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Jan 1, 1915

By Richard Hamburger

Calculating machines permit the use of the more rapid cotangent and semigraphic solutions of plane triangulation. The results of these methods are as accurate as those of other methods. Simple adjustment of the net, and ease of calculation encourage more complete field work. Errors in field work or in computation are easily localized.

Jan 2, 1950

By James R. Evans

Forecasting demand is an art as well as a science, and much personal judgment is required. National forecasts made for sand and gravel, crushed stone, and/or aggregate may be misleading or unhelpful locally. This is because of significant variation in demand within different geographic and/or political areas in the US, and/or the use of an inadequate data base and forecasting methodology. The best forecasts may be made for local or regional market areas, irrespective of geographic or political boundaries, provided a proper data base is available.1 The Bureau of Mines compiles detailed statistics on commodities sold or used in the construction industries and, therefore, is in an advantageous position to make national aggregate demand forecasts.

Jan 1, 1979

By Ira N. Holli

A meeting of Engineering Council was held on Thursday, Jan. 22, 1918, at the Engineering Societies Building, New York. Present: Chairman Ira N. Hollis (A. S. M. E.); Dr. Charles Warren Hunt, Alex. C. Humphreys and F. H. Newell (A. S. C. E.); B. B. Lawrence and .J. Parke Charming (A. I. M. E.); Charles Whiting Baker, D. S. Jacobus, and George, J. Foran (A. S. M. E.) ; H. W. Buck, E. W. Rice, Jr., N. A. Carle, C. E. Skinner and Comfort A. Adams (A. I. E. E.) ; Clemens Herschel and Calvert Townley (United Engineering Society); also, by invitation, D. W. Brunton, Chairman, War Committee of Technical Societies of Engineering Council. Of the several actions taken at this meeting, the following are selected as being of most general interest. Chairman-Baker-presented a resolution on the conduct of the war, to which objections were made. It was referred to a special-committee; Charles Whiting Baker, Charles Warren Hunt, and Calvert Townley, for re-drafting and presentation later in the meeting. The revised resolution submitted by this committee led to further discussion and as no agreement could he reached, the matter was laid on the table.

Jan 3, 1918

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 Otto C. Kopp, Thomas B. Crattie, Dennis R. Owen

Whole-rock analyses of limestones, fine-gralned dolostones and coarser-grained dolostones adjacent to mineralized breccias (Coy mine, Mascot-Jefferson City district) were compared with similar lithologies adjacent to apparently non-mineralized breccias at the new Thorn Hill section located approximately 39 km north of the Coy mine. Specimens were analyzed for Ca, Mg, Si, Al, K, Fe, Mn, Sr, Br, C1, S, Ti and P using X-ray fluorescence analysis. The concentrations of the major and most minor elements for Thorn Hill specimens fall within the range of concentrations for Coy mine specimens; however, significant differences (probability < 0.05) were noted for Fe, C1 and Br for fine-grained dolostones and for MgO, Fe and Mn for the coarser-grained dolostones. No significant differences were detected for the limestones.

Jan 1, 1985

By P. H. Mell

The little village, from which this formation receives its name, is situated on a bluff of the Alabama River, 175 feet above water level. This bluff is a portion of high table land that begins in the western portion of Choctaw and extends through Clarke and Monroe counties. We find points on this ridge more than 100 feet higher than Tuscaloosa, and nearly as high as the Tennessee River at Tuscumbia. Through this the Alabama River cuts its way, exposing a beautiful cross-section of the strata, of which the accompanying sketch may give some idea. The fossils are found about 75 feet below the surface and 100 feet above the level of the river. There are seven distinct strata. 1. The lowest, extending from the water&apos;s edge up the bluff 80 feet, is a soft calcareous rock containing about 15 per cent. of carbonate of lime, with occasional specks of mica. In this a few Ostrea, Turritellæ, and Flustræ were found, but so friable as to fall to pieces when handled. 2. Next comes a stratum varying from 2 to 8 feet, consisting of

Jan 1, 1880

By J. D. Dixon

Procedures are given for calculating stresses in underground tunnel supports which accounts both for the structural behavior of the support and that of the adjacent rock mass. Stresses in the support are caused by service loads and rock reactions. Service loads are due to rock pressures, hydrostatic and hydraulic pressures, selfweight of the support, or other utilitarian-type loads. Rock reactions, equal and opposite those in the support, are due to the deformational interaction that results as service loads deform the tunnel support against the adjacent rock mass. The procedures developed for solving this problem are an application of matrix structural analysis. The principles involved in this method allow for the consideration of the deformable characteristics of most tunnel support systems and an iterative solution procedure is applied to determine the areas of support-rock interaction. Numerical results of example problems are given.

Jan 1, 1972

By A. Bentzen, S. S. Wong, W. K. Fletcher, B. J. Price, A. J. Sinclair

One hundred eleven pyrite samples from three porphyry-type deposits in the Canadian Cordillera were analyzed (many in duplicate) by AA spectrophotometry for Co, Ni, Cu, Pb, Zn and Mn. All elements have density distributions that are lognormal or combinations of lognormal populations. Co and Ni in pyrites show zonal patterns that relate generally to mineralogical zones in the porphyry systems, particularly if contoured as the Co/Ni ratio. High Cu and Mn values in pyrites also correlate with Cu-rich mineralogical zones. Other elements studied appear less regular in their distribution patterns, although Pb and Zn highs in pyrite seem to occur sporadically near the margins of porphyry systems. These data considered with two other studies permit construction of an empirical model for the distribution of certain minor elements of pyrites from porphyry systems of the calc-alkalic suite. In particular cases pyrite geochemistry shows potential as an exploration tool to aid in target definition for detailed exploration.

Jan 1, 1978

By M. G. Taverner

Research was conducted into cold briquetting dross arisings and metallurgical coke fines from an Imperial Smelting Furnace (I.S.F.) as an economic means of agglomerating fine materials for smelting in a blast furnace. A mechanism was postulated whereby strong bonds were developed within the briquettes; laboratory scale smelting trials and full scale plant trials are included in the paper with a description of a two tonne/hour briquetting pilot plant. Benefits from smelting briquettes in an I.S.F. were measured directly in metallurgical coke savings and, indirectly, by a significant improvement in sinter plant productivity.

Jan 1, 1977

By R. J. Brison, O. F. Tangel

The development of a new method of mineral separation was sponsored by the International Salt Company, which requested Battelle Institute to investigate means for improving the quality and appearance of rock salt from the Company&apos;s Detroit mine. Although developed specifically for removing impurities from rock salt, the general method may be applicable to other separation problems. The principal impurities in rock salt from the Detroit mine are dolomite and anhydrite which represent 2 to 5 pct of the weight of the mined salt. In the size range from 114 to 112 in. (the range of primary interest in this project) the impurities are only partially liberated from the halite in normal production. Further size reduction to improve the liberation of impurities is not practicable in view of the market requirements for the coarse grades of rock salt. Laboratory separations in heavy liquids showed that, to improve the quality and appearance of the rock salt substantially, it would be necessary to remove not only free gangue particles but also a large proportion of the locked-in particles.

Jan 8, 1960

By Forrest W. Kinsey

The use of pellets in North American blast furnaces has made the mixes used in the associated sinter plants unique. These mixes generally contain a high percentage of fine waste oxide materials as the principal iron bearing portion of the mix, with iron ores and concentrates added in minor amounts only. Additionally, the sinter basicity is always above one and can be three or higher. This paper will discuss the large body of knowledge and experience developed by one company on this type of sinter mix. Results of laboratory tests will be used to illustrate how mix composition and feed preparation affect sinter productivity and quality.

Jan 1, 1977

By H. F. Yancey

COAL mine operators recognize coal as an abrasive material, because the wear of drilling, cutting, and conveying equipment is reflected as a cost item for replacement of parts. Similarly, industrial consumers of coal experience abrasive wear on all coal-handling equipment. Operators of pulverized fuel plants are doubtless most keenly aware of the abrasiveness of coal, because under the high contact pressures developed between coal and metal in pulverizers, abrasive wear is increased many fold. Moreover, experience in operating pulverized fuel plants has demonstrated that some coals are much more abrasive than others.

Jan 3, 1951

By Robert E. Snow, Douglas J. Cosler

The application and development of computer models for simulation of transient ground water inflow to underground mines can assist in mine planning and operation as well as environmental impact assessment. Applications include planning for water handling, treatment, and disposal operations based on predicted mine inflow rates, determination of mining impacts on ground water movement and potentiometric surfaces in neighboring aquifers, evaluation of methods for minimizing ground water inflow, and determination of ground water inflow quality. The potential ground water inflow components to a mine consist of direct inflow from an adjacent aquifer and infiltration through intervening geologic formations. The rates of inflow are controlled by the geologic conditions, the potentiometric surface of the aquifer, and the hydrogeologic characteristics of the water-bearing and confining formations. The capabilities and potential use of a computer model for simulation of mine inflow are illustrated through an example problem.

Jan 1, 1983

By B. H. Sage

ATTEMPTS have been made to predict the volumetric and phase behavior of naturally occurring hydrocarbon mix-tures1-5 but these methods have not been extended to the higher pressures and tem-peratures that are currently encountered in some producing formations. Furthermore, the methods of prediction at present avail-able have not been tested in a sufficient number of cases to ensure their applica-bility to all naturally occurring hydrocar-bon mixtures, even at the lower pressures and temperatures. For these reasons the behavior of a number of hydrocarbon mix-tures from a field in which the subsurface pressures are above 4500 lb. per sq. in.? and the temperatures are in the neighbor-hood of 250°F. was investigated.

Jan 1, 1940

By H. G. Kok

The continuous increase in energy costs has made it necessary to consider a broader use of belt conveyors for the transportation of material from the mine pit to the processing plant. Hard rock has to be crushed before it can be moved by belt conveyors. Systems are in the planning stage for mining hard rock, such as copper and iron ore, by using high-capacity, mobile, or semi-portable crushers. The mobile crusher is located in the pit, and the crushed material is transported by energy-efficient, shiftable belt conveyors out of the pit.

Jan 1, 1983

An abstract of a paper from the Canadian Mining and Metallurgical Bulletin of August 1978 by E. Stamboliadis, J. McHardy, T. M. Salman, Department of Mining and Metallurgical Engineering, McGill University, Montreal, Quebec, states that: “The recovery of gold, silver and other heavy metal cyanides from mill solutions is technically possible using the ion exchange technique. However, the costs involved are greater than the costs of the zinc precipitation technique used for gold recovery. There are two main reasons for this: one, the fact that in gold ore cyanidation metal cyanides other than gold and silver occupy most of the resin capacity and hence reduce the adsorption efficiency of the resin for the Au and Ag cyanides; secondly, the high cost of the eluting agents.” Resin, therefore, cannot in most cases be efficiently used for recovery of precious metals. With copper in solution, only 1.47% of the resin capacity is used for gold and 0. 8970 for silver; the rest is occupied by unwanted metal cyanides, such as copper occupying 73.7%. On the other hand, although activated carbon will adsorb copper cyanides, they will be preferentially displaced by gold and silver cyanides. Ion exchange is by one or two orders of magnitude more expensive than the conventional method of zinc precipitation. The cost of removing impurities, such as copper from the resin, is greater than the cost of recovering gold. With an oxide ore amenable to cyanidation and with a low content of other metals, such as may occur with some of the Soviet gold deposits, ion exchange would be an efficient as Carbon-In-Pulp.

Jan 1, 1981

By Sylvain Pirson

THE number of seismograph field crews employed in the active survey of potential oil territories is still on the increase, owing to the ever pending threat of a shortage in the supply of crude oil. It is to be expected that for years to come the seismograph will be responsible for discovering many new oil fields, both in wildcat territories and in deeper formations, and that the seismographic campaign will go on unabated. Yet improvements in instrumental design, in the field and interpreta-tive techniques, are brought about year after year, and lead to the reshooting of areas many times surveyed previously. Notwithstanding the experience gained by the past eight years of active work in reflection seismographic surveys, the results given by this method of mapping deep formations have in many instances been at variance with the information subsequently obtained by the drill. To overcome this shortcoming, geophysicists have used closer spacing of the shot points and closer control of the depth points. The method dis-cussed here is being used actively in the Mid-Continent region and endeav-ors to reduce the interpretation work to a mere mechanical technique, leaving as little as possible to the opinion of the interpreter.

Jan 1, 1937

By F. D. Waltman

Under the hot, baking sun, engineers at the AEC&apos;s Nevada Test Site have been busy for several years in the sinking of 48-in. diam shafts to depths varying anywhere from 1800 to 4800 ft below the surface. In so doing these men have evolved several new techniques which should be of interest to the mining industry. Surface Facilities Designed For Speed: "Expediency plus efficiency" is a key phrase at the Site. Because of the relatively short duration of actual mining operations, all equipment has been packaged to decrease time and cost of "set up" and "take down". The headframe, designed specifically for use over 48-in. cased shafts, can be erected or dismantled within 48 hours. The back legs are pinned and hinged to the front legs for ease of installation and, when dismantled, for movement to another site with a minimum of delay.

Jan 6, 1966

By Kenneth K. Humphreys, R. M. Quinlan, Stan Venkatesan

INTRODUCTION 1 * The coal industry in the United States has undergone significant economic changes in recent years. For example, the price of coal remained relatively constant from 1950 to 1969 (see Figs. 5-1 and 5-2) but steam coal prices tripled and metallurgical coal prices doubled from 1969 to 1974. This price structure has created a new economic environment for coal preparation. Contributing factors to these price trends include: 1) Coal Mine Health and Safety Act of 1969. 2) Mid-East oil embargo of 1973.

Jan 1, 1979