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By Paul D. Merica

Jan 1, 1932

By Donald W. Scott

THE year just ended was the 50th anniversary of that first flight at Kittyhawk, N. C., in 1903. In this 50-year period the aviation industry made startling developments from flight distances of 120 ft-at snail's pace-to speeds of over 1300 mph and flights that circle the globe. And 1953 also was the 50th anniversary of the Utah Copper Co., the Father of our mass production porphyry copper ventures. How do developments in the mining industry stack up with the aviation industry? The mineral industry can be as proud of developments over the past 50 years as the aviation industry. Only for the developments of the mineral industry could aviation and other allied industries advance as they have. The year 1953 made its contribution to this progress, with the normal number of process and equipment developments and an abnormally high amount of activity in new plant capacity, particularly copper. Tonnages are on the increase and operating troubles are becoming more and more problems in materials handling and control. We're approaching molecular dissemination of ores with hydro and pyro methods coming to the front to take over where flotation leaves off.

Jan 2, 1954

By Walter Harvey Weed

introduction,.............715 "WHY ORE-DEPOSITS ARE Common about Igneous Contacts,. ..716 Outline of a Genetic Classification OF Ore-Deposits,.. .. 717 Ores of Igneous Origin.. .. .. .. .. 717 Igneous-Emanation Deposits........ 719 Fumarolic Deposits..........719 Gas-Aqueous Deposits.........719 Deposited by Meteoric Waters ........720 Contact Metamorphic Deposits.........720 Classes of Deposits......... 731 Contact Zones..........722 Character of Gangue..........722 Character of Ore-Deposit.........723 Literature...........724 Geographic Distribution.........724 Copper-Deposits—Cananea Type......725 British Columbia—Boundary District....725 Mexico..........727 Germany.......... 729 Gold.Deposits,...........731 Bannack Type.........732 Elkhorn..........733 Similkameen.........734 Changes in Rocks due to Contact Metamorphism....735 Changes in Mass. Volume. and Mineral Composition... 736 Genesis of Contact Metamorphic Deposits..738 Cause of Contact Metamorphism..738 Permanence in Depth............744 Mineral Veins near Igneous Contacts........745 Conclusions..............746 Introduction. This paper deals with certain ore-deposits whose structural features or mineral contents (or both) result. directly or indirectly. from igneous intrusions and their afier-effects. It is largely a discussion of contact metamorphic ore-deposits based upon the physical changes in rocks due to contact action. It involves a classification of ore-deposits only so far as is abso-

Jan 1, 1903

By J. B. Scuffham, G. Eggett, W. R. Hopkins

With solvent extraction now being accepted as a major method for recovering copper from leach liquors, the authors' company decided that in tankhouse design full advantage was not being taken of the benefits available from sol- vent extraction produced electrolytes. Consequently, a major development program was undertaken to examine means of operating such tankhouses with current densities in excess of current electrowinning practice. Techniques investigated included high circulation of liquors, current reversal and the application of ultrasonics. At the same time there was a necessity for improving the quality of cathodes produced from electrolytes of high free acid content. The application of anodes which are capable of reducing or eliminating the lead content of cathodes is described in the paper. The other problem area in eletrowinning from solvent extraction produced electrolytes is the production of a higher degree of acid mist. Techniques for alleviating this problem are described bearing in mind their possible effects on the solvent extraction section of the plant.

Jan 1, 1973

By William E. Ford, Edward Salisbury Dana

Examination in the Wet Way Examination by Means of the Blowpipe 479. The complete investigation of the chemical composition of a .mineral includes, first, the identification of the elements present by qualitative analysis, and, second, the determination of the relative amounts of each by quantitative analysis, from which last the formula can be calculated. Both processes carried out in full call for the equipment of a chemical laboratory. An approximate qualitative analysis, however, can, in many cases, be made quickly and simply with .few conveniences. The methods employed involve either (a) the use of acids or other reagents " in the wet way," or (b) the use

Jan 1, 1922

By Lester Uren

WITH the depletion of our older, and relatively shallow, oilfields and the necessity for securing new production from deeper horizons, much attention is being given to the improvement of oil-well pumps in order that they may function satisfactorily under the more difficult conditions imposed by increased depth. Until recently, practically all of the world's petroleum was secured from wells less than 3000 ft. deep, whereas horizons are now being explored to depths of from 5000 to 7000 ft. in some of the more prolific fields, and it seems probable that the greater part of the future supply must come from depths in excess of 3000 ft. While much of the early production in a new field is obtained by natural-flow methods, when the stimulus of high gas pressure fails, recourse must be had to some method of pumping. The perfection of a pump capable of economically and efficiently lifting oil from depths ranging from 3000 to 7000 ft. is therefore a matter of prime importance to the oil-producing industry. This paper is offered as an estimate of the present state of development of the oil-well plunger pump and as a review of the general principles involved in its operation in deep-well pumping. A design for a new type of oil-well pump embodying several novel features, is also described.

Jan 9, 1925

Jan 2, 1953

By W.C Ellis, Earle E. Schumacher

Nonferrous alloys upon which desirable properties can be conferred by heat treatment are becoming of increasing industrial importance. The alloys of copper with a constituent which has a solubility varying with temperature are materials of this character. Some of the constituents which are effective in producing a change in the mechanical properties of these alloys upon heat treatment are, according to Corson,' nickel and silicon, iron and silicon, cobalt and silicon, and chromium and silicon. In addition to these elements, Gregg2 states that the combination of beryllium and silicon is effective in producing age-hardening characteristics in copper. The effect of these elements, however, as dispersion-hardening constituents in the copper alpha solid solutions does not seem to have been studied in any considerable detail. This paper deals with the heat treatment and properties of three alpha brasses containing 3 per cent. of nickel plus silicon in the proportion necessary to form the compound nickel silicide, Ni2Si. Some information of a preliminary nature in regard to the hardening by heat treatment of phosphor bronze containing the same percentages of nickel and silicon is included. The method of hardening the alloys, which is effective in increasing the tensile strength and proportional limit, is similar to that used in the case of duralumin type aluminum alloys. It consists of a quench from a temperature at which the hardening constituent is in solid solution, followed by an aging at a lower temperature to precipitate the dissolved constituent in a dispersed condition. This results in an increased resistance of the alloy to deformation with an attendant improvement in the tensile properties.

Jan 1, 1929

By Earle E. Schumacher, W. C. Ellis

Nonferrous alloys upon which desirable properties can be conferred by heat treatment are becoming of increasing industrial importance. The alloys of copper with a constituent which has a solubility varying with temperature are materials of this character. Some of the constituents which are effective in producing a change in the mechanical properties of these alloys upon heat treatment are, according to Corson,' nickel and silicon, iron and silicon, cobalt and silicon, and chromium and silicon. In addition to these elements, Gregg2 states that the combination of beryllium and silicon is effective in producing age-hardening characteristics in copper. The effect of these elements, however, as dispersion-hardening constituents in the copper alpha solid solutions does not seem to have been studied in any considerable detail. This paper deals with the heat treatment and properties of three alpha brasses containing 3 per cent. of nickel plus silicon in the proportion necessary to form the compound nickel silicide, Ni2Si. Some information of a preliminary nature in regard to the hardening by heat treatment of phosphor bronze containing the same percentages of nickel and silicon is included. The method of hardening the alloys, which is effective in increasing the tensile strength and proportional limit, is similar to that used in the case of duralumin type aluminum alloys. It consists of a quench from a temperature at which the hardening constituent is in solid solution, followed by an aging at a lower temperature to precipitate the dissolved constituent in a dispersed condition. This results in an increased resistance of the alloy to deformation with an attendant improvement in the tensile properties.

Jan 1, 1929

By C. K. Leith

Jan 1, 1906

By John D. Sullivan, Chester R. Austin, Edwin J. Rogers

The problem of making a building unit combining the necessary physical and mechanical properties and good thermal insulation has been foremost in the minds of architects and ceramic and construction engineers for many years. This paper presents the results of studies on thermally expanding shales or clays to produce lightweight cellular products suitable for making building units. An expanded clay block suitable for building purposes should be large enough qo that substantial savings may be effected in labor costs in laying the wall. The permeability should be low and it should have sufficiently good "dry-wall" characteristics to permit exposing the exterior surface to the elements, and to permit plastering directly the inside wall surface. The thermal conductivity should be low and the mechanical properties should be adequate. Obviously, a unit possessing satisfactory qualities for constructing an - outside wall would be satisfactory for interior walls and for back-up purposes. The results of studies on bloating various shales or clays† and the properties of the expanded products are reported. In another paper1 basic factors involved in bloating of clays are discussed. Manufacturers of ceramic products, partitularly structural clay, may encounter bloating of the ware during burning, and precautions must be followed to avoid this phenomenon. About 1927 the C. F. Burgess Laboratories, Madison, Wis., while carrying on an investigation for the American Face Brick Research Corporation, conceived the idea of intentionally bloating clay while holding it in a restrained condition, with the hope of producing a unitary cellular mass. Work was carried on until about 1931, when studies were terminated because of business conditions. These studies were continued later by The Western Brick Co., Danville, Ill., which developed a process of "inwardly expansive bloating."² The major purpose of the latter investigation was to produce back-up tile to compete with concrete blocks made from Haydite or cinder aggregate. Haydite is a light-weight aggregate formed by heating certain clays or shales rapidly in a rotary kiln. While the investigations at the C. F. Burgess Laboratories or at Western Brick Co. were not carried far enough to lead to the commercial production of material for the construction of walls, particularly outside walls, they showed that certain clays could be thermally expanded and that it was possible to produce a material of low permeability with a large percentage of the total voids or cells closed. commencing in 1939, the Ozark Chemical Co. sponsored a research program at Battelle Memorial Institute for the Purpose Of determining whether it is technically feasible to make thermally expanded building units, and specifically to get answers to the following questions:

Jan 1, 1942

By J. B. Reed, T. A. Read, H. Rosenthal

Although the season cracking of brass has been a subject of experimental investigation for more than thirty years, the mechanism that is responsible for this phenomenon is still obscure. While at- tempts to elucidate the stress-corrosion cracking of some alloys have been relatively successful, the principal accomplishments made in the studies of the season cracking of brass have consisted of improved techniques for the fabrication of articles of alpha brass, which reduce the danger of season-cracking failure in service. The primary purpose of the present paper is to collect the published experimental data which appear to be of importance to the development of an adequate theory of the mechanism of the season cracking of brass. Some of the possible mechanisms which have been proposed will also be discussed, together with some promising avenues of future attack on the problems. Several excellent survey papers on season cracking are available, including the recent ones by Croft and Sachs(1)2 and by Gibbs(2). The principal facts concerning season cracking, as presented in these papers, may be summarized as follows. The season cracking of alpha brass is a special type of stress-corrosion failure, which may occur in atmospheres containing ammonia, air, and water vapor. The stress causing failure may be either the

Jan 1, 1945

By H. M. Chance

(Butte Meeting, August, 1913.) ADEQUATE treatment of the difficulties surrounding the valuation of mineral lands requires that agreement be first reached defining value as understood for the purpose of appraisal. To define value as the price of a product is not sufficient, and does not assist us in using the factors that cause variations in values and in relative values. The real value of any product depends primarily upon its relation to the necessities, comforts and pleasures of mankind. As the necessities, comforts and pleasures of the civilized races differ-from those of more primitive man, the value of products varies with the degree of civilization and the environment of the consumer. Coal has no value to the savages of warm climates, and arrow-head flint none to the residents of New York. It has long been recognized that what has. been termed ?intrinsic value " must be limited to materials that are essential to existence-air, water, food. But " intrinsic value " cannot be measured in monetary terms. The intrinsic value of a bushel of wheat is due to the fact that it will support the life of an individual for a certain definite time, but this fact does not enable us to measure or to express that value in monetary terms. It has often been proposed to adopt as a measure of the value of any product the quantity of labor necessary to produce it, but this method is of limited application, and will not apply to what may be termed " intrinsic values." For many reasons it might be well, while assenting to the fact that any material may be intrinsically valuable, to abandon the use of the term "intrinsic value." One of these reasons is the tendency to confuse the idea of " intrinsic value with a value that is conferred by economic conditions, that is purely artificial and that may be permanent or evanescent. Intrinsic value must from its nature be permanent and unchangeable.

Jan 7, 1913

By Gealy W. Wallwork

INTRODUCTION The administrative processes of coal mines are becoming increasingly complex. As society evolves into a more complicated structure with greater emphasis on individuality, government regulations reach deeply into every activity in an effort to force individuals into a standardized mold. These contradictory pressures add an extra burden to the administration of a mining operation. Recent years have brought a substantial change in the skills needed by mine supervisors and managers. As a result, a better understanding of the administrative functions is necessary. The mine superintendent has the overall responsibility for the mine; for effective operation he must be sufficiently knowledgeable to oversee all the complex functions that make up the mine. This chapter does not cover all the administrative requirements because of the variation in mine operation and in company policies and organizational structure. It does attempt to identify the administrative functions that would be required at a large mine with a preparation plant. It is assumed that the mine operation is decentralized with very little duplication of functions at the organizational levels above the mine. Thus each function is assumed to be relatively complete at the mine and under the general supervision of the mine superintendent. EMPLOYMENT PROCEDURES Throughout the mining industry, in deep or surface mining, in union or nonunion companies, the success or failure of an organization is directly related to the caliber of employees who make up the organization. A company is nothing more than a group of people working together with

Jan 1, 1981

By Delbert E. Gann, Richard D. Hagni

Ore microscopic study of copper-bearing shale at the Creta mine in southwestern Oklahoma reveals a variety of copper sulfide grains and shows that each has originated by replacement of original constituents In the Permian Flowerpot Shale at Creta. The largest grains, about 120 pm in diameter, are replacements of megaspores with triletes morphology. Their interiors are shown by Auger microprobe analyses to be organic matter. The interior organic matter and the spore exines have been replaced by anilite and djurleite. Digenite and anilite replace collomorphic pyrite averaging 40 pm in diameter. Grains 10 pm or less in d~ameter are mostly euhedral, six-sided, platy crystals that have anllite compositions and are pseudomorphous after pyrrhotzte. Other 10 pm copper sulfide grains are pseudomorphous after octahedra and cubes of pyrite. The results of this study indicate that the copper minerals are epigenetic and were deposited from fluids introduced into the Creta shale when it was relatively uncompacted and permeable. The shale served as a favorable reducing environment that contained a source of sulfur in the form of pyrite and pyrrhotite.

Jan 1, 1985

NORTH AMERICA ALASKA Anchorage.-Culver, H. W. Geehan, R. W. Strandberg, H. Chicagof.-Russell, J. C. Tracy, Q. S. College.-Dorsh, J. B. Fox, E. F. Joesting, H. R. Smith, M. C. Wilcox, H. G. Douglas.-Cahill. W. E. Fairbanks.-Adams, J. M. Barber, R. J. Beistline, E. H. Crawford, J. D. Doheny, L. C. Earling. R. B. Greves, J. H. Harris. Q. P., Jr. Henton. H. M. Herbert, C. F. Nester, W. B. Hopkins, J. E. CANADA ALBERTA Calgary.-Allen, R. E. deHart, J. B. Dunn, W. Gray, J. G. Johnson. R. V. Link, T. A. Slipper. S. E. Soul, N. Thorne, B. L. Thorne, H. L. Edmonton.-Ball, M. W. Lilge, E. O. Pitcher, N. C. Nordegg.-Shanks, J. Turner Valley.¬MacKenzie, W. D. C.

Jan 1, 1941

By Richard D. Harvey, Arthur M. Squires, Robert A. Graff, George Kan

Particles of half-calcined dolomite (CaC03 + MgO) that had undergone cyclic absorption of H2S and regeneration with C02 in laboratory tests reveal enlargement of the crystallite grain structure, reduction in the number of pores but enlargement in their size, and partial development of a relatively dense mosaic microstructure on outer surfaces of cyclically reacted particles. Scanning electron microscopy, X-ray microanalysis, microprobe analysis, and X-ray diffraction techniques were used to evaluate microstructural properties of particles after tests conducted at pressures of 1 and 21 atm and temperatures of 7000 to 9000 C. The tests conducted at 7500 C and 21 atm showed the most favorable absorption and regeneration capacities of the dolomite tested. The changes in structure and pores play a major role in reducing the sulfur reactivity of half-calcined dolomite particles. The mosaic microstructure forms more rapidly at 1 atm than at 21 atm pressure. Once it occurs it seals the surface of the natural pore channels that existed in the half-calcined dolomite and restricts further conversion of crystallites of CaCO3 within the particles. Although a relatively coarse, granular mosaic of crystallites is present on some particles cycled at 21 atm pressure after only three absorption-regeneration cycles, it does not completely cover the particles, and that is true even after 30 cycles. Individual crystallites of MgO were not resolved by the X-ray microanalysis, but we believe that during the tests the MgO occurs as crystallites no more than 0.1 um in diameter that are homogeneously distributed through the particles, and it remains essentially inert during the reactions. The MgO contributes to the maintenance of the original fine-grained and microporous structure of the particles, an effect that is most advantageous to absorption and regeneration.

Jan 1, 1976

By W. L. Remick

WHEN the senior author of this paper presented an article on Fine Coal Cleaning by the Hydrotator Process,1 at the February, 1927, meeting, that process had been developed in the anthracite region only to clean what is known as "slush" or "silt." This size constitutes all of the material passing the finest screen used at any particular colliery. Some use a 3/32 -in. round-hole screen and others use a 1/16 -in. round hole. Practice varies throughout the anthracite region, but the tendency seems to be toward the finer screen.

Jan 1, 1929

By E. A. Reilly, G. R. Gardner, F. P. Lasseter

THE methods that may be applied to the treatment of slurries and water, as these are related to practical coal-preparation problems, are concerned essentially with the movements of solids suspended in water. It is assumed that there are no fundamental differences between the principles involved in the treatment of coal slurries and the phenomena encountered in general mineral-dressing practice, and the latter are presented in some detail. Basic principles ,are correlated with present practice for both the anthracite and the bituminous coal fields, and methods are discussed which are designed to utilize best all the material subjected to treatment and suggest a sound approach to the solution of problems relating to the return of clear water to process or to streams. In order to approach the practical phases of the subject with sufficient understanding of the basic principles, it is necessary to discuss two types of phenomena that are applicable. The first is flocculation and the second is sedimentation. Descriptive matter is given covering the various methods and types of equipment employed to conduct these operations, with emphasis on their application to water and coal-slurry treatment. DEFINITION OF TERMS Definitions of terms are consistent with modern developments, and on form, in general, with their usage in mineral-dressing practice. Because of variations in coal-preparation methods, it is impossible to define a rigid upper limit of particle size for a coal slurry or sludge which will apply generally. Limits vary somewhat with the particular treatment method employed at a given plant. For purposes of definition, this limit is chosen as the particle size for which preparation methods such as Chance cones and jigs are usually dispensed with, and other methods, such as the Hydrotator, tables, and froth flotation, are employed. Generally the limit will be 10 to 6 mesh. In assuming this variable upper limit of particle size in a coal slurry, it is recognized that the size ranges discussed will duplicate sizes dealt with

Jan 1, 1943

By W. M. Albrecht, M. W. Mallett

The solubilities of hydrogen in titanium and several of its alloys were determined at 600 to 1000°C and pressures of 0.05 to 10µ of mercury. Solubility increases with increasing beta phase in the alloys. Factors found to affect degassing rates are specimen size and presence of thick surficial oxide. Removal of hydrogen by heating in vacuum and in flowing inert atmospheres was studied. Practical curves predicting minimum degassing times are presented. THE presence of hydrogen in titanium and titanium alloys has detrimental effects on the mechanical properties of the metal.'"," The hydrogen content of commercial titanium is sometimes of the order of 200 ppm by weight' and varies with alloy composition. As a consequence, titanium and some titanium alloys as normally processed are sometimes not ductile unless treated to lower the hydrogen content. The best known hydrogen-removal treatment is heating the material in a vacuum. The rate of removal (degassing) at a give temperature determines the duration of the treatment required to attain a satisfactory low hydrogen level.

Jan 1, 1959