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By Herbert D. Drechsler

Mining Finance-is the interrelated aspects of "determining the total amount of funds to employ in a mining firm; allocating these funds efficiently to various assets; and, obtaining the best mix of financing in relation to the overall valuation of the firm". The first section is an overview of the financing problem through examination and discussion of the Balance Sheet and Income Statement. The next section is a discussion of the nature of the criteria developed in feasibility study. The third section describes type of capital funds, and the final section describes case studies of mining finance.

Jan 1, 1978

By W. H. Blauvelt

The subject of fuel-briquetting has attracted much attention on the part of engineers. and investors for the past 15 or 20 years, and especially in recent years, during which a number of plants have been built, with more or less commercial and technical success. Our technical literature contains numerous descriptions of certain processes, and discussions of the industry in general. For a history of the development of the art in the United States, and for descriptions of many of the processes which have been tried, reference may be made to the files of our Transactions, and, for more recent information, to a paper by C. T. Malcolmson, read before the First Annual Convention of the International Railway Fuel Association in June, 1909. The purpose of the present paper is to describe the briquette-plant of the Solvay Process Co. and the Semet-Solvay Co. at Detroit, Mich., which, after a period of long and costly evolution, is now operating satisfactorily on a commercial basis. I believe that it will be of interest to some of our members to have the details of operation, power-consumption, labor, etc., as worked out on a practical and commercial scale in a going operation.

Jan 1, 1911

By Robert Glass Cleland

THE MEMBERS of the Phelps-Dodge, Phelps-James co- partnership differed widely from one another in certain aspects of temperament and personality; but in one thing Anson Phelps, William Dodge, and Daniel James were fundamentally alike. They were all bred in the English Puritan tradition. Their creed, moreover, was the stern, militant, uncompromising creed of John Calvin and John Knox. The present generation, harshly intolerant of such a creed, has little understanding of the authority it exercised on the thinking and conduct of its adherents or of the contributions that those same adherents made to human welfare and social progress. The men who accepted its authority "were characterized by a blend of strong individualism and an equally strong sense of social duty, and they submitted their own souls to the same searching scrutiny that they applied to their business ledgers." To all three of the immediate founders of Phelps Dodge, their religion was the most real and important thing in life. It was with them day and night, in joy and sorrow, in loss and prosperity, in their most trivial personal affairs, in business transactions of the greatest moment. It was with

Jan 1, 1952

By M. R. Geer

THE importance of the size composition of coal is reflected in the differ-ence in price of the various sizes of the same coal and in the large number of primary sizes and mixtures of sizes produced by the modern preparation plant to meet the demands of a market that in late years has grown increasingly conscious of coal size. The importance of size in the indus-trial and domestic uses of coal has its counterpart in the role played by size composition in the laboratory examination of coal. Investigation of many of the physical properties of coal in their relation to its uses requires an evaluation of size composition. In fact, the Standards on Coal and Coke issued by the American Society for Testing Materials in 1936 contains 12 standard methods of testing that involve some use of size composition. The screen analysis is, of course, the standard method of determining size composition, whether the material is coarse run-of-mine coal or fine pulverized fuel. Customarily, the analysis is reported as the weight percentages retained on or passing each of a series of testing screens, the number of which may range from only two or three to as many as 20. When more than two or three sieves are used, which is usual, the number of weight percentages obtained is so great as to make the analysis difficult to comprehend. Direct comparison of analyses made on the same sieves is hard, and comparison of analyses covering the same range of sizes but made oil different sieves is next to impossible. Consequently, a frequent purpose of sizing tests-correlation of size with properties and charac-teristics related to size-is rendered difficult.

Jan 1, 1938

By R. W. Raymond

The Mining Law of New Pork, contained in Title XI., Chapter IX., Part One of the Revised Statutes, is as follows: Section 1. The following mines are, and shall be, the property of the people of this State in their right of sovereignty : (1.) All mines of gold and silver discovered, or hereafter to be discovered, within this State. (2.) All mines of other metals discovered, or hereafter to be discovered, upon any lands owned by persons not being citizens of any of the United States. (3.) All mines of other metals discovered, or hereafter to be discovered, upon lands owned by a citizen of any of the United States, the ore of which, upon an average, shall contain less than two equal third parts in value of copper, tin, iron, and lead, or any of those metals. Sec. 2. All mines and all minerals and fossils discovered, or hereafter to be discovered, upon any lands belonging to the people of this State, are, and shall be, the property of the people, subject to the provisions hereinafter made to encourage the discovery thereof. Sec. 3. All mines of whatever description, other than mines of gold and silver, discovered, or hereafter to be discovered, upon any lands owned by a citizen of any of the United States, the ore of which, upon an average, shall contain two equal third parts or more, in value, of copper, tin, iron, and lead, or any of those metals, shall belong to the owner of such land. Sec. 4. Every person who shall make a discovery of any mine of gold or silver within this State, and the executors, administrators, or assigns of such persons, shall be exempted from paying to the people of this State any part of the ore, produce or profit of such mine for the term of twenty-one years, to be computed from the time of giving notice of such discovery, in the manner hereinafter directed. Sec. 5. No person discovering a mine of gold or silver within this State shall work the same until he gives notice thereof, by information in writing to the Secre-

Jan 1, 1888

By Oscar A. Glaeser

It is common knowledge that the iron orebodies of the Mesabi Range lie nearly horizontal and are of trough or blanketlike types. These orebodies are from a few feet to several hundred feet thick and vary from a few acres in extent to the size of the largest one, at Hibbing, Minn., which is over 1 mile wide and 3 miles long. They are covered with sand, boulder and clay overburden and occasionally shallow depths of ledge material, varying in total depth from about 20 to 200 ft. Large areas are not capped with overlying ledge material; the top of the ore lies directly underneath the surface material. Because of the comparatively great tonnage of ore, open-pit mining has made tremendous strides since the first open-pit ore was shipped from this range by the Merritt brothers, from the Mountain iron mine in October, 1892, and along with the great development of open-pit mining on the Mesabi Range has gone a tremendous change in the character of. equipment used. Early Stripping Operations The first stripping at the Burt mine at Hibbing, Minn., started in 1902. The engineers spent a long time in selecting the most suitable location for a small pit area, involving a stripping contract of 350,000 cu. yd. This property afterwards had several million yards of stripping and several million tons of ore removed from it, but inasmuch as it was the first open pit of the Oliver Iron Mining Co. in this district it was necessary to try several different locations for the small pit area, to uncover maximum tonnage and the best grade of ore so as to sell the idea of open-pit mining and discontinue the underground operation then going on. The writer's first open-pit work on the Mesabi Range was in 1903 as an Oliver company mining engineer on a stripping job of 1,500,000 cu. yd. at the Monroe mine, Chisholm, Minn. Here the contractor, an old-timer used to railroad methods, was, to a small extent, using teams of horses hitched to 2-yd. narrow-gage cars and hauling the stripping material from the pit area to outside of the pit limits. The dirt thus moved was loaded by hand. The same contractor was also using 60-ton and 70-ton railroad-type shovels with dippers of 21/2 and

Jan 1, 1930

By Thos Stroup

RECENT contributions to the literature relating to the problems of coal mine management have discussed the pros, and cons of unionism among the miners as bearing upon the immediate problems of the industry, but have devoted singularly little thought to the underlying causes, and the fundamental reasons. for the remarkable growth of union sentiment among the miners, a growth paralleled only in the case of the railroad workers. It is all very well to revile their organization, its obvious stupidity and stubbornness, its multitude of economic and social crimes, but it is also well to realize that there have been deep-seated causes for all these things, causes that, while operating in all industries and amongst all workers, have in none of them found the optimum conditions for development such as exist in the coal mining industry. The rise of the United Mine Workers of America to a position of importance in the industry synchronizes roughly with the introduction of short-time operation; of course seasonal shutdowns and slow-time working have always been evident in our bituminous fields, but these evils have grown steadily worse since 1895 and the U. M. W. of A. has grown steadily stronger; yet short-time operation alone cannot account for this tremendous growth for, witness the signal failures that have always attended the attempts to organize the harvest workers, the fruit packers and other highly seasonal workers.

Jan 9, 1923

By E. E. Carpenter

Believing that the results accomplished in the mill of the Churchill Milling Co., Wonder, Nev., during the fiscal year ended Sept. 30, 1914, will be of interest, I am presenting the more prominent facts and figures showing the progress made in treating this ore with especial reference to tonnage, supplies, costs, and extractions. The mill is situated at Wonder, Nev., in the Wonder mining district, 55 miles east from Fallon, Nev., the nearest railroad point. All supplies are hauled this distance by freight teams, this method of transportation having been found more reliable for continuous service than truclis, the price paid for hauling being slightly under one cent per pound. In this mill are treated the ores of the Nevada Wonder Mining Co. Ore is Unusually Hard The company which tested this ore before the mill was built reported "This ore is an unusually hard, tough, oxidized quartz, carrying a small percentage of high-grade sulphides, containing good values in both gold and silver. None of the rebellious silver minerals appear to occur in appreciable quantities." ... "In regard to the mill tonnage this ore is unusually hard and tough, and a high stamp duty cannot be expected. Using a 20-mesh screen and 1,050-lb. stamps, our best work was three tons per stamp per 24 hours." It is very probable that the ore delivered to the testing plant was harder than the regular mill run has proved to be. However, at present the mine is developed to a depth of 1,000 ft., and still shows hard ore in places at this depth in about the same proportion as on the upper levels from which the test ore came; during this year's work, ore was treated from nearly all levels. Together with this hard ore in the mill feed a considerable proportion appears to be broken down and tending to crumble, thus making an ideal mixture for stamp milling. A small proportion of talc is also noticeable, which sometimes increases in amount to the point where it is very troublesome in the thickeners.

Jan 1, 1916

By J. W. Marx

A method is given for predicting the complete gravity drainage characteristics of arbitrarily long columns from centrifuge drainage measurements on reconstituted core samples. Oil residuals corresponding to hundreds of years of normal gravity depletion can be obtained in a few hours on the centrifuge. The gravity flow rate at any stage of the depletion process may be determined from the time correlation derived, and experimentally checked, in this study. INTRODUCTION Apart from the original observations of Muskat et al1, research publications2,3,4 on the subject of gravity drainage have been largely concerned with establishing in detail the saturation, S as a function of the height, z, in a draining column at any given time, t. Some form of numerical integration must be employed to obtain production rates and cumulative production even when S(z, t) is known. Furthermore, the relevant experimental work has been concentrated on drainage of a single wetting liquid from unconsolidated media. Since oil production usually concerns the drainage of a partially wetting liquid from consolidated media, in the presence of connate water, and since it is unlikely that sufficient information exists to establish S(z, t) in detail for any natural reservoir, the published research work appears to be, at best, only qualitatively applicable to production problems. With this in mind, the present study was undertaken by the writer. Experiments were planned whose results would have two advantages over existing measurements: 1. Observations were to be made on specific reservoir rock, reconstituted with formation water and formation oil. This would reduce their generality, from the research viewpoint, but increase their utility for production purposes. 2. The measurements were to be self-integrating, i.e., the phenomena were to be described and interpreted in terms of cumulative results. THEORETICAL DEVELOPMENT It was commonly known that centrifuging a liquid bearing porous medium increases the drainage rates and minimizes capillary end effects. The specific problem lay in selecting an acceleration, a, such that the mean residual saturation of a model cylinder was equal to the residual saturation of an arbitrarily long prototype column when the latter was drained by earth gravity alone. The physical conditions required to permit a valid scaling of model drainage time, tm with prototype drainage time, t, may be stated as follows: (a) At t = tm = O, So = Smo; (b) At t = tm? 8 Sr. = Smr.; (c) For all intermediate values of t and dS/dt=dsm/dtm whenever S = Sm; (d) S(z) = Sm(z) = a constant when t = tm = 0. 1 Here S = T I S(z)dz, where h is the length of the « Jo cylindrical column being drained and the subscripts S,Sm, and refer to model, initial, and residual systems, respectively. The first three conditions mean, simply, that an 3 vs t plot will be numerically identical with an S, vs t, plot,

Jan 1, 1957

By Paul L. Russell

7.5-1. introduction. The possible engineering uses of nuclear explosives were recognized with the first nuclear detonation. Subsequent experiments have demonstrated the ability of nuclear explosives to move very large volumes of rock and earth efficiently and at costs below conventional earth-moving methods. The ability to package a quantity of energy equivalent to a few million tons of conventional explosive in a container approximately 20 ft long and 36 in. in diameter enables easy emplacement and thus provides the potential for excavation on scales heretofore impossible. Space does not permit detailed discussion of the many experiments with conventional high explosives and with nuclear explosives that were performed in developing the information presented here. A bibliography is included for those wishing detailed information. Material from those sources and from personal experience has been used freely. 7.5-2. Nuclear Explosives. An explosion, in general, results from the very rapid release of a large quantity of energy within a limited space. This is equally true for both conventional and nuclear explosions, although the energy is produced in quite different ways. In the case of a conventional explosive, this energy arises from chemical reactions. In a nuclear explosion, the energy is produced as a result of the formation of different atomic nuclei by the redistribution of the protons and neutrons within the interacting nuclei. Nuclear energy is of a much higher order of magnitude than chemical energy when equal masses are considered, and the release of this energy is a thousand times more rapid than the fastest chemical detonations. Explosions may be produced by fission or fusion reactions. FISSION. When a free (or unattached) neutron enters the nucleus of a fissionable atom, it can cause the nucleus to split into two smaller parts. This fission process is accompanied by the release of a large quantity of energy. The complete fission of 1 lb of uranium can produce as much energy as an explosion of 9,000 tons of TNT.

Jan 1, 1968

By Howard N. Eavenson

One who has been trained in belief in the law of supply and demand and its effect upon prices finds it difficult to adjust himself to the minute regulations imposed by the New Deal, and also to the bewildering changes of government policy as expressed within a short period of time between the antitrust laws and the N.R.A., and later by the Bituminous Coal Conservation Act of 1935. A survey of the coal industry since the World War, both in this country and Great Britain, however, shows that regulation of some sort is needed if any stabilization is to be achieved and if the wage structure and economic welfare of the many communities dependent solely upon coal are to be maintained. Let us look at what has happened to the industry since 1920, which can be considered as the end of the period affected by the war influence. This discussion will be confined solely to bituminous coal, although many of the general conditions are equally applicable to anthracite, the position of which now is at least as bad as that of the softer variety. Since 1920—to the end of 1934—the production of coal has decreased from 568.7 million to 358.4 million tons, or 37 per cent; the number of mines from 14,766 to 6,258, or 58 per cent; the average annual production per mine has changed from 38,512 to 57,425 tons, or 50 per cent. The number of large mines has increased considerably, and the number of men employed has decreased from 639,547 to 458,011, a reduction of 28 per cent, while the average output per employee has changed from 4.0 to 4.4 tons, or an increase of 10 per cent. The average price per ton of coal at the mine has varied from $3.75 to $1.75. During that time wages decreased largely until 1933 and since that time have increased, until now the rates paid are considerably above those in other occupations, although the actual yearly earnings are low, because of part-time work. From 1920 to the signing of the Jacksonville wage agreement in 1924, about two-thirds of the men were union members and practically all of the nonunion mines were south of the Ohio River; with the fixing of the high wage scale of that agreement, which soon proved to be an uneconomic one, many of the mines found that they could not retain their business, so gradually changed to nonunion. By 1928 the proportion

Jan 1, 1936

By Milton E. Wadsworth, J. Brent Hiskey

INTRODUCTION Fifteen years ago a distinguished electrochemist referred to electrochemistry as an "underdeveloped science " In the article in question, Professor Bockris (1) stated that many areas of.natura1 phenomena and applied technology are not perceived as being electrochemically based At that time, this was especially true for much of non-ferrous extractive metallurgy and was a particularly accurate description of hydrometallurgy During the last decade, there has been considerable advancement in applying the theory of electrochemistry to our know1 edge of hydrometallurgical processes and in understanding the mechanisms of underlying electrode reactions. Impressive as these advances are, there is still a growing need for electrochemical research of mineral systems and electrochemical engineering to apply this work in practical situations In a broad sense electrochemistry is defined as the physical chemistry of ions in solution and of phenomena which occur at the electrified interface. Bockris and Reddy (2) refer to electrochemistry as being divided into two fundamental domains, ionics and electrodics ionics is restricted to the behavior of ions in solutions, examples being many familiar redox processes Electrodics represents the main part of electrochemistry, and is the study of charged interfaces and the conditions governing charge transfer reactions across them. Considering hydrometallurgical applications, electrodics suggests the following relationship for a conducting solid (bulk or surface)

Jan 1, 1981

By F. V. Lenel, M. V. Rose, A. B. Backensto

WHEN aluminum-flake powders are compacted and hot pressed and the resulting compacts are extruded or hot forged, a group of materials with unique properties is obtained. Not only do they exhibit high room-temperature strength of the order of some of the aluminum alloys, but they maintain this strength even after prolonged heat treatment at temperatures up to 900°F. Moreover, their strength decreases much less with increasing temperature than that of aluminum alloys of comparable room-temperature properties. Irmann,'" who discovered and first described this group of materials, which was called SAP, showed that the room-temperature mechanical properties of the extrusions are a function of the oxide content of the powders and therefore the oxide content of the extrusions. The higher the oxide content, the higher are their tensile strength, yield strength, and hardness, and the lower their ductility. Lyle" investigated the relationship between mechanical properties at elevated temperature and oxide content in the course of the development work of the Aluminum Co. of America on materials, called APMP, similar to those developed in Switzerland. He found that at 600 °F, just as at room temperatures, tensile strength and yield strength increase and elongation decreases with oxide content. A careful study of his data (Fig. 3, loc. cit.) shows, however, that the scatter is more pronounced than at room temperature. Gregory and Grant's data on the creep5 and stress-ruptureb roperties of the one commercial grade of the Swiss SAP and the various grades of APMP indicate that creep strength and stress to rupture also generally increase with increasing oxide .content. Ever since this new group of materials was discovered, attempts have been made to explain the mechanism by which they obtain their high room-temperature and particularly their elevated-temperature strength. In most of the attempts the new material was considered as a dispersion of aluminum oxide particles in a matrix of aluminum. Ir-mann, Von Zeerleder, and Rohner' applied a theory on dispersion strengthening developed by Rohners to the flake-powder extrusions. According to this theory the elastic limit S, of a dispersion would depend upon the average distance between the dispersed particles L according to the equation: 2 E ¦ a where E is the modulus of elasticity and a the distance between nearest neighbors in the lattice of the matrix material. Irmann and co-workers assumed

Jan 1, 1958

By Theodore Simons

The rapid and comparatively recent development of flotation has opened so fascinating a field for study and research that the older processes of gravity concentration no longer receive the attention they deserve. The early work of Munroel and Richards12 and the more recent contributions by Clevenger and Coe,3 Laist and Wiggin,4 Ammon,5 Bardwell,6 Crowfoot,' and Hayden8 (to mention only some which have appeared in our own Transactions) and by Schu1z,9 have furnished so much data that to offer something new seems a difficult task. It is still possible, however, to present known facts from a different point of view, and, with this in mind, the writer has undertaken to express basic principles of gravity concentration in terms of simple mathematics and mechanics; the conclusions thus reached will be found to correspond, in general, with those obtained by experimental methods. Rittinger, in his classic Aufbereitungskunde (1867)) reached analogous conclusions by way of intricate higher mathematics, for which reason his interesting investigations have remained a sealed book to most of us. The writer hopes that a more elementary treatment of the subject, based in part on Rittinger's metheds, may arouse new interest in the study of basic principles.

Jan 1, 1923

By R. R. Sayers

Ventilation may be defined as the process by which vitiated air of an enclosed or partly enclosed space is continuously replaced by fresh air. Fresh air has been defined as invigorating pure air. Pure dry air at sea level contains the following gases:1 Analysis of Air at Sea Level Per Cent. Oxygen.................................................. 20.94 Nitrogen................................................. 78.09 Carbon dioxide........................................... 0.03 Argon................................................... 0.94 Helium, krypton, neon, xenon, hydrogen, hydrogen peroxide, ammonia, ozone........................................ traces Carbon Dioxide Limit For many years carbon dioxide was used as an index of the purity of the air vitiated by the metabolism of people. It was, however, well known that the untoward effects produced on those exposed to such air was not due to the concentration of the carbon dioxide. It has been found that the untoward effects on the comfort and efficiency of those so exposed are due to the increased temperature and humidity. It has been found that men can breathe air containing many times the amount of carbon dioxide found in our worst ventilated theaters and assembly halls, which, according to Rosenau, do not contain above 0.5 per cent, carbon dioxide. Nevertheless, in mines it sometimes occurs in sufficient quantities to cause symptoms in men or even unconsciousness and death. One-half of 1 per cent. of carbon dioxide in normal air causes a slight and unnotice-able increase in the ventilation of the lungs, that is, a man exposed to one-ha,lf of 1 per cent. of carbon dioxide will breathe a little deeper and a little faster than when in pure air. If 2 per cent. of carbon dioxide is in the air, the lung ventilation will be increased about 50 per cent.; if there

Jan 1, 1927

By A. V. Pegler

As with most rheologically defined materials, rocks react differently in different environments to similar forces. Physical changes and deformations depend as much on the rate of change of stress as the magnitude of stress. In many instances the rate of change is more important. Under load, all real materials will flow if given time. If there is no time for flow, materials tend to react in a brittle manner. Particular characteristics are developed in rocks during their periods of formation and postformative geologic history. Whatever their mode of occurrence, rocks are a record of their formation and changes. Where analyses are possible, advantage should be taken of the natural inherent characteristics to help design economical functional structures. A number of techniques of measurement and analysis have been developed. The fracturing of rock by hydraulic pressure has been examined by many authorities but few within the scope of available published literature have used the actual rocks concerned in tests to examine directional characteristics or preferred strain propagation rates and directions. In a number of investigations of the properties of rocks for mine design purposes and stress analysis problems in which the writer has been associated, it has been demonstrated that there are definable preferred shear planes in most rocks. Preferred shear planes can be identified by a photoelastic method of analysis, and the information can be used to improve design of optimum drilling and breaking directions for mining purposes. Definable principal strain directions can be determined to facilitate design directions of optimum stability for permanent mine openings. In field fracturing operations the same directional characteristics as outlined above should be used to define preferred fracturing directions as in the laboratory from oriented samples. It is mainly with this aim that

Jan 1, 1968

By Michael Tenenbaum, T. L. Joseph

In a previous investigation1 the authors studied the effect of pressure on the reduction of iron ores by hydrogen. With hydrogen as a reducing agent, the rate of reduction was increased substantially by increasing the pressure from 1 to 2 atmospheres. The results with hydrogen prompted the present study of the effect of pressure on reduction with carbon monoxide and with mixtures of carbon monoxide and nitrogen. Features of Reduction Process The gas stream in the lower part of the blast furnace always contains sufficient concentrations of reducing gases to complete reduction provided sufficient time is allowed for the reaction to proceed. Reducing gases react immediately with the iron oxide on the surface of lumps of ore. However, as the unreduced surface recedes from the easily accessible exterior of the lump, the reaction proceeds by virtue of the diffusion of the gases into and out of individual pieces. The rate of diffusion of gases, which undoubtedly plays an important role in the reduction of iron ores, depends on several factors, most important of which are: (1) molecular weight or density, (2) pressure, (3) temperature, (4) concentration gradient. Thus, the rate of reduction of a lump of iron ore at any temperature will depend not only on the specific reaction rate but also upon: (1) available surface of unreduced iron oxide, (2) rate of diffusion of the reducing gas to the reacting surface, (3) rate of effusion of the gaseous products of the reaction from the reacting surface, (4) adsorption of the gases on the reacting surface. The various features of the reduction process were discussed in previous work and need not be reviewed. However, in order to explain

Jan 1, 1940

By R. E. Zimmerman

ALTHOUGH flotation of coal is considered relatively new in the United States by coal-preparation engineers, actually it has been practiced to some extent for the past 30 years, It is practiced much more widely in Europe than in the United States. Commercial plants are operating in nearly all major coal-producing countries of the world. A froth flotation plant has been operating since 1930 at the Champion No, 1 preparation plant of the Pittsburgh Coal Co. Unfortunately the term flotation is widely used in the United States by coal-preparation engineers to designate dense medium processes of coal cleaning. As used here, flotation means those processes for cleaning fine sizes of coal in which the coal is collected in a froth or matte at or near the surface of a pulp. The refuse particles remain in the pulp. Two distinct types of flotation are practiced: froth flotation and agglomeration. FORMS OF FLOTATION The theory of the principles of flotation and of the physicochemical foundations surrounding this process has become a complex and scientific field and coal-preparation engineers contemplating use of flotation processes would do well to study the works of Gaudin, 2, 5 Taggart, 3 Zimmerman, 4 Wark, 6 Ralston, 7 Petersen. 8 Bulk Oil Flotation.-In this process the separation of mineral from gangue is accomplished by virtue of the fact that minerals of metallic lustre, as sulphides, or hydrocarbons, as coal and graphite, are wetted preferentially by oil in the presence of water and consequently pass into the interface between oil and water; while gangue or rock is wetted by water and remains in the medium. Beginning in 1860 with Haynes and later between 1897 and 1907, at least 25 patents were granted for bulk oil flotation. Large quantities of oil are required, generally 3 to 25 per cent by weight of feed, and recovery of such oil is a major problem. The Elmore process 3 (1901 and 1902) is an example of a bulk oil process, The Trent process (1902-25) has been used for the cleaning of coal on a commercial scale, According to E. W, Davidson 9 there were five such plants operating in the United States by 1925. They have since been abandoned.

Jan 1, 1950

By W. H. Bassett

IN their paper on the directional properties in cold-rolled and annealed commercial bronze,1 Phillips and Samans suggest that cupronickel, under distinctly different treatments, shows both "45° ears" and "90° ears. " Fig. 1 shows the ears on some cupronickel cups made some 17 years ago for bullet jackets for small arms ammunition. In this case the material heated to 425° C. had "45° ears, while that annealed at 950° C. showed FIG. 1.-CUPRONICKEL, 0.032-in. GAGE, CAST WITH MAGNESIUM. ANNEALED AT TEMPERATURES INDICATED (DEGREES CENTIGRADE) AND CUPPED. long "90° ears" when drawn with the same tools. The method of cupping, the shape of cupping tools, etc., were found to have very little influence on the earing tendency, but the deeper the cup was drawn, the higher the ears would be.

Jan 1, 1932

By G. W. Toop

In a recent publication,31 Darken has derived an equation to describe thermodynamic behavior in ternary metallic solutions with compositions near pure component 1: Eq. [I] is understood to be a general equation, consistent with the ternary Gibbs-Duhem equation, which is proposed as a logical formalism in view of observed behavior in some binary metallic solutions31'32 rich In Eq. and am are constants obtainable from the 1-2 and 1-3 binaries. The parameter 023 may be determined from measurements on the ternary The purpose of this discussion is to compare Eq. [I) or [3] with other ternary formulations involving binary terms, within the regions of validity of Eqs. [I], [2], and [3]. First, the ternary point is considered to be at the intersection of two composition paths, one with constant N1 and another with constant N2/N3 as shown in Fig. 10. The terms in Eq. [3] may be related to the binary points shown by multiplying the first term on the right-hand side of Eq. [3] by N2 (1) /l -N1, the second term by the third term by and the fourth term by each multiplier being unity: It should be noted here that no suggestion has been made that either the binary or the ternary systems form regular solutions. However, Eq. [5] and hence Eq. [3] shows that the contribution made to the ternary excess free energy from the 1-2 and 1-3 binaries has the same form as for a regular ternary system.1 Before considering the term a23 for the above case, a second geometrical relationship is examined with the ternary point at the intersect ion of three composition paths with constant N1/N2, N2/N3, and Nl/N3, respectively, as shown in Fig. 11. For this geometry, ternary values of NZ and N3 in terms of the binary values shown may be substituted into Eq. [I]. Then by making use of identities of the form Eq. [6] contains terms that are similar to those in a ternary regular solution formulation34 based on the geometry shown in Fig. 11. Although at finite concentrations, unless the 1-2 and 1-3 binaries form

Jan 1, 1968