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By C. W. Merrill

The cyanide process in the United States, notwithstanding numerous failures made under the direction of the owners of the patent-rights, and others, has now passed its experimeiital stage, and can, undoubtedly, be made successful when intelligently applied to suitable material. Much, however, remains to be known as to the exact conditions under which this process is applicable to the treatment of gold-bearing ores. If the owners of the patent-rights in this country have ever scientifically investigated the matter, they have never published any valuable informatioil on the subject. Other parties who are now using the process (often independently of the patentees), have nothing to gain by publishing their experience; and, moreover, many of the chemical reactions described in the text-books refer to the use of solutions of potassium cyanide many times stronger than are used in the metallurgical process.

Jan 1, 1896

By F. S. McNicholas

IN the first big blast at Climax, a "loop back" (three-wire system) was used (Fig. I), with the idea of securing a wiring system that would give to all series the same amount of current. Single-phase, 60-cycle, 13,800-volt [ ] power was furnished to the blasting transformers, each of which has a rated capacity of 600 amp. at 480 volts. Two blasting leads were taken from these transformers, giving a blasting current of single phase, 60 cycle, 480 volts, with an instantaneous capacity of more than 600 amp. The blasting switch was on the secondary leads from the transformers, to avoid lag in energizing them.

Jan 1, 1938

SINCE I have mentioned the art of alchemy in. many parts of this treatise of mine, especially when 'came to the description of the practice of various operations,* I do not here intend to argue as to whether it may be called true or not. But in case it is true, inasmuch as it is seen in operation to be a result dependent on the actions and virtues of fires, I should not pass by in silence without speaking at all of this art here, nor would I wish to do so, especially since I think that you do not really know what it is except in so far as common report is heard everywhere to the effect that whoever carries it to completion makes silver and gold with it. Because of this belief, many seek it with much time, labor, and expense, as I know you have often heard related, if not elsewhere, by me in the chapter on gold that I have written in this volume. Now do not think that I wish to teach you this art here, for I am one of those who do not know it. Therefore I shall tell you here, so that you may know more, only. that those workers who so eagerly follow after and seek it proceed by just two pathways. One is that which takes its enlightenment from the words of the wise philosophers, by means of which they think to attain it. This they call the just, holy, and good way, and they, say that in this they are but imitators and assistants of Nature, indeed, manipulators and true physicians-of .mineral bodies, purging them of superfluities and assisting them by augmenting their virtue and freeing them from their defects. In this way they sometimes proceed to corrupt these bodies in order to be able to separate the elements they contain so as to reduce them, if possible, to their primary materials, as they call them, or sometimes they convert them into new substances by means of this art or by adding another spirit different from the first one. Thus they seek in this way to bring these materials to a certain point of corruption or to a separation of elements, or to remove or add spirits to things, or to make coarse materials subtle and sometimes to make subtle materials coarse. Therefore, as you can understand, these persons, with bridle broken, run a circular track night and day, without ever having rest; and surely I do not know whether anyone has ever arrived at the desired goal. Nevertheless, even though the goal of this art were emptiness, as many

Jan 1, 1942

Jan 1, 1965

Jan 1, 1922

By M. R. Hoover, J. H. Kim, S. J. Kloda, R. E. Carmola

Feed preparation circuits, which involve such unit processes as size reduction, classification, and beneficiation are inherently a capital and operating cost intensive part of synthetic fuels plants. These circuits, as encountered in similar minerals industry operations, have until now been designed more or less by individual experience and preference mainly because of the large number of variables involved. As a first step towards a computer-aided design tool, a flowsheet simulator has been developed based on an executive program which can connect and drive modular subroutines according to the proposed circuit. The most efficient and appropriate mathematical models were selected as modular sub- routines among available sources such as SPOC, ASPEN, and DOE. Advantages and limitations of this kind of approach are discussed from the system architecture and methodology transfer standpoints with special emphasis on synfuels circuits.

Jan 1, 1983

By Nicholas T. Camicia

Coal is one of our oldest known commodities. Historic evidence indicates that this fossil-formed fuel was used in China and in Wales some 3000 to 4000 pears ago. Coal was discovered in North America in 1679 by French explorers in northern Illinois, and in 1700 a colony of Huguenots came across bituminous coal in Virginia. One might think by this long history of a single commodity that the string was about played out. Quite the contrary, coal is in greater demand than ever before and coal mining today is a modern industry. It is in an unprecedented growth period as the nation-and the world-demands more and more energy coincident with dwindling reserves of other fossil fuels. By the year 2000 the demand for coal is expected to at least double the current level of some 600 million tons annually despite the advent of nuclear power. To meet this challenge, the coal industry is vitally in need of an increasing supply of technically trained and progressive manpower. And, coupled with a serious shortage of engineers and technicians, it represents a rich vein of occupation opportunities-all the way up to top career levels. Today, coal mining is a complex, highly specialized industry concerned with more than just getting coal from the earth and putting it into the furnaces of the consumer. The industry is concerned with the environment, with maintaining a viable ecology. Recognizing the ramifications of global economics, the industry is very much aware of its important position in contributing to a constantly rising standard of living throughout the world. The key to rewarding employment in the coal industry is skill-skill that has been developed by education, training, and experience. None of these alone is enough; all three are necessary today to produce the skill needed to meet the employment requirements of the coal industry. Routine manual labor will no longer do the job in coal mining. In the United States coal mining has been mechanized to a degree unsurpassed anywhere else in the world, and the coal worker must be thoroughly

Jan 1, 1973

By Edgar Rickard

E UGAR RICKARD comes of a long line of mining men and was born at Pontgibaud, France, in 1874, where his father was then in the course of his professional work. Later his father came to California and was until his death prominently connected with milling in that state and Nevada. Edgar Rickard grew up at Berkeley, attended the University of California, graduated in 1895 from the mechanical engineering course, and remained a year longer for post-graduate work in the College of Mining. His first job was as assarer for the Mountain Copper Co., Keswick, Cal., in 1896. The following year he was assayer and surveyor for the Cornucopia Mines, Oregon. In 1898, he joined the staff of the Venture Corporation, London, and for two years made examinations for them in various parts of the world. He served as mine manager at Cripple Creek and at the Briseis tin mine, in Tasmania. From 1901 to 1905, he was general manager of the Progress Mining Co. in Lower California, but when his cousin, T. A. Rickard, bought the Mining and Scientific Press he was persuaded to come to San Francisco as business manager of that periodical. A few years later the two cousins went to London and started the Mining Magewine there as a joint venture, Edgar being the business manager. In 1915, he took over control, T. A. Rickard returning to California to devote his time to the Mining u.rbd Scientific Press. In 1917 Edgar Rickard sold out to his British associates and came home to serve in the Food Administration through the war. Rickard was one of the first of the American engineers called to his staff when Herbert Hoover began his relief work by helping stranded Americans home at the be- ginning of the war and he has been with him constantly since in the Commission for Relief in Belgium, the

Jan 1, 1929

Jan 1, 1889

By R. W. Shoenberger, J. A. Grina, R. J. VanPelt

The many alternatives open to coke plant operators for improving overall coke quality and strength are discussed in this paper. Programs undertaken by US Steel research and coal operations during the previous ten years to improve coke strength are described. New techniques in use, or being considered for future use, are also discussed.

Jan 1, 1982

By M. Cross

The main results from a programme of theoretical work on various aspects of the pelletizing operation are presented. This paper is primarily concerned with the modelling of: (i) The balling drum operation. A model is outlined which clearly demonstrates the characteristic surging behaviour of the balling circuit. It is used first in a control analysis and, subsequently, in the design and testing of various control schemes. (ii)The grate-kiln-cooler induration process. Models describing each of the constituent processes are outlined and a composite model of the whole induration process presented. The main results from each of these models are discussed.

Jan 1, 1977

By Nicholas J. Grant, John S. Benjamin, Bill C. Giessen

In the course of a study of hard particle-duc tile binder composite alloys, interest arose in the nature of the products of the reaction between the inter metallic compound NiAl and the binder niobium. No published information was then available. A program to

Jan 1, 1967

By Regis Chauvenet

I have been requested to sketch the iron resources of the State of Colorado, with reference both to existing, i.e., working mines, and to prospects more or less developed, but not contributing anything as yet to actual shipments. I should mention, though disliking apologies, that there is one region of the State which I believe to be important, and which has been assigned to me (with reference to its iron-deposits particularly) in the field-work of the present year for the School of Mines, which has not been systematically explored, and whose data are not in such shape as to enable me to give them in this paper. The region in question is Pitkin county and part of the adjoining country. Regarding the geological positions of the veins or deposits, they are sufficiently varied. In Boulder county there is a well-defined vein of titaniferous magnetite in ancient granite or gneiss, while in Park county there may be seen a deposit now under construction, as will later be described; when finished it will belong, let us say, to the post-quaternary. Between these, in Cambrian, Silurian, and Lower Carboniferous formations, are various deposits, and even the

Jan 1, 1890

By Christine Alexander

Twenty years ago, the northern Oquirrh Mountains overlooking Salt Lake City were bare. Heavy logging and overgrazing combined with erosion and uncontrolled forest fires had severely denuded the mountains by the turn of the century. As a final coup de grace, a copper smelter was built there in 1906, and for the next 50 years its sulfurous fumes killed off what little vegetation remained. In 1956, Paul Rokich, a biology student at the Univer¬sity of Utah, started to surreptitiously restore the mountains. For the next 17 years, Rokich devoted his spare time and money to replanting the Oquirrhs, with the result that several thousand acres of the mountains are green again, and animals have returned: deer, elk, and rabbits thrive among olive, maple, and fruit trees, wheat grass, and sunflowers.

Jan 10, 1975

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Jan 2, 1969

William Metcalf, Pittsburg, Pa. (communication to the Secretary*): I am greatly pleased that some one has at last reached what I have long regarded as the only rational explanation yet given of the reasons why steel hardens. Mr. Field claims originality; and doubtless he is entitled to it, but not to priority, mhich must be granted to Prof. John W. Langley.' The difference between them is that Langley says " Tension, probably molecular," and Field says " Tension, probably atomic "; in either case the vital thing after solution is tension. Mr. Field's argument carries with it the idea of increase of density with hardness; if he mill study the facts farther he will observe that the case is just the reverse; that is, the greater the hardness the less the specific gravity; it was just this fact that led Langley to his conclusion, in mhich I have always concurred. Field agrees with Langley that the first requisite for perfect hardening is complete solution of the carbon, not combination; and all of the facts agree with this conclusion. The fact that increase of hardness causes reduction of density was first brought to my notice some 40 years ago, when Major William Wade was testing Jones & Laughlin's cold-rolled iron, and I mas his assistant. We found the well-known increase of tenacity, compressive strength, torsional resistance, and hardness. Specific-gravity tests showed that the cold-rolled iron was less dense than the hot-rolled bars. Major Wade was so surprised at this result that he gave me a lot of samples to weigh, saying that he was not satisfied with

Jan 1, 1904

Jan 1, 1938

Jan 1, 1938

By James W. Malcomson

The Tigre Mining Co. of Mexico, owned by the Lucky Tiger Combination Gold Mining Co. of Kansas City, decided early in 1910 to enlarge its mill, which consisted of a concentrator milling 3,000 tons of ore per month. The enlarged plant was designed to crush and concentrate 6,000 of ore and to cyanide 7,500 tons per month. The extra tonnage cyanided was to be obtained from tailings which were stored below the old mill. Power was supplied to the old mill from four boilers; a 150-h-p. Corliss engine and two Weber 60-h-p. gas-engines using producer-gas made from charcoal. The total horse-power required, including 60 h-p. used for machine-drills in the mine, was approximately 275. Cord-wood cost $4.32 per cord, 8 by 4 by 3 ft., and charcoal $15 per ton. The fuel supply in the surrounding country was approaching exhaustion; more than 150 mules and 50 men were engaged in cutting and transporting this fuel, and the unsettled political conditions in Sonora were such that it would be practically impossible to keep an organization of this kind together. The price of fuel was steadily rising and at times it became almost impossible to get sufficient fuel to operate. It was estimated that the enlarged plant, together with the mine, would require 750 h-p., as follows: Horse-Power. Old mill, which was left unchanged,..............180 New concentrator,.......................90 Cyanide-plant,........................380 Mine and other requirements,................. 100 Total,........•..................750 In a study of the best manner to obtain power the following alternative propositions were considered:

Jan 1, 1914

By A. J. Shaler, B. F. Oliver

Jan 1, 1961