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NEW MEMBERS The following list comprises the names of those persons who became members during the period Nov. 10 to Dec. 10, 1914: Members ABBOTT, Louis BENJAMIN, Chief Engr., Consolidation Coal Co., Elkhorn Div., Jenkins, Ky. ANDERSON, THORVALD J 542 S. Seventh Ave., Mt. Vernon, N. Y. BALFOUR, A. M P. 0. Box 301, Republic, Wash. BOUDWIN, WALKER J., Mech. Engr 159 Pierpont Ave., Salt Lake City, Utah. BRADLEY, LINN, Engr Research Corpn., 63 Wall St., New York, N. Y. BROKAW, ALBERT DUDLEY, Asst. Prof., Min. and Econ. Geol., Univ. of Chicago, Chicago, Ill. BUTLER, PERCIVAL PACE, Asst. Supt., Copper Queen Reduction Wks., Douglas, Ariz. CAJANDER, SVEN G., Mech. Engr Braden Copper .Co., Rancagua, Chile.

Jan 1, 1915

By C. Willard Hayes

One of the most productive iron-ore districts of the southern Appalachians lies in the vicinity of Cartersville, in northwestern Georgia, where the ore-deposits are so directly related to the stratigraphic and structural features of the region that a description of its geology possesses economic as well as scientific interest. Stratigraphy.—The area shown on the accompanying map, Fig. 1, occupies the southeastern portion of Bartow county, Georgia. It is about equally divided between the older crystalline and metamorphic rocks which occupy the Piedmont plateau and Appalachian mountains on the east, and the Paleozoic formations which occupy the Appalachian valley on the west. The line separating these two groups of formations enters the mapped area near the northeastern corner, and, pursuing a somewhat irregular diagonal course, leaves it, as shown on the map, near the southwestern corner. This line marks

Jan 1, 1901

By H. Foster Bain

The recent admirable paper on the general subject of coalcutting machines presented to the Institute by Mr. E. W. Parker* leaves but little to be desired so far as the well-proven and widely-used machines are concerned. The general character of the machines in use and the range of their adaptabilities have been very well stated. It will be noted that in all cases these machines are being used in room-and-pillar work, and indeed (though attention was not directed especially by Mr. Parker to that point) they are practically confined to that work. It is probable that neither the chain breast- nor the pick-machine is, or can be, used to any great advantage in long-wall work.

Jan 1, 1900

By A. Tobey Yu

Despite its inherent low Btu content, western coal's low sulfur content may provide a near-ideal answer to satisfy US goals for clean air and energy self-sufficiency. Vast reserves, amenable to low-cost strip mining, serve as a powerful economic basis for its viability as a primary and dependable source of energy for the coming decades. A major consideration, the solution of which may not be obvious, is the transportation cost. These deposits are remote from the utilities of the heavily populated eastern regions of the US (Fig. 1). A coal mine in Montana is likely to be more than 1500 miles from its utility market, while an eastern coal mine may be situated only 200 miles away. Thus, the question raised is: how can the haulage cost of western coal be substantially reduced to an acceptable level?

Jan 7, 1975

By Herman Blumenthal, Ronald Silverman

lnfiltrability of a porous Tic compact, produced by powder metallurgy technique, depends on the capillarity of the compact and the surface condition and nature of the individual particles. Capillary forces raise the liquid metal infiltrant into the interconnected pores of the compact and the complete filling of these pores is a function of their geometry as well as the wettability of the Tic particles. The paper deals especially with the improvement of this wettability through surface conditioning of the Tic particles. INFILTRATION, a technique for preparing dense powder metallurgy parts by filling the void spaces of a porous body with a liquid metal, has been used for the manufacture of titanium carbide-base cermets. Although the infiltration process was

Jan 1, 1957

By R. Buehl, John Wulff, H. Hollomon

Although the main features of the transformations occurring in 18-8 have been published already, certain conclusions merit questioning and discussion. The questions may be summarized as follows : 1. If ferrite is formed by cold-working austenite, what happens to the carbon with which the ferrite and austenitc are both presumably supersaturated? 2. What is the nature of the alpha-ferrite formed at grain boundarices by chromium-carbide precipitation at these boundaries?

Jan 1, 1940

Jan 1, 1920

By J. M. Johns

INTRODUCTION The Climax Mine is located on the continen¬tal divide, on Fremont Pass, about 145 Km south west of Denver, Colorado. Molybdenum, along with the by products, tungsten, tin, and pyrite are produced from both the open pit and under¬ground operations. The underground operation utilizes a panel caving mining system, and produces in excess of 27,000 mt per day. In the mid 1930's, the Climax mine began changing from a grizzly level layout to the slusher drift system which is still in use to¬ day. Over the years, the slusher drift layout has been refined to correct, improve, and sim¬plify minor operational problems. In common with most older hardrock mines, the development equipment used at Climax was the standard rail mounted, pneumatic mining machinery. This type of equipment remained in use, at least to some degree, until about four years ago. For production, 112 Kw electric slushers were used, while mine traffic was rail with trolley locomotives. Beginning about ten years ago, Climax began

Jan 1, 1981

By G. W. R. Kuzyk, John D. Smith

Tantalum Mining Corporation of Canada Limited has been mining tantalum ore from the Bernic Lake pegmatite dyke since 1968. The shallow nature of the dyke and relatively high strengths of the various rock types led to the choice of a room and pillar mining method. Rock mechanic studies have indicated that the original pillar dimensions of 50 feet x 50 feet are conservative for existing rooms. Therefore, a plan to reduce the size of pillars using rock mechanics instrumentation to monitor the resulting stress on pillar remnants and stope backs was devised. The paper describes the test work done on the rock types within the pegmatite dyke. The use of Irad stress cells and extensometers in monitoring the stress in pillars is described. The actual results of the program to date are presented.

Jan 1, 1983

By A. E. Austin, J. R. Doig

Ti-Cr alloys age harden after B-quenching by formation of an W-phase. The structure and orientation of this transition phase have been determined. The hardness ap-pears to be caused by strain in the B-matrix produced by concurrent enrichment of alloy content in the W-phase. EARLY studies of age hardening in B-stabilized titanium alloys revealed the formation of a transition phase named o' This phase was detected by X-ray diffraction in binary alloys of Ti-Fe, Ti-Cr,

Jan 1, 1958

The Library of the above-named Societies is open from 9 A.M. to 9 P.M. on all week-clays, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is, given that most careful service will be rendered to them.

Jan 9, 1913

By Gordon M. Matheson, Charles V. Logie

The current state-of-the-art design of mine pillars can be grouped into empirical and numerical design techniques. Numerical design techniques are based on sophisticated computational techniques which analyze the stresses and strains through the interstices of a pillar. Empirical techniques are less exact, but have been widely used, particularly for coal mine pillar design, because of their ease of computation. Over the years numerous empirical equations have been proposed to calculate the ultimate strength of coal mine pillars. This paper presents a review of the various equations which are most frequently utilized and examines the fundamental assumptions, limitations and applicability of the design formulae. The review intends to provide the practicing mining engineer with an understanding of the assumptions and mathematical basis of each equation to aid in the selection of the criteria most applicable to his specific design problems. Recommendations are made of the empirical equations that are presently most acceptable for design.

Jan 1, 1983

By G. M. Ritcey

Purification of solutions can involve various treatment methods. In the normal sequence of metals recovery by hydrometallurgy, the ore is initially prepared for leaching by grinding to the desired optimum mesh size as dictated by the leaching parameters. Following leaching and liquids- solids separation, the resultant solution is ready for purification. The use, or introduction of solvent extraction into a plant, can be either a major or a minor part of the metal recovery process as shown by the following list where solvent extraction is normally considered: a) recovery of a metal by a simple leaching of the broken ore, e.g., copper from dump leaching where there are only the three main steps of leaching, solvent extraction, and electrowinning (1);

Jan 1, 1978

By R. A. Wyman

KYANITE schists in the Sudbury area have been generally described by Haw,' who has also given particuLar information on preliminary treatment of three large samples from Dryden township, Ontario.' Kyanite, garnet, biotite, quartz, and feldspar comprise the main ingredients of this ore. Kyanite is the valuable mineral. About 5½ tons of —35 +200 mesh product, made by dry rod milling, screening, and separation on the Exolon magnetic separator, were available for treatment by flotation. Magnetic separation had effectively reduced garnet and biotite so that flotation feed consisted essentially of kyanite, quartz, and feldspar, the kyanite content averaging 32 pct and representing about 86 pct of the kyanite in the original ore. Earlier work on kyanite at the Mines Branch, Ottawa, s-c employed an acid circuit, but to avoid production difficulties in the use of acids and at the same time take advantage of the fact that industrial minerals respond somewhat to soap flotation, it was decided first to investigate the higher pH levels. Exploratory tests using —65 +200 mesh feed ended with production of 96.6 pct kyanite concentrate rep-

Jan 1, 1959

By Charles Mitke

EXCLUDING top-slicing, and sublevel caving, large production caving methods may be divided into two general classes, the branch raise, or undercut caving method, and the combined shrinkage and caving method, each of which has a number of variations, the result of continual efforts towards obtaining lower costs and better extraction, by the introduction and substitution of minor improvements and modifications. EARLY CAVING METHODS Present caving methods are the cumulative result of developments covering a period of many years, with the most rapid growth during the past 15 years. They originated, presumably, from early English stoping methods, and, as far as is generally known, were first introduced in the Michigan iron district. They have had their greatest expansion and application in the large low-grade porphyry coppers. In their present form, they are probably a development and combination of sublevel caving and shrinkage (back-stoping on ore) with gravity handling of broken material. Sublevel caving, as practiced in the Michigan district today, is a combination of drift, or crosscut, mining, with top-slicing, and caving, supplemented by later refinements in the shape of mechanized handling of broken ore. A height of anywhere from 16 to 20 ft. is generally taken, and the ore is drilled and blasted along the drift or crosscut for half this height (say 8 to 10 ft.), after which the upper 8 to 10 ft. caves and breaks of its own weight, with comparatively little assistance from drilling. This

Jan 1, 1928

By M. J. Sheriff, D. H. Smith, W. Macdonald

The paper outlines the basic procedure used in electrical system planning and design. Consideration is given to the use of applicable codes and standards, development and use of a system One Line Diagram, power availability, load requirements and power factor. Also discussed are the factors influencing the selection of power supply and distribution arrangement, voltage levels, system grounding, distribution and utilization equipment such as switchgear, transformers, motor control, cable systems, motors. Short circuit calculation methods and system protection are discussed.

Jan 1, 1978

By George F. Becker

Complexity of Rock-Fractures.—The strains to which rocks have been subjected are manifestly very complex, and it is entirely safe to presume that every possible mode of deformation and rupture is exemplified. The most superficial inspection of any ordinary mountain region is sufficient to assure the observer that the rocks have been pressed, stretched, bent, buckled, twisted, and shorn. The study of torsional rupture cannot fail, therefore, to throw light on geological phenomena. The question is how areas which have been broken in this manner are to be distinguished from those which have yielded to other systems of forces. Phenomena of Joints.—It is well known that a large part of the more homogeneous rocks and some very heterogeneous rocks are intersected by partings often ailed joints. These partings are frequently flat surfaces even when seen in very large exposures, but are sometimes surfaces of moderate, single, or double curvature. Joint, usually occur in groups, in each of which the several partings are parallel to one another, and several such groups often intersect the same rock-mass. In such cases the different systems make large angles with one another. Nearly all students of the subject of jointing have reached the conclusion that joints are faulted surfaces, the dislocations usually being of small amplitude; and this conclusion receives abundant support from the study of thin sections under the microscope. It has thus been shown that much even of what would be regarded in hand specimens as mere slaty cleavage

Jan 1, 1895

By C. B. Manula, R. Venkataramani, T. V. Falkie

A linear programming model has been developed to solve a production planning problem for a multi-plant stone operation serving several customers. The factors considered are production capacities, inventory restrictions, demand requirements, and available stone reserves. The objective function to be optimized is the total annual net returns from the quarry operations. For the purposes of model testing, annual stone sales from each plant were divided monthwise, productwise, and assigned to a market. The concept of assigning demands to market sectors and not to any particular plant creates the self-correcting interplay between the plants and the markets. Along with the inventory restrictions, and ending inventory requirements, this interaction enables the model to minimize the external diseconomics. The model was tested against an operating prototype and a number of alternative problems were also considered. Finally, the basic linear programming model has been enlarged by the addition of another dimension and the problem has been derived in a decomposition format.

Jan 1, 1972

By E. Ackerman, L. Y. Tu, S. C. Sun

The use of ultrasonics in forming emulsions is not new. As early as 1927 Wood and Loomis' reported preparation of emulsions with ultrasonics. In 1935 Rschevkin and Ostrawskyz described the use of great ultrasonic power in producing fine emulsions of various oils and paraffin in water. Recently Oyama and Tanakahmployed ultra-emulsification to increase the effectiveness of sodium ethyl xanthate in flotation of chalcopyrite and galena. An emulsion is a two-phase system consisting of two incompletely miscible liquids, the one being dispersed as finite droplets in the other. The dispersed liquid is known as the internal or discontinuous phase, and the surrounding liquid is termed the external or continuous phase. There are two types of emulsions; one is oil-in-water (O/W) and the other water-in-oil (W/O). The word oil refers to the liquid other than water. Circumstances exist in which the emulsion type is not clearly defined, and the internal and external phases both contain portions of the opposite phase. This is said to be a dual emulsion. Among the many hypotheses', 6v proposed for the formation of emulsions, the Bancroft's adsorbed film or double interfacial tension theory is widely accepted. Bancroft ""educed that in the process of emulsification the interfacial tension between oil and water is lowered by the formation of an emulsifying film, which contains the adsorbed molecules and/or ions from the emulsifying agent and the two liquids.

Jul 1, 1955

By Helmer Hedstrom

THE purpose of this paper is to direct attention to the importance and the usefulness of phase measurements in electrical prospecting for ore, a subject about which virtually nothing has been published. The paper describes a new field method for ore prospecting, the "Turam" method, which makes use of phase measurements, and which has been used with great success for five years. Of the principal geophysical prospecting methods, the gravimetric and magnetic methods determine the direction and strength of the static fields of force of the earth. By seismic and electrical methods, fields of force are applied to the block of ground under investigation. By these methods a third parameter can be measured, besides the direction and strength of the field; namely, the time of arrival of the applied field at the different observation points. This time of arrival has been practically the only parameter measured in seismic work, while in electrical pros-pecting it has generally not been considered, the measurements having been limited to determination of direction and strength of the applied field.

Jan 1, 1937