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By D. A. Sangrey, D. Marcus, S. A. Miller

A methodology was developed wherein the increase in compressive strength, mineralogical changes, and pore water composition were studied simultaneously as a function of moisturized spent shale curing time. From these results the relationship between the nature of cementation process and the composition of pore water was established. Heavy metals were entrapped in the cementing constituents and the pore water became mainly a solution of alkaline sulfates. The specific data are applicable only to the material studied. But the methodology and general conclusions are useful for evaluating the environmental factors in spent shale disposal and expected leachates composition.

Jan 1, 1986

By C. M. St. John

INTRODUCTION The stress redistribution accompanying the excavation of a deep tunnel may induce failure of the rock. The role of the support system is to control the extent of the failed region and hence to limit closure of the tunnel within an allowable amount. In such circumstances, the design of the support system is generally based on the Ground Reaction Curve (GRC). The GRC is the relationship between the support pressure and the induced displacement at the tunnel wall for a circular tunnel under hydrostatic loading. In the calculation of the GRC (see Brown et al. (1983) for an exhaustive list of reference), the rock is generally treated as an elastoplastic material characterized by cohesive-frictional yield strength and by dilatancy during plastic deformation. A recent analytical development (Detournay, 1983) has allowed the generalization of the GRC concept for some cases of non-hydrostatic in-situ stress fields (Detournay and Fairhurst, 1982). As an application of that development, this paper describes design charts that provide powerful means of performing parametric analysis for tunnels subject to non-hydrostatic loading. BACKGROUND The in-situ stress in a plane perpendicular to the tunnel axis can be decomposed into mean and deviatoric components, Po and So (see Fig. 1). Since it is assumed that the rock is characterized by a Mohr-Coulomb yield strength, the deviatoric invariant So must be less than the limiting value Sl0 given by

Jan 1, 1984

By J. David Lowell

On a low desert ridge six miles south of Cairo lie the remains of the world's earliest known mining town, Maadi of predynastic Egypt. Copper artifacts, including ingots and an ax head which was spoiled in casting, indicate that copper ore was smelted in Maadi, and radio- carbon dating has placed the activity at least as early as 3300 B.C. This is the oldest documented date for the use of smelted copper, the first industrial metal used by man. Copper was mined and smelted almost as early in Asia Minor and on the island of Cyprus, but the greatest development of the budding copper industry was in Egypt, where specific historical records show that about 10,000 tons of copper metal were produced in the period from 1850-1580 B.C. Contrast this production of 35 tons per year with the present world production of about 7 million tpy.

Jan 1, 1970

By Oscar Aguilar, Jin-ichi Nakamura, Kazuo Nakamura

Michiquillay deposit is porphyry copper type with over 500 million tons of 0.70% Cu ore. In order to reflect the true nature of the orebody as to shape and value distribution and to compensate for insufficient data in the outer perimeter and lower portion, "Triangular Interpolation Method" is used in the computation, wherein block grades are determined by "Plane Regression". The results thus obtained are compared with the data from additional investigation and are found to match well with each other. Aside of total Cu, assays of Fe, S, MoS2 and geological data such as alterations, rock types, faults, mineralogical compositions are also stored in the computer. By this system, their distribution and relation to alteration become clear and classification of ore into types affecting recovery become possible. The outputs of this system make clear the characteristics of the orebody and furnish valuable geological data on the orebody.

Jan 1, 1976

By John B. Gustavson, Thornton L. Neathery

A geochemical survey was conducted in the gold district in Alabama. Eight old mines were found to be sufficiently large in tenor and tonnage to be economical today. Four of these appeared to be amenable to exploration for new blind deposits. A gaseous aspiration AA method was used on soil samples. The results indicate that arsenic, antimony, and zinc may be good pathfinders for lode gold and residual placers in the saprolite. Antimony and zinc display a high correlation coefficient at gold-bearing locations in contrast to non-mineralized areas. The low cost of this method could make it a tool for selecting detailed targets to be drilled and trenched in the saprolite. Outcrop sampling was found to be inefficient due to paucity of outcrops and lack of correlation between the trace elements and gold in the rock samples, due to extensive weathering. Schistosity changes and silicification, on the other hand, have been found to be helpful in exploration around granite plutons.

Jan 1, 1977

By William D. Carter

When the first Earth Resources Technology satellite (ERTS-A) is orbited by NASA next year, mineral exploration is expected to take a giant leap forward. There are many inherent advantages in going to space to study large regions of the earth, as existing space data have shown. A preview of what can be expected has already been provided by Gemini and Apollo color photographs taken over many parts of the world in the equatorial belt to 30ºN and S latitude. These comprehensive views cover some 100 sq mi, depicting prominent geologic features in a regional context. Placed side by side with mosaics of aerial photographs covering identical areas, the space pictures point up many inadequacies in the present airborne methods of data acquisition. To obtain a regional picture from aircraft, one must piece together many bits of data, and the final result suffers from variations in lighting and photographic reproduction that may obscure features important to the mineral explorer. By contrast, space photographs provide unsegmented synoptic views of large areas as they appear in a single instant under uniform lighting conditions.

Jan 1, 1971

Jan 1, 1918

By J. J. Bodmer

IN 1855, Franz Uchatius patented, in England, his process of manufacturing cast steel. The first experiments, on a practical scale, were made at the Ebbw Vale Iron Works, Monmouthshire. The charge consisted of a mixture of cast iron with about 20 per cent. of a pure iron ore, and with or without other ingredients. In order to obtain the cast iron in a subdivided condition, Uchatius granulated molten pig-metal by running it into water, which during the operation was kept well agitated, and found that "the finer the iron is granulated, the softer will be the resulting steel." The writer is not aware that granulated iron has been used practically, otherwise than in the above-named process ; and until 1866 no other process of subdividing iron than by granulation was known. In April, 1866, an English patent was obtained by the writer for subdividing blast-furnace and other slags and metals in a molten condition, by passing the same through one or more pairs of rolls. In reference to iron the idea was, in following up the direction pointed out by the Uchatius process, to obtain better results in the puddling process by means of a thorough amalgamation (not simply a mixture) of the iron with the oxides and other ingredients in the charge itself. Experiments were made. A quantity of iron direct from the blast-furnace was subdivided (or laminated) by passing it through a pair of plain rolls. The rolls were hollow, and water was made to pass through them to keep them sufficiently cool. Without giving differential speed to the rolls, sheets were obtained about one-sixteenth inches thick, and from about one hundred square inches surface, downwards. With differential speed, the iron falls from the rolls in

Jan 1, 1874

By Edward B. Durham

At the Richmond mecting in February, 1901, I presented for discussion the proposed rail-specifications of Committee No. 1 of the American Section of the International Association for Testing Materials, with a review of their work, and other matters relating to the heat-treatment and chemical composition of steel (Trans., xxxi., 455). In order to bring out the views of our members on the important points referred to, I offered for discussion the following questions and comments (trans., xxxi., 972): " 1. The advantages to be gained by using more metal in the flanges and web of the heavier sections of rails.

Jan 1, 1903

Conservatively, there are a half million square miles in Australia just like it, this spot near the western border of New South Wales. Space and distance are the elements. Mulga tree and salt bush, silvery under the sun, hug the ground too close to make welcome shade. To the east a wrinkle on the empty plain marks the line of lode, the Broken Hill bonanza. Strangely, the outback stops at a cyclone fence close by the ridge. Beyond, the peculiar island continent vegetation flourishes with the same frosty patina of the mulga and the salt bush. A city of 30,000 people is hidden behind the screen of vegetation. Once, the city was ugly and the people miserable from marching, flying sand. Now with a protective screen of vegetation, it is an oasis in the outback. The secret of the oasis is the fence. All regeneration plans failed until it was built to keep kangaroo, rabbit, sheep and man from destroying the plantations.

Jan 10, 1964

By A. B. Fly

Borehole mining combines the principles of hydraulic mining, slurry mucking and rotary drilling. The borehole is drilled with conventional equipment and is cased down to the top of the mining zone. The borehole mining tool is comprised of the kelly-swivel assembly, multiple drill-pipe sections, and the jet-pump barrel assembly as shown in Fig. 1. The kelly swivel is fitted with a bail to support the mining tool. The kelly drive bushing engages the rotary table to allow the rotation of the mining tool while it is being operated. The jet-pump barrel assembly is comprised of the sidewall jet nozzles, the jet-pump assembly, the suction screen, and the tricone rock bit. Clean fluid is pumped at high pressure through the kelly hose to the high-pressure swivel on the mining tool. The high-pressure pipe conducts the fluid down to the sidewall jet nozzles, the pump jet nozzle, and the tricone rock bit. The sidewall jet streams cut the formation and wash the cuttings down to the rock bit. High-pressure fluid issues from the water courses to clean the bit and to agitate the cuttings. Rotation of the mining tool causes the rock bit to grind any oversize material enough to permit its passage through the suction screen. High- pressure fluid issues from the pump jet nozzle to provide the lift needed to pump the slurry to the surface. The slurry is discharged into the settling pits where the cuttings are deposited and the clean fluid is returned to the suction of the high-pressure pump.

Jan 3, 1969

By C. E. Capes

A number of novel but increasingly-important methods of size enlargement in liquid systems are reviewed. These techniques use relatively strong bonding and specialized equipment to form dense and substantially permanent agglomerates directly from particles in liquid suspension. In addition to separation of particles from suspensions, these methods have other broad objectives, including the production of granular (often spherical) materials, displacement of suspending liquid from the product and the selective agglomeration of one or more components of a multi-particle mixture. The underlying principles of the methods discussed include agglomeration by immiscible liquid wetting and by polymeric flocculants. Other procedures to produce granular, free-flowing products based on dispersion and solidification in liquids are also noted briefly. Applications in a variety of fine particle systems are considered with emphasis on minerals and fuels beneficiation and on waste treatment.

Jan 1, 1980

By M. Muskat, H. H. Evinger

A METHOD of calculating productivity factors for oil, gas, and water systems in the steady state is presented as an illustration of the quantitative application of the fundamental data on the flow properties of heterogeneous- fluid systems. While the numerical results of the calculations cannot be applied directly to field conditions, because they are based on permeability data for unconsolidated sands and involve specific assumptions regarding the nature of the reservoir fluids, the methods of analysis and interpretation should have significance in considering certain specific field situations when the necessary field and laboratory data become available. Moreover, it is felt that even under the idealized conditions to which the numerical calculations refer they should serve to give at least the orders of magnitude of the effects of gas-oil ratio and connate water on observed productivity factors. Within the indicated limitations, the computations imply that the foregoing factors can explain only a part of the apparent discrepancy between the homogeneous fluid productivity factors and those obtained recently in field measurements on the West Coast.

Jan 1, 1942

By Edward Estabrook

THIS paper gives a brief account of the geologic and production problems encountered in the Grass Creek oil field, the methods used in their solution, and the beneficial results obtained from the work. The author wishes to acknowledge the assistance received from J. H. Pearson and Miss Ninettta A. Davis in the collection of the data and the preparation of the cross-sections. Permission for its publication was given by the officials of the Midwest Refining Co. and the Ohio Oil Co. The Grass Creek oil field is located in Ts. 98-99 W., R. 46 N., Hot Springs County, Wyo. The productive area includes about 2 1/2 mi. (4 km.) on the apex of a great anticlinal fold occupying more than 150 sq. mi. Fig. 1 shows the structural contours of the field. Oil was dicovered in the field in June, 1914; development proceeded rapidly and production rose to a maximum in 1918. The marketed production has been approximately as follows: BARRELS BARRELS 1915 94,073.5 1918 2,946,774.27 1916 1,404,183.97 1919 2,000,584.84 1917 2,780,697.51 1920 1,485,080.94 About 350 wells, 800 to 1500 ft. (243 to 457 m.) deep have been drilled to reach the upper oil sands; two companies, the Ohio Oil Co. and the Midwest Refining Co., operate the entire field.

Jan 2, 1922

By Daniel L. Murphy

The iron ore province of Quebec and Baffin Island trends from the southern shore of Baffin Island northeasterly through the Labrador Trough to Matonipi Lake, approximately 185 miles northwest of Seven Islands, but future geologic field studies will very likely extend the limits of the province to include the ferruginous and associated rocks of the Lake Mistassini area. Recent improvements in the beneficiation of low-grade iron ore have stimulated widespread exploration for deposits amenable to concentration, particularly along the southwest extension of the Trough. GENERAL LITHOLOGY Pleistocene and recent deposits of clay, sand, gravel and erratic boulders cover roughly 60% of the land surface. All of the bedrock is of Precambrian age (Table I). Paragneisses and paraschists together with metasedimentary iron-formation, marble and quartzite are abundant and, for the most part, appear to be metamorphic equivalents of the relatively unmetamorphosed rocks of the Labrador Trough to the north beyond the "Grenville Front." Bodies of amphibolite are widely scattered. A large portion of the metamorphic rock shows some degree of permeation by granite material as well as alteration by hydrothermal solutions. The youngest bedrock consists of a complex containing slightly altered ultramafic to monozonitic intrusives.

Jan 9, 1962

By C. R. Garr, A. R. Troiano

FLAKING or hair-line crack formation has been a major problem confronting the producer of large alloy steel forgings.' Today it is generally conceded that hydrogen in one or more forms in alloy steel sections is a requisite for flaking. Hence an obvious remedy is a thermal cycle that reduces the hydrogen content to some low level. In practice, this generally means holding the material at some subcritical temperature for a period of time depending on the size of the ingot or forging. Another method that will suffice in some cases is to cool large forgings slowly, i.e., bury in ashes. In practice, this hydrogen bake is sometimes accemplished inadvertently by a series

Jan 1, 1958

By Garth M. Crosby, F. McIntosh Galbraith, Bronson Stringham

THE Hercules mine is located in the northeastern section of the Coeur d'Alene district, approximately 1 1/2 miles north of the town of Burke, Idaho. Surface indications of the ore deposit were first discovered in 1886, but regular mine production was not started until 1902 and was continuous until April 1925, when the known ore had been extracted. Incomplete records show that from 1912 until operations were suspended the mine produced 2 1/2 million tons of ore containing 9.4 pct lead and 7.7 oz of silver per ton, together with an estimated 2 pct zinc, 0.3 pct copper, and 20 pct iron. This operation was the first in a series of mining enterprises culminating in October 1947 with the consolidation of Day Mines, Inc. In the same year it was decided to unwater the levels below the collar of the Hercules shaft in the hope of finding some indication of a recurrence of ore. The unwatering operation has been described in a previous paper.1 The initial exploration, following recapture of the workings, showed sufficient promise to warrant a detailed study of the mineralogy with modern techniques.

Jan 12, 1953

By William C. Cooley

INTRODUCTION Considerable research has been conducted on the use of steady and pulsed jets of water at high pressures to produce slots or holes in rock, and to fracture rock. The primary objectives of prior research have generally been to determine the feasibility of excavating or drilling rock or minerals and to determine the optimum jet parameters for this purpose. The present study was undertaken in order to identify the pertinent dimensionless parameters involving jet and rock properties which characterize the liquid jet penetration process and to develop empirical correlations of the existing test data which would permit engineering prediction by means of scaling relationships. The present paper is in the nature of a progress report, because not all the existing test data have been processed. Also effort has been concentrated on correlation of data on the specific energy (jet kinetic energy per unit volume of rock removed or broken), rather than correlation of jet penetration depth, hole diameter, kerf depth or kerf width. However, it is clear that this method of correlating data on specific energy in terms of dimensionless parameters shows great promise and provides insight into the nature of the physical processes of jet erosion and fracture. It therefore can help to avoid drawing incorrect conclusions from limited experimental data. DIMENSIONAL ANALYSIS The method of dimensional analysis is particularly valuable where the mathematical relationships controlling a physical process are unknown or complex. The grouping

Jan 1, 1971

By J. A. Herbst, J. L. Sepulveda, J. D. Miller

Lead cake, a zinc smelter flue dust residue, consists primarily of lead sulfate. Characteristic properties of lead cake were determined in order to aid the understanding of reaction mechanisms involved in bismuth removal from lead cake by sulfuric acid digestion. Sp gr (specific gravity) measurements, surface area measurements, and photomicrographs revealed that the particles of lead cake are quite porous and seem to consist of an agglomeration of submicron grains (0.4 pm) fused together in a manner similar to cement clinker. Analysis of experimental rate data, which was independent of particle size, indicates that the dissolution reaction involves two distinct, rate limiting steps. The initial stage of reaction appears to be limited mainly by intergranular diffusion of the reactant, hydrogen ion, while the latter stage of reaction appears to be controlled by diffusion of soluble reaction products through the reaction product layer of the individual grains.

Jan 1, 1979

By E. T. Dumble

THE development in the Gulf Coastal Plain for the year 1923 was entirely devoid of any spectacular feature and was considerably less than that of 1922. No large fields were discovered and the principal advances lay in the extension of the old fields and the finding of a new dome and other possible producing structures, which, however, so far, have given only small wells. While the production of some fields, such as those at Hull and Orange, was materially increased at times by comparatively large wells, the output as a whole shows a marked decrease over that of the preceding year. TABLE 1.-Production by Fields in Gulf Coastal Plain in 1923 FIELD BARRELS FIELD BARRELS Anse La Butte 16,942 Jennings 212,376 Barber's Bill 172,660 Markham 39,290 Batson 391,857 North D ayton 74,983 Big Hill (Jefferson County) 13,853 Orange 5,311,995 Blue Ridge 332,445 Pierce Junction 332,565 Damon Mound 822,355 Richmond (Big Creek) 17,545 Edgerley 176,964 Saratoga 700,661 Goose Creek 6,251,761 Sour Lake 2,091,961 High Island 19,018 Spindletop 309,315 Hull 7,732,139 Vinton 2,134,430 Humble 2,449,744 West Columbia 6,598,589 36,203,448

Jan 3, 1924