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By B. N. Thompson

Main industrial minerals produced in New Zealand are nonmetallic - clay, dolomite, limestone, pumice, salt, serpentine, and silica sand. Other minerals, some with minor production, include diatomite, feldspar, magnesite, sulfur, asbestos, and perlite. Energy and metallic minerals and aggregate are excluded from this account. These industrial minerals occur in a wide range of rock types and geological ages. For example, clays are known from the weathering products of Cretaceous rhyolite and leaching of Eocene coal measures; from Quaternary weathering of contemporary loess and shallow marine sediments, and of greywacke of Triassic-Jurassic age; and from the hydrothermal alteration of late Cenozoic acidic volcanic rocks.

Jan 1, 1984

By L. F. Reinartz

FROM the earliest times when our prehistoric ancestors laboriously fashioned crude tools and weapons from meteoric iron until our day when we manufacture steel in 150-ton open-hearth furnaces, the production of iron and steel has played a dramatic and important role in the development of civilization. Progress in the science of refining iron ore into iron and steel was painfully slow for many centuries. The keen scimitars of Damascus, the broadswords of the English knights, the coats of mail of French knights, and the Iron Pillar of Delhi are well¬known examples of medieval metallurgical technique. Expense and the scarcity of raw materials originally limited the distribution of iron and steel products. It was not until the nineteenth century that a determined effort was made to adapt the use of steel to peaceful pursuits. The spectacular and rapid strides made in the manufacture of steel during the last hundred years were hastened by the invention during the decade 1860 to 1870 of two great steelmaking processes-the Bessemer and the open-hearth process.

Jan 1, 1936

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

NAME AND OBJECT. SEC. 1. This Institute is incorporated under the Membership Corporations law of the State of New York ; its corporate name is American Institute of Mining Engineers; and its objects are such as are stated in its Certificate of Incorporation. ARTICLE II. MEMBERS. SEC. 1. The membership of the Institute shall comprise four classes, namely 1. Members ; 2. Honorary Members ; 3. Associates ; 4. Junior Members. All members shall be equally entitled to the privileges of membership, except¬ing that Honorary Members, Junior Members, and Members and Associates whose residences shall be outside of the United States, Mexico, and Canada shall not be entitled to vote. Members and Associates residing within the United States of America, Mexico, and Canada, and not in arrears for dues, shall be entitled to vote in person at the meetings of the Institute, or, as hereinafter provided for, by letter ballot. SEC. 2. The following classes of persons shall be eligible for membership in the Institute, namely : as Members, all professional mining . engineers, geologists, metallurgists, or chemists, and all persons actively engaged in mining and metallurgical engineering, geology, or chemistry ; as Associates, all persons desirous of being connected with the Institute who in the opinion of the Board of Directors are suitable.

Jan 1, 1923

By L. W. Eastwood

THE structure of eutectics has been studied by a number of investi-gators, and the complexity of the structural relationship of the compo-nents has been agreed upon, especially that of the "eutectic colony," type III of Portevin's1 classification. This paper does not attempt to alter the present classifications of eutectics; rather, it discusses the relationship between the macrostructure and the microstructure of the copper-cuprous oxide eutectic, and describes in detail the mechanism of the formation and the structure of the eutectic. Further, throughout the entire discussion it attempts to point out certain misconceptions in regard to the interpretation of the observed structure of the copper-cuprous oxide eutectic, one of the so-called "eutectic colony" types, and to correlate as much as possible the work done by the writer with that done by other investigators. Of the three types of eutectics listed by Portevin,2 the eutectic colony type has presented the greatest difficulty in interpretation. Although the copper-cuprous oxide eutectic is typical of the eutectic colony type in appearance, it may not be truly representative because the copper forms about 96 percent of the eutectic and the cuprous oxide about 4 per cent. The interpretation of the origin and structure of the "eutectic colony" given here is strictly limited, therefore, to the copper-cuprous oxide eutectic.

Jan 1, 1933

Jan 1, 1930

Jan 1, 1945

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Jan 1, 1938

By H. Foster Bain

THE "miracle of production." which was such an essential element in winning the European war, was nowhere more in evidence than in our Western States. In shipbuilding alone the Pacific Coast States -et a mark never before equaled, and in production of war goods of many kinds, both Rocky Mountain and Coast States accomplished more than their proportionate share if measured by population standards. This was only possible because of the building of immense new plants of many types, largely financed with Government money. Their operation has built up payrolls in the West and brought a measure of prosperity which Westerners are naturally anxious to have made permanent. A widespread doubt obtains, however, throughout the nation and even in the Western States themselves, as to whether, and if so to what extent, this may prove possible. The question has been raised as to whether the national treasury has not been raided to stock the Western ranges with a voracious breed of white elephant .

Jan 1, 1945

By M. C. Fuerstenau, R. K. Price, R. D. Wellik, B. M. Wakawa

Median lethal concentrations of pure and commercially available ethyl xanthate, isopropyl xanthate, amyl xanthate, diethyl dithiophosphate, dibutyl dithiophosphate, and isopropyl ethylthionocarbamate for rainbow trout have been established utilizing static bioassays.

Jan 1, 1975

By C. A. Mezger

These districts are limited approximately on the north by the railroad from Salisbury to Ashville, and comprises the counties of Alexander, Catawba, Burke, Rutherford, McDowell, Cleveland, Lincoln, Polk and Henderson in North Carolina, and Greenville, Spartanburg, Union and York in South Carolina. The occurrence of monazite at Amelia Court House, in Virginia, belongs evidently to the same geological system, as its distance from the Alleghenies corresponds with that of the above-mentioned districts, and all the stratification runs parallel with those mountains.

Jan 1, 1896

By W. L. Hill, W. H. Armiger, S. D. Gooch

The physical properties, chemical behavior under thermal treatment, and fertilizer value of fluorine-containing pseudowavellite (hydrous calcium aluminum phosphate) that occurs as phosphate clay admixed with quartz sand in an extensive deposit near Bartow, Fla., were determined by experiments in laboratory, pilot-plant, and greenhouse. When the mineral was heated at 500°C, 80 pct of the phosphorus became citrate soluble. The heated product, however, deteriorates markedly under moist conditions such as obtain in the soil.

Jan 6, 1950

By R. E. HORE, J. B. Tyrrell

IN the vicinity of Kirkland Lake, northern Ontario, several gold mines are producing, and three are at present being operated very profitably. At these three mines and on the adjoining properties east and west of them there have been important developments during the past year, and additional equipment has been installed to permit a large increase in output. At the end of 1924 the total production amounted to $13,688,600. For the year 1926 the production is estimated at about $19,000,000, and during 1926 the output should be much greater than that of 1925. The mines which are being operated most profitably and are producing a large part of the ore now being milled are the Wright-Hargreaves, Lake Shore and Teck-Hughes. Others which have contributed smaller amounts are the Tough-Oakes-Burnside and the Kirk- land Lake Gold mines.

Jan 1, 1926

By J. G. Davis, P. C. Thakur

Hazardous methane gas in coal mining is receiving increased attention due to the increased US demand for coal which has resulted in the exploitation of deeper seams and the utilization of more productive equipment. Problems posed by methane emission has the Mining Research Division of Continental Oil Co. (Conoco) accelerating efforts that began in the early 1950's with Consolidation Coal Co. (Consol).1 The program's focus is on finding new techniques for degasification of virgin areas as well as control of methane in gob areas.

Jan 10, 1977

By Charles R. Holmes

MORE than 70 igneous pipes and dikes are known to occur in Cambrian sediments throughout an approximately circular area of about 75 sq miles, in southwestern Ste. Genevieve County and southeastern St. Francois County, Mo., across the southern portion of the Farmington anticline, which is outlined in fig. 1. From evidence obtained from fossil fragments taken from some of the intrusives, and from the similarity in composition of the more basic intrusives to those of known age in surrounding states, these pipes and dikes are believed to be at least post-Devonian and probably Cretaceous in age. As first postulated by Rust[1], these intrusives are believed to represent explosion tubes, or diatremes, punched through great thicknesses of solid rock by gaseous pressure.

Jan 11, 1950

By E. C. Wright, P. W. Mumma

This paper describes some properties of steels in the composition range 0.10 to 0.30 per cent carbon and 1 to 7 per cent chromium. It is well known that some steels of this type develop high tensile strengths upon receiving comparatively simple heat treatments, such as ordinary air cooling from appropriate temperatures, with or without subsequent tempering treatments. These high strengths are frequently associated with unusual toughness as measured by the Izod or Charpy impact test. The chromium content, in addition to imparting the above properties, enhances the resistance to corrosion and improves the strength and oxidation resistance at elevated temperatures. Moreover, these steels have good forging and fabricating properties, as evidenced by the fact that several thousand tons of seamless tubing have been made during the past five years from steels containing 0.10 to 0.25 per cent carbon and 5 per cent chromium. Composition and Properties of Materials Tested Twelve 15-lb. induction furnace heats of the compositions shown in Table 1 were prepared, using low-carbon open-hearth steel base melts

Jan 1, 1933

Jan 1, 1923

Jan 1, 1923

By FREDERICK W. BRADLEY

MINING is one of the world's oldest industries and has pioneered the civilization of all new lands. Today, mining is not only one of the essential and basic industries of the world, but it is constantly growing in magnitude and becoming more important. We think that the most of our mining is done in the western portion of this country, but in the old State of Pennsylvania mines and products derived from minerals account for about two-thirds of the entire productive wealth of the State. As our forests are denuded, mining furnishes substitutes for timber in the way of concrete, gypsum board, etc. ; and as civilization increases the wants of mankind, mining is producing metals and minerals of every kind in increasing quantities. For example: during the past ten years the per capita consumption of copper in the United States has increased 49 per cent, to 14.56 Ib.; that of lead has increased 35 per cent, to 12.24 lb.; and that of zinc has increased 70 per cent, to 9.57 Ib. The consumption in European countries is about one-half of this, and there are other countries with large populations where there is virtually no consumption; so when all other countries catch up in consumption with our country, you can see what an enormous demand there is going to be for the metals, even to the extent of having to find substitutes for copper, lead, and zinc.

Jan 1, 1929

By Robert W. Thompson, Darry A. Ferguson

In August, 1977 the United States Congress passed Public Law 95-87 which has been commonly referred to as the Surface Mining Control and Reclamation Act (or SMCRA). This title is somewhat misleading in that the act creates as many regulatory requirements for underground coal mines as for surface coal mines. How- ever, this paper will concentrate on the effects of SMCRA on designs and stability for various activities of surface coal mines, specifically those concerning "Disposal of Excess Spoil". In the past, the objective of most laws and regulations applicable to the mining industry has been to achieve goals of safety or environmental concerns for all types of mining. However, SMCRA is unique in that it sought to regulate-all-activities of coal mining from initial data gathering, exploration, mine design and facilities design to reclamation activities and design. More specific to the stability of the activities of surface coal mining, special criteria for design and construction performance standards have been promulgated for the construction and maintenance of roads, dams and embankments, coal processing waste, ex- cess spoil piles, backfilled reclamation and pit slides. The criteria for design for the previously mentioned facilities has been enumerated by regulations and in many ways restrict the use of site specific design parameters. The restrictions imposed by regulations significantly inhibit the engineer's ability to develop the best practical and economical design and in some cases may re-

Jan 1, 1983