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By Paul M. Tyler

MUCH information concerning pegmatites which was thought to be true a few years ago has been proved false, and what is now actually known about some pegmatites is not true of many others. The erratic and seemingly unpredictable structure and variable composition of this class of mineral deposits has been widely emphasized. Even parts of the same pegmatite body exhibit marked differences in texture, mineral composition, width, and attitude. Constructive geological thinking in respect to pegmatites now aims to establish general laws rather than to stress the confusing diversity of features having no special economic significance.

Jan 9, 1953

By Arnulf Muan, Klaus Schwerdtfeger

Activity-composition relations in Pt-Cr and Pd-Cr alloys of low chromium concentrations UCr < 0.3) have been determined in order to ascertain quantitatively the extent of reactions to be expected between Cr2O3-containing oxide phases and platinum or palladium crucibles used as containers in studies of oxide equilibria at low oxygen pressures. This work is a continuation of similar work previously

Jan 1, 1965

By E. C. Weichel, J. H. Carpenter, J. C. Detweiler, J. L. Gillson, J. P. Wood

ILMENITE, rutile, zircon, and other heavy minerals are found in small amounts in the sand that covers most of Florida. Small enriched deposits occur on the beaches and coastal dunes. One beach deposit east of Jacksonville was worked during World War I and another near Vero Beach during World War 11. Both ceased operation when the resumption of imports reduced prices.

Jan 8, 1953

By Dorsey Hager

One of the most interesting fields in North America was discovered, early in 1922, near the towns of Sunburst and Kevin, Toole County, Mont. This field produces oil from the Jurassic beds, which heretofore have been of but little importance as oil producers, and promses to be the

Jan 1, 1923

By Robert E. Delavault, Harry V. Warren

Geochemistry in all its branches is playing G an increasingly important part in the business of mine finding. Although geochemical studies were commenced more than 50 years ago, interest in this subject did not become widespread until the late 1930&apos;s when in Scandinavia and the U.S.S.R. a whole series of investigations were initiated. Unfortunately for those in North America, the results of these investigations have only recently become available. In Canada and the U.S. geochemistry as a serious mine finding tool dates back only to the period following World War II. This article deals primarily with soils, which have found widespread acceptance as a useful tool in geochemical prospecting. Actually soils vary greatly in texture, structure, profile, and mineral background. Soil sampling poses no hardship for normal intellects, but it does assume an elementary knowledge of soil science and of the chemical problems involved in determining the absolute and relative amounts of a particular element in any particular soil.

Oct 1, 1956

By John Birkinbine

IN all metallurgical processes and mining operations, water is an element which receives attention from the management ; and provision is required either for a means of supply, or for the disposal of accumulation. In many works the quantity of water to be furnished is sufficiently large to place the item of water supply of equal importance to the reception of material or disposition of product ; and the means to be employed receive, or should receive, the most careful investigation. There are exceptional cases where mines or quarries possess a natural drainage, but a large majority of the useful ores and the fuels delved from the earth are obtained from workings in which water accumulates and must be removed. Often the quantity to be

Jan 1, 1877

By John Birkinbine

In all metallurgical processes and mining operations, water is an element which receives attention from the management; and provision is required either for a means of supply, or for the disposal of accumulation. In many works the quantity of water to be furnished is sufficiently large to place the item of water supply of equal importance to the reception of material or disposition of product; and the means to be employed receive, or should receive, the most careful investigation. There are exceptional cases where mines or quarries possess a natural drainage, but a large majority of the useful ores and the fuels delved from the earth are obtained from workings in which water accumulates and .must be removed. Often the quantity to be

By Donivan L. Gordon, Fred H. Dorheim

Often, as viewed by the public and many in the mining industry, abandoned limestone and gypsum quarries offer a simple, economic solution to the twofold problem of solid-waste disposal and land reclamation. In a state where about 75% of the existing quarries are in hydrologic connection with carbonate aquifiers the rationale for considering the storage of solid waste in them must be critically examined. Consistent with the requirements of water resources protection, criteria are suggested to evaluate the potentiality of using abandoned limestone and gypsum quarries as sanitary landfill sites.

Jan 1, 1975

By A. C. Noble, D. E. Ranta

Orebodies with intricate three- dimensional shapes (such as porphyry molybdenum deposits) are difficult to model using geostatistics or other computer- assisted methods. &apos;The strong trends in their spatial grade distributions occur as mathematically complex shapes and prevent the customary assumption of local stationarity that is required for accurate ore reserve estimation. "Zoned Kriging", a new method developed by AMAX, solves this problem directly by using the geologist&apos;s interpretation of the ore zones as a parameter in the kriging equations. The geological basis and methods used in the Climax ore zoning technique are reviewed and discussed relative to their application in zoned geostatistical modeling. The Zoned Kriging technique is described and demonstrated using data typical of mineral de- posits.

Jan 1, 1984

By William Kent

A MOST startling and as yet unexplained, failure of steel boilerplates, in two different sets of boilers, is reported in a paper by Arthur J. Maginnis, published in the London Engineer, December 11th, 1885, and reprinted in the American Engineer, January 14th, 1386. The facts of the case, as condensed from Mr. Maginnis&apos;s paper and from a number of letters in the subsequent issues of the Engineer, are as follows: 1. The material used for two different sets of boilers on two different steamers, each set consisting of three circular boilers with horizontal steam-chests, passed all tests required by the Board of Trade

Jan 1, 1886

By P. E. Queneau

This study confines itself to an examination of the two million square miles of the northern hemisphere which the geographer defines as the terrestrial Arctic, a land region in which the mean temperature of the warmest month is below 50°F-in effect, the area lying north of the tree line. The engineering and human problems there are of a different order of magnitude than is generally true of the sub-Arctic. Whether in Dawson Creek or Matanuska, in Mo i Rana or Skelleftea such problems are of the same general order as in Hibbing or Noranda. The same is not true in Kong Oscar&apos;s Fjord or Lancaster Sound.

Jan 7, 1961

By J. B. Mackintosh

The quantitative determination of copper, by means of electrodeposition, offers so many advantages, that it is to he preferred, when properly executed, to 611 other methods for ease and accuracy. The object of the present paper is to give the results of a number of experiments made during the past few months, and to indicate some sources of error, which must be avoided in order to attain the necessary accuracy. In 1867, C. Luckow, in competition for a prize offered by the directors of the Mansfield Copper Works, submitted the following

Jan 1, 1882

F. E. BASH, Philadelphia, Pa.-In order to make a definite check on the emissivity of crucible steel under works conditions, a test was planned and executed by the plant of the Midvale Steel Co., by a Sub-committee, as follows: Five crucibles were put in a crucible furnace with-the normal charge and were treated in the same manner as a number of others that were charged at the same time; the only difference was that the five cur-cibles had lids with.2-in. holes in the center. It was thought that after the crucibles were removed from the furnace a reading could be made through the hole in the lid with the optical pyrometer and that such a reading would give the true temperature of the steel as black-body con-ditions should prevail inside the crucible. If after obtaining the true temperature, the crucible lid were removed and the steel poured into the ladle, the apparent temperature could be taken by sighting on the steel stream and the emissivity obtained from the two temperature values. Such a test was carried out with five crucibles. About a third of the crucibles charged into the furnace with the five experimental ones were first drawn from the furnace and poured into the ladle. The experimental crucibles were then drawn and readings of the true temperature were made

Jan 12, 1919

By C. R. Pelley

Abstract-This paper describes the analytical characteristics of Western subbituminous coal and the manner in which these characteristics apply to their use in a utility-sized steam generator. It compares these characteristics with those of typical Midwestern coal and Eastern bituminous coal. The paper also reviews in detail the design considerations that must receive attention when various blends of these three coals, or any combinations thereof, are planned to be used. This research paper describes variations in analytical and utilization characteristics when coals from different origins are blended in order to achieve a predetermined sulfur content for the purpose of predicting sulfur oxides emissions as they affect environmental regulations and the resulting alterations in utilization characteristics such blending would cause, and how such blends of coal would affect a utility-sized steam generator.

Jan 1, 1978

By Jonathan Ludlow, Paul J. Guay

Based on two studies that were funded by the U.S. Department of Energy, the authors provide an overview of the benefits expected from mining deeper webs on United States longwalls. The first study, completed in November 1979, identified the limits and potential gains from taking deeper webs with presently available equipment. The second on-going study discusses the conceptual design and benefits of a future system for taking very deep webs.

Jan 1, 1981

By Clarence Linville

FULTON1 says: "Speiss is an artificial arsenide of iron containing smaller amounts of other metals. In constitution it is similar to a matte except that arsenic replaces sulfur." For the purposes of this paper it will be necessary to broaden the definition, and I propose the following: Speiss is an artificial mixture of arsenides, of which arsenide of iron may be taken as a type, but iron may be replaced in part or wholly by other metals (such as copper, nickel, cobalt, lead and zinc) and the arsenic may be replaced in part or wholly by antimony. In addition to antimony and arsenic, speisses often contain sulfur. Speisses usually also contain both silver and gold. Table 1 illustrates the variations that may be encountered. TABLE 1.-Speiss Analyses

Jan 5, 1925

By S. C. Oliphant, George H. Fancher

Two samples of drilling mud from the Hastings oil field, Texas, were tested, and the solids in each were separated into small fractions of a limited range in particle size. The mineral composition of each fraction by X-ray analysis is reported, and the results are interpreted in relation to other measured quantities, such as the physical properties of the original samples and the density of the various fractions. It was found that only 7 to 8 per cent by weight of the solids was of colloidal dimensions and that neither of the samples contained montmorillonite but did contain illite. Considerable calcite was also found. These data should be useful to the geologist interested in the origin and history of sedimentary strata as well as to the petroleum engineer.

Jan 1, 1942

By Ichiro Ito

At present, in Japan, the application of in-place leaching technique to the mined-out stopes has been carried out at two copper mines in a comparatively large scale. These mines are the Kosaka mine and the Tsuchihata mine, both are situated in the north-east district of Japan. At first, the author would like to tell about the in-place leaching operations and their results at these two mines. Then, the problems involved in the application of in-place leaching technique to the Japanese metal mines and the possibility of the future development of this technique in Japan are referred, too. Next, as to the research works, the author would like to explain briefly about some of the important results obtained in the recent studies on in-place leaching as well as on bacterial leaching in Japan.

Jan 1, 1976

Recognizing the fact that the problems of the committee named by the Board to prepare the "official ticket for officers and Directors of the Institute are various and difficult; and desiring to assist this committee by setting forth some of the principles that should guide the committee and some of the qualifications that should be required of candidates, the following instructions are formulated and the Secretary is directed to publish them in MINING AND METALLURGY concurrently with the publication of the names of each newly appointed Nominating Committee and to send a copy to each member of the Committee.

Jan 1, 1937

By F. Lynwood Garrison

The enormous growth of the manufacture of Bessemer steel in this country within the last few years, due to the almost constant large demand for steel rails, renders it very desirable that our knowledge of the physical and chemical properties of a material upon which we place so much dependence should be increaqed by every possible means. It was with this end in view, and also in hopes of learning something of the causes affecting the regularity of the Bessemer product, that I took up the subject of this paper a short time ago. The lise of the microscope as an instrument of research in the metallurgy of iron and steel is now fairly well established;

Jan 1, 1887