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By Charles L. Bauer

WHEN a single crystal is annealed following plastic deformation recrystallization usually occurs rather than polygonization. Consequently, re-crystallization has received the overwhelming amount of attention albeit the intrinsic mechanisms by which dislocations rearrange and annihilate one another are just as well revealed by crystal polygonization. It is the purpose of this note to demonstrate the usefulness of studying the polygonization process by means of an etch-pit technique in sodium chloride. Sodium chloride deforms easily (the slip system is of the [110], (110) type), readily cleaves on (100) planes, and can be chemically etched so as to reveal the intersection of dislocations with a free surface. Thus it is possible to observe the distribution of dislocations after a crystal has undergone a specific deformation and annealing cycle. Various phases of the polygonization process

Jan 1, 1965

By Donald W. Scott, Adam L. Wesner

THE inevitable depletion of Mesabi direct-ship- ping iron ores, hastened by recent wars, has increased the importance of developing methods to concentrate iron-formation materials. Many mining companies, independent research organizations, chemical companies, and equipment manufacturers are devoting attention to this important work. It is only natural that magnetic iron-formation materials have received major emphasis, since magnetic recovery methods apply and reserves of Mesabi magnetic taconites are large. However, the non- magnetic* iron-formation materials are likewise believed to represent a large reserve and their study has not been neglected.

Jan 6, 1954

By Thomas M. Drown

In experimenting in connection with Mr. P. W. Shimer (now chemist of the Thomas Iron Company, Hokendauqua, Pa.) on methods for the determination of silicon in pig iron, in order to find one which should be accurate and yet give results in a few hours, I have adopted the following procedure, which, as far as my experience goes, leaves nothing to be desired. About one gram of pig iron or steel is treated in a platinum or porcelain dish with 25 cubic centimeters of nitric acid (sp. gr. 1, 2). When action has ceased, 25 to 30 cubic centimeters of dilute sulphuric acid (one of acid and three of water) are added, and heat applied until the nitric acid is nearly or quite driven off. The heat of a water-bath is sufficient, though the process may be hastened by heating higher on a sand-bath. Water is then cautiously added (as soon as the free sulphuric acid is sufficiently cool) and the contents of the dish heated until the crystals of ferric sulphate are completely dissolved. The solution is then filtered as hot as possible, the residue washed first with hot water, then with 25 to 30 cubic centimeters of hydrochloric acid (sp. gr. 1, 12), and finally with hot water. After drying and igniting, the silica will be found to be snow-white and granular. The following are some results obtained by this method compared

Jan 1, 1879

By Laszlo Valentyik, John T. Patton

A conventional heavy-media separation process utilizes a mixture of finely ground solids like magnetite, ferrosilicon, or shale and water. The always-present clay in the medium acts as a stabilizing agent since the coarse heavy-media solids would quickly sink if they were mixed only in water. As the pseudoplastic nature of polymer solutions has excellent suspending properties, laboratory investigations were conducted at the Institute of Mineral Research on whether polymers could be used as suspending agents for finely ground heavy media. The preliminary results (published previously) of the laboratory research studies have shown that sufficient stabilities of heavy media can be obtained at a relatively low polymer concentration. This paper is a continuation of the previous work and it presents some of the results of recent studies where the rheological properties of the heavy-media suspensions were studied in a newly developed settling tube and the already familiar concentric-cylinder-type consistometer. In the investigations bentonites as a stabilizing agent also were included so that comparative results would be available to the plant engineer to assist him in the choice of the most suitable material for stabilizing various heavy media.

Jan 1, 1977

By Bernard E. Weichman

The oil shales of the Green River formation were deposited in an inland lake which contained abundant plant and animal life. A high percentage of sodium bicarbonate existed in the lower water layers. Digestion of the kerogen-rich mud accumulating on the lake floor lowered the pH of the interstitial waters and precipitated the sodium minerals dawsonite and nahcolite in the kerogen-rich mud. After about five million years of existence, uplift of land areas around the lake caused an influx of clastic sediments which filled up the lake. Continued tectionics gently folded the basin and caused fracturing of the kerogen-lean oil shale. Nahcolite existing in the fractured lean oil shale was dissolved by subsurface waters leaving a tremendous aquifer in a portion of the oil shale. The extent and porosity of the "Leached zone" aquifer is dependent upon the percent of kerogen and nahcolite originally deposited in the oil shale.

Jan 1, 1975

By William E. Ford, Edward Salisbury Dana

276. Cohesion, Elasticity. - The name cohesion is given to the force of attraction existing between the molecules of one and the same body, in con- sequence of which they offer resistance to any influence tending to separate them, as in the breaking of a solid body or the scratching of its surface. Elasticity is the force which tends to restore the molecules of a body back into their original position, from which they have been disturbed, as when a body has suffered change of shape or of volume under pressure. The varying degrees of cohesion and elasticity for crystals of different minerals, or for different directions in the same crystal, are shown in the prominent characters: cleavage, fracture, tenacity, hardness; also in the gliding-planes, percussion-figures or pressure-figures, and the etching-figures.

Jan 1, 1922

SINCE I told you in the preceding chapter how the potter's art is followed in practice, now in this following one I wish to tell you how mortar* and bricks are made, and how and to what purpose they were discovered, although I know you will answer that you know it, inasmuch as it is an art known not only to skillful men but also to the unskilled ones by whom it is practiced, and that bricks and mortar were made and always will be made for the purpose of building. This I admit, but probably everyone does not know it as you do, and you perhaps, do not know its beginnings, although I remember having told you of them. Wishing to repeat it better now I shall begin with long ago, so that both you and I may be better satisfied. Therefore I tell you that you should know that all the arts that men practice in the world have been learned by them either through the process of reasoning from the principles of natural phenomena, from the actions of animals, by chance, or when forced either by some necessity or

Jan 1, 1942

By A. Filers

IN a former paper on Western Smelting Works, I mentioned the great difficulty of obtaining accurate information in regard to the economy of the processes in practice ; and to-day, although nearly two years have elapsed since my former paper was written, I am sorry to say that very little improvement has taken place in the keeping of accounts, and in the direction of a more systematic management in the majority of these works. But I am quite certain that by this time even the most sanguine furnace managers must have become convinced, from the experience of the last year, that somewhere in their processes there are enormous losses. Rates for the purchase of ores in 1873 were not as high as they were in former years in certain parts of the country ; labor was no higher than formerly ; the demand for unparted lead was good throughout the year, with the only exception of the time of the panic, in the fall of 1873; yet there are, of between 40 and 50 works, not more than two or three in Utah and Nevada to-day, that have paid a reasonable interest on the capital invested.

Jan 1, 1875

Would you briefly describe how you chose the minerals industry and reflect upon some of your earliest experiences? I wish that I could say that I had a well-formulated career plan early in life and that mining engineering was always foremost in it, but I cannot, In fact, I was quite indecisive before I finally chose my life's vocation. But in another respect, I am glad my career unfolded in the manner it did because it gave me a better insight into advising others on career opportunities. Probably the greatest problem confronting our youth, and the one I find preys upon their minds the most, is their inability to select a career path early in life. This indecision frequently has a deep psychological effect upon them and they become down on themselves. Therefore, it fortifies them somewhat to learn that others who have become successful in their careers had difficulties choosing a career path early in life. However, while assuring young people that an early choice is not absolutely essential for success, I caution them to work toward as early a decision as possible.

Jan 3, 1979

By Gunnar Almgren

Hole deviation has great consequences on mining economy, especially for long hole drilling technique. First of all the bore hole datas are concerned but also such factors as development, loss of ore and waste rock dilution are influenced. Hole deviation for sublevel open stoping is illustrated with examples from some mines. The deviations are indicated as mean values but also as standard deviation values, owing to their statistical distribution. The economic influence of the hole deviation is especially studied for steep, small lowgrade orebodies, mined with big hole blasting. Hole deviation can thus influence costs up to US$ 3-4 per ton for operating, development, losses of ore and rock waste dilution. This cost is of the same magnitude as the total operating costs for many sublevel stoping mines. The economic savings in accurate drilling are therefore substantial and are worth all attention.

Jan 1, 1981

By Y. P. Chugh, Rajiv Singh

This paper presents the feasibility analyses of terrace pit mining a single seam for depths beyond 33 m (110 feet) in a hypothetical model mine and at an operating mine in southern Illinois. One or two shovel- truck benches near the surface and a large dragline for the last bench are considered for overburden stripping in the proposed mining scheme. Mining and reclamation operations are integrated and reclamation efforts are minimized by proper spoiling techniques. The proposed mining scheme was optimized using the OPMHS (Open Pit Material Handling Simulator) model developed by Penn State. Equipment selection and economic analyses were also conducted using the simulation model. The effect of pertinent variables such as thickness of the coal seam, annual production, initial capital requirements, size of haul trucks, selling price of coal and expected rate of return were analyzed on the feasibility of terrace pit mining. Sensitivity analysis charts for the effect of these variables are presented in the paper.

Jan 1, 1983

By Clement K. Chase, F. Milton Lewis, Roshan B. Bhappu

In situ extraction for copper, gold and uranium, generally involves several common alternative processes and techniques. These include dump leaching, heap leaching, leaching of fractured ore in-place or bore hole mining and unit operations such as cementation, solvent extraction, ion-exchange or carbon-in-pulp. Since the metallurgical effectiveness and economics of such processes and unit operations are well established, it would be possible to select the optimum alternative for extracting either copper, gold or uranium from their ores using in situ extraction technology. In this paper, efforts have been made to provide metallurgical evaluation as well as capital and operating costs for the various processes and unit operations. Attempts have also been made to utilize the above costs in preparing feasibility studies for in situ extraction of these metals.

Jan 1, 1976

By Alexander Bowie

Of the following problems, some have been suggested by recent articles in technical journals, which have led me to believe that the mathematical discussion here submitted may be of use to mining engineers. Problem I. To Find the Grade or Angle of Inclination upon which the Power Required to Move a Loaded Car Down-hill Will Haul an Empty One Up-hill. Let a be the desired angle of inclination; C, the coefficient of' friction; W and w, the weight in pounds of the loaded and of the empty car, respectively.

Jan 1, 1902

By W. H. Tuttle, H. R. Ahlquist, A. J. Carlson

Variations of the EVOP technique are accepted as the foun- dation in the development of Erie Mining Company's mining, concentrating and pelletizing complex at Hoyt Lakes, Minnesota. The basic one-variable- at-a-time technique served its purpose through the laboratory pilot plant as well as the full-scale production sized pilot plant. However, recognition by Erie Mining Company management of the potential of computer application and statistical experimentation in plant operation and testing led to acquisition of an IBM 1620 computer in 1961. Adaptation of established techniques in statistically designed experimentation and analysis of results is presented in actual case form including the following: 1. Determination and use of variance, standard deviation, standard errors; application of t-test in determining true differences between daily aver ages of product assays; formulation of quality control limits; determining sample size; and application of normality tests will be discussed. 2. Use of mathematical modeling and regression analysis for establishing mill storage conditions based on bin level indicator lights. 3. Polyvariable random balance design of a balling circuit test and resultant identification of primary control variables.

Jan 1, 1969

By H. I. Smith

WHEN Spain established colonies on the North American continent, some of her land grants, in what is now the United States, reserved to the Crown deposits of gold, silver, and mercury. Later mineral rights were reserved under some of the English Crown charters involving land in the eastern part of North America, with provisions for the payment of royalties thereon to the Crown. Reservation of mineral deposits to the United States Government was instituted by an ordinance of Congress on May 20, 1785, which applied to such deposits in the Northwest Territory, then north of the Ohio River and east of the Mississippi River, and provided that there should be reserved "one third of all gold, silver, lead, and copper mines, to be sold or otherwise disposed of as Congress shall hereafter direct." Little was known then of the mineral resources of the country; the Great Lakes copper region had just come into the possession of the United States by treaty and much of the western mineral land still belonged to France and Spain.

Jan 4, 1954

By Clarence Linville

FULTON1 says: "Speiss is an artificial arsenide of iron containing smaller amounts of other metals. In constitution it is similar to a matte except that arsenic replaces sulfur." For the purposes of this paper it will be necessary to broaden the definition, and I propose the following: Speiss is an artificial mixture of arsenides, of which arsenide of iron may be taken as a type, but iron may be replaced in part or wholly by other metals (such as copper, nickel, cobalt, lead and zinc) and the arsenic may be replaced in part or wholly by antimony. In addition to antimony and arsenic, speisses often contain sulfur. Speisses usually also contain both silver and gold. Table 1 illustrates the variations that may be encountered. TABLE 1.-Speiss Analyses

Jan 5, 1925

The regular activities of the Insti¬tute are financed mainly by income derived from members' dues, from advertising in MINING AND METALLURGY, and from the sale of publications to the public. In addition, collateral activities and special projects are financed each year by means of income from endowed funds controlled and administered by the Institute. In the aggregate, the principal sums of these endowments amount to more than $530,000. An active effort is being made to in¬crease the endowment funds of the Institute through a standing committee, of which H. T. Hamilton is chairman, and of which the other members are: W. H. Aldridge, George D. Barron, Cleveland E. Dodge, D. C. Jackling, Henry Krumb and J. V. W. Reynders. This committee feels that there exists a tremendous opportunity for the Institute to be of ever-growing service to the public, to the mineral industries, and to the profession. It welcomes suggestions as to names of men of means who are vitally interested in the mineral industries, and to whom the opportunity to make a contribution or bequest might appeal favorably if presented in the proper light by the committee.

Jan 1, 1942

By John D. Gill

The purpose of this paper is to invite attention away from the obvious. direct monetary costs of oil-field overdevelopment (as distinguished from "social costs") to a consideration of the role played by the exercise of freedom to create even allegedly excessive1 plant facilities in contributing to the maintenance of equilibrium in the wholc economy and in promoting material progress. The obvious and most commonly discussed effect of overdevelopment of oil fields is illustrated by the allegation that already the excessive development of the East Texas field has cost upward of $162,000,000;2 in other words, the drilling of 12,500 wells more than the number estimated as the requirement for economical recovery of the reserve has unnecessarily raised the total cost of development that amount. Many other illustrations of so-called excessive development of oil pools could be presented. Some of them, like Cushing, Powell and Long Beach, might be drawn from the era antedating widespread discussion in the trade of such matters as optimum well spacing, reservoir energy, the conservation rate of depletion of reserves, etc. Numerous other cases can he found in the records of the current era, which began with the introduction of rationalized restriction of production. Besides East Texas, there may be mentioned Oklahoma City, Centralia and. more recently, the town-lot development of Bloomingdale, Michigan.

Jan 1, 1940

By J. C. Savins, G. C. Wallick, W. R. Foster

The dual differentiation-integration method of rbeological analysis is applied to Couette flow. Using machine processing techniques, a spectrum of characteristic derivative functions for a variety of ideal Generalized Newtonian and viscoplastic models has been developed; As for the case of Poiseuille flow the functions for Generalized Newtonian models as a class are strikingly different from the corresponding functions for the class of viscoplastic models. It is shown that this dual scheme of analysis is a highly sensitive analytic method for dotermining the applicable range if a rbeoloaical model. The unique characteristics of this function in the case of viscoplastics may lead to a more precise detection and evaluation of the yield point or yield stress in these materials. INTRODUCTION It has been shown 1,2 that the dual differentiation-integration method of analysis is a discriminating and flexible method for interpreting flow behavior and determining the applicable range of a particular model from Poiseuille flow experiments. In the preceding paper3 the basic equations governing the Couette flow experiment were reviewed and the significance of changes in boundary conditions on data analysis in the case of the viscoplaaic discussed. In this paper the dual method of analysis is applied to Couette flow using the suites of rheological models considered previously.

By D. C. Seidel, E. F. Fitzhugh

Nickel sulfide ores lend themselves readily to concentration before smelting or pressure leaching, but neither of the major oxidized ore types-the iron-rich laterites and magnesium-rich, soft silicates-has been directly concentrated. Upgrading of crude ore in current practice is limited to cobbing lumps of the harder, lower grade rock (protore) from the softer, enriched silicate ore, because only a small percentage of the nickel in these ores occurs in discrete, contrasting mineral particles. There is no apparent mineralogical contrast in the superficial, iron-rich lateritic ores and, in fact, there is no firm assurance that the nickel atoms are within the lattices of the limonite minerals, or else irregularly adsorbed on the limonite. Within underlying, "rotten rock" silicates, occasional veinlets of garnierite and related nickeliferous silicates are found.1 The garnierite veinlets are only incidental, and the majority of the nickel atoms occur as erratic replacements of magnesium atoms in the micaceous chlorites of the ore mass.

Jan 4, 1968