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By John S. Crandall

The mineral garnet, while ordinarily considered a semiprecious gem stone or a second-grade industrial gem, has also proved itself in the field of industrial abrasives. Its use is well known as a sand-paper grain, and as a sandblasting sand its qualities are rapidly becoming recognized in more and more industries. Production of garnet as an abrasive is confined chiefly to two areas in the United States, North Creek, N. Y., where the Barton Mines Corp. operates, and Emerald Creek, Benewah County, Idaho, where the Garnet Mines, Inc., and the Idaho Garnet Abrasive Co. with mills at Fernwood, Idaho, operate. This paper is confined to a discussion of production and marketing of garnet sand by Idaho Garnet Abrasive Co.

Jan 5, 1950

By Robert W. Bruhn

An investigation was made of ground response to pillar retreat mining in a 1.7 meter thick seam at 108 meter depth at a site in northern West Virginia. This paper describes mining-related stress changes and movements at mine level, displacements within the overburden, ground surface subsidence and groundwater level variations. Subsidence approached 40 per cent of the mine height and continued more than a year after mining. Water levels declined in certain deep-lying strata.

Jan 1, 1984

PRESIDENTS DAVID THOMAS 1871 R W RAYMOND 1872-1874 A L HOLLEY1875 ABRAM S HEWITT 1876 T STERRY HUNT 1877 ECKLEY B COXE 1878 - 1879 WILLIAM P SHINN 1880 WILLIAM METCALF 1881 RICHARD P ROTHWELL 1882 ROBERY W HUNT 1883 JAMES C, BAYLES 1884-1885 ROBERT H RICHARDS 1886 THOMAS EGLESTON 1887 WILLIAM B POTTER 1888 RICHARD PEARCE 1889 ADAM S HEWITT 1890 JOHN BIRKINBINE 1891-1892 H M HOWE 1893 JOHN FRITZ 1894 J D WEEKS 1895 E G SPILSBURY 1896 THOMAS M. DROWN 1897 CHARLES KIRCHHOFF 1898 JAMES DOUGLAS 1899-1900

Jan 1, 1952

By Joseph D. Weeks

FIFTY-eight years and a day, full of labor, of achievement and of honor had been completed when, at Pittsburgh, on the 5th day of May, 1892, the wheels of a life that had but just before lost its inspiration stood still, and the work here of William Powell Shinn was at an end. Born at Burlington, N. J., May 4,1834, he received such an education (and it was. the only school education he ever had) as the public

Jan 1, 1893

By R. W. Raymond

IX the death of William H. Scranton, which occurred at Oxford, N. J., June 19, 1889, the Institute has been called once more to mourn the loss of a name from the fast diminishing list of those who constituted its membership in the first year of its existence. But it loses more than a name—a friendly presence and an intellectual force have departed ; a fruitful life has been cut short. Mr. Scranton was born in Belvidere, N. J., on the 13th of January, 1840. He was the eldest son of Colonel George W. Scranton, the

Jan 1, 1890

By W. J. C. Venter

The use of activated carbon to improve the selectivity in the separation of base metal minerals from bulk concentrates played an important role in the development of separation techniques employed at Tsumeb Corp.'s Tsumeb and Kombat mines. The Kombat mill fiowsheet and metallurgical data are given with particular reference made to the separation techniques using activated carbon. The mine's historical background, geology, and mining methods are described briefly.

Jan 1, 1974

By K. S. Choi, B. S. Shin

The adsorption characteristics of sodium silicate on scheelite, calcite, and fluorite minerals were investigated. Adsorption equilibrium took about 60 minutes. Adsorption data show that the masimum amounts of adsorption of sodium silicate occurs at about pH 9.8. The adsorptivity was in the order of calcite > fluorite > scheelite. The amount of adsorption of sodium silicate increased with the increase in temperature of sodium silicate solutions. The amount of adsorption of sodium silicate decreases in the low concentration range of ferrous sulfate, while in the high concentration range of ferrous sulfate, the adsorption of sodium silicate increases.

Jan 1, 1986

The primary purpose of the Institute is to advance the technologic and engineering arts embraced by it through interchange of knowledge This can best be done by the presentation and discussion of technical papers by its members Short practical papers are especially welcome An author should always satisfy himself that his material is of a quality that will be a credit to him and to the Institute The preparation of a good paper frequently leads to a reorientation of the author's thoughts, and publication contributes much to the professional standing of the author Members are urged to submit papers presenting the results of their work Attention to the following suggestions will greatly further the prompt and efficient handling of manuscripts

Jan 1, 1952

By L. M. Litz

Study results are presented in which gaseous oxygen was dissolved in the leach liquor at concentrations of the order of 300 ppm. This oxygen-containing solution was injected into portions of a field being operated on a commercial basis with hydrogen peroxide as the oxidant. Comparative results indicate that uranium concentrations and production rates were essentially equivalent with these two oxidants.

Jan 1, 1983

By N. J. Olson, G. W. Toop

A regular solution is characterized by a finite molar heat of mixing and entropy due only to ideal or random mixing. The thermodynamic properties of binary regular solutions which exhibit constant atomic coordination number and constant atom-atom intefac-

Jan 1, 1967

ENGINEERS AVAILABLE (Under this heading mill be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, technical graduate, aged 35, with experience as surveyor, sampler, assayer, and cyanide superintendent, desires position as engineer or cyanide operator.. No. 157. Member, technical graduate, aged 34, with 12 years' experience, including engineering, construction, and management of gold, silver, copper, and quicksilver mines, desires position of 'superintendent of gold or silver property. No. 158. Technical graduate, aged 24, with experience as mine surveyor and instructor in chemistry, desires position as instructor in mining. No. 159. Member, aged 29, technical graduate, with experience in exploration, prospecting, mining, concentration, smelting, and as assayer and chemist, engineer, and draftsman (smelter) in United States, Canada, Africa, South America., and Australia, desires to become connected with a firm of consulting engineers. Speaks Spanish. No. 1130.

Jan 11, 1914

By J. P. Hammond, C. J. McHargue, J. R. Holland

IT has been reported that both berylliumL and zirconium&apos; developed the same basic textures during rolling at temperatures up to 1475 °F as at room temperature, differing only by an increase in the spread of basal planes toward the transverse direction as the temperature of deformation was increased. Iodide titanium&apos;&apos; rolled at 1050°F has a texture similar to the cold-rolled texture, {000l}, 25° to 30" from the rolling plane toward the transverse direction, <1010>, Rolling iodide titanium at 1450°F produced a more random condition with the basal planes parallel to the rolling plane and no direction strongly aligned with the rolling direction.

Jan 1, 1957

By George E. Erdman

Gouverneur Talc Co. had sought an effective means of depicting its mine at Balmat, N. Y. since it commenced operations in 1947. After considerable research the engineering department settled on the idea of a model made of plexiglas at a scale of 1 in. to 50 ft. The solid portion of this model represents the actual underground excavations. Talc is mined from two metamorphic tremolite-talc orebodies which are part of a complex fold system in this region. In the mine, stopes are laid out in panels and developed into openings 50 ft wide, 10 to 80 ft high, and perhaps 200 ft in length. Pillars usually approximate 30 ft in width. All present mining operations are contained within a block 2000 ft long, 1700 ft wide, and 1500 ft thick.

Jan 11, 1960

HAVING taught you to make aqua fortis and to cleanse and reduce it to perfection, before I teach you the work of parting on a large scale, I wish now to teach you how to make an assay of the amount of gold present in a quantity of silver, so that you may proceed to your work with open eyes in order to become aware of mistakes when you have erred yourself or have been deceived by someone else. Therefore it is necessary to know very exactly, before you take it out, how much gold should be in your cucurbits from the weight of the silver that you put in. Thus you may see the gain or loss, if you had to deliver it to someone else or if you had bought it. If you did not do this you would proceed blindly in your work.

Jan 1, 1942

By U. Max, P. R. Geoffroy, J. A. Lawrence

When shaft sinking was begun on the Vendome Mines property in the Barraute area of north-western Quebec, there was no indication of the flat mud seam that was later encountered, and no special precautions were taken in applying conventional methods of grouting. Failure of the first cementing attempt emphasized the important fact that mud is an adverse condition in grouting. A method was then devised that would remove the clay from those portions of the seam adjacent to the shaft, replacing it by a bulky mixture of cement and sawdust. Tests were carried out to insure that the seam had been properly sealed and that excavation could be resumed without endangering the shaft.

Nov 1, 1955

By Gifford Pinchot

The proposition that forest reserves are, from the mining point of view, not only desirable but necessary, is not one which would have received enthusiastic support in. the West a year ago. It is, nevertheless, easily susceptible of proof. A short and simple statement of the facts has seldom failed to carry conviction as to the wisdom of the forest-reservation policy. Hostility to mining interests was never contemplated by the men to whom the forest reserves are chiefly due, and it is most unfortunate that the opposite belief should have obtained wide

Jan 1, 1899

By Mark W. Springett

The sampling of precious metal deposits entails inherent problems due to the low mineral abundances, high mineral specific gravities, skewed grade distributions and wide ranges of mineral particle sizes. Sampling practices and precautions are discussed with particular attention to each of the tripartite stages of sampling - sample acquisition, sample preparation and sample assaying. Practical examples of approaches to the sampling problem are given and some examples of significant sources of error are provided from gold and silver deposits in North America.

Jan 1, 1984

The June meeting was held on June 27, 1919, at 9.00 P.M., eight Directors, the Secretary and Assistant Secretary of the Institute, and eleven guests were present. An invitation was extended to Herbert C. Hoover to be a guest on his arrival in the United States. The President was authorized to appoint a committee to obtain a portrait of Herbert C. Hoover. The announcement was made of the receipt of $100,000 from the bequest of Dr. James Douglas, and the Finance Committee was authorized to invest this money and devote the income to the support and maintenance of the Library. The price of the Year Book was established at $2.00. S. A. Taylor was appointed delegate from the Institute to attend the dedication of the buildings of the Bureau of Mines at Pittsburgh. The President was authorized to appoint a committee to confer with the Development Committees of the other Founder Societies. Reports of the Treasurer and Finance Committee were presented and ordered filed.

Jan 8, 1919

By R. W. Smith

An amine used as a collector in a commercial flotation process is usually a rather impure substance. The differences in ionization constants and solubilities of various amines undoubtedly affect their collecting power or strength. This investigation explores some of the differences among several amines of similar (although not precisely the same) chain lengths. An attempt is made to relate the differences to both observed contact angle and Hallimond tube flotation behavior in quartz systems.

Jan 1, 1974

By Frank M. Howell, Claude E. Schmidt

To counteract the spiralling costs of labor and materials against the fixed sale of its product, namely, gold at $35 per oz, Homestake Mining Co. has revised the milling flowsheet once and effected increases in the daily milling rate twice in the past 12 years. During this period the mining department has been able to hold production costs steady by increased productivity through technical improvements and utilization of the most modern mining by CLAUDE E. SCHMIDT and FRANK M. HOWELL, JR. 46-MINING ENGINEERING, APRIL 1963 equipment. The flowsheet alteration occurred during 1951-1953 when the two crushing plants at the shaft head frames were converted to a three-stage crushing system with the third stage closed circuited to produce a minus 5/8-in. product as rod mill feed.

Jan 4, 1963