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By Raymond Franz

Of the many types of capital equipment found in a surface operation, draglines and mining shovels are probably subjected to the most severe service. Yet, some excavators have seen a generation or more of continuous service-proof, if any is needed, of their ruggedness. To keep these expensive pieces of machinery operating, a continuing maintenance program which includes field weld repairs is essential. During an excavator's working life, minor cracks may appear in parts of the steel structure, caused by fatigue and sometimes material defects-defects so small they could not be detected during manufacture.

Jan 6, 1978

By P. Barnes

In vol.33 of the Proceedings of the Institution of Civil Engineers, London (part 2, for 1870-71), may be found a statement of the cost of two blast furnaces, together with a somewhat detailed description. The attempt will he made in this note to restate these items of cost, so that the information may be rendered perhaps more accessible to our members than in its present place of record, and also in order that the items may be more intelligibly compared among themselves, or with similar items in other cases.

Jan 1, 1879

By H. M. Chance

The failure of the carbonic acid gas method at the Kehley Run Colliery has given rise to a conviction of the inefficienoy of the process ; but a careful survey of the facts, and of the conditions under which it was tried, mill show that a fair trial of the method was not and could not be made at this colliery; its failure in this particular instance therefore, should not be held as evidence against, the process. In itself, thc method seems to be theoretically perfect, but in prac-

Jan 1, 1881

By H. M. Chance

THE failure of the carbonic acid gas method at the Kehley Run Colliery has given rise to a conviction of the inefficienoy of the process; but a careful survey of the facts, and of the conditions under which it was tried, will show that a fair trial of the method was not and could not be made at this colliery; its failure in this particular instance therefore, should not be held as evidence against the process. In itself, the method seems to be theoretically perfect, but in prac-

Jan 1, 1881

By Richard V. Wyman

Leaching of a granitic rock mass by slightly acid groundwater brings uranium and genetically related ions into solution in groundwater. Uranium and related ions are moved through the vadose zone by groundwater which in turn moves through zones of greatest transmissivity into a deep zone of increased hydrostatic pressure. Cyclic wetting causes the hydrostatic condition to fluctuate causing recycling described by Gruner (op cit). Multiple cycling flushes the uranium ions from rock being leached and moves it via this method to permeable beds-channels-in the deep zone.

Jan 1, 1970

By M. A. Mahtab

When characterizing orientations of rock joints in an engineering site with respect to mean values of the existing clusters or joint sets, a need may arise for a similarity test that allows grouping of observations from several adjacent sampling stations. Subjective judgment, though based on experience, may not produce realistic groupings in the data. A similarity test is developed in this paper for objective grouping of samples of joint orientations in engineering sites. The test is applied to the data from a large, geologically complex site of a potential open pit mine.

Jan 1, 1984

By Roger Holmberg, Kenneth Mäki

This paper describe; open pit studies where blasting damage introduced in the remaining rock has been investigated. Results from two open pit mines are described and discussed. Parallel performed laboratory experiments, where simulated blasting damage has been introduced into samples before shear strength testing took place, are also reviewed. These studies are tied together in order to throw some light upon how the blasting damage influences the slope stability. A mathematical model is also described which will make it possible to optimize the blast design for a specified damage zone in the rock mass.

Jan 1, 1983

By J. L. Whitlock

An attached growth aerobic biological treatment process has been developed at Homestake Mining Co.'s Lead operation which not only oxidizes free and complexed cyanides, including the stable iron complexed cyanides, but also thiocyanate, and the oxidation byproduct ammonia. Through the employment of a mutant strain of bacteria which has been gradually and specifically acclimated to the waste, these potential pollutants are mineralized to relatively harmless sulfates, carbonates, and nitrates. The resultant effluent, through toxicological testing, has been shown compatible with the receiving stream, which serves as a cold water marginal trout fishery.

Jan 1, 1985

By L. Alan Weakly

Abstract-The Bureau of Mines has pursued a program of research on mine illumination that has defined the coal miner's illumination needs. St. Joe Minerals Corporation, recognizing the need for improving the illumination of the working places in their mines, entered into a cooperative research agreement with the Bureau of Mines to utilize the Bureau's expertise in this field. Some similarity in the environment, in which coal and hard rock miners work, has allowed the application of developed coal mine illumination technology and equipment to be utilized in hard rock, room and pillar mines.

Jan 6, 1978

By John D. Siddle

Efficient energy utilization in the electrolytic zinc process, relative to other zinc processes, is one of the reasons for its wide adoption in recent years. Designers and operators of electrolytic zinc plants have pioneered process improvements, new equipment, and operating techniques to conserve energy. As energy costs advance still higher in the future, and competitive pressure against the less efficient producers increases, these or alternative energy-saving methods will be looked upon as a necessity for economic survival. Estimated energy savings which may be achieved by various equipment and techniques are included.

Jan 1, 1977

By C. L. Baker

The total production of petroleum in the Gulf Coast in 1927 was 54.541.180 bbl., .5.655.665 bbl. more than in 1926. The Texas total was 49.129.910 bbl. (Table 1) and the Louisiana tota1 5.411.270 bbl. (Table 2). Louisiana production decreased 278.028 bbl., compared with that of 1926. Spindletop produced nearly 44 per cent. of the Texas total. Initial production in Louisiana amounted to 62.865 bbl. and in Texas to 352.955 bbl.' The Oil and Gas Journal gives a total of 1145 wells

Jan 1, 1928

By L. Alan Weakly

The Bureau of Mines has pursued a program of research on mine illumination that has defined the coal miner's illumination needs. St. Joe Minerals Corporation, recognizing the need for improving the illumination of the working place in their mines, entered into a cooperative research agreement with the Bureau of Mines to utilize the Bureau’s expertise in this field. Some similarity in the environment, in which coal and hard rock miners work, has allowed the application of developed coal mine illumination technology and equipment to be utilized in hard rock, room and pillar mines.

Jan 1, 1979

By S. S. Hsieh

Important carboxylic acid components of tall oils were tested individually as phosphate flotation reagents. These included C18 unsaturated fatty acids and C10 to C18 saturated fatty acids and resin acids. These experiments were conducted to evaluate such factors as the degree of unsaturation, hydro-carbon chain length, isomeric form, side-group modification, and cyclic structure. The effects of mineralogical characteristics on flotation response also were considered. Results of this systematic evaluation provide guidelines for selecting efficient substitute reagents and fundamental data for further research on improved flotation technology.

Jan 1, 1983

The regular activities of the Institute are financed mainly by income derived from members' dues, from advertising in MINING ENGINEERING, JOURNAL OF METALS, and JOURNAL OF PETROLEUM TECHNOLOGY, and from the sale of publications to the public In addition, collateral activities and special projects are financed each year by means of income - from endowed funds controlled and administered by the Institute. An active effort is being made to increase the endowment funds of the Institute through a standing committee, of which Wilfred Sykes is Chairman, and of which the other members are N G

Jan 1, 1952

By W. H. Eatock

In its infancy, the potash refining industry in Saskatchewan was heavily influenced by practices developed in Carlsbad, NM, resulting in modern, highly productive plants. The first 15 years has been a period of reduced production, due to excessive capacity, when improvements tended to be emphasized in the mining rather than the refining functions. However, some innovations have been developed and applied in Saskatchewan and the industry is entering a period of massive expansion which will produce further advances. This paper discusses, in general terms, some of the different approaches and recent trends.

Jan 1, 1983

By J. F. Pashak, T. E. Leontis

The effects of zirconium on the properties of sand cast Mg-rare earth metal alloys were discussed in detail in an earlier publication.' It was shown that a significant improvement in strength properties at temperatures up to 400°F resulted from the zirconium addition. In general, the properties of cast Mg-Didymium-Zr alloys were superior to the corresponding alloys containing Mischmetal and the optimum rare-earth level was approAmately 3 pet. Jessup, Emley, and Fisher have also shown the advantages of didymium in Mg-rare earth-Zr alloys, 2

Jan 1, 1961

The regular activities of the Institute are financed mainly by income derived from members' dues, from advertising in MINING AND METALLURGY, and from the sale of publications to the public In addition, collateral activities and special projects are financed each year by means of income from endowed funds controlled and administered by the Institute In the aggregate, the amount of these endowments totals more than $830,000 An active effort is being made to increase the endowment funds of the Institute through a standing committee, of which Harvey S Mudd is Chairman, and

Jan 1, 1952

By A. J. Lynch, J. A. Holmes, F. C. Bond, D. W. Fuerstenau

This is an outstanding paper on comminution theory and represents a considerable advance in mathematical formulation. It clears the way for a discussion that should ultimately decide whether the work index should be considered as a parameter according to the Third Theory or as a constant. In the empirical differential equation dE = C dx/xn either C or n must be treated as a variable to satisfy known crushing and grinding conditions. The author has chosen the exponent n as the variable, with C as a constant.

Jan 4, 1958

By Weldon B. Smith

When faced with excavating vast amounts of overburden at its surface coal mining operation in Centralia, Wash., the Washington Irrigation and Development Co. (Widco) chose to utilize a bucket wheel excavator and shiftable conveyor system. In the early 1970s, Widco-a subsidiary of the Washington Water Power Co.-held reserves of sub-bituminous C coal estimated at some 180 million tons (200 million st). Subsequent investigation of the overlying land formations revealed the need to excavate millions of bank cubic yards of material as part of the mining plans.

Jan 7, 1979

By T. W. Healy, D. R. Dixon

The mechanism of activation of ZnS by metal ions and the subsequent flotation induced by xanthate has been considered as a surface redox reaction. By ultraviolet (UV) irradiation of ZnS suspensions, the normally inert ZnS is caused to react with xanthate in the absence of activator. By similar UV irradiation, the rate of adsorption-exchange of activator ions at the ZnS-H2O interface is also increased. Mechanisms of these reactions are proposed and compared to current electrochemical and semiconducting models of sulfide flotation.

Jan 1, 1976