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By Burdett Loomis

The advantages of gaseous fuel have been too fully set forth during the past few years to need recapitulation. Papers, arguments, and editorials have been issued, in a more or less general way, that would make volumes. Systems have found zealous advocates, and many promises of results that have sounded strangely in the ears of old-fashioned gas-makers, have been born of theory, and have died in the earliest throes of trial; while in some few instances success has demonstrated the value of practical effort. With few exceptions, however, everything attempted or accomplished has tended towards the one end-—the realization of more perfect results than we can

Jan 1, 1891

CHEMICAL PRECIPITATION U.S. 4,067,789 - Removal of soluble manganous ions from a zinc sulfate solution formed by leaching roasted zinc sulfide ore with spent electrolyte. An excess of ammonium persulfate or like oxidant is added to the leach solution to convert manganese to insoluble, filterable gamma-manganese dioxide, and the precipitate separated from the solution by filtration. L. Harris and A. K. Hanson, Jr., assigned to Newmont Exploration Ltd. Jan. 10, 1978. 11 pp. (204-119). Filed: 5-3-76 (682.442). (Drawing on page 67.)

Jan 1, 1979

Jan 1, 1901

By Stuart McGill

This case-study of the financing of the Ok Tedi project illustrates the nature of project financing and outlines the arrangements made in the case of this project; it also demonstrates that the limitation of financial exposure is an important goal for Governments involved in developing the resources sector. The account includes a chronological description of the process by which the sponsors prepared for the financing of the project and the lenders became involved in it. The type of security arid loan documentation required for such financing is described, together with a broad analysis of their content and the manner in which the various risks involved in development are apportioned among the sponsors and lenders. The ability to apportion and limit financial liability is an important development for the owners of capital and resources.

Jan 1, 1985

Within the last century, and largely during the latter half of it, the increase of our knowledge of the development of man, both in his search for a livelihood and for power, and in the growth of his reason and conscience, has been greater than all we had known before. The great interest in all kinds of archaeological work and the many excavations made of buried and long forgotten places has put at our disposal historical records-not available, and in many cases not known before, and a study of these and other records of human progress from paleontological and geological sources has given us a much broader view of what we call "civilization" than was possible even a short time ago. The old idea that men were created with fully developed minds, speech and reason has yielded to the view that in the upward progress of the human race the development of the mind and reason has been a comparatively recent occurrence, as we think of the half million, and probably more, years that have passed since our earliest records of man were made. The traits that come to us without effort

Jan 1, 1939

By Arthur S. Coffinberry, Ralph Hultgren

WE have studied the gold-aluminum system by X-ray diffraction and by the microscope over the entire range of composition for temperatures between 300° and 500° C. Results obtained are shown in Fig. 1, combined with the work of Heycock and Neville1 at higher temperatures. The diagram differs in important details from that given by Hansen2 in his critical compilation of the literature of binary alloy systems. This work was undertaken both because of the intrinsic value of a knowledge of the phase diagram of this system and because of the need of theoretical metallurgy for precise and accurate data, particularly X-ray diffraction data. Systematic studies of equilibrium diagrams, particularly by Hume-Rothery,3 have shown regularities that yield a certain insight into the nature of alloying forces. It has been shown, for example, that solid solubility depends on the concentration of free electrons in the alloy, on the relative radii of solvent and solute atoms, on the forces of attraction between atoms, and on the relative stability of intermediate phases. The well-known Hume-Rothery rule states that the crystal structures and compositions of many intermediate phases depend on the electronto-atom ratio. This has been confirmed and extended by wave mechanical calculations.4 A knowledge of the forces between atoms in alloys, even an imperfectly developed empirical one, should be a valuable guide in the preparation of technological alloys of desirable properties. Furthermore, such information is basic in such problems as rate of diffusion, age-hardening, phase transformations, and others. The most valuable data for this purpose are furnished by X-ray diffraction studies. Unfortunately, work has been

Jan 1, 1938

Jan 1, 1955

By I. E. Rosenzweig

The problem considered in this paper is as follows: An arbitrary horizontally stratified area is given. The electrical properties of this area are characterized by a function p(z) (Fig. I), which shows the relationship between resistivity p of the soil and the depth z. For such general case the apparent resistivity p* will be computed, by earth-resistivity measurements carried out by any given configuration of electrodes. General solutions of this problem appear to be very important for interpretation of field results of resistivity measurements, concerning structural investigations. Such solutions have been given by many authors for the special case of a finite number of homogeneous layers (Fig. 2)lV4 as well as for the more general case of continuously ranging resistivities.5-8

Jan 1, 1940

By Robert O. Davis, Phillip A. Abbott

The response of geologic materials subject to nuclear weapon effects is of considerable interest in the design of buried protective construction. Recently, more consideration has been given to placing such structures in rock rather than in soil. Although rock has the obvious advantages of high strength and low deformability, discontinuities such as joints and fault planes severely complicate any response analysis. Nevertheless, some knowledge of the effects of these discontinuities must be developed, even if that knowledge remains largely qualitative in nature. In this paper, we present a constitutive description of cracked rock subject to uniaxial shock loading. The constitutive equations are based on certain average response characteristics of a particular cracked rock model. Rather than attempt to represent each material discontinuity individually, we have incorporated the discontinuity effects into constitutive relationships for a continuous medium. The resulting equations are suitable for use in hydrodynamic computer codes presently used for ground motion calculations. APPROACH The continuum description which will be presented below is based on a detailed analysis of a particular cracked rock model. This model can be visualized as a sequence of plates (representing the intact rock) separated by gaps (representing the discontinuities). This so-called "plate-gap" model was first used by Thouvenin (1) in an effort to explain the behavior of porous materials at high

Jan 1, 1971

By F. S. McNicholas

In the first big blast at Climax, a "loop back" (three-wire system) was used (Fig, I), with the idea of securing a wiring system that would give to all series the same amount of current. Single-phase, 60-cycle, 13,800-volt power was furnished to the blasting transformers, each of which has a rated capacity of 600 amp. at 480 volts. Two blasting leads were taken from these transformers, giving a blasting current of single phase, 60 cycle, 480 volts, with an instantaneous capacity of more than 600 amp. The blasting switch was on the secondary leads from the transformers, to avoid lag in energizing them.

Jan 1, 1940

By William G. Brissenden

Gaspe Copper Mines Ltd., a subsidiary of Noranda Mines Ltd., operates a completely integrated copper mining, milling and smelting plant at Murdochville, on the Gaspe Peninsula of Quebec. Operating six days a week, the mine produces 8000 tpd of ore. The mill runs continuously and capacity is rated at 6500 tpd of ore. Treating Gaspe concentrate output plus a certain amount of custom concentrate, the smelter produces between 3700 and 4000 tons of copper anodes per month.

Jan 9, 1959

By Harlowe Hardinge

THE sound made by ball, pebble and rod mills has long been used by the operator as the "telltale" of their operation. The nature of this sound depends upon local conditions and the type of mill used. By experience an operator can tell whether the mill is running properly or not. Some operators are able to detect the difference in sound much better than others and get better results running the same mill tinder the same conditions. The automatic operation of a mill using sound as the fundamental means for maintaining control presents many problems. The satisfactory solution of these problems requires, for given operating conditions, a greater average output, with improved product for subsequent processing, than can be obtained by manual control.

Jan 1, 1939

By R. Clare Coffin

The production of petroleum in the Rocky Mountain district increased from 27,104,436 bbl. in 1929 to 33,048,630 bbl. in 1930. This increase was due to the development in southeastern New Mexico; which is in reality a portion .of the West Texas province. Disregarding production in southeastern New Mexico, the Rocky Mountain district produced 25,799,027 bbl. in 1929 and 23,164,988 bbl. in 1930, a decrease of 2,634,039 bbl. for the period. The daily production in January, 1930, averaged 70,839 bbl. for the entire district and in December, 1930, the daily production was 98,995 bbl. Total production by states is given in Table 1. Three important discoveries of oil and one of gas occurred in the district during 1930 in structures not, previously known to contain oil or gas. Oil was discovered in Dry Creek structure, Carbon County, Mont.; in the Midway structure, Natrona County, near Casper, Wyo.; and in the Greasewood structure, Weld County, Colo., northwest of Fort Morgan. Gas was discovered in the Bell Rock structure in Moffat County, western Colorado. Seven deep tests in as many different fields encountered oil in lower horizons than those already exploited. All of these discoveries were in the state of Wyoming. They occurred in the Salt Creek field, Natrona

Jan 1, 1931

By N. A. DeCecco, H. M. Meyer

IN the early stages of a titanium brazing investigation, binary titanium systems partially or completely known and fundamental metallurgical data were surveyed to select the pure metal most likely to be satisfactory for producing a ductile high strength joint. The phase diagrams for the purpose of this survey were classified into two groups: 1—systems with large solubility in ß titanium, but negligible solubility in a titanium, and 2—systems with large solubility in a titanium. Those metals with melting points believed to be too high or too low for titanium brazing (Tim = 1730°C) were eliminated from consideration. The melting points of vanadium, tungsten, tantalum, hafnium, zirconium, and the platinum group are too high and those of zinc, lead, cadmium, and tin are too low. The remaining metals were grouped as follows: 1—large ß solubility: Cr,¹ Mn,² Fe;³ CO,4 Ni,5 Cu,6 Be,' Si." —large a solubility: Al.9

Jan 1, 1954

By Walter Harvey Weed

The enrichment of mineral-veins as a result of the migration of material from an upper oxidized or disintegrated part of a vein to a lower level, where it is redeposited, is now, I believe, quite generally accepted as one explanation of the occurrence of bonanzas in gold- and silver-veins, as well as that of bodies of high-grade ores in cupriferous deposits.* Vogt has called attention† to the fact that there are numerous examples of such rich shoots which are " of exclusively primary character, and dependent upon the laws which governed the original ore-deposition." To this I would add that there are also other examples which are neither of primary origin nor due to descending waters, but. result from a reopening of the veins and their penetration by ascending heated waters whose metallic contents are deposited by reaction with the primary pyrite (and possibly other minerals), forming "secondary" enrichments. My studies of the copper-veins of Butte, Montana, show: That the veins there are of several ages and systems; that the older primary quartz-pyrite veins were reopened by later movements, correlated with a period of volcanic activity; and that they were penetrated by hot alkaline waters carrying copper and arsenic in solution, which was deposited presumably by reaction with the pyrite of the original vein. The enormous development of the Butte deposits, attendant upon the extraction of nearly 10,000 tons of ore a day, has revealed many facts concerning the nature and distribution of the ores. Enargite, the copper sulpharsenate, formerly a relatively rare mineral, is now found to be the chief ore of some veins,

Jan 1, 1903

By Earle J. Klohn

Mining operations have been carried out in British Columbia since the time of the first settlers in the area. The early developments were mainly small volume, high-grade operations, producing small quantities of tailings wastes. In these early days the nearest stream was a logical first choice for tailings disposal. Where streams suitable for accepting the tailings were not available or where streams crossing the International Border could not be used for this purpose, the nearest convenient land site was selected for storing the tailings. Old tailings waste piles exist at many locations in the Province and are readily evident, for example, in the Princeton and Hedley areas. Figs. 1 and 2 are photographs showing the present condition of two of these old tailings dams. [ ]

Jan 1, 1972

By Donald E. Crowell

In the fall of 1969, ASARCO and Newmont Mining Co. began the design of the 700tpd concentrator at their Black Cloud shaft located near Leadville, Colo. The concentractor would treat by flotation a Pb-Zn-Ag ore containing minor gold values. Flowsheet design was based on laboratory test work performed at the Minerals Research Testing Laboratory of ASARCO. Since the concentrator is located at an elevation of 11,000 ft, cold weather was a major factor in design considerations. The original capacity was designed as 700 tpd but for various reasons an ultimate capacity of 1,000 tpd was desired. This necessitated special consideration in the design of several areas, particularly the grinding circuit. The grinding circuit chosen was a single 9 X 12 ball mill operating in closed circuit with one 20-in. cyclone. The ball mill will operate at low speed and as an overflow type originally. The mill can be speeded up and converted to grate type for handling the larger tonnage when required. Thickeners and filters were oversized and space was left for additional flotation cells in order to handle the increased tonnage in these areas. Pumps were sized so that they could handle the increased tonnage by increasing their speed. Construction began in May 1970; the Black Cloud concentrator went on-stream in April 1791.

Jan 1, 1974

By W. H. W. Husband

Rock salt has been solution mined for many years in many countries. Attempts have been made in the past in Canada and various other countries to produce potash by the same method. However, only Kalium Chemicals Ltd. has been successful, possibly because the conditions in Saskatchewan are the most favorable to be found so far for the development of a solution-mining method for potash. In view of the fact that few studies of solution mining of potash have been attempted, only one company has succeeded in using the method, and no information has been released by this company, the application of solution mining of potash ore bodies has to be presented on the basis of available theory, past small-scale studies, and recent patents. A simple mining method is outlined and possible methods of recovering the potash from the brine are discussed. Dissolution data pertaining to solution mining of potash, flowsheets, and material balances are presented. The available information is brought together in a cost analysis to show capital and product costs in terms of 1966 dollars.

Jan 1, 1972

By John Dresser

General THE controlling supply of asbestos for the world is obtained from southern Quebec, 150 miles or less north of the international boundary line between Canada and the United States, and about 75 miles south of the city of Quebec. The principal production is furnished by eight mines, seven of which occur within a distance of 6 miles, but there are also several smaller properties in the vicinity. The industry was begun in a small way some 35 years ago and has advanced more or less regularly ever since. The annual production now exceeds 100,000 tons and its value is about $3,000,000. It represents over 80 per cent. of the world's production. History Asbestos has been known in the eastern townships of Quebec since 1847, when attention was called to it in an official report by Sir William Logan, the first Director of the Geological Survey of Canada, but it was not until 30 years later that it came into commercial importance. The largest deposits, those of Thetford and Black Lake, were found in 1877 during the construction of the Quebec Central Railway. Work was begun upon them almost at once and has been continued ever since. The Danville mine, the next largest producer, was opened in 1879, and the slip-fiber deposits of East Broughton were located shortly afterward. For the first 15 years only the "crude" asbestos was recovered; that is, fiber long enough to be extracted by hand cobbing. Although this is still a valuable part of the production, it is now a relatively small part of the total output.

Jan 9, 1914

By AIME AIME

COUNCIL.* PRESIDENT OF THE COUNCIL. CHARLES KIRCHHOFF NEW YORK, N. Y. (Term expires February, 1912.) VICE-PRESIDENTS OF THE COUNCIL. BENJAMIN B. LAWRENCE NEW YORK, N. Y. JOSEPH W. RICHARDS SOUTH BETHLEHEM, PA. ALBERT SAUVEUR CAMBRIDGE, MASS. (Term expires February, 1912.) S. B. CHRISTY BERKELEY, CAL. W. A. LATHROP PHILADELPHIA, PA. GARDNER F. WILLIAMS WASHINGTON, D. C. (Term expires February, 1913.)

Mar 1, 1911