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By Walter C. Lawson

The first plans were made in 1930 for the mining by open-pit methods of the low-grade disseminated ore body now known as the Morenci open pit. It was not until 1937, however, that final plans were completed and the decision reached to go ahead with the actual development. Many advances were made in open-pit mining equipment during that period of seven years, therefore the ways and means of attack actually used were very different from those originally contemplated. Diesel-operated bulldozers, big trucks, full-revolving electric shovels and electric churn drills constitute the major equipment finally purchased for this modern stripping operation. Neither the bulldozers nor the big trucks were considered in the early operating plans, for at that time bulldozers had not been used in mining operations and the trucks as yet were undesigned. The full-revolving shovel and the churn drills were not new developments in open-pit equipment, but both had undergone remarkable manufacturing transition, emerging far more efficient and far more dependable than their predecessors. Even the ordinary drilling steel had been fundamentally changed. It was now threaded so that the dulled cutting bits could be detached and replaced, thus eliminating the costly transportation of long bars to the drill shop for resharpening. The decision to use trucks in the preliminary stripping operations was based on the desirability of this type of transportation to economically prepare the pit for rail haulage, coupled with the success that the contractors had had with them on other big excavation jobs. There are at present no plans for the use of trucks beyond the preliminary work, inasmuch as rail haulage will give lower costs after roadbeds and benches are once established. For many years to come, both ore and waste haulage will be over favorable grades. The average length of ore haul between the pit and an assembly yard will be about two miles. From there the crushers will be 1? miles with a connecting track grade of 0.4 per cent. The upper ore benches of the pit will be reached from the yard by a series of four switchbacks over a ruling grade of 4.0 per cent compensated for curvature. Tracks to the dumps will be on 0.2 per cent grades.

Jan 1, 1940

By Walter C. Lawson

The first plans were made in 1930 for the mining by open-pit methods of the low-grade disseminated ore body now known as the Morenci open pit. It was not until 1937, however, that final plans were completed and the decision reached to go ahead with the actual development. Many advances were made in open-pit mining equipment during that period of seven years, therefore the ways and means of attack actually used were very different from those originally contemplated. Diesel-operated bulldozers, big trucks, full-revolving electric shovels and electric churn drills constitute the major equipment finally purchased for this modern stripping operation. Neither the bulldozers nor the big trucks were considered in the early operating plans, for at that time bulldozers had not been used in mining operations and the trucks as yet were undesigned. The full-revolving shovel and the churn drills were not new developments in open-pit equipment, but both had undergone remarkable manufacturing transition, emerging far more efficient and far more dependable than their predecessors. Even the ordinary drilling steel had been fundamentally changed. It was now threaded so that the dulled cutting bits could be detached and replaced, thus eliminating the costly transportation of long bars to the drill shop for resharpening. The decision to use trucks in the preliminary stripping operations was based on the desirability of this type of transportation to economically prepare the pit for rail haulage, coupled with the success that the contractors had had with them on other big excavation jobs. There are at present no plans for the use of trucks beyond the preliminary work, inasmuch as rail haulage will give lower costs after roadbeds and benches are once established. For many years to come, both ore and waste haulage will be over favorable grades. The average length of ore haul between the pit and an assembly yard will be about two miles. From there the crushers will be 1? miles with a connecting track grade of 0.4 per cent. The upper ore benches of the pit will be reached from the yard by a series of four switchbacks over a ruling grade of 4.0 per cent compensated for curvature. Tracks to the dumps will be on 0.2 per cent grades.

Jan 1, 1940

Dec. 2, American Mining Congress, annual membership meeting, University Club, New York. Dec. 2, Society for Applied Spectroscopy, Socony-Vacuum Training Center, New York City. Dec. 4-6, AIME, Electric Steel Furnace Conference, Hotel William Penn, Pittsburgh. Dee. 5, Atlanta Meeting of Southeast Section, AIME, Ansley Hotel, Atlanta. Dec. 7-10, American Institute of Chemical Engineers, annual meeting, Hotels Cleveland and Carter, Cleveland. Dec. 8, AIME, Arizona Section, all-day meeting, Tucson. Jan. 6, 1953, Society for Applied Spectroscopy, Socony-Vacuum Training Center, New- York City. Jan. 14, 1953, AIME Connecticut Section, Hammond Metallurgical Laboratory, Yale University, New Haven, Conn. Jan. 14-16, 19th Annual Meeting of Society of Photogrammetry, Shoreham Hotel, Washington, D. C.

Jan 1, 1952

By William R. Webster

At the Richmond mecting in February, 1901, I presented for discussion the proposed rail-specifications of Committee No. 1 of the American Section of the International Association for Testing Materials, with a review of their work, and other matters relating to the heat-treatment and chemical composition of steel (Trans., xxxi., 455). In order to bring out the views of our members on the important points referred to, I offered for discussion the following questions and comments (trans., xxxi., 972): " 1. The advantages to be gained by using more metal in the flanges and web of the heavier sections of rails.

Jan 1, 1903

Prof. H. S. Munroe, New York City : In his reference to cop per-dressing at Lake Superior, p. 325, Mr. Douglas says that " the .. concentration .. . has been carried out with greatest financial economy,... I do not say with the greatest economy of min eral." And again, on p. 344, referring to the same, " it would not pay to reduce the quantity treated, and increase hand-labor, in order to save a few hundredths of one per cent. of copper." Mr. Douglas probably has in mind the fact that the copper lost is all included copper, locked op in grains of sand. To save this, the rock must be crushed finer. If the mesh of the stamp-screens be reduced, the stamps will crush less; and thus we shall have to reduce the quantity treated in the mill per day, while the labor re mains the same per day, or is increased per ton, as he says. Submitting to the loss of copper, however, is not the only solution of the difficulty. A large quantity of rich sand is now collected by the jigs, and it would be easy to save so much of this material that the escaping sands would be quite poor. What is wanted at Lake Superior, and at many dressing-works in this country, is an efficient crushing-machine to treat the sands thus collected. Abroad, we have the Heberle machine and the Schranz mill for this purpose, the latter being the more successful. The Heberle grinder was tried at the Calumet and Hecla mill for crush ing these rich sands, with what success I do not know. I should like to ask Mr. Douglas if we have no American crushing-machine that will reduce jig-sands to a fine state of division

Jan 1, 1894

By W. N. Best

THIS paper is not intended as a scientific discussion of the combustion of oil but is written from, the standpoint of an operator who has the experience and qualifications necessary to guide others in producing the most economic results in the use of liquid fuels. Oil, in this paper, usually, means petroleum or its products but incidental reference is made to other liquid and gaseous fuels, so that the term may be considered, as referring to all liquid and gaseous hydrocarbons in comparison with solid fuels, as coal and. wood. However, only a few of the principal factors in the use of oil as a fuel can be given. The present, and prospective, high price of coal is causing users of fuel to renew inquiry as to the merits of other forms of fuel for industrial purposes. Crude oil (petroleum) is proving to be one of the world's most valuable mineral resources. The recent discovery that oil underlies a considerable area of the United States, Mexico, and other parts of the world to a greater extent than was formerly believed and the large production of some of the wells in these areas shows the probable quantity of fuel oil that may now be available. Through the energy of Lord Cowdrey, who was one of the pioneers of the oil industry in Mexico, oil has been discovered in England; some prominent geologists believe that it may be found yet, in quantity, in Great Britain. For years, oil has been known to be of great value in the manufacture of metals. It has proved incomparable in forge shops, steel foundries, heat-treating furnace s, and wherever accuracy of temperatures is essential, or where a maximum output is desired as well as quality of metal. In some types of equipment, the output produced with oil as fuel is double that obtained with coal and, at a reduction of 50 per cent, in the cost of the fuel. For example, in drop-forging plants, the metal is always waiting for the man when oil is used as fuel, whereas with coal, the man must wait for the metal to become sufficiently heated.

Jan 8, 1920

Jan 1, 1928

By B. Y. Ekber, A. S. Gorbachev

The development of economically effective and safe methods of mining thick coal seams allow considerable coal reserves to be used as an energy resource all over the world.

Jan 1, 1979

By P. E. Palmer, A. H. Daane, C. E. Habermann

Jan 1, 1965

By K. L. Meissner

It is well known that the so-called pure aluminum contains noticeable amounts of impurities, chiefly iron and silicon, and many investigators have studied the forms in which these impurities exist. Hanson and Archbutt1 state that iron exists in aluminum as FeA13 and silicon as elementary Si. The solubility of FeA13 in solid aluminum is practically zero, or at least so small that the smallest trace of this compound is always visible as a separate constituent. Under the microscope an untrained eye can hardly distinguish, without etching, the two constituents FeA13 and Si, but they can be differentiated by suitable etching reagents. Anderson2 also found the same results. At the same time, Merica, Waltenberg, and Freeman3 found a constituent of unknown composition. They found a small thermal effect, at 610" C., on the cooling curves of aluminum with small amounts of iron and silicon. The intensity of this effect increased with increasing silicon content, until an effect occurred at 576" C. due to the eutectic between aluminum and silicon. The authors ascribed the effect at 610" C. to a compound, which they call "X constituent." It was thought to be a ternary compound containing iron and silicon and could be observed under the microscope as dark particles. Dix4 has published unetched photomicrographs of an aluminum with 0.51 per cent. iron, 0.99 per cent. silicon, and 0.32 per cent. copper that shows three constituents: the dark Si (black in the figure), the lighter FeA13, which appears in half tone and crystallizes in needles, and a constituent of the same color as FeAL3 but of different crystal form, often resembling Chinese script. This last constituent, Dix thought, is a compound of Fe and Si; not the compound FeSi but a compound containing a relatively small amount of silicon. Therefore an alloy of aluminum. iron, and silicon (the copper should not be regarded in the following considerations) must contain the following four constituents: Al, FeA13, Si, and a compound of Fe and Si. This, however, does not agree with the laws of chemical equilibrium.

Jan 1, 1926

By Frank Calvin Roberts

An examination of the various devices employed for operating blast-furnace charging-bells has led me to design the arrangement slrown in the accompanying figure. In order to contribute to the even distribution of stock, the movement of the bell should be in a vertical line, since any tendency to side-thrust which may be in-

Jan 1, 1888

By W. W. Schmittroth, A. Y. Bethune

THE commercial analysis of Special High-Grade zinc usually involves the determination of lead, iron, copper and cadmium as impurities in the base metal. Over the past 20 years, as the result of metallurgical improvements in the art of producing Special High-Grade zinc metal there has taken place a gradual exclusion of almost all extraneous elements, and the few that do remain in the final product have been virtually reduced to the vanishing point. Thousands of tons of zinc .are now commercially produced annually and made available to the trade, in which impurities are present only in the order of 0.0010 per cent or less and the sum total of all impurities does not exceed 0.0025 per cent. To such zinc the term "superpurity" might well be applied without undue exaggeration. The techniques used for production control and final analysis of Special High-Grade zinc by means of emission spectra in the laboratories of the electrolytic zinc plant of the Sullivan Mining Co. are based on the premise that self-electrodes are to be preferred over all other forms for the examination of the zinc in question. Furthermore, after a survey of the literature and considerable experimental work,1 it was decided that the spectrographic method of internal control, the principle of which was first announced by Gerlach,2 using a modification of the high-voltage alternating-current arc source introduced by Duffendack and Thompson,3 with the calibration of each photographic plate as recommended by Wolfe,4 would yield the most accurate and reproducible results. Self-electrodes were chosen in order to make use of one of the unique advantages inherent in spectrographic analysis; namely, the rapid and almost effortless detection of elements other than those being quantified by the analyst; or conversely, the proof that the zinc is free from such impurities if no spectral line of the suspected element appears. This fact was verified for certain elements, and will be discussed later. Carbon electrodes impregnated or packed with zinc salts chemically prepared from the zinc to be assayed were avoided for a number of reasons. First, the chemical manipulation was another time-consuming step, which increased the chances for contamination. Second, none of the common zinc salts, such as the chloride, nitrate or sulphate, yielded reproducible results under our conditions, nor did the spectral line of the impurity appear as readily in the low concentrations as when using zinc metal. Third, no commercial carbon, except the very expensive, was pure enough to use with this grade of zinc and the continued time, effort and expense incurred in the purification of carbon was not desirable. The use of Special High-Grade zinc self-electrodes introduces certain complications with regard to obtaining satisfactory excitation conditions, because it seems necessary to raise the temperature

Jan 1, 1946

By Robert W. Fullerton, Donald T. King

INTRODUCTION AND THEORY by Robert W. Fullerton In coal preparation plants, as in any industrial operation where raw materials are handled, nuisance problems arising from the generation of dust are inevitable. Devices for the control or collection of dust are there- fore essential components of the plant process equipment. The general term "aerosol" is applied to small particles suspended in a gaseous medium, usually air, whose velocity under the force of gravity is small enough that the particles remain suspended for a reasonable length of time. Aerosols can be classified as dust, smokes, fumes, mists or fogs. Dust includes particles originally formed by pulverization of materials by such processes as crushing, grinding, drilling, blasting and abrasion. Smoke includes particles formed from the burning of organic materials. Fumes are particles formed by processes such as condensation and sublimation, usually at high temperatures. Mists or fogs are particles formed by the condensation of water or other vapors on some nuclei. The size of aerosol particles is generally designated in units of microns, there being 1000 microns to a millimeter and 25,400 microns to an inch. Particles of about 10 microns or above are visible to the naked eye. Table 14-1 shows size characteristics of the general classifications of particles discussed above and includes typical examples of particles commonly en- countered. Table 14-1 also shows the relationship between micron size and standard screen mesh sizes. Smoke and fume are usually in the range of 0.01 to one micron, dusts are in the range of one to 400 microns, mists are in the range of 0.1 to 100 microns, and fogs are in the range of one to 100 microns. For purposes of dust control, particles greater than 10 or 20 microns in size are considered large, particles one to 10 microns are considered fine and particles below one micron are ultrafine. Sources of Dust Because coal is relatively friable, the mining and subsequent handling operations break part of the coal into dust that can be readily carried by currents of air. In a coal preparation plant mechanical handling operations such as unloading, transferring from one belt to another, screening, cleaning, and crushing in a dry state result in the generation and release of varying amounts of additional dust. The dust problem, of course, is much less serious in plants employing entirely wet processing. In addition to dust from handling operations, thermal drying of the fine coal product frequently presents another dust collection problem. Most coal driers are

Jan 1, 1968

By H. Maleki

Gob pressure measurements were made in a Western U. S. coal mine as part of a long-term program to evaluate cave progress and to determine the influence of geological discontinuities on caving conditions, load transfer, and resulting instabilities. Gloetzl cells were selected for the measurements due to their simple, robust construction and a history of being able to monitor pressures in a broken medium. A methodology was developed for the successful installation and protection of the cells and hydraulic lines in the gob as the face retreated. The measurements indicated a cave progress controlled by the frequency of major faults. The pressure-mining progress profile was compared to those observed in other parts of the world. It was concluded that the significant differences in profiles was caused by the thick-bedded strata, the existence of high lateral stresses, and the spacing between faults. Recommendations are given for future applications of Gloetzl cells for gob pressure measurements.

Jan 1, 1984

By H. O. Jahns, R. A. Greenkorn, R. E. Haring, L. K. Shallenbarger

This paper is a study of the effects of heterogeneity on flow in an analog of porous media, the Hele-Shaw model. l-3 A set of experiments in heterogeneous Hele-Shaw models showed streamlines through and around heterogeneities of various sizes, shapes and levels. (A level, we define as the ratio between the transmissibility of the heterogeneity and that of the rest of the model.) The heterogeneities were restrictions or expansions of the flow stream analogous to variations in the transmissibility of porous media. The experimental data agreed well with numerical results and with an analytical solution, which we derived for a circular heterogeneity in an infinite field. This study considers the flow-stream distortion due to the shape, size and level of heterogeneities. Size and level are much more important than shape provided the heterogeneity is not long and narrow. Our analytical solution shows that a circular heterogeneity in a large field can be replaced by an equivalent circle of either zero or infinite permeability. The radius of the. equivalent circle is a simple function of size and level of the actual circle. INTRODUCTION With the availability of high-speed computers and numerical procedures to predict reservoir behavior, we are faced with an important question. How much information about the reservoir do we need to justify the cost of the computer in any given case? To answer this question, we have to know how various reservoir parameters affect flow behavior. Reservoir heterogeneity is one of these parameters. In this study, we used a simple, two-dimensional model of porous media, the hele-shaw model, to investigate the effect of heterogeneity on flow behavior. We restricted ourselves to linear, single-phase, steady-state flow in a rectangular field with a single heterogeneity at its center. The analogy between flow in Hele-Shaw models and in porous media is easily verified. Let us first consider a homogeneous Hele-Shaw model with constant plate separation h. (The Hele-Shaw model is constructed by placing two plates, usually glass, very close together and allowing liquid to flow between them. Streamlines are made visible by introducing colored fluid into the space between the plates at a number of points across the model.) We assume a cartesian coordinate system with its origin in the middle between the plates and the z axis directed perpendicular to the glass plates (Fig. 1). The fluid flow is always in a direction parallel to the glass plates and varies from a maximum value to zero in the very small distance from the middle (z = 0) to either plate (z = h/2). For slow motion of an incompressible fluid, neglecting inertia and body forces, we have the viscous flow equation: where p is the fluid pressure, p the viscosity, and v the velocity vector with components u, v and w in the x, y and z directions, respectively. In our rase. and the derivatives of 3 with respect to x and y are small as compared with the derivative in the z direction. Therefore, approximately, with Vp and v being two-dimensional vectors in the x-y plane. Two integrations with respect to z give

Jan 1, 1965

By W. H. Pelton, P. G. Hallof

Outlining small pods of high-grade, massive sulfide, copper-zinc mineralization was the object of an intensive exploration program by Long Lac Mineral Exploration Ltd., near York Harbour, Newfoundland, Canada. Efforts to define the ore zones using surface dipole-dipole induced polarization techniques were not entirely successful due to the poor size-to-depth ratio of the targets and widespread disseminated mineralization. Additional information on the size and shape of the sulfide bodies was obtained by placing a current electrode directly within a mineralized drill intersection and systematically measuring the resultant potential on the ground surface. Some simple potential field sources were interpreted from the data and their validity has been shown by an extension to the underground workings.

Jan 1, 1973

"The zinc concentrator of the Butte & Superior Copper company, shown on the opposite page, represents an industry which is coming into importance in Butte. The existence of large bodies of zinc ore in some of the silver veins of Butte has been realized for years, but it is only recently that some of them have proved amenable to successful concentration. Most of the zinc ores thus far found in the camp are mixed with considerable pyrite, but those found in the Black Rock and Elm Orlu mines contain very little pyrite, so that a concentrate low in iron is possible.The Butte & Superior mill is rated at 1,200 tons daily capacity. The ore is sphalerite, most of which is finely disseminated through a hard quartz gangue, with small quantities of galena, pyrite, chalcopyrite, rhodocrosite and rhodonite. In mining, the included granite and the low grade vein matter are sorted out and used for waste filling so that the ore as it goes to the concentrator will carry about 20 per cent of zinc, 1 per cent lead, .25 per cent copper, 8 to 10 ozs. silver and a little gold. The ore bodies ranging from 5 to 103 feet in width, are mined by the square set method and filling of stopes with waste rock.The ore is hard and tough requiring extensive crushing and grinding equipment, consisting of Blake and gyratory crushers, 54-inch and 42-inch high speed rolls, Chili mills, Tube, and Conical mills. All of the lead con¬centrate and part of the zinc concentrate are recovered in the upper part of the mill by jigs and tables. The classifier overflow and the re-ground jig and table tailings go to settling tanks and from there to the Hyde Flotation process, where the balance of the zinc concentrate is recovered, and the tailing go to waste."

Jan 1, 1913

By D. L. Gardner, H. L. Barr

The following report covers the history of the development of the mine, present equipment, methods and costs of mining and milling. In addition, a description of the ore deposit is given with emphasis on the origin of the fractures, mode and types of ore occurrence, and mechanics of granite emplacement. An endeavor has been made to present a complete and accurate statement of the San Mauricio mine, the highest grade gold mine in the Philippine Islands. Credit is gratefully acknowledged to the mine staff for descriptions and details regarding their particular field of work. All analyses were made by Mr. T. A. DeVore, head chemist, San Mauricio Mining Co. Messrs. Edward Wisser, J. E. Fyfe, A. F. Skerl and W. B. Meek, geologists, have contributed geologic information and ideas, for which thanks are extended. The Executive Committee of Marsman and Co., Inc., Managers of the Company, has kindly given permission for publication. Mr. J. B. Stapler, Division Manager, Marsman and Co., has had the courtesy to read the manuscript and to give critical and helpful suggestions. Location of Area and Scope of Work San Mauricio Mining Co. controls a group of 113 claims that lie immediately north of the town of José Pafiganiban (formerly Mambulao), Camarines Norte, Luzon, P. I. (Fig. 1). Exploration work commenced in the spring of 1934; active development began in the fall of that year and has continued to the present date. Mill construction was begun Ocl,. 15, 1935, and production started March 10, 1936. Total production to June 1, 1939, is P10,499,105.15 ($5,249,552.57).

Jan 1, 1941

By D. L. Gardner, H. L. Barr

The following report covers the history of the development of the mine, present equipment, methods and costs of mining and milling. In addition, a description of the ore deposit is given with emphasis on the origin of the fractures, mode and types of ore occurrence, and mechanics of granite emplacement. An endeavor has been made to present a complete and accurate statement of the San Mauricio mine, the highest grade gold mine in the Philippine Islands. Credit is gratefully acknowledged to the mine staff for descriptions and details regarding their particular field of work. All analyses were made by Mr. T. A. DeVore, head chemist, San Mauricio Mining Co. Messrs. Edward Wisser, J. E. Fyfe, A. F. Skerl and W. B. Meek, geologists, have contributed geologic information and ideas, for which thanks are extended. The Executive Committee of Marsman and Co., Inc., Managers of the Company, has kindly given permission for publication. Mr. J. B. Stapler, Division Manager, Marsman and Co., has had the courtesy to read the manuscript and to give critical and helpful suggestions. Location of Area and Scope of Work San Mauricio Mining Co. controls a group of 113 claims that lie immediately north of the town of José Pafiganiban (formerly Mambulao), Camarines Norte, Luzon, P. I. (Fig. 1). Exploration work commenced in the spring of 1934; active development began in the fall of that year and has continued to the present date. Mill construction was begun Ocl,. 15, 1935, and production started March 10, 1936. Total production to June 1, 1939, is P10,499,105.15 ($5,249,552.57).

Jan 1, 1941

By AIME

IRWIN W. ALCORN, present Chairman of the Petroleum Division, was born Sept. 5, 1899 at Marietta, Ohio, and moved with his family to Robinson, Ill., at the time of the early oil development there. This was in the days of the Star spudders, mud, mules, and Stanley steamers. Al graduated from Robinson High School after participation in basket ball, also attaining the captaincy of the football team of that school. He entered Missouri School of Mines and Metallurgy in 1918 and was ushered by the Army into the S.A.T.C. In 1920 he transferred to the Massachusetts Institute of Technology, later to return to receive his B.S. degree -in metallurgy at Rolla, also joining the AIME. On graduation, he worked for the Skelly Oil Co. at Cushing, Okla., shifting to the Moore Refining Co. at DeNoya, Okla., as superintendent of a small pipe-line system. After an interval of two years with the National Supply Co. in Tulsa, he joined the Independent Oil and Gas Co. of that city, and at various times was chief engineer of the Texas division, superintendent of the West Texas pipe-line system, chief engineer of pipe-line construction, and chief engineer of the refining division. Al organized the Company's production engineering department. In 1930 the Company was merged with the Phillips Petroleum Co. The depression was in and Al was out, 'as was true nine months later when the Smith Separator Co. whose chief engineer he had become, was liquidated. The next few years was spent with Oil Well Supply Co. as a subsurface pumping equipment engineer

Jan 1, 1948