gershon

A mixed-integer formulation of the mine scheduling problem is discussed and applied for the purpose of optimizing both the mine production sequencing and the mill blending and processing problem simultaneously. Previous attempts at solving these problem separately, although successful, fail to take into account the interrelationships between these problems. Project structure selves as the outline of this paper Generalized in its organization, this concept is useful for long, intermediate, and short range scheduling. Actual applications that show the concept also is applicable to mining a variety of ore are mentioned.

Jan 1, 1984

By H. Reinhardt, P. Haglund, J. Rydberg, B. Lunden

As legislation to minimize pollution in effluent streams becomes stricter, it is important to treat used acid pickling baths before discharge. This is usually achieved by neutralization of the acids and precipitation of the dissolved metals in such a way that neither acids nor metals can be re-used. A process has been designed and tested on a pilot plant scale to recover both acids and metals from a stainless steel pickling bath leaving only Na2SOs in the effluent. In this process, H2SOr is added to the spent pickling liquor and the recovery of the pickling acids HN03 and HF is achieved by solvent extraction, using TBP in kerosene as the organic solvent. The extracted acids are stripped with water, giving an acid concentration high enough for direct use in the pickling bath. Molybdenum is also extracted by TBP and is recovered in a separate step. The other metals, Fe, Cr and Ni, are precipitated from the raffinate as hydroxides, dried and recycled to the metal process. In evaluating this process, comparative experiments with mixer-settler and pulsed column have been performed. The process described is being considered for use by a Swedish company pickling 70,000 tons per annum of stainless steel.

Jan 1, 1973

By Paul Billingsley

The term Boulder batholith was first applied in 1897 by W. H. Weed2 to the extensive mass of granite in western Montana within whose borders occur the ore deposits of Butte. In a general way this was known to extend from Helena on the north to the Highland Mountains near Butte on the south, and to be relatively narrow in its east-west diameter. Its intrusive relations to the surrounding sedimentary rocks, and its probable Tertiary age, were described by Weed, but in many ways his statements, based upon incomplete data, have required revision. Most notable of the errors of this description of the batholith were the failure,3 since corrected, to recognize the intrusive contact of the granite with the capping of andesite, and the complete absence of any reference to the many extensions of the granite beyond the somewhat narrow limits of its largest exposure.

Jan 1, 1915

By A. Kounosu, T. Fujita, J. Shimoiizaka, K. Nakatsuka

Stable aqueous dispersion of magnetite colloid of about 10 nm in diameter was obtained by allowing an anionic or nonionic surfactant to adsorb on the hydrophobic surface of magnetite particles prepared by monomolecular adsorption of oleate. Sodium dodecylbenzene sulfonate, sodium oleate and poly (oxyethylene) nonyl phenyl ethers whose hydrophilic-lipophilic balance (HLB) are higher than 12 were suitable for giving a second adsorption layer to obtain a stable dispersion. Stability of the colloidal suspensions depends upon pH of the solution and is controlled by the dissociation of the adsorbed surfactant in the second layer. The addition of ethyleneglycol, which was used for lowering the freezing point of the dispersion, did not affect the stability when used in amounts smaller than 60% of water. Preparation of diester-based ferrofluids was also attempted by the same procedure using a nonionic surfactant as second layer molecule. Hydrophobic magnetite colloid, which had been preliminarily coated with mono-molecular oleate, was suspended in di(2-ethylhexyl) agipate, azerate, and sebacate respectively, and dispersion stability was investigated by adding various poly (oxyethylene) nonyl phenyl ethers of different HLB values. It was found that those with HLB values between 10.9 and 13.3 were suitable for this purpose. Stabilities of the dispersions in a magnetic field were investigated up to 1 T by applying an electromagnetic field. No separation of dispersant was observed and each magnetite dispersion displayed the characteristics of a magnetic fluid.

Jan 1, 1980

By L. A. Roe

Magnetic separation occupies an attractive position in the field of ore beneficiation. It is a simple yet effective method, used for some 150 years and steadily growing more important. This type of beneficiation orginated in 1792, when William Fullarton was issued a British patent covering the separation of iron ore by magnetic attraction. What is magnetism, and why are some materials capable of being magnetized and others not? The study involves many unknowns, and even a partial answer to these questions would be a dissertation in solid state physics and perhaps other fields of science. But the last two decades have revealed basic facts as to why certain materials are magnetic and what happens to them when they are magnetized.

Jan 12, 1958

By Dan G. Cojocariu, E. Ene-Danalache, I. Huber-Panu

A general model which represents not only batch but also continuous flotation in multi-cell machines is presented. This model considers both the size distribution and the distribution of flotabilities in a size class for valuable mineral particles in the pulp. The general expression is shown to reduce to several previously reported models. In addition, a number of new models are found to arise for different specific assumptions concerning the flotability distribution and/or the size distribution of the particles undergoing flotation. Several of these new models are tested experimentally using laboratory-scale batch and pilot-scale continuous data. Model parameters are estimated from this data and a comparison of calculated recoveries and those experimentally determined are presented. Finally, the influence of the feed rate, aeration rate and valuable mineral content of the feed on the recovery is examined.

Jan 1, 1976

Jan 1, 1888

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

By Stuart S. Forbes

Changes and additions made to the Canadian Copper Refiners Ltd. electrolytic refinery between 1949 and 1955 are reviewed. The effect of high current density on current efficiency and section work is discussed. OPERATING and physical changes which have been made to the electrolytic tank house of Canadian Copper Refiners Ltd. suggest a review of present conditions. Previous papers1 a have described the general arrangement. Since then, expansion, closer anode spacing, and higher current densities have increased annual cathode capacity from 112,000 to 182,000 tons. A recent extension to the tank house, begun in the spring of 1954 and completed in August 1955, was undertaken to handle the monthly production of about 3,000 tons of anodes from Gasp6 Copper Mines. The anticipation of these additional receipts and large stocks of unrefined copper caused by the increase in custom smelting at Noranda made it necessary to increase production without immediately available additional cell capacity. Accordingly, from December 1954 through March 1955, the tank house was operated successfully at a current density of 24.0 amp per sq ft. Again, as of September 1955, one of the two tank house circuits is being operated at this high density. Although other refineries may operate at current densities higher than 24 amp per sq ft, none is doing so with anodes which contain silver and gold content as high as those being refined at Canadian Copper Refiners Ltd. General Arrangement The original building consisted of two parallel bays, each 660 ft long and 60 ft wide, with a 24 ft pump bay extending along the west side of the building. A previous expansion, completed in 1939, was to the west of the original building and consisted of two 60 ft parallel bays 240 ft long. The length of these two bays was extended in 1954 to 540 ft, adding one stripper and 12 commercial sections to No. 2 electrical circuit. Space is still available for an additional six commercial sections and one stripper section. Construction on these seven sections started in September 1955, and will be completed early in 1956. The tank house capacity will then be 206,000 tons of cathodes per year. In the two tank houses there is a total of 900 cells distributed as follows—commercial, 468; stripper, 36; total, 504 in the No. 1 tank house (No. 1 circuit): commercial, 360; stripper, 36; total, 396 in the No. 2 tank house (No. 2 circuit). Section arrangement consists of nine cells to a tier and two tiers or 18 cells to a section. Anodes, weighing 620 lb each, are cast with a Baltimore groove and are refined by the multiple system. Solution enters each cell through a bottom inlet at one end and overflows at the top of the opposite end. Rate of solution flow through the cells is controlled by valves at each section to 4.5 gpm. Electrical power to the tank house is now provided by nine 675 kw motor generator sets. Each set consists of a 135-12 v 5000 amp dc generator, driven by a 980 hp 2300 v synchronous motor. When No. 1 circuit is operated at 22,000 amp, five sets, at 4400 amp each, are connected in parallel. As the maximum allowable current on No. 2 electrical circuit has recently been set at 18,000 amp, only four sets are connected in parallel on No. 2 circuit. A tenth set, now being installed, will be reserved as a spare, for use in either circuit as required. Recent Changes In 1949, the annual capacity of the tank house was increased from 112,000 to 132,000 tons by closing the

Jan 1, 1957

NORTH AMERICA Number Members Alaska 36 Canada 323 Mexico 184 Newfoundland 3 United States Alabama 40 Arizona 111 Arkansas 8 California 646 Colorado 171 Connecticut 90 Delaware 21 District of Columbia 136 Florida 16 Georgia 7 Idaho 66 Illinois 208 Indiana 66 Iowa 11 Kansas 24 Kentucky 32

Jan 1, 1934

By Charles E. Wait

The old laboratory at the School of Mines was among the notoriously bad ones, being situated in apartments of the main collegebuildings not originally intended, and conspicuously unfit, for the use to which they were put; while, as in many of our schools and colleges, the assaying was done in the basement of the college. Prominent among the disadvantages of such an arrangement are insufficient light, poor ventilation, and little or no provision to carry off offensive gases. It is not my intention now to present a complete description of this building. I wish merely to call attention to a few points in its construction and equipment, which may prove of interest to those who contemplate erecting buildings for snch work, and who may be, as we were in this instance, limited as to funds. In this laboratory every room is well lighted; all rooms used by students are well ventilated, and are provided with closed hoods for

Jan 1, 1887

By W. D. Felix, R. D. Smith, J. A. Campbell

The mechanism most consistent with available information on atmospheric trace element emissions involves the volatilization of a significant fraction of many trace elements during coal combustion, with subsequent condensation on fly ash as the combustion gases cool. The larger surface-td-volume ratio of the smaller particles leads to an enrichment of the volatile trace elements. From an environmental viewpoint, the submicron size particles are of greatest concern. These particles show the highest concentrations of trace elements, are least efficiently collected by pollution control devices, have high atmospheric mobilities, and are deposited preferentially in the pulmonary and bronchial regions of the respiratory system. The mechanisms for trace element enrichment and formation of submicron particles will be described.

Jan 1, 1981

By F. Lynwood Garrison

There is probably no subject for study in the metallurgy of iron and steel of greater interest than the effect of manganese upon the properties of iron. Some of the peculiarities of iron and steel containing appreciable quantities of manganese were observed many years ago by Heath, Robert Mushet, and others; but it was not until the introduction of the Bessemer process, when a demand was created for large quantities of iron-manganese alloys, that such compounds of iron and manganese became articles of commerce. Since that time the demand for these alloys has steadily increased, the use of ferro-manganese not only becoming an absolute necessity in the ordinary Bessemer practice, but also essential to the manufacture of open-hearth, crucible steel and steel castings; in fact it is the only source of supply for all the manganese used in metallurgical opera-

Jan 1, 1893

NEW MEMBERS The following list comprises the names of those persons who became members during the period Oct. 10, 1918, to Nov. 9, 1918. ALLER, FRANK D., Copper Met., Ore Purchaser, American Smelt. & Refin. Co., 120 Broadway, New York, N. Y. AVÈRY, PAUL W., Met. Engr., Esperanza Min. Co., Apt. 8, El Oro, Mex., Mexico. BAKER, CHARLES A., Leaching Foreman, Copper Leaching Plant, Anaconda Copper Min. Co., Anaconda, Mont: BREED, CHARLES H Met., Crown Cork & Seal Co., Baltimore, Md. CHASE, R. L., Min. Engr 102S First National Bank Bldg., Denver, Colo. EICHELBERGER, FRANK, Vice-pres. and Engr., New York-Montana Testing & Engrg. Co., Helena, Mont. GESTER, G. C., Geol., Standard Oil Co. of Cal., 616 Standard Oil Bldg., San Francisco, Cal. GRIFFIN, JOHN, Mgr., Anthracite Territory, The Dorr Co., Board of Trade Bldg., Scranton, Pa. HAYNES, ELWOOD Pres., The Haynes Stellite Co., Kokomo, Indiana. Hsi, T. C:.. Sec'y, Tayeh Iron & Steel Works, Tayeh, China. HYDE, AUSTIN T., Mgr., Keokuk Plant, River Smelt. & Refin. Co., 607 Franklin St., Keokuk, Iowa.

Jan 12, 1918