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By A. J. Brown

THE causes that have formed fissures in the earth's crust, and the agencies that have converted them into metallic beds, are amongst the most important and interesting subjects that can engage the attention of the mining engineer or the scientist. They lie at the very base of the whole system of vein geology, and until something like a correct theory can be arrived at with regard to them, the science as such is necessarily very incomplete. The data for such a theory, owing to a lack of careful and systematic observations in countries pre-eminently metalliferous, like Mexico and the States of Central and South America, are almost entirely wanting. Doubtless there has been abundant speculation on the subject, from the earliest times down to the present, in every country where mining has been one of the leading industries of the inhabitants. Perhaps the theory of Elie de Beaumont more nearly approaches a satisfactory explanation than that of any contemporary authority. The most recent investigations, both in Europe and on this continent, tend to produce the conviction that the phenomena of metallic fissure lodes are in some way connected with, and- dependent upon, plutonic agencies-not, however, as the direct product of volcanic activity, but rather as the result of chemical agencies called into play through its aid. Active volcanoes generally produce only the well-known types of volcanic rocks, though, perhaps, well-marked cases can be shown where these contain ores of copper, etc., evidently derived from the same deepseated source as their hypogene gangue. To prove that there is a connection between metallic lodes and plutonic rocks, it is not necessary that the ores should in all cases occupy fissures within the limits of masses of propylite, rhyolite, or other like rocks, or be

Jan 1, 1874

By Harold H. Goe, Louis V. Bender

The recovery of arsenic was started at the Washoe Reduction Works (later called the Anaconda Reduction Works) in 1904, when an arsenic plant was constructed adjacent to the lower end of the 60-ft. main flue.' This plant originally consisted of a Brunton roasting furnace for treatment of flue dust and a small reverberatory furnace for treating the crude arsenic produced in the roasting operations, together with the necessary kitchens for condensation of the fumes and grinding and barreling apparatus for preparing the refined white arsenic for market. The Brunton furnace was fired with wood. It was 14 ft. 6 in. in diameter with two outside fireboxes. The hearth revolved upon a central shaft. The charge was fed through a dust-tight hopper on to the center of the hearth and slowly moved to the outer edge of three rows of stationary rabbles fastened in the roof of the furnace. There was a 3-ft. space between the hearth and roof. A crude arsenic was condensed from this furnace. The hot flame from the fireboxes passed directly over the charge, vaporizing the As203 that was carried through brick flues to the condensing chamber. This chamber was 8 ft. high, 16 ft. wide and 240 ft. long, divided into small kitchens by partitions spaced every 7 ft. It was connected with the main flue system to provide draft and to receive any losses from the chamber. The small kitchens were connected by openings in such a way that the fumes took a zigzag course, causing them to come in contact with the cold walls and ceiling and condense the arsenic. There was an opening from the outside into each kitchen, for the removal of the deposited arsenic, which was closed by a wooden door. The refining furnace was a small coke-fired reverberatory having a hearth 10 by 20 ft. in dimensions. It had three hoppers through which the crude charge was introduced, and one firebox placed at one end. The hot gas from the burning coke passed over the charge, volatilizing the arsenic and carrying it to the kitchens.

Jan 1, 1934

By S. S. Arentz

An organized safety program has reduced accidents at Pioche because effort is first devoted to arousing and maintaining interest in safety, followed by training in accident prevention, assigning responsibility for the detection and removal of safety hazards, and finally, by keeping score through an adequate system of records. A health program is intergrated with the safety program.

Jan 2, 1950

By A. A. Schweizer

A method to improve the quality of Magmont zinc concentrates to become acceptable feed to an electrolytic zinc refinery is described. The magnesia content of zinc concentrates produced was too high due to particle locking with sphalerite in coarse fractions. Regrinding the concentrates to a very fine particle size and then refloating the sphalerite was chosen to eliminate a sufficient amount of the magnesia to make the concentrates acceptable.

Jan 1, 1984

By James J. Norton, Lincoln R. Page

Effective methods for determining grade and reserves of pegmatites in advance of mining have been developed in recent years. When intensive work began on the economic geology of pegmatites during the early years of World War II, it was widely believed that grade and reserves could be estimated only in a most general way. The literature indicated that not all pegmatite deposits are unpredictable, but statements emphasizing unpredictability and irregularity seem to have been more widely accepted. Many standard references reflect the prevailing opinion that minerals are unsystematic in their occurrence in pegmatites. Pegmatites have been de- scribed as "notorious for their irregular structure," and minerals within pegmatites as "irregularly distributed," "irregularly disseminated,'' of "erratic occurrence," "proverbially erratic in distribution," "characterized by extreme irregularity in size and distribution of the essential minerals, and variety and proportion of the accessory minerals, and "spotty."

Apr 1, 1956

GEORGE K. BURGESS,* Washington, D. C. (written discussiont).-Professor Sauveur refers to the International Aircraft Standards Board in terns that would indicate his non-familiarity with, the organization and the working of this Board which, of course, is excusable on account of Professor Sauveur's absence in Europe at the time. He implies .that the work of this Board was entirely dominated by American interests, whereas diametrically the opposite was the case. The Board, was organized for the purpose of facilitating purchase in the United States, on the basis of common specifications, by the Allied air, services in the United States, and the Board performed a very valuable service in unify-ing the specifications of Italy, Great Britain, France, Canada, and the United States for such purposes. The proceedings of the Board were car-ried out on the basis of unanimous agreement of the representatives of the five countries and all the members from each of the countries were technical specialists or, had the advice of technical assistants. It would be difficult to find an instance of greater unity of purpose, readiness to' compromise, and efficient production than was shown by this Board, which produced seventy-eight specifications, in the preparation of which representative American manufacturers appeared before the Board.

Jan 12, 1919

By Ali Altway, M. E. Tunison, T. W. Chapman

Simulations of various contactor configurations for simultaneous extraction or stripping of two metals reveal the dependence of conversion and selectivity on operating and design parameters A two-film mass transfer model is used to provide the rates in countercurrent column and stirred-tank cascade calculations Even in these mass-transfer-limited cases the stoichiometry of the extraction reactions introduces nonlinearities and interactions between the two metal transfer rates, but these can be represented In a suitable model One conclusion is that a countercurrent column should be considerably more efficient than a cascade of mixer-settlers of comparable size.

Jan 1, 1981

By Dan A. Permenter

This paper assesses some of the critical factors that must be considered and addressed in the implementation of small computer systems for technical applications within a coal company. Aspects of hardware selection that are somewhat specific to the coal industry are discussed, and a table of potential areas of application is presented. The dilemma of internal software development is presented and a software development program based on a users group approach is outlined and discussed in detail.

Jan 1, 1983

By N. S. Keith

(Read at the Wilkes-Barre Meeting, May, 1877.) THIS question is suggested by a statement made by Dr. Siemens, widely printed in the journals of the day, that a continuous rod of copper, thirty miles in length and three inches in diameter, is capable of conveying that distance, electrically, energy equal to 1000 horse-power. It is not attempted to advance the statement that the source of power shall be zinc, nor even coal, but waterfalls, which from their situation are not practically available for manufacturing establishments in their immediate vicinity. In order to fully consider this subject., we must understand the doctrine, I may say the science, of the correlation of the forces, so called. We must understand that all matter is endowed with an amount of force, and that each atom and molecule, simple and compound, has its specific portion of the whole. This force, at rest, is called latent heat, intrinsic energy, or potential. In motion it is called heat, light, electricity, chemical affinity, attraction, magnetism, power, etc., according to its sensible manifestations. These are the effects of the one force active in different substances, or in different assemblages of matter. Force put in motion comes to rest by reason of the resistance to motion which it encounters; in overcoming

Jan 1, 1878

By R. H. Sayre

.... The subject is one of great interest in every point of view to railroad managers and steel-rail makers. It has occurred to me that if in this connection your society would take up the matter of the shape or section of steel rails and the form of joint, and be able to arrive at such form for difEerent weight of rails as you could recommend to the railroa~ls of tbis country with a view of obtaining uniformity, it would be, in caseof adoption, of great value both to the railroads and makers of wils. My idea is that if botb your society and that of the civil engineers ahould join in the adoption of templates and their recoalmendation, it would be more likely tb have the desired effect. Youm truly, Robert H. Sayre..

Jan 1, 1881

By A. W. Ashbrook

The constraints which are being imposed on metallurgical operations in respect to the environment and worker hygiene are having a substantial influence on the various processes which are being studied and developed for future use. The unit process of solvent extraction can be no exception. It is therefore vital that sufficient be known about the effects of a solvent extraction process in terms of its environmental and hygiene impacts before the process gets to the construct- ion stage. The purpose of this section is to bring these matters to the readers' attention, and to indicate, albeit briefly, some of the problems, and what we know about the effects, of SX processes from an ecological point of view. Hydrocarbons Petroleum hydrocarbons are bio-degraded to form C02; several factors may limit the rate of bio-degradation, which are as follows:

Jan 1, 1978

By Walter Nummela

This acronym may be readily deciphered, and it represents the programming theme for the SME Sessions at the Centennial Meeting of AIME in New York in 1971. The Concentration Committee thus charged out to grab, to induce, and to accept volunteered papers within that framework. The program for the Concentration sessions is in and hopefully all deadlines will be met as specified in the instructions to authors. Without spelling out what is to be seen and heard in New York, how well did the Committee satisfy the theme described in the title? Perhaps it was by virtue of the international makeup of the Committee (Member Dan Pickett is with the Mines Branch in Ottawa) that an international slate of authors was assured. Four countries are to be represented-Bolivia, Canada, Italy, and the United States.

Jan 1, 1970

By R. H. Terhune

THE enormous production of pig-iron, together with the many difficult and interesting problems with which its manufacture is fraught, has secured to this industry the exclusive attention of scientists with reference to the chemistry of iron, while some of the minor departments of its metallurgy have suffered neglect. Particularly is

Jan 1, 1873

By Chairman Hill H. H.

The Round Table Discussion on Petroleum Engineering Research was planned for two purposes. First, to review the work that has been done by petroleum engineers during the past few years on problems that have confronted the industry and, second, to suggest new studies that should be made either on the problems that have been the subject of research during the past or on problems that have arisen only recently. It was believed that by holding an informal discussion of the problems in which the petroleum engineer is vitally interested it would be possible to bring out new ideas as to the relative importance of the different problems that should be studied and to suggest new methods for attacking some of the problems that have resisted the energies of research workers throughout the industry. It was also believed that by arranging for an exchange of experiences between the different engineers it would be possible to prevent a large amount of duplication of effort in conducting research work. Those engaged in petroleum engineering research realize that there is a broad field for study and by coordinating the work it will be possible to obtain the maximum amount of information in the shortest possible time. In planning the program on Petroleum Engineering Research, nine subjects were selected for discussion and each was assigned to a man who is doing work on that subject. These men were asked to lead the discussion on the problem assigned to each one. An effort was made to choose problems of a practical nature and upon which considerable work is being conducted at the present time. Some of the men who were asked to lead the discussion were unable to attend the meeting but most of them submitted a written discussion- of the subject assigned, with the result that there was a discussion of eight of the nine problems. Professor Uren, who was asked to lead the discussion on the subject of Recent Developments in Methods for Reducing Gas-oil Ratios, was unable to attend the meeting and advised that he did not have any new ideas to contribute.

Jan 1, 1928

Are Stockpile Requirements Exaggerated? THE federal stockpile of strategic and critical materials was created for an emergency. The emergency has occurred but no withdrawals are being made from the stockpile. On the contrary, the-rate of stockpiling is being increased. A serious dislocation between supply and demand for metals exists and purchases for the stockpile are a significant contributing factor in this situation.

Jan 3, 1951

By W. E. C. Coxe

MANY of you who are interested in the manufacture of iron and steel, have no doubt heard of the "Wheeler process for combining iron and steel." Mr. Wheeler has formed a company, styled the "Combination Trust Company," whose business is to grant licenses for the use of this patent process in producing what he calls "iron-clad steel." It has been proposed to apply it in the manufacture of car or wagon axles, also to shafting, having steel cores or centres covered with iron; to tubes of steel with an inner and outer skin of iron ; to structural purposes, such as girders and beams; bridge and tie-bolts, where the strength of the iron and the rigidity of the steel would be desirable. In answer to a request from Mr. Wheeler, permission was accorded him to make some experiments at the rolling mill of the Philadelphia and Reading Coal and Iron Company, at Reading, Pennsylvania, with a view to manufacturing some steel-headed rails. In making this kind of a rail two difficulties are encountered. If the iron is brought to the requisite heat to weld properly, the steel is likely to be burned ; if the steel is cared for, to prevent burning, the several layers of iron are not brought up to the proper welding heat. Mr. Wheeler claimed that the steel slab covered with iron which be furnished for the head of the rail could not be injured by any heat to which it might be subjected in the ordinary course of heating the rail-pile. He claimed, also, that by this method the porosity, which he thought was characteristic of all solid rails of Bessemer steel, would be overcome. Four steel slabs were furnished for this experiment, being Bessemer steel of .61 carbon, made at the Edgar Thomson Steel Works, and covered with iron in one of the Pittsburgh mills. The slabs were in section seven inches wide by three inches thick, and the iron covering was one-eighth to three-sixteenths inch thick. Each slab was placed on a pile of iron made up in the ordinary way for a rail fifty-six pounds per yard and thirty feet long. The heating was under the personal direction of Mr. Wheeler, and

Jan 1, 1879

By Tuncel M. Yegulalp, Malcolm T. Wane

In general, many problems relating to the exploitation of mineral deposits are probabilistic in nature. This derives from the fact that the geologic universe is inherently random. Probability theory and statistics have been found useful for forecasting the behavior of natural events that occur in the geologic universe. The objective of this paper is to outline the application of the theory of extremes to this forecasting problem. Consider the design of an underground structure or the design of a rock slope. The initial step is the formulation of the various possible structural actions which result from the geometry of the layout. For a given structural model, various intensities of behavior are possible depending upon the load, deformation, and material characteristic spectra, respectively. Of popular interest to mining people is the failure behavior or condition. A necessary feature of the analysis is the rupture strength of the material. Information on the rupture strength is derived from testing either in situ or in the laboratory and the usual outcome is a variation in the test results. This variation is overcome by constructing a frequency distribution of rupture strengths, and then determining a measure of central tendency and variability. The main feature of interest in the analysis is the failure characteristic and its percentage chance of occurrence. Hence, one is naturally led to examine those areas of a distribution curve which are termed the tails. The statistical concepts which can most efficiently handle such areas are contained within extreme value statistics.

Jan 8, 1969

By William Catron

BECAUSE the rich La Colorada orebody of the Cananea Consolidated Copper Co. does not outcrop at surface, after its discovery (by churn drill) and before mining was begun, a large amount of development work was done to learn the shape and extent of the ore and to provide for eco-nomic and effective mining. As these openings progressed, the actual shape of the orebody became known and with this knowledge came the realization that mining this rich and unusual deposit without loss of ore or danger to workmen presented several difficult problems. This paper will describe one of these problems; namely, the handling of an inverted cone-shaped core of barren rock, on the periphery of and below which the ore occurred. It was clear that as the ore was mined out from around and under this inverted cone of rock, weighing about 3,000,000 tons, it would hang over the workings, held suspended only by its own tensile strength and threatening to crash into the stopes below with disastrous results to men and mine. The method of mining developed during the years 1928, 1929 and 1930 anticipated and provided for the eventual collapse of this core of rock. In November 1936 the core settled clown gradually on the edges of the stopes, descending a total of about 50 ft. vertically. The men in the stopes had ample to warning and no lives were endangered. There were no air blasts in the mine. The core broke loose from its top support at the 500-ft. level along old fracture planes and evidently is crushed to the ninth level. Movement was of short duration; the following shift went to work in the stopes as usual. No ore was lost.

Jan 1, 1938

By A. S. C. Owili-eger

Coal mining is one of the major activities that may affect the natural or existing hydrologic equilibrium of a basin. Consequently, the mining industry is committed to the conservation and protection of the hydrologic balance within and around mining environments. This commitment embodies thorough and careful consideration of the quantitative and qualitative variations and, in general terms, the environmental impacts of mining activity on the natural water systems. A research program was undertaken to study the impacts of full extraction coal mining on the ground water systems at one of the coal basins in the Appalachian region. The primary objective was to provide reliable information for determining the local and possibly the regional effects of longwall mining on well yields, and the hydraulic and hydrogeochemical parameters of the immediate surface and subsurface water resources.

Jan 1, 1985

By Fred Van Covern

Before getting into a discussion of the subject of my paper, I want first to make it clear to everyone that I am speaking as an individual; and that any expressions of opinion that are contained herein, or may be expressed in any oral discussion that may follow its presentation, are entirely my own, and must not be construed to be the official opinion of the American Petroleum Institute. Demand fob Motor Fuel, 1936 During the year just closed the domestic demand for gasoline exceeded 481 million barrels. This compares with 434,810,000 bbl. consumed during 1935 and indicates an increase of 10.46 per cent. Export shipments amounted to 27,831,000 bbl. while in 1935 they totaled 30,613,000 bbl. Total demand, therefore, was 509,422,000 bbl., or 9.16 per cent above the 465,423,000 bbl. of 1935. Following are the figures for several years: Already we are supplying gasoline domestically and as foreign shipments at a rate almost 25 per cent greater than our low level of 1933. Before giving figures for 1937, I should like to spend a moment or two in discussion of gasoline inventories, from the point of view of minimum working stocks and other requirements and of probable actual levels. Inventories of Gasoline The year 1936 closed with about 62,900,000 bbl. of finished and unfinished gasoline in storage—about 6 million barrels more than was on hand

Jan 1, 1937