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By John I. Yellott

SINCE the days of Newcomen and Watt, when men first sought to turn the energy of fuels to useful purposes, coal-generated steam has supplied most of the power needed for both stationary and mobile applications. The low efficiency and large water requirements of the nineteenth century steam-power plant caused many engineers to turn their thoughts toward more direct means of converting heat into power. As far back as 1791, John Barber secured an English patent on a combination' which he might well have called a "gas turbine." He proposed to generate procducer gas from coal or charcoal, to burn it under pressure in air obtained from a reciprocating compressor, and to drive a turbine wheel with the resultant hot combustion products. With the optimism characteristic of the inventor, he hoped that the turbine would not only operate his compressor but also perform useful work. There is no record that Barber ever built his machine, but if he had done so he would have learned that useful power can result from such a combination only when both turbine and compressor are highly efficient and when the temperature of the gas entering the turbine is not far below 1000°F. Hot-air prime movers continued to attract attention, and both Stirling in England and Ericsson in America2 built reciprocating engines that operated with some success upon coal-heated air. The internal-combustion engine, burning liquid fuels, supplanted the hot-air type, and, for the first time, challenged the supremacy of both the steam cycle and its familiar fuel, coal. LIQUID FUELS COMPETE WITH COAL As the increasing use of the automobile multiplied the demand for gasoline, the supply of residual fuel increased rapidly, and heavy oil declined in price to the point where it became competitive with coal. First in the marine field and later in stationary plants in areas adjacent to refineries, oil began to be widely used. Oil's greater convenience and higher heating value per pound of weight or per cubic foot of bunker space have caused it to take over much of the marine field. The introduction of the highly efficient diesel engine, capable of burning a fuel that is cheaper than gasoline, again threatened the position of coal, for the operating costs of the diesel became directly competitive with those of coal- burning equipment. In isolated power plants and smaller marine installations, the diesel provided the medium by which oil again successfully invaded fields formerly dominated by coal. The diesel engine, provided with an

Jan 1, 1946

By Wilbur E. Sanders

At some period during the operation of metalliferous and other commercially valuable mineral-deposits in connection with their underground mining, when the developments therein have become so extensive that their description is tedious and confusing, some scheme for naming or numbering the various workings and their parts is necessary for convenience of reference. A simple and symmetrical yet expansive system of classification must be devised, one that is capable of being extended to cover all possible exigencies and conditions of future operations within the property. Such a scheme, properly arranged, greatly simplifies communication between the various departments of the mining business, as, for instance, between the administrative and the operating departments of the concern, and is of the greatest assistance to the officers of the mine in enabling them to locate and describe particular points and parts of workings and specific kinds of work. Again, in the proper segregation and differentiation of mine-accounts, when they are carried out with that detail which will furnish ready information concerning the cost of a particular piece of work, or the various items and totals of expense connected with the development, operation and repair of each or all of the mine-workings, some such method of clesignatioi~ becomes a necessity. Moreover, such a plan is acl- mirably adapted to the needs of the mining engineer, who, in connection with his reports upon mining-properties, is sometimes required, in his descriptions of certain blocks of ore, to locate lists of assays of samples taken from many and various places, and to designate workings and parts of workings that are located in different parts of the mine, sometimes at points wide apart. To write out in full a sufficient description of any particular

Jan 1, 1907

PROF RICHARD ÅKERMAN Stockholm, Sweden DR. FRANK DAWSON ADAMS Montreal, Canada PROF RICHARD BECK Friberg, Germany ANDREW CARNEGIR New York, N.Y. DR. JAMES DOUGLAS New York, N.Y. PROF HATON DE LA GOUPILLIERE Paris, France SIR ROBERT A. HADFEILD London, England PROF HANS HOFFER Leoben, Austria PROF HENRI LOUIS LE CHATELIER Paris France EZEQUIEL ORDONEZ Mexico City, Mexico ALEXANDRE POURCEL Paris, France DR. ROSSITTER W. RAYMOND New York, N.Y. DR. ING H. C. EMIL SCHROEDTER Dusseldorf, Germany JOHN E. STEAD Middlesborugh, England JAMES M. SWANK (Associate) Philadelphia, Pa. PROF DIMITRY CONSTANTIN TSCHERNOFF St Petersburg, Russia PROF TSUNASHIRO WADA Tokyo, Japan CHARLES D WALCOT Washingtion D.C.

Jan 1, 1917

By J. B. Scott, J. S. Nelson, G. H. Kruse, W. S. Johnson, K. L. Zerneke

The economics of pressure tunnel design emphasize the utmost utilization of the least expensive pressure-resisting material available, namely, the rock surrounding the tunnel. A major difficulty in the design is the problem of transferring internal hydraulic pressure to the rock through a tunnel lining or membrane provided to maintain watertight conditions. The lining is necessary not only to prevent water loss, but to prevent the diffusion of water at high pressure through joints and fractures beyond the confines of the tunnel, an occurrence which could ultimately affect the stability of the rock mass through which the tunnel passes. Because of its toughness and ability to bridge localized areas of weakness, steel is used for a lining material whenever high internal pressures are involved. The steel lining is coupled to the surrounding rock mass through an annular ring of concrete backfill. It is paradoxical that the steel lining, needed primarily to assure water tightness, must of necessity be incorporated into the structure as a major pressure-resisting component, not to augment the bearing capacity of the concrete and rock, but to limit the strain for the safety and preservation of the steel lining itself. With the deformation modulus of the steel so much greater than that of the rock, the liner approaches its yield strength before the load capacity of the rock can be fully mobilized. An economical determination of plate thickness for steel liners is therefore dependent upon measurement of the properties of the surround-

Jan 1, 1970

By J. E. Campbell, G. D. Calkins, N. M. Ewbank, M. Pobereskin, A. Wesner

GRINDING for size reduction affects the economics of many processes and products. It is essential as the first step in many industrial processes and is also a finishing step for materials with properties depending on particle size, such as talc, cement, and silica sand. Intermediate and fine grinding are vital operations in the U. S. cement industry, which is producing more than 250 million bbl of cement per year.1 Wear of the grinding media is a large part of the grinding operation cost. Problems encountered in grinding cement are so complex that evaluation of efficiency and economy of grinding media is difficult.2 It has been especially difficult to evaluate the relative effectiveness of different types of balls because there are no good testing techniques.

Jan 12, 1957

Mr. Address Member is hereby proposed by the undersigned, as a Associate Junior Member of the American Institute of Mining Engineers. Signatures of three Members or Associates. Place of birth Year of-birth Education, when, where and how acquired, with degrees, if any. A technical education is not requisite for membership. Dates Please give record of experience on following page with dates; for e. ample, in the form used by "Who's Who In America" and similar publications.

Jan 6, 1917

Mr. Address Member is hereby proposed by the undersigned, as a Associate Junior Member of the American Institute of Mining Engineers. Signature of three Members or Associates (not Junior Members). Place of birth Year of birth Education, when, where and how acquired, with degrees, if any. A technical education is not requisite for membership. Dates Please give record of experience on following page with dates; for example, in the form used by "Who's Who In America" and similar publications.

Jan 1, 1918

Mr. Address - Member is hereby proposed by 'the undersigned, as a Associate Junior Member of the American Institute of Mining Engineers. Signature of three Members or Associates (not Junior Members). Place of birth Year of birth Education, when, where and how acquired, with degrees, if any. A technical education is not requisite for membership. Dates . . Please give record of experience on following page with dates; for example, in the form used by "Who's Who In America" and similar publications.

Jan 2, 1918

By H. L. Ames, P. H. Jennings, R. W. Stanley

A process has been developed for leaching copper, lead and calcium from molybdenite concentrate. The leachant is a solution containing an oxidizing chloride (e. g., CuC12, FeC13) and an alkaline earth metal chloride (e. g., CaC12). Cupric chloride and ferric chloride, in the presence of 20-30% calcium chloride, are effective oxidants for chalcopyrite and galena. Calcium chloride, in addition to promoting the rate of leaching, serves to lower the solution pH and raise the boiling point. Leaching for two hours at 110'~ with a 1 % CuC12-10% FeC13- 30% CaC12 solution results in the extraction of up to 98% of the copper in molybdenite, 98% of the lead, and 79% of the calcium. Less than 0. 5% of the molybdenum is dissolved. The leach solution can be rapidly and effectively regenerated with gaseous chlorine and recycled. Build-up of copper and lead in the leach solution is controlled by discarding about 30% of the leach solution each cycle.

Jan 1, 1973

By W. H. Geis

THE following pages summarize the causes that led to the suggestion of unit operation of the Paloma field, the organization of committees, preparation of the Paloma Operators Agreement and the reasons for rejection of the plan.

Jan 1, 1942

By Edward I. Salkovitz

RECENTLY a set of crystallographic angles for bismuth was calculated and a standard (111) projection was constructed. Since these calculations

Jan 1, 1957

YEAR OF ELECTION 1913. FRANK DAWSON ADAMS Montreal, Canada. 1935. GUILLAUME DANIEL DELPRAT Melbourne, Vic., Aust. 1920. HENRY STURGIS DRINKER Merion Station, Pa. 1933. KARL EILERS New York, N. Y. 1922. FEDERICO GIOLITTI Trino,Italy. 1906. SIR ROBERT A. HADFIELD London, England. 1921. FRANK WILLIAM HARBORD London, England. 1917. HERBERT HOOVER New York, N. Y. 1931. WALDEMAR LINDGREN Cambridge, Mass. 1921. C. MCDERMID London, England. 1913. EZEQUIEL ORDOAEZ Mexico City, Mexico. 1935. ROBERT PEELE New York, N. Y. 1937. GEORGE S. RICE Washington, D. C. 1911. ROBERT H. RICHARDS Cambridge, Mass. 1934. T. A. RICKARD..... Victoria, B.C., Canada. 1933. ALBERT SAIVEUR CAMBRIDGE, MASS.

Jan 1, 1937

By Robert I. Kingman

SUFFICIENT testing has been performed with the Dutch State Mines Cyclone for thickening and desliming flotation feed at the concentrator of the National Lead Co., Tahawus, N. Y., to prove its application for this work. It is the purpose of this article to present some of the test results, operational details and advantages of cyclone thickening and classification. The metallurgy of the mill operation was described by Frank R. Milliken, assistant manager of the titanium division.l The present flowsheet for the recovery of ilmenite consists in grinding the crushing plant product in four open-end rod mills in closed circuit with mechanically vibrating screens to approximately -20 mesh. The screen undersize is treated in Crockett magnetic separators which produce three products: magnetic concentrate, nonmagnetic tailing containing ilmenite and gangue, and a Crockett slime overflow. The non- magnetic tailing is classified into eight sizer spigots products and a classifier overflow. The spigot sand products are tabled separately to produce a rough ilmenite concentrate, a middling product and a tailing. The table middlings are returned to Crockett feed. The table concentrate is dewatered and dried and further concentrated on Wetherill magnetic separators to produce the finished ilmenite concentrate.

Jan 8, 1950

By R. A. Ronzio, P. B. Queneau, C. A. Born

The molybdenite flotation operation of Climax Molybdenum Co., Division of AMAX Inc., near Leadville, Colo., generates a rougher tailing containing 0.03% W03 and 0.005% SnO2. This tailing is subjected to a series of mineral beneficiation steps for production of wolframite and cassiterite concentrates. However, these byproducts are contaminated by small quantities of UsOa. This paper describes application of sulfuric acid-sodium chlorate leaching for substantial elimination of the radioactive impurities, particularly the mineral brannerite. The leached residue is amenable to magnetic separation of wolframite from cassiterite.

Jan 1, 1976

By Donald W. Gentry

Many firms in the minerals industry are facing enormous capital-equipment requirements for existing operations, planned expansion programs, pollution control systems, etc. Yet, because of existing economic conditions, mining companies find it increasingly difficult to obtain reasonable financing for the acquisition of large, high-cost capital equipment. One way of obtaining the use of mining and other major pieces of high-cost capital equipment is through leasing. The popularity of this approach is evidenced by the growing number of leasing companies, equipment manufacturers, and financial institutions now offering this service to their customers. Indeed, leasing has become a billion-dollar industry, and many commercial banks have developed sizeable portfolios in this area. "Should we buy or lease?" This question eventually comes up whenever a mining company needs additional major capital assets. Unfortunately, many buy-or-lease decisions are made on an emotional basis-rather than on a proper financial evaluation that would yield the…

Jan 9, 1975

By R. Y. Williams

IN the United States, fully 98 per cent. of the anthracite and bituminous coal tonnage obtained from underground operations is mined by the room-and-pillar system. Under this system, the total cost of the coal f. o. b. railroad cars contains as its greatest single item the money paid for "labor." Each labor dollar in an. average bituminous mine may be subdivided into 85 c. paid for work done inbye the gathering turnouts (including all work at the face), and 15 c. outbye that point (including all work in and under the tipple). In an average anthracite mine, the corresponding figures are 70 c. and 30 c., the larger breaker force accounting mainly for the difference between these and the bituminous figures. The next largest single item after "labor" is usually "supplies and power;" and a division of this item inbye and outbye the gathering turnouts shows somewhat the same relative proportions as has been noted under the case of "labor". During the past 10 years, the chief advances made in the coal industry have been to obtain economies through complete mechanization covering that portion of the work which lies outbye the gathering turnouts. These results have been accomplished by applying scientific principles to railroad yard layout, to cleaning and sizing machinery, to dumping facilities, to roller-bearing haulage equipment, and to heavy-rail, well-ballasted trackage. But these improvements, while gratifying in their resulting economies, apply only to 15 to 30 per cent. of the important cost items. Obviously, then, the big problem before the engineers of the coal industry today has to do with the methods of mining and the layout inbye the gathering turnouts. Four years ago, Weston Dodson & Co., Inc., determined to have an exhaustive study made of the conditions which must be met in order to gain complete face mechanization, and in order that such a mining layout would be based on, correct underlying principles. The result of that study, which was made by the writer, led to the adoption of a method of longwall mining wherein the. roof is worked on the caving system and is supported as an overhang along the face by steel jacks.

Jan 1, 1928

The suggestions of the members of the Institute are very much desired by the Committee on Nominations prior to deciding upon its nominations to fill the places of those officers who retire early in 1917. The Committee must make its final report to the Board of Directors early in October. The members are, therefore, asked to send in promptly their .suggestions for Directors as well as for Vice-Presidents and President. The Committee hopes to hear from a large number of the members. The officers to be elected at the annual meeting in February, 1917, are: One officer, known as Director and President. Two officers, known as Director and Vice-President

Jan 8, 1916

By V. Steve Reed, Ed L. Reed

The in situ leach mining process generates a waste stream that is high in sulfates, total dissolved solids, and radium 226. During the mining phase, the volume of the waste stream is relatively low and consists primarily of the bleed stream. During the restoration phase, larger volumes of waste water are generated. These waste streams require environrnentally sound disposal. The low net evaporation rate in the Coastal Bend area precludes pond evaporation as a feasible disposal alternative. Reverse osmosis is a practical method of reducing the volume of the waste water handled, but the concentrated waste stream from the reverse osmosis unit must be disposed properly. Deep well injection into highly saline reservoirs is considered a sound method of disposing of the liquid waste generated by in situ mining in the Gulf Coast uranium district. Thirteen injection wells have been permitted to serve the disposal needs of the leach mining industry in Texas. Of these 13, 11 have actually been drilled. Seven applications are pending. The injection zones for the permitted wells range from depths of 3050 to 6200 feet. Pressure limitations imposed on these wells range from 500 psi to 1350 psi. The following criteria are used to determine the desirability of a disposal well site: 1. A minimal number of nearby, improperly plugged borings which penetrate the disposal zone; 2. Minimal crustal disturbance; 3. Sufficient salinity of the water contained in the disposal zone; 4. Protection of oil and gas producing zones; and 5. Sand of sufficient permeability and areal extent to handle the desired volume without fracturing the reservoir. 1. Improperly plugged borings: During the early part of the century, oil wells, gas wells and test holes were drilled using cable tool equipment, often with a minimum amount of surface casing. Production casing, when it was set, was often partly removed when the holes were abandoned. Thus, wells drilled prior to 1940 frequently have less than 100 feet of surface casing and either no production casing or the upper part of the production casing removed. Additionally, these holes are often plugged only with mud. The close proximity of these holes to an injection well location are a concern in that they can provide an avenue for injection-depth fluids to migrate up the bore hole and jeopardize shallower fresh water reservoirs. Usually, where there are more than 6 or 8 poorly plugged borings in a 2 1/2 mile radius of the well site, it is preferable to examine deeper zones for disposal well potential. The deeper zones are especially attractive where the borings are not in a cluster, which renders monitoring more difficult. Often, even the deeper disposal zones are penetrated by a few improperly plugged borings. When this condition arises, the potential for leakage through the borings can be addressed in the following ways. a. Demonstration that the static head in the boring is higher than the anticipated increase in bottom hole pressure generated at the boring by the disposal well. A 100 psi differential between these two pressures is recommended. The calculated increased pressure at a boring caused by injection should be refined using annual bottom hole pressure measurements in the disposal well. Figure 1 illustrates an injection pressure map which can be overlain on the oil well map to determine the anticipated increase in pressure expected at each oil, gas or abandoned hole. b. Shallow ground water monitoring. A shallow monitor well is drilled next to the boring and both pressure and quality measurements are made periodically in the shallow well. c. Disposal zone monitoring. Recently there has been a tendency for regulators to require disposal depth monitor wells instead of shallow well monitoring. We consider disposal depth monitoring to be a less effective method of monitoring because it provides only indirect evidence of potential problems. Assumptions have to be made for the unplugged borings, such as mud weight, that are not addressed by the disposal zone monitoring program. There is little improvement with this system to that discussed in "a" above. A shallow zone monitoring program, however, yields direct evidence of a developing problem with an unplugged boring. Leakage by the boring will be detected quickly by an abnormal increase in pressure in the shallow well. Quality monitoring will detect upward migration of poor quality fluids. The pressure data provide an early warning of impending leakage; the quality monitoring will detect actual fluid migration.

Jan 1, 1980

By D. M. Wyslouzil

Standard testing methods are described that are presently used for the selection of grinding equipment. Correlation between laboratory batch grinding tests and pilot plant continuous tests are established by means of particle size distributions and flotation results. Conventional and autogenous grinding circuits are discussed showing the relationships of the controllable circuit parameters.

Jan 1, 1982

By H. R. Hanley

ELECTROLYTIC zinc produced from sulfate solution and, with pure lead anodes is always contaminated with a small and varying percentage of lead. The purpose of this investigation is to determine the characteristics of several lead alloys and their influence on the products of electrolysis and power consumption. The study of alloyed anodes has been a matter of interest for some years. Tainton, Taylor and Ehrlinger prepared a highly interesting paper1 on this subject a year ago, in which the effects of silver-lead and some ternary alloys of lead-silver-tin were described. The present paper describes a study of various combinations of 10 metals. The general plan of the work provides for the fabrication of the alloyed anode, its adequate conditioning by preparatory electrolytic operation, the production of cathode zinc and its analysis, the determination of the anode polarization, and other features. A list of the anodes tested, showing composition and polarization at various current densities together with the lead assay of the cathode zinc, is shown in Table 1.

Jan 1, 1930