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By Carl R. Davis

The cost of mining during the past history of these mines has been excessive, principally by reason of the inefficiency of labor under the wage-system. The amount of labor performed per man was unsatisfactory; and Mr. Edmund B. Kirby, the general manager, decided to adopt the contract-system as a remedy. For this purpose the method now in use was devised by the writer (then and now the superintendent), as best adapted to the local conditions. On March 12, 1900, this system was presented to the miners of the War Eagle and the Center Star. The issue remained unsettled for several weeks,

Jan 1, 1902

By Charles O. Thompson

In 1867 the city of Worcester walled in the Mill Brook for its main sewer. This stream, one of the important affluents of the Blackstone River, flows through the city in a southwestenly course from Salisbury Fond, and along its valley a considerable part of the heavy manufactories of the city are placed. At two points, a mile apart, a sufficient fall occurs to be turned to account for motive power, and at many points it was the right and practice of the riparian proprietors, prior to 1867, to use the water for steam and other manufacturing purposes. But the

Jan 1, 1881

By R. B. Strathmore Cooke, Eugene L. Talbot

The perfluoro acids and derivatives show unusual surface-active properties that qualify them as possible flotation reagents. They lower the surface tension of water from 15 to 20 dynes below that obtainable with the corresponding hydrocarbon compounds. Fluorochemicals adsorb very strongly on solid surfaces to give films that exhibit larger contact angles than films of the corresponding hydro-carbons. The large contact angles probably result from the terminal –CF3 group. The perfluoro acids are made by electrolysis of the corresponding carboxylic acid in anhydrous hydrogen fluoride. From the perfluoro acids many derivatives may be obtained, such as amides, amines, alcohols, xanthates, ethers and esters and others.

Nov 1, 1955

By R. A. Matuszak

Abstract-Throughout the history of power excavating machines, engineers have continuously tried to shape the main drive speed-torque characteristics to provide an optimum performance from each main motion. Selection of prime mover for the various motions has been the subject of many engineering studies and most forms of energy conversion have been tried. A new form of electrical power conversion looms on the horizon as the most optimum yet. Controlled frequency operation of a squirrel cage induction motor increases the reliability of the most reliable form of energy conversion (electrical) found thus far, and improves the performance characteristics.

Jan 2, 1978

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons. ) An experienced gold and silver metallurgist. specializing in cyaniding is desirous of obtaining a position in America. Speaks Me icon Spanish fluently. A member, a technical graduate, with four years' experience in railroad work and general construction, two years' on mine examination and geological reconnaissance, and two a half years' drilling exploration in placer work and petroleum, together with prospecting and geological interlope-tion, desires a position as a mining engineer or mining geologist. An experienced mine superintendent, manager, or field engineer, is open for engagement. Ire has had 12 years' experience as superintendent and manager of large mines in the United States and Mexico, and experience in mine examination. A member of the Institute with several years? experience in mining in the Lake Superior copper district, is open for engagement. A member, at present in the Southeast, desires a position as assistant superintendent or assistant. manager with a mining company operating in Washington or Alaska. Experienced assayer and engineer.

Jan 7, 1913

JoHN W. BELL, Montreal, Quebec, Canada (communication to the Secretary*).-Mr. Taggart's reply illuminates a puzzling element in his original paper. Unconsciously, he has allowed practical considerations to influence some of his conclusions. In certain cases, he accepts the direct conclusions indicated by his Stadler efficiencies, and these are proved wrong by both the Rittinger and practical method for estimating efficiency. In other cases, a direct conclusion based on his Stadler figures would be so unsatisfactory to him, that he is. compelled to argue how he could have obtained satisfactory results if lie had crone something that

Jan 10, 1917

By Robert H. Weber

Increasing acceptance of perlite products, chiefly in the fields of lightweight structural aggregates and thermal and acoustic insulation, has led to expanding market demands that have encouraged many new producers to enter the field. In some instances, however, the failure of these producers to anticipate the variable response of perlite to conventional processing methods has led to difficulty in establishing an economical flowsheet by which a predictable specification product could be obtained. It is not the writer's intent to provide a solution to these problems, but rather to summarize their nature. It is to be hoped that members of the industry who have hurdled some of these obstacles will document solutions arising from their experience.

Jan 2, 1955

By J. Winter, W. C. Setzer, A. J. Goldman

ANISOTROPY in cold worked tempers of commercial aluminum alloys is manifested in deep drawn products as protuberances or ears 45 deg to the rolling direction. This reflects the {123}(412) rolling texture.' In fully annealed material, 0 to 90 deg ears in and per-

Jan 1, 1970

Executive SIDNEY J. JENNINGS, Chairman GEORGE D. BARRON J. E. JOHNSON, JR. EDWIN LUDLOW ROBERT-M. RAYMOND Membership LEWIS W. FRANCIS KARL EILERS, Chairman J. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR L. WALKER Finance GEORGE D. BARRON, Chairman CHARLES F. RAND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY.1 Chairman. ALEX C. HUMPHREYS3 GEORGE C. STONE2 J. H. JANEWAY4 BRADLEY STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 2, 1919

By I. Iwasaki, K. A. Smith

A chlorination process for treating metal sulfide flotation concentrates is described. The process involves low temperature chlorination combined with sulfur chloride conversion and selective oxidation to produce nonferrous metal chlorides, elemental sulfur, and ferric oxide in a three-stage fluidized bed reactor. The nonferrous metal chlorides may then be water leached, separated, purified, and electrolyzed to recover copper and nickel metals and to regenerate chlorine for recycling.

Jan 1, 1986

By W. N. Lacey, R. H. Dourson, B. H. Sage

THE compositions of coexisting phases in the methane-propane-n-pentane system were determined at 160° and 220°F. throughout the two-phase region, at pressures above 500 lb. per sq. in. The experimental results permitted the calculation of gas-liquid equilibrium constants as well as the establishment of the critical behavior of this ternary system. The experimental results are presented in tabular form and a number of diagrams illustrating the phase behavior of this system have been included.

Jan 1, 1942

By W. F. Mullen

WITH few exceptions, unit operations in the Pennsylvania slate industry in 1950 did not differ appreciably from production methods described by Behre1 and Bowles 2-4 several decades ago. Many traditionally picturesque but relatively inefficient hand operations continued to contribute to high operating costs in an industry in which the margin of profit, for various reasons, was admittedly low. As part of a general program in which the Pennsylvania State College has been assisting the slate industry to solve some of its problems, time and method studies were used in an effort to determine the bottlenecks of production flow. The results are as applicable to other stone industries as they are to slate.

Jan 12, 1951

New York Meets first Wednesday after first Tuesday of each month. L. W. FRANCIS, Chairman, WILLARD S. MORSE, Vice-Chairman,. THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. P. A. MOSMAN, Treasurer. LOUIS D. HUNTOON. - WILLIAM A. POMEROY. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. ROBERT H. RICHARDS, ALBERT SAUVEUR. Columbia Holds four sessions during year. Annual meeting in September or October. FRANK A. ROSS, Chairman. RUSH J. WHITE, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. FREDERIC KEFFER, FRANCIS A. THOMSON.

Jan 5, 1915

By Harry A. Perry

The Highlad underground uranium mine is located in the southern Powder River Basin, Converse County, Wyoming. Development by Exxon Minerals Company began in 1973 and average production from the complex roll- front deposit ranges from 500 to 600 stpd. A staff of six eight grade control technicians work within the Geology Department to guide and monitor production, to minimize waste and to account production to reserve estimates. A thorough knowledge of the complex roll- front deposit aids in accounting production to reserve estimates. Grade control technicians assist the mine geologist in making geologic cross sections, in estimating reserves, and in predicting monthly and quarterly production grades.

Jan 1, 1980

By A. T. Stroebel, J. A. Goodwin

Diatomite deposits, the skeletal remains of tiny aquatic plants called diatoms, are found in many parts of the world. Only a few of these deposits are of commercial value. Open pit mining is used in nearly all deposits now being worked. Processing methods range from simple drying, crushing, sizing and packaging to carefully controlled and highly sophisticated calcining and air classification procedures, employing the latest control and testing techniques. The major uses of processed diatomite are infiltration as filter aids and fillers and extenders.

Jan 1, 1983

By Zhu Weishen, Xu Dongjun

In the 1st part of this paper a comparassion of the different methods for determining the modules of elasticity and deformation of hard rock is made. It is found that the plate bearing method has a serious shortcoming. The slit flat-jack method seems to be a mare reasonable technique, which is recommended as a desirable method for in situ testing. In the 2nd part, a new test method to determine the properties of deformation and strength of weak plane in rock mass is recommended. Then the relation of weak plane character to the character of stress-strain curve, the relation of normal stress to the character of shear displacement curve and the yielding criterion of weak plane are discussed.

Jan 1, 1982

The Institute is custodian of funds for support of numerous gold medals and prizes and has representatives on boards awarding still others. Details regarding the Institute Awards are given be- low. The Institute is represented on the boards of the John Fritz Medal, the Hoover Medal and the Washington Award, in connection with the three national societies of Civil, Mechanical and Electrical engineering; and, also, in the case of the Washington Award, with the Western Society of Engineers. The Institute is represented with these four societies on the committee in charge of the Alfred Noble Prize.

Jan 1, 1934

By Richard H. Terhune

It cannot be said that the development of processes for roasting in Utah has been evolutionary. Some of the best systems were contemporaneons with smelting here, and one of the most primitive methods, pile roasting, is still entrenched, to the exclusion of all others, at one works. This is certainly not because we have not had sulphur, in place and out of place, to contend with, but rather because roasting has not been a necessity, we having, like most other smelting districts in America, a good share of oxidized ores.

Jan 1, 1888

By B. Heide, A. Bergrnann

The Meggen mine and the concentrator plant of the Sachtleben Bergbau GmbH are located in the southern part of the Ruhr district of the Federal Republic of Germany. The mine has been in operation for more than 100 years, but the concentrator described in this paper was started up in January 1963. The Meggen orebody is of sedimentary origin and occurs in a zone of limestones, graywacke and shales of Devonian age. The average thickness of the deposit is 3 meters and due to an intense folding of the area, the mineralized zone dips steeply at 80º towards the north.

Jan 6, 1973

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman, JOHN H. JANEWAY, Vice-Chairman. F. E. PIERCE. Secretary, 35 Nassau St., New York, N. Y. P. A. MOSMAN, Treasurer. LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. HENRY A. WENTWORTH, Secretary-Treasurer, 60 India St., Boston, Mass. ROBERT H. RICHARDS, ALBERT SAUVEUR. Columbia Holds four sessions during year. Annual meeting in September or October. FRANK A. ROSS, Chairman. RUSH J. WHITE, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. FREDERIC KEFFER, FRANCIS A. THOMSON.

Jan 8, 1915