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By Patrick H. O’Neill

The Choco placers, mined continuously since the earliest expeditions of the Spanish conquistadors, were exploited by the Indians prior to the conquest. Platinum is found in varying percentages with gold throughout the Choco placers and is found in minor percentages in some placers in other parts of Colombia. The Choco Department is on the west coast of Colombia between the western range of the Andes and the Pacific Ocean and extends from the San Juan River north beyond Panama to the Caribbean. The first reference in European literature to platinum was by Julius Caesar Scaliger in 1557. He did not assign any name to it but referred to it as an infusible metal found in the mines in the New World. The Spaniards had given it the name platina, which is the diminutive for plata, the Spanish word for silver. Don Antonio de Ulloa first recorded the name while on an official visit to the Choco from Spain in 1735.

May 1, 1956

By A. M. Gaudin, A. F. Taggart

Flotation of ores is a practical utilization of the energy that resides in the surfaces of solids and liquids. The best known manifestation of this energy is called surface tension; an equally important, though less apparent, phenomenon is adsorption. This paper reviews some of the recent investigations of these phenomena, and gives the results of certain experiments performed by the authors. Surface tension is a manifestation of energy having its seat at the bounding surface between the adjacent phases of a multiphase system. Thus, at the interface between a liquid and a gas, or between two immiscible liquids, or between a solid and a gas or a liquid, there are forces capable of doing work, their magnitude depending on the nature of the adjacent phases and the extent of the bounding area. These surface forces are inappreciable when the ratio of surface to volume of the adjacent phases is small, but they become powerful when this ratio becomes large, as it does when one of the phases is highly dispersed. Froth flotation, which consists in buoying solids heavier than water to the surface of water by means of gas bubbles, utilizes the force of surface tension to attach the solid particles to the gas bubbles and again to maintain the floating mass of bubbles as a more or less persistent froth at the surface of a pulp for a sufficiently long time to allow its removal. It follows from the second law of thermodynamics that the potential energy of a system in equilibrium is a minimum. Therefore a multiphase system, tending toward equilibrium, will arrange itself in such a way that the total energy of the interfaces will be the least possible. This end can be accomplished in two ways: by a change in shape that will reduce the interfacial area; by a change in the nature of the surface layer in

Jan 1, 1923

By A. F. Taggart, A. M. Gaudin

Flotation of ores is a practical utilization of the energy that resides in the surfaces of solids and liquids. The best known manifestation of this energy is called surface tension; an equally important, though less apparent, phenomenon is adsorption. This paper reviews some of the recent investigations of these phenomena, and gives the results of certain experiments performed by the authors. Surface tension is a manifestation of energy having its seat at the bounding surface between the adjacent phases of a multiphase system. Thus, at the interface between a liquid and a gas, or between two immiscible liquids, or between a solid and a gas or a liquid, there are forces capable of doing work, their magnitude depending on the nature of the adjacent phases and the extent of the bounding area. These surface forces are inappreciable when the ratio of surface to volume of the adjacent phases is small, but they become powerful when this ratio becomes large, as it does when one of the phases is highly dispersed. Froth flotation, which consists in buoying solids heavier than water to the surface of water by means of gas bubbles, utilizes the force of surface tension to attach the solid particles to the gas bubbles and again to maintain the floating mass of bubbles as a more or less persistent froth at the surface of a pulp for a sufficiently long time to allow its removal. It follows from the second law of thermodynamics that the potential energy of a system in equilibrium is a minimum. Therefore a multiphase system, tending toward equilibrium, will arrange itself in such a way that the total energy of the interfaces will be the least possible. This end can be accomplished in two ways: by a change in shape that will reduce the interfacial area; by a change in the nature of the surface layer in

Jan 1, 1923

The visitors to the October meeting will be given opportunity to visit the coal fields in Illinois, adjacent to St. Louis, the steam-shovel operations near Pittsburgh, Kan., and the Oklahoma oil fields. The coal mines of Illinois, Missouri, Kansas, Oklahoma and Arkansas furnish fuel over all of the central region of the country. Especially at this time, this district is of importance because of the necessity of producing enormous quantities to meet the country's demand. Some of the mines produce as much as 5,500 tons in 8 hr., and. the total output of Illinois, alone, in 1916, was 63,000,000 tons. Visitors may see elaborate underground electric tram systems, large underground machine repair shops, surface plants equipped for rapid loading, and some of the most modern coal-washing installations. The conditions for mining here are somewhat simpler than in the east.

Jan 8, 1917

The plans for the activities of the Petroleum Division for the coming year do not differ materially from those of the past several years. The fall meeting is scheduled for Oct. 12 and 13 and is to be held at Tulsa, Oklahoma. The Division, of course, will take part in the annual meeting of the Institute at New York. A fall meeting will also be held in California at approximately the same time as the meeting at Tulsa. A number of papers are to be presented at the two meetings simultaneously. The various committees are at work arranging the programs. The Division will continue to be active in its various fields of endeavor, such as stabilization, production reviews, and economics, but special stress is to be laid on the engineering and research fields. In the past the Division has served as a forum for open and frank discussion of problems confronting the engineers in the oil industry. It is hoped that it will continue to function in this capacity. Papers presenting original ideas and extending the boundaries of knowledge and understanding in the field of petroleum production will be welcomed. Members who have interesting information to contribute should not wait until called upon by one of the Committees, but should offer a paper at the earliest opportunity. The past year has seen a decided strengthening of the control over production, with prospects of even more rigid control in the future. It is essential that production programs under such control be carefully planned and it is highly desirable that petroleum engineers take an active part in the planning, to insure efficient production of oil and minimize the waste of this natural resource. At a time like this, when it is difficult to keep the production of oil within reasonable limits, it may seem unnecessary to improve the efficiency of production methods, but, as has been aptly said, the trouble is not that we have too great a reserve of oil but that we are producing tomorrow's oil today. Therefore it behooves those who are entrusted with the engineering and scientific phases of production to learn how to get the greatest yield economically possible from the present and future fields in order that we may enjoy the advantages of petroleum products for a long time to come.

Jan 1, 1934

Jan 1, 1881

By Lewis Carroll

AS he contemplates the numerous good things the hard-working committees have evolved for the 140th Meeting of the Institute, the Editor knows just how the walrus felt when he uttered his memorable, if somewhat lugubrious lines. For there are the Annual Reception and Dinner at the Commodore, 'the Gold Supply Symposium, the luncheons, general and special, and the Annual Institute of Metals Lecture, a Round Table on Iron Ore and a wonderful Informal Dance at the Grand Central Art, Gallery, substantial general sessions, a Smoker-and many other things. -Old, friends and new, reminiscences and confidential chats, horizons pushed back by new information and adjusted perspectives, courage revived and ambitions stimulated-one with a flair for the modernistic might make something-or nothing-of the kaleidoscopic preview 'of the coming Annual Meeting.

Jan 1, 1931

By H. J. C. MAC DONALD

THE mining engineer must have a chest of books snug enough for a camelback or to be stowed away in a canoe; at the lowest possible cost, as he needs it the most in those early years when he earns the least; but at the same time one having an unusually wide range, for he may have to cut down a forest, put up a sawmill, build mine towns, construct dams, power houses, power lines, and railroads. In fact he may be called upon for many unexpected accomplishments and all in extension of the characteristically broad demands of his profession. Suppose that an average mining engineer with a thorough theoretical training and a specialized mining education has accumulated, during a cosmopolitan experience, a complete and up-to-date library, but, unfortunately, in accepting a long term assignment to a far country he is forced to discard the greater part of

Jan 1, 1925

By William Campbell

FiRst I must express my deep appreciation for the honor of being privileged to give the Howe Memorial Lecture this year and at the same time my feeling of inadequacy to do justice to the subject. The first Howe lecturer was most fittingly, Professor Sauveur, his contemporary and friend, and the subject was beta iron. Last year the second Howe lecture was delivered by Dr. Mathews, one of his most distinguished pupils, who spoke on austenite. This year, the Howe Professor of Metallurgy was chosen to deliver the third annual lecture, and the subject ought to be martensite. No one but Professor Sauveur could have brought to life what was considered by many to have been dead and buried, and he so persuasively and convincingly proved to us by his experiments the existence of something that the followers of that new cult "X-Ray and Crystal Structure " would have us believe is simply alpha iron. And Dr. Mathews from his wide practical experience was so easily able to convince us that austenite was not only the most wonderful of the iron-carbon series, but that it was the wonder alloy of the future. If I were to follow in the footsteps of my distinguished predecessors, I would talk to you about martensite. But when I had planned this lecture, I found that I was writing about Professor Howe and his work and his influence on the science of metals of today, and that martensite had become the secondary theme. And when finally I was obliged to choose a title, I remembered that it was in 1901 I came from Roberts-Austen with a letter of introduction to his very dear friend, Henry Marion Howe, at the Columbia School of Mines, to continue my work at the next bench to Dr. Mathews. Since then a quarter of a century has gone by, and during that time all branches of science seem to have been remade, so great has been our advancement in knowledge and discovery. And now that Metallography has finally established its place as an important branch of science, with its own textbooks and literature, I would like to review what seem to me to be the most important advances we have made in the last 25 years. To do this, I would start with Howe's "Iron, Steel and Other Alloys," and end with Jeffries and Archer's " Science of Metals." In the preface of the former, Professor Howe wrote: My warmest thanks are due to the friends who have aided me with their counsel and knowledge. In particular, let me thank most sincerely Prof. Margaret E. Maltby

Jan 1, 1926

By L. C. Raymond

Valuations in the mineral industry differ from those of other enterprises because mines and oil wells have a definite life so cannot be considered a perpetuity. This requires that in any mineral-property evaluation the recovery of invested capital is necessary during the life of the property. Capital write-offs for nonextractive industries are assumed to be continuously plowed back to sustain the operation and produce yields on the capital invested. The extractive or mineral industry, however, generally attempts to return to the investor both interest and principal during the life of a property. Normally this is done currently and the dividend includes both items. Where the mineral property possesses large reserves and the life factor approximates a perpetuity, the return on investment is generally comparable to that of industrial stocks. The valuation of a mineral property, at best, is based on educated estimates and judgment factors. This is particularly true as it relates to estimating selling prices over a long term or assessing the quality of management. Also, it is possible to make various assumptions as to rapidity of working out the deposit, varying time for start-up of operations, varying earning rates, so as to obtain different results with the same basic facts. Thus it is not surprising that two engineers, irrespective of their abilities, may not agree exactly even when given the same facts, but their results should be close enough to be used in establishing a fair value for trading purposes. The valuation is no better than the source of basic data and the soundness of judgment factors. Fundamentally the basic principles of mineral valuation are similar for base metals, sulfur, oil, or any other mineral. Each mineral, however, requires an engineer to have a knowledge of such factors as its occurrence, distribution, mining and processing methods, and marketing problems in order to gather and analyze all the facts and data that have a bearing on the earning potential of the property. Present Value of a Mineral Property In essence the present value of a mineral property is a sum of money in today's dollars that future income from the property are worth. It differs from the total anticipated earnings by the amount of the interest that the unrecouped investment could be expected to earn during the period of recoupment. Thus, if one could accurately estimate what a mineral property will earn during its life, after deducting all operating, administrative, capital, interest, and tax charges, the determination of present value would be a relatively simple mathematical calculation. Normally, where the expected life of the mineral property extends beyond 20 or 25 years, the discounted value of earnings beyond this period is relatively small. The petroleum industry generally discounts the annual cash flow of an operation rather than earnings since, for tax-saving purposes, earnings are kept

Jan 1, 1976

By J. Burns Read, S. Tour

It is the purpose of this paper to summarize, as far as possible, the metallurgical information and experience gained by the Ordnancc Department, during the war, in the manufacture of artillery cartridge cases, to describe the tests to which artillery cartridge cases were put, and to summarize the knowledge and experience gained in this testing. The authors wish to acknowledge the aid given by manufacturers, army officers, and civilian employees of the Department in obtaining data. Artillery cartridge cases are cold drawn from circular disks punched from strips of rolled brass. The rnanufacture involves from 25 to 30 main operations, which are done almost entirely on a punch press. Descriptions of the operations have appeared in various periodical:: and, therefore, will not he given here. After each cupping, or drawing, operation, except the last, the cases are annealed at from 540" to 650" C. (1000" to 1200°F.), to remove all the hardening stresses set up in the metal and to allow complete recrystallization. After each annealing, the cases are pickled in niter cake or sulfuric-acid solution and then washed in water to remove all traces of acid. In some instances, the cases arc then immersed in a cyanide-salt solution, and afterwards rinsed in water, to remove the thin layer of copper that forms on the surface of the cases during the acid pickle. The last cold-drawing operation is followcd by the heading operation which, by flattening the head of the case on the outside, causes the metal to flow on the inside to approximately the proper finished dimensions. The mouth, or open end, is then annealed at 430" to 450" ('. 1800" to 900" F.) by immersion in a salt bath or by gas flames. After being washed, the eases are tapered, when they arc ready for machining, inspection, and testing. Cartridge-case Disks Good disks of proper composition and physical properties are essential to the production of good cartridge cases. The Ordnance Department

Jan 1, 1923

By J. Burns Read, S. Tour

It is the purpose of this paper to summarize, as far as possible, the metallurgical information and experience gained by the Ordnancc Department, during the war, in the manufacture of artillery cartridge cases, to describe the tests to which artillery cartridge cases were put, and to summarize the knowledge and experience gained in this testing. The authors wish to acknowledge the aid given by manufacturers, army officers, and civilian employees of the Department in obtaining data. Artillery cartridge cases are cold drawn from circular disks punched from strips of rolled brass. The rnanufacture involves from 25 to 30 main operations, which are done almost entirely on a punch press. Descriptions of the operations have appeared in various periodical:: and, therefore, will not he given here. After each cupping, or drawing, operation, except the last, the cases are annealed at from 540" to 650" C. (1000" to 1200°F.), to remove all the hardening stresses set up in the metal and to allow complete recrystallization. After each annealing, the cases are pickled in niter cake or sulfuric-acid solution and then washed in water to remove all traces of acid. In some instances, the cases arc then immersed in a cyanide-salt solution, and afterwards rinsed in water, to remove the thin layer of copper that forms on the surface of the cases during the acid pickle. The last cold-drawing operation is followcd by the heading operation which, by flattening the head of the case on the outside, causes the metal to flow on the inside to approximately the proper finished dimensions. The mouth, or open end, is then annealed at 430" to 450" ('. 1800" to 900" F.) by immersion in a salt bath or by gas flames. After being washed, the eases are tapered, when they arc ready for machining, inspection, and testing. Cartridge-case Disks Good disks of proper composition and physical properties are essential to the production of good cartridge cases. The Ordnance Department

Jan 1, 1923

By C. K. Leith

THE purpose of these conferences has been to find some basic principles to guide us in the chaos which confronts us, to arrive at elements of a national policy. None such exists, nor, as a matter of fact, have there been any concerted efforts by the public or the mineral industry to evolve one. In the absence of such a policy the administrative agencies of the government can hardly be expected to be consistent or really effective in their handling of mineral problems, domestic or foreign. Basic Facts MINERAL reserves are unequally distributed among the nations. The principal world supplies are grouped around the north Atlantic, and nearly three-fourths of the world's total is controlled politically and commercially by English-speaking people. No one nation has a complete supply of the minerals necessary for modern industry; specialization, reciprocity, and large-scale movements between the nations are inherent in nature's unequal distribution of them. The principal sources of supply are relatively few compared with the nations to be served-a fact which determines broadly certain natural outlines of the world flow. National isolation with regard to minerals can be accomplished only through backward steps in industry and lower standards of living even in the nations possessing the most of the mineral supplies. A certain measure of unified commercial control, international in scope, is a natural consequence of the limited number of the large sources of supply. Mineral supplies for the world as a whole are so large that there is little need for concern about early exhaustion, but every nation has important problems of early exhaustion of particular minerals, which must affect their policies.

Jan 1, 1933

By Waldemar Lindgeen

PART I.—General Features. PAGE Purpose and Extent of Inquiry ; Definitions (Fissure-Veins, Metamorphism, Metasomatism, Impregnation, Cementation, Weathering); Metasomatism in Connection with Mineral Deposits, Especially Fissure-Veins; Calcu lation of Analyses ; Criteria of Metasomatism; Crystallization of Sec ondary Minerals in Other Bodies; Secondary Alteration of Veins; Structure and Composition of Metasomatic Vein-Rocks and Their Rela tion to General Metamorphism,.759 PART 11.—Minerals Developed by Metasomatic Processes in Fissure-Veins. Quartz, including Chalcedonite and Opal; Rutile and Anatase; Fluorite; Calcite ; Magnesite and Dolomite ; Siderite; Muscovite and Sericite ; Biotite; Chlorite; Pyroxene and A mphibole; Garnet; Epidote ; Ortho clase ; Albite ; Tourmaline ; Topaz ; Kaolinite ; Zeolites ; Pyrite ; Mar casite ; Chalcopyrite ; Arsenopyrite; Pyrrhotite ; Galena; Zinc-blende and Other Sulphides; Tellurides; Native Copper ; Gold and Silver,. 601 Resistant Minerals,........... 619 PART III.—The Fissure-Veins Classified According to Metasomatic Processes. 1. Topaz-Cassiterite Veins (Altenberg and Zinnwald, Saxony ; Mt. Bischoff, Tasmania),..........620 2. Scapolite-Apatite Veins,.........625 3. Tourmalinic Gold-Copper Veins,.. 626 4. Biotitic Gold-Copper Veins,........ 641 5. Propylitic Gold and Silver Veins (General Features; Comstock Lode; The Veins of Nagyág, Hungary; Pachuca, Mexico ; New Zealand; Alaska ; Silver Cliff, Colorado; Silver City, Idaho),. .. .645 6. Fluoritic Gold-Tellurium Veins (Cripple Creek ; Other Occurrences),. 654 7. Sericitic and Kaolinitic Gold- and Silver-Veins (General Remarks; The Freiberg Veins ; De Lamar, Idaho; Summit District, Colorado),. . 6.58 8. Sericitic and Calcitic Gold-Silver Veins (The Gold-Quartz Veins of Cali fornia ; Idaho Types ; San Juan, Colorado ; Treadwell Mine, Alaska ; Gold Veins of Ontario, Canada; Schwarzwald Fissure-Veins),. . 664

Jan 1, 1901

By AIME AIME

A SPECIAL meeting arranged by the Petroleum and Gas Committee of the American Institute of Mining and Metallurgical Engineers was held on Tuesday and Wednesday, Sept. 21 and 22, in the Assembly Room of the American Annex Hotel, St. Louis, Mo. Preceding the first session on Tuesday morning, the members and guests were registered and presented with the usual Institute badges. The morning session was opened at 10:30 by Ralph Arnold of Los Angeles, Calif., Chairman of the Petroleum and Gas Committee. In his opening remarks, he suggested that the petroleum section specialize more and more on the technical problems of the oil industry and that an effort be made to enlarge the membership of the Institute among the technical men of the industry. The following program was presented : OIL FIELDS OF RUSSIA, by A. Beeby Thompson and T. G. Madgwick, of London, England. Presented by H. A. Wheeler; discussed by Arthur Knapp and R. VanA. Mills. This most comprehensive paper was one of what is hoped to be a series to be presented by some of our foreign members. It is by far the best description in English of the world-famous Baku and other fields of Russia.

Jan 1, 1920

By W. L. Honnold

AS BOTH South Africa and diamond mining are unfamiliar subjects it seems best that on such an occasion as this I should endeavor to reflect the atmosphere of the place and to picture the mines from an industrial rather than from a technical standpoint and, because of long absence, my remarks must necessarily be sketchy and in some particulars not up to date. The preferable route to South Africa is via England, direct steamers from America being inferior as to service and effecting no saving of time. The newer boats are of about 20,000 tons capacity and very comfortable. Seventeen days are required for the voyage and only one stop is made-that at the island of Madiera, three days out. Between Southampton, the port of departure, and Madiera the weather may be warm or cold and the

Jan 1, 1925

By M. R. Campbell

Coal is the geological product of entombed vegetal tissues. This view of its origin led Stopes and Wheeler to define it as "mummified plants." They evidently intended this term to be used in a broad way and to mean the preservation of the organic material, as such, regardless of the means employed to accomplish the purpose. The term " coal" should be regarded, therrfore, as broadly generic, and applicable to all accumulations of vegetal tissues as soon as they are covered and protected either by water or by earthy material. In this sense peat should be regarded as the first stage of coal formation and the term coal should include the resultant products of transformation in all other stages of the process until they have lost all resemblance to the original matter from which they were derived. If this idea of the development of coal is accepted and it is admitted, as the geologists claim, that the forces which produced this transformation of the coal have been active since vegetation began to grow upon the land, and are still in operation, it is obvious that somewhere in the world there are all gradations of this material from peat just forming in the swamps of today to graphitic anthracite which presumably marks the most advanced stage that can be recognized with certainty as belonging to the series. Some of these coals, particularly those occurring in the upper part of the series, are fairly well known because they are the ones that are most widely distributed and have been mined and utilized most extensively. On the other hand, the coals in the lower part of the series are but little known because they are not so abundant and, owing to their relative inefficiency, have been only slightly exploited and utilized, especially in regions where the better coals are abundant. The result of these conditions is that much research work has been done on coals of the higher ranks and a great body of facts regarding their physical and chemical properties and the uses to which they are best adapted has been accumulated, but little information is available regarding the coals of the lower ranks. Many able scientists, particularly chemists, have attempted to bring some order of the chaos of coals of various compositions and uses by

Jan 1, 1930

By AIME

WE got our chance to talk with Arthur J. Blair at the Annual Meeting at the Pennsylvania Hotel. By two o'clock Wednesday afternoon things had quieted down enough so we had our interview in the foyer to the Ball Room. There were the usual questions. Where were you born? In La Salle County, Ill., on March 26, 1885. Where did you go to school? Northwestern University, B.S. degree in 1906. Where did you start work? For E. J. Longyear right after leaving school. One's ability as a geologist was measured by one's ability to wield a brush hook and ax. He stayed on the job as geologist for three years and then got to thinking about the advantages of a warmer climate. The advantages stacked up favorably, so off he went to Birmingham, Ala., just about the time U.S. Steel took over the Tennessee Coal, Iron and Railroad Co.

Jan 1, 1948

By H. N. Eavenson

In a discussion in the Transactions of the Institute (vol. Xl, page 835 et seq.) the writer gave some data about the explosions of gas and dust in the coal mines of the United States, Canada, and Mexico…

Jan 1, 1915

The economics of aerial survey and the technical processes by the aid of which vertical and oblique aerial photographs are turned into line maps showing the most profuse topographical detail such as contours, rivers, roads, plantations, habitations and cultivated lands do not concern us here. They have been ably and exhaustively described in the publications of the British War Office, handbooks on surveying methods and on photogrammetry and in the South African mining, engineering and geological press. Suffice it to mention that for geological interpretation vertical photographs are used on such scales as 1/5000 to 1/10,000, overlapping each other by 55 to 60 per cent in the direction of flight and some 10 to 20 per cent sideways on to the next sequence or strip. Through this duplication in the overlap the stereoscopic examination becomes possible. The standards by which monochrome aerial photographs are interpreted can be grouped under the following headings: 1. Continuity.—The continuity of topographic relief not obtainable on the ground owing to the smallness of man relative to that relief. Here lies the greatest value of aerial survey with relation to geology. An immediate alignment can often be made of drainages running in different directions on each side of a hill; saddles and gorges in the mountainsides; abrupt termination of outcrop or indubitable signs of faulting. Most conclusive evidence is thus often obtained about faults which may be perfectly visible at one place on the ground but cannot elsewhere be identified because of decreased throw. Similarly, dikes can often be followed notwithstanding frequent interruption and disappearance under the soil. Scattered outcrop in scrub-covered or bush-covered country can be conveniently located and often correlated, with a large saving of time compared with field work. The same applies to geological contacts. Once these have been established at a few points on the ground, the intervening stretches can be drawn in.

Jan 1, 1937