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By Robert Longyear

IN, diamond-drill work, a true sample consists of all the material cut by the bit-both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little value if an inaccurate sample is obtained. The engineer in charge must study his material and lay out the plan of sampling, and then see that the drill runner follows his instructions; for the runner may be more interested in obtaining a large footage than in developing accurate methods of sampling. FIG. 1.-CORE BOX. When the core has been removed from the core barrel, it should be placed in a core box in the exact order in which it is taken from the ground. This box, Fig. 1, is usually a shallow tray 4 or 5 ft. (1.2 or 1.5 m.) long, with partitions running lengthwise between which the core

Jan 12, 1921

By C. J. Barber

This paper Donald describes how New Jersey Zinc Co. made surveys for a connection between the Ivanhoe and Van Mater shafts at Austinville, Va. Except to say that the two faces had to meet "accurately" on line and grade, Donald does not indicate the required precision. Assuming that there were 24 angles in the 1 ½ -mile traverse and 15 in the one-mile traverse, it can be shown that if the average error in plumbing each shaft was ±30" and the average error in measuring each traverse angle was ±10", then the average error at the point of connection would have been about ±1.9 ft normal to the line between the shafts. This calculation assumes that any errors in the triangulation would be negligible compared with the errors in the plumbings and traverses, and it also neglects taping errors. With no constant errors or blunders, the latter would be important only in lines normal to the line between the shafts.

Jan 7, 1959

By R. S. Handy

The No. 2 unit of the West Mill of the Bunker Hill & Sullivan Mining & Concentrating Co., which went into commission Apr. 17, 1912, is structurally a twin of the No. 1 unit, which was started Nov. 9, 1909. Up to the point where the ore enters the concentrating-de-partment, it follows precisely the process described by G. Cae-tani in his article entitled, Milling of Lead-Silver Ores,' under the heading, Preparation of the Mill-Ore. The process from this point forward, in the No. 2 section, is outlined on the accompanying flow-sheet. In describing it I shall attempt to analyze the products of each separate process. The constancy of the tonnage and the uniformity of the quality of the feed render this practicable. No. 1.—550 tons of feed, all having passed 30 mm., is washed into two 15-mm. trommels, 4 ft, in diameter, 60 in. long, 17 rev. per min., 1 in. slope, 3/8-in. gauge steel.

Jan 1, 1913

By Edmund E. Getzin

Of all the developments in the post-war history of Western Europe, none has been more remarkable in its aims and in the progress it has achieved than the movement toward European integration. It is not an exaggeration to say that this movement marks a virtual revolution, an about-face, in the long and complicated history of European states over the past three centuries. Although sporadic efforts to achieve European integration can be traced back for at least a 100 years, it remained for the breakdown of the European economies as a result of World War II and the subsequent Russian threat to give new impetus to the concept of broader economic and political integration. In fact, the economic integration of Europe following the end of the war was considered so essential that, in 1949, the administrator of the European Cooperation Administration, Paul Hoffman, spoke of the economic integration of Western Europe as an objective of American policy embodied in the Marshall Plan.

Jan 6, 1963

By Raphael D. Schilz, Michael F. Dunn, Edward D. Thimons, Francis S. Kendorski

During a mine fire or other emergency, it may be desirable to reverse the air flow in order to provide an escapeway or to control a fire. Also, in colder areas, the air flow may be reversed to prevent ice build-ups. When reversing main mine fans, the operator usually does not know what operating characteristics of flow and pressure to expect. Laboratory testing of vane axial main mine fans has been completed in order to establish forward and reverse performance characteristics under controlled conditions, with the results presented here. Preliminary tests under field conditions have also been conducted. The data obtained suggest that reverse performance characteristics are dependent upon the blade angle and the hub to tip ratio. There is also evidence that reverse performance can he predicted for a family of blade angles in a given hub to tip ratio. In general, the air quantity delivered by the fan is 30% to 60% less in reverse than when operating in the normal forward mode.

Jan 1, 1982

By R. J. Lutton

Basic features occurring on tensile fracture surfaces in rock are hackle marks, steps, and rib marks. Rib marks define the leading edge of the fracture and indicate that it was free of irregularities. In turn, fractures characterized by these features are believed to have propagated elastically and to be truly brittle. On the other hand, most fractures in rock exhibit hackle marks and steps in a plumose arrangement, indicating a ductile fracture process. Accordingly, the edge of the fracture apparently advances by extending en echelon fingers, each of which is in turn a small plumose fracture. Plastic-like deformation takes place in this zone prior to complete rupture. Some of the propagation is directed sideways and some shearing also occurs in this direction. Such lateral movement contributes little to forward propagation and may make this process particularly sensitive to load rate and duration and help account for greater fracture strengths of materials under dynamic loads.

Jan 1, 1971

By W. J. Travers

SEVERAL new procedures for completing oil wells have been developed in recent years. Each method when used where properly applicable promises to be a definite aid to operators in lowering development or operating costs, or in developing the full potentialities of the oil well. Multiple-zone completions are now frequently used, in contrast to the older practice of setting a solid water string over each zone to be produced. Gravel packing in unconsolidated formations often prevents sand troubles formerly experienced where a conventional perforated liner was used. Light-weight bentonitic clay muds and oil-base drilling fluids are definite steps toward eliminating mudding damage, which occurs when heavy rotary mud is used. Since in each case the new procedure developed is an alternate of older conventional methods, a problem of selection is presented. The purpose of this paper is to suggest methods of arriving at these choices and to present practical observations that may be of aid in their application.

Jan 1, 1942

By Carl Henrich

In the planning and erection of smelting-works, especially of such as contain the modern large water-jacketed blast-furnaces, we are often confronted with an insufficiency in the watersupply. It may be impossible to find in the immediate neighborhood of the selected site a sufficient supply to furnish the jackets with cold water. Or there may be enough water for this purpose, but it may be highly charged with scale-forming minerals held in solution. Or, the main water-supply, if pumped from the workings of a mine, may carry iron- or copper-salts, or even some free acid in solution, all of these substances being derivable from the oxidation of sulphuret-ores in the mine. Moreover, such mine-waters sometimes contaminate the waters of the creeks, so that these become unavailable, and we have to fall back on an inadequate supply of pure water furnished by some spring or springs, entirely too small in

Jan 1, 1896

By Earl Greiner

THE constitution of the iron-silicon alloys containing from 14 to 33.4 weight per cent silicon has been studied by a number of investigators, whose results have been reviewed in a monograph published by the Engineering Foundation1. In these previous researches, the solubility of silicon in iron was determined by thermal, microscopic or magnetic methods and the compound Fe3Si2 was reported to be stable at tempera-tures from 0 to approximately 1030° C. This paper describes the results of an X-ray investigation of the solubility of silicon in iron and gives data which prove that the Fe3Si2 phase is unstable below 825° C. In order to obtain the present results on the solubility of silicon in iron, the authors have utilized the lattice constants of the alpha-phase iron-silicon alloys given in a previous publication2, and also some addi-tional data which will subsequently be described.

Jan 1, 1936

By T. M. Olson, B. G. Lewis

The adsorption of selenite on bentonite, kaolinite, and an iron--coated illite was studied to determine the importance of several soil variables on selenite removal from uranium mill tailings pond seepage. Adsorption capacities of the clays of selenite varied by orders of magnitude and decreased in the following order: illite > kaolinite > bentonite. Maximum adsorption of selenite on the clays was observed between pH 2.5 and the clay's zero-point-of-charge. Substantially less selenite was adsorbed on these clays in actual mill tailings solutions than in model systems. Virtually all selenite was removed from the tailings at pH 7. The principal removal mechanism at this pH is suggested to be the adsorption of selenite on freshly precipitated metal hydroxides. It is concluded that selenite can be removed from tailings seepage in soil or in clay liners in the presence of kaolinitic clays and iron oxides. Selenite would also tend to be removed from tailings seepage in calcareous strata.

Jan 1, 1984

By Rudolph G. Wuerker

With stepped-up work in rock mechanics, more and more data on strength and elastic properties of rocks has become available. Results of measurements of tensile strength, in addition to determinations of compressive strength, allow us to deter- mine, even if only in an approximate way, the third property influencing failure of a brittle material: shear strength. It is fairly generally agreed upon in rock mechanics, in drilling and blasting research, that Mohr's theory provides an acceptable method for explaining the failure of a brittle material. Mohr states that a material may fail either 1) through plastic slip when shearing stress Y in the planes of slips has reached a limiting value (which in general depends on the normal stress, X, acting normal to the surface), or 2) when the largest normal tensile stress has reached a limiting value. The mode of failure depends upon which of the two stresses is the smaller.

Jan 10, 1959

By H. S. McQueen

THE insoluble residue method for the examination and correlation of limestones and dolomites, or other sedimentary rocks containing calcium and magnesium carbonates, originated and was developed in the laboratory of the Missouri Geological Survey. The numerous and ever-increasing problems in the field of applied geology, and the need for a tool or aid in the solution of them, led to experimental work with samples collected from deep wells, in the early part of 1924. The success attained, almost at the outset, with this method was so great that the method has now been developed from the state of the experimental to the realm of large-scale, every-day routine. In a previous paper the writer' described the procedure in detail and the characteristics of the residues obtained from certain Paleozoic forma-tions in Missouri. The purpose of the present paper is to discuss the economic application of the insoluble residue method.

Jan 1, 1936

By Robert Davis Longyear

In diamond-drill work, a true sample consists of all the material cut by the bit—both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little value if an inaccurate sample is obtained. The engineer in charge must study his material and lay out the plan of sampling, and then see that the drill runner follows his instructions; for the runner may be more interested in obtaining a large footage than in developing accurate methods of sampling. When the core has been removed from the core barrel, it should be placed in a core box in the exact order in which it is taken from the ground. This box, Fig. 1, is usually a shallow tray 4 or 5 ft. (1.2 or 1.5 m.) long, with partitions running lengthwise between which the core

Jan 1, 1923

By Richard B. Greenwalt, John M. Bertram, George E. Aiken

Agglomeration developments in the iron ore industry of North America over the past twenty years are closely related to shifting patterns in commercially acceptable ore grades and even the definition of iron ores. As early as WW II the rich Mesabi hematites were depleted, ending a 50-year era of direct shipping ores that included reserves of an estimated three billion tons. Decreasing ore grades and rising costs began to force the closing of many underground iron mines and processes were being developed to use domestic low-grade iron deposits. This resulted in the rapid development of iron ore beneficiation processes and signaled the coming trend toward concentration, sintering and pelletizing. Yet even today when agglomeration facilities are treating 90 % of the Mesabi Range product much remains to be done in keeping world-wide competitive forces in check and in ensuring the long- term utilization of these expansive ore supplies in an up-until-now captive U.S. market.

Jan 10, 1973

By Thomas Elliott

It is now clearly evident that 1963 is witnessing a record year for prospecting and exploration in British Columbia and Yukon Territory, as substantiated by the following facts: ? About 60 large mining companies and many smaller ones are active in the search for new ore deposits. ? More than 500 prospectors and exploration geologists have been in the field this season. ? It is estimated that $10 million has been spent this year on the search for new ore deposits. ? Claim staking in B. C. to July 31, totalling 14,250, is up 2000 over 1962. ? Helicopter companies report a record total of 25 aircraft chartered to mining groups, with additional numbers used in oil-gas exploration. ? Leading assayers state that business with the industry is double that of the previous year. ? Diamond drillers report an increase of approximately 25% in the amount of contracts now on hand. The question is often asked, "Why is mining so active in Canada's Pacific Northwest?"

Jan 12, 1963

By Norman Visnes

EARLY in 1954, as initial development of the Galena mine was being finished, plans for stoping operations became the foremost consideration of the operating management. The Galena is being operated under lease agreement with the owner, Vulcan Silver-Lead Corp. Started in 1947, the Galena is a deep level development of American Smelting & Refining Co. and Day Mines Inc. under the management of ASARCO, in the Coeur d'Alene mining district. Lead mineralization was found on the 3000 level in 1950. In 1953 development on the 3000 level disclosed a siderite vein, later known as the Silver vein, which contains commercial quantities of silver in Tetrahedrite. This vein was explored on the 2800 and 2400 levels and later on the 3400 level, the lowest in the mine. Work above the 2400 level to date has indicated that the vein dissipates to weak mineralization, and ore values are uncertain above the 2200 horizon.

Jan 1, 1957

By Robert Stefanko

Longwall mining which has a long history abroad, was used only on a limited scale in the United States until less than 20 years ago. Modern longwall mining in this country can be said to have begun in 1960 with the first installation of self-advancing props in a coal mine in southern West Virginia. In Europe, because of adverse natural conditions, longwall mining is frequently the only practical method, but, in the United States, the system has had to compete economically with highly productive room-and-pillar systems. However, because it is inherently continuous, it has greater productive potential than room-and-pillar systems, and, therefore, although only about 5% of the total U.S. underground production today is the result of the longwall system, its growth potential is great. As mining, by necessity, progresses deeper and must be done under poorer natural conditions, less opportunity will exist for the room- and-pillar system, and the longwall system will have to be used.

Jan 1, 1981

By Robert Davis Longyear

In diamond-drill work, a true sample consists of all the material cut by the bit—both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little value if an inaccurate sample is obtained. The engineer in charge must study his material and lay out the plan of sampling, and then see that the drill runner follows his instructions; for the runner may be more interested in obtaining a large footage than in developing accurate methods of sampling. When the core has been removed from the core barrel, it should be placed in a core box in the exact order in which it is taken from the ground. This box, Fig. 1, is usually a shallow tray 4 or 5 ft. (1.2 or 1.5 m.) long, with partitions running lengthwise between which the core

Jan 1, 1923

By George C. Reynolds

INTRODUCTION The overall importance of the minerals industry during the next 20 years was highlighted In "The Global 200 Report to the President" (Barney, 1982) in the following terms: "The industrial and agricultural processes that are taken for granted today would be severely disrupted of any one of dozens of critical minerals ceased to be available in dependable, reasonably priced supply. Supply in turn has become highly energy intensive and international In scope ...... because resources are not uniformly distributed geographically, political considerations (also) become an Important determinant of price and trade patterns." In attempting to determine Australia’s contribution of bauxite raw materials to the world of the future, this paper necessarily also concerns itself with the alumina and aluminium industry to which it supplles the raw material. It is an industry which is energy intensive, International in scope and heavily influenced by political considerations. The aluminium industry has shown a remarkably rapid growth during the past 20 years (Fig. 1).

Jan 1, 1982

By E. Peters

As in other fields of Extractive Metallurgy, Hydrometallurgy is preoccupied with separation processes and with oxidation-reduction processes. The physical chemistry of each type of process can be described in terms of thermodynamic equilibria and in terms of reaction kinetics. Reaction kinetics are much more important at the low temperatures limiting hydrometallurgical processes than in com- parable pyrometallurgical operations and the number of cases in which the kinetics can be described by simple liquid-phase mass-transfer models are sharply limited. It is convenient to subdivide the applicable rate phenomena into processes in which (a) interface reactions control the rate,(b) mass transfer processes control the rate, (c) solid state process affect the rate, (d) thermodynamically predicted phase changes or molecular reactions fail to take place, (d) metastable substances or supersaturated phases persist, and (elchomogeneous reactions in solution affect the chemistry and the kinetics. Examples are drawn from the unit steps of leaching, cementation, hydrogen reduction, and electrowinning.

Jan 1, 1973