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By Walter Bradley

MINING by hydraulic process of the important gold-bearing gravels of the Sacramento Valley in the basins of the Yuba, Bear and American rivers began in 1853, and continued at an ever-increasing rate for 30 years. In its most active days it reached an annual production of $15,000,000, and averaged $10,000,000 per year over the 30 years. During that period no provisions were made to prevent the debris from being dis-charged into the water courses, and ultimately large quantities of silt, sand and gravel were washed down to the lower valleys; filling channels, causing overflow of agricultural lands and difficulty in maintaining navigable depths in the Sacramento River. Agitation and suits filed because of these damages finally resulted in the injunction decision of Judge L. B. Sawyer,1 in the U.S. Circuit Court, Jan. 23, 1884, which closed down practically all hydraulic mining operations not having means to restrain their debris. In 1893 (approved March 1, 1893), Congress passed the act introduced by Representative Anthony Caminetti, of California, creating the California Debris Com-mission, composed of three officers assigned from the Engineer Corps of the U.S. Army, and since that time it has been legal and possible within the drainage systems of Sacramento and San Joaquin rivers to conduct hydraulic mining of gold-bearing gravels behind dams built under this commission's permit and supervision. In the watersheds of the Trinity and Klamath rivers, which flow directly to the Pacific Ocean and do not affect navigation or agriculture, operating permits from the California Debris Commission are not required. There is a measure of restriction there, however,. through what is known as the Trinity and Klamath River Fish and Game Dis-trict. Chap. 215, Stat. 1931, in order to secure relatively clear water for the fishing season, provides that between July 15 and October 15 each year there must not be discharged into these rivers debris that will cause a turbidity greater than a content of 50 parts per million in the

Jan 1, 1936

By J. J. Sense

This paper deals with the Asarco method for the determination of equipment availability. It is apparent that no single availability equation will provide all of the information necessary for the complete record of equipment availability. In the Asarco system, three separate availability records are carried on major equipment. The first is mechanical availability, the second is operational availability, and the third is a historical record of equipment use. The derivation of the three items and the definitions of the time elements used in the various availability equations are presented and discussed. The Mission unit of American Smelting and Refining Co. is located in Pima County, Ariz., approximately twenty miles southwest of Tucson. The unit consists of an open pit copper mine and concentrator. The concentrate is shipped by rail to company smelters at Hayden, Ariz., or El Paso, Tex. Mine stripping began at Mission in the fall of 1959, and construction of the 15,000 tpd concentrator was started in the spring of 1960. The first ore was treated in midsummer of 1961 and full ore production was reached in August 1961. At that time over 46 million tons of material had been moved from the pit. Current production (ore and waste) averages over 100,000 tpd. Total production to date (ore and waste) is over 120 million tons. Major equipment currently in operation at the Mission pit is as follows: 3 P & H 1800 Electric Shovels - 9 cu yd dippers 1 P & H 1900 Electric Shovel - 9 cu yd dipper 2 B.E. 190-B Electric Shovels - 9 cu yd dippers 35 Euclid LLD Trucks - 60-ton capacity 6 KW-Dart 55-T Trucks - 55-ton capacity 1 KW-Dart D-2550 Truck - 65-ton capacity 1 LeTourneau Westinghouse 65 Haulpak - 65-ton capacity 3 Euclid S-18 Scrapers - 274011 capacity 4 Caterpillar D-8 Dozers 4 LeTourneau Westinghouse Tournadozers 1 Michigan 280 Dozer 2 Caterpillar Model 12 Motor Graders

Jan 1, 1964

By Frederick Laist

I. INTRODUCTION The new slime-concentrating plant at the Washoe Reduction Works, Anaconda, was put into operation during March, 1914. This plant, which has a capacity of 26,000,000 gal. of slime pulp carrying 2,500 tons. of solid matter per day, consists of Dorr thickeners and Anaconda multiple-deck slime concentrators.' This plant is the culmination of a great deal of experimental work extending over a considerable period of time, which work will be described briefly in the following pages.

Jan 8, 1914

By H. C. Theuerer

EVEN the highest purity silicon available for semiconductor use contains significant amounts of donors and acceptors, usually aluminum, phosphorus, and boron. Aluminum and phosphorus can be removed from silicon by adaptations of the zone refining techniques' widely used with germanium. Removal of boron, however, has been a difficult problem. The approximate distribution coefficient for boron in silicon is 0.8, so that while zone refining is possible, it is not very effective in any reasonable number of passes. It has been found, however, that boron can be effectively removed from silicon by treatment of a liquid zone with hydrogen and water vapor. Starting with 40 ohm-cm, n-type silicon, use of zone refining coupled with hydrogen

Jan 1, 1957

By R. C. Patterson

IN view of the circumstance that very few important changes have been made within the last 15 or 20 years in the equipment of rod and wire mills, the description of a new process introduced by Grenville Mellen, of Llewellyn Park, N. J., to take the place of the present laborious system of producing rods of lead, zinc, brass, copper, aluminum, etc., may be interesting to members of the Institute. This new process consists in the production of cast rods at one operation in a small continuous casting machine. The hot liquid metal is transferred from the melting crucibles directly into an endless chain of mold blocks in the machine, where solidification takes place, and the rod comes out continuously in a solid form at one end as long as the molten metal is supplied. The operation of these mold blocks so as to produce a solid rod of uniform structure constitutes an important part of Mr. Mellen's invention. The machine (Figs. 1 and 2), 12 ft. in height over all, 2 by 3 ft. in horizontal- cross-sectional area, and 6,000 11). in weight, has a framework of cast iron, holding in position two endless chains of mold blocks, which are made in sections and join in center alignment. The mold orifice is made up of these mold sections, into which the liquid metal flows. The molding chains are composed of steel blocks, grooved on one face to form the molding cavity, and linked together with flexible joints. Each block is carried on four rollers which guide the chain around the end sprockets and carry it in its course through the machine. The accuracy of alignment requisite to the production of a perfect rod in the mold groove formed by these sections is secured by careful machine work, and by building the four ways, down which the alignment takes place, so that two of the sides are fixed permanently, while the opposite sides are held to their position by spring pressure. The guides carrying the molds, while in casting position, are water-cooled square tubes.

Jan 5, 1915

By J. C. Danko, R. D. Stout, A. H. Holtzman

The deformation characteristics of pearlite have been studied by light and electron microscopy.1,2 In the electron-microscopic work, deformation was found to take place by 1) ferrite slip which is parallel to the lamellae, 2) slip transverse to the lamellae with both cementite and ferrite deforming, and 3) ferrite-cementite interfacial slip. The transverse slip gives a step-like appearance to the lamellae in light microscopic work. It was thought that spheroidization of deformed pearlite would commence at the regions of maximum cementite deformation, the "stepped" areas. Although there is no possibility for seeing slip in the microstructure if the specimen is polished after deformation, the step-like appearance of the lamellae clearly indicates the transverse deformation. Thus, the areas of cementite deformation are apparent after polishing and the effect of deformed areas on spheroidization may be studied by the usual metallographic techniques. This note reports the result of a metallographic investigation which substantiates that spheroidization begins in the "stepped" areas. An AISI 1080 steel was normalized, re-austeni-tized at 1040°C, and isothermally transformed at 700 ± 4°C for 4 hr. Cubes, 5 mm to a side, were compressed between parallel plates to strains of 20, 40, and 50 pct. After deformation, specimens were heated to 600, 650, and 700°C; withdrawn at increasing time intervals and examined metallo-graphically for the percentage and distribution of spheroidite. The percentage of spheroidite was determined by lineal analysis. A micro structural region considered as spheroidized was one in which a lamellar skeleton was not distinguishable. Table I gives the times necessary for 95 pct spheroidization for each condition of strain and annealing temperature. Fig. 1 shows the microstructure of coarse pearlite compressed 20 pct, then polished and etched. Here the lamellae form a step by bending at two

Jan 1, 1959

By A. Eilers

Although the process to which I refer in this paper has been in successful operation for nearly five years, during which time it has been introduced, superseding all other processes having in view the same end, in almost every lead refinery in the country, no description of it, giving economical data, has ever appeared in print, nor has the process been known in its details to any considerable number of engineers beside those conducting it at their works. A discussion of this subject at the present time becomes especially interesting in view of a late publication in the Prussian ministerial organ for Mining and Metallurgy, by Dr. Wedding, in which the method of treating the zinc-silver-lead alloy by distillation, as finally settled upon at Tarnowitz, is very minutely and fully described. It is the more interesting, because in that article reference is made to the American method in an unfavorable light, while, at the same time, it is clear from the article itself, that the most important details of the process, besides the one that it is conducted in black-lead retorts, mere not at all understood. In publishing herewith the details of our American method, one of my objects is to invite comparisons between our simple and direct process and the elaborate one at Tarnowitz. In extracting the silver from work-lead by means of zinc, it is always the intention, in this country, to obtain a zinc-crust so rich in silver that the rich lead resulting from subsequent distillation

By C. E. Corson

The experiments of which the results and significance are set forth in this paper do not by any means cover the whole subject of the heat-treatment of the material referred to, yet they constitute a contribution to that general subject, rather than to the special department of' annealing. The material here considered is acid open-hearth steel, containing from 0.50 to 0.80 per cent. of carbon, with a nearly uniform percentage of other elements. This class of steel is rapidly increasing in commercial importance. It is even rumored that the rail-specifications of some railroads will hereafter require open-hearth steel. Yet this particular grade seems to

Jan 1, 1907

By G. M. T. Marshall

Plans to bring the Geco Mines property in Manitouwadge, Ont., into production began in 1954. At that time over 12 million tons of copper-zinc ore were indicated in a zone 2700 ft long. A concentrating plant was built to handle 3300 tpd of ore and a production shaft was sunk about 1500 ft. MINE LAYOUT Vertical attitude, width, rake, and competent country rock of a 4-million ton orebody west of the main diabase dike suggested a system of blasthole stopes, undercut with scram drifts connected by a transfer raise system to a crusher on the 1250-ft level and this system was employed. A 42-in. conveyor on this level transfers the ore about 1200 ft to a loading pocket at the No. 1 shaft. The system has a number of advantages: 1) Cost of tramming is eliminated. 2) Rate of extraction from any stope is controlled only by the scraping capacity of the scram. 3) Rate of extraction from the stoping area can be very rapid. Fast extraction makes it possible to cut mining costs for the following reasons: The number of stopes actively producing is kept to an economical minimum; the operating area is concentrated-manpower can be used more effectively; and active life of the stoping block is short, making ground support problems simpler and less costly.

Jan 8, 1959

By F. M. F. Cazin

Some twenty years ago the author of a book,* by which, for the first time, molecular action was made to account for nearly all phenomena in hydrodynamics, began his preface as follows: " It is contrary to all experience, that any branch of science should suddenly cut short its own line of reasoning, and drop all connection with its past, and yet as quickly re-establish itself on an entirely new basis. It is, therefore, not without justification that this book should be met with caution and even distrust." When the newly-discovered natural facts and laws presented in this paper were, in 1891, first laid before the officers of the American Institute of Mining Engineers, they might have been preceded by a preface to the same effect; and the expression would have found its justification by the actual experience these facts and laws met with. Since then, as the result of their publication in one of the most prominent

Jan 1, 1895

By J. H. Nead

The subject of this paper is one to which there are many references in the literature on the manufacture of steel in the open-hearth furnace, but few actual experimental data have been published. For that reason, the presentation of results obtained from two open-hearth heats where attempts were made to measure the sulfur absorption will be of considerable interest and value. The two heats on which the experiments were made were Armco ingot-iron heats and differ from the usual open-hearth heat of medium- or mild-carbon steel in that the refining is carried further; in this product the carbon and manganese are reduced practically to traces. In most other respects, and especially in respect to the absorption of sulfur from the producer gas, the two heats are typical of usual open-hearth practice. The object of the experiments made on the first Armco iron heat was to determine the fluctuation of the composition of the metal bath and the slag throughout the course of the heat, with especial reference to the variations in sulfur. It was hoped to determine whether there was an increase in sulfur in the bath from the producer gas and if so at what stage in the process the increase occurred. The experimental method consisted of charging analyzed scrap and pig iron, so that the sulfur in the charge could be calculated. Then, throughout the duration of the heat, metal and slag samples were takcn every half hour, beginning as soon as there was enough molten metal to take a sample. These samples were analyzed; the results are given in Table 1. All domestic scrap was used and the charge was made up as follows: Head End Finish Pounds Pound Pig iron........................ 36,300 Pig iron....................... 23,900 Sheet scrap bundles............. 36,200 Sheet bars..................... 23,900 Sheet bm..................... 40;200 The total charge, exclusive of the re-pig added near the end of the heat, was 160,500 Ib. The limestone charged was 21,400 Ib., or 13½ per cent.

Jan 1, 1924

NEW MEMBERS The following list comprises the names of those persons who became members during the period Apr. 10, 1916 to May 10, 1916. ALLEN, WILLIAM R.... Pres., Boston and Montana Development Co., Butte, Mont. BARKER, EDGAR EARL, Min. Engr. Mine Supt., Chile Exploration Co., Chuquicamata, Chile, S. Amer. BAYLESS, JOHN Z., Met. Engr Alaska Gastineau Min. Co., Thane, Alaska. BLACKWOOD, ARTHUR E., Mgr., Sullivan Machinery Co., 30 Church St., New York, N. Y. BREYER, FRANK G., Chief Testing Dept., The New Jersey Zinc Co., (of Pa.), Palmerton Pa. CARPENTER, JAY A., Mill Supt... . West End Cons. Mining Co., Tonopah, Nev. CORLESS, GEORGE BRADFORD, Geol., Missouri Bureau of Geology and Mines, Joplin, Mo.

Jan 6, 1916

[Abrahamson, Guy C., (5'43) 1st Lt., A.C., 0-880861, Base Weather Sta., Fairfeld-Suisun AAB, Suisun, Calif. Adam, Howard Wilbur, (S'46) 45 Eaton Ave., Woburn, Mass. Aguilar, Ruperto G., (S'43) Texas College of Mines, El Paso, Texas. Ainge, Ronald Farra, (S'43) Otago University, Dunedin, New Zealand. Albala, Américo, (S'44) Casilla 4106, Santiago, Chile. Albrecht, Theodore J„ (S'42) Pfc., Co. F, Syme Hall, Rm. 1, SCU 3421, ASTP, N. C. State College, Raleigh, N. C. Aldridge, E. E., Jr., (S'39) Box 58, Eagle Pass, Texas. Alfred, Robert M., (S'40) 25 South St., Brighton, Mass. Allan, Douglas H. W., (S'40) 460 Main St., E., Hamilton. Ont.. Canada.]

Jan 1, 1946

By John H. Schissler

INTRODUCTION AND SUMMARY Complex copper-lead-zinc ore is mined from underground workings high in the Western Cordillera of the Andes mountains about 100 km in a stralght line north of the city of Arequipa in southern Peru. The Madrigal mine is situated in a steep-walled canyon into which the six operating levels "daylight". Production is from cut-and-fill stopes currently producing approximately 740 dry metric tons per day. The Santa Rosa vein, the most important producer in the district, outcrops for a distance of about 4 km, bearing N 75º W and dipping about 70º NE. In places the vein splits into two or three branches; widths of each vary between 1 and 4 m and total mineralized widths of up to over 8 m occur. Principal ore minerals are chalcopyrite, galena and sphalerite. Ore reserve grades for the Madrigal mine average about 1.45% Cu, 2.6% Pb and 5.0% Zn, 2.9 ozAg per metric ton. [Compania] Minera del Madrigal is a California limited partnership; the general partner and operator is [Compania] Madrigal, a wholly-owned subsidiary of Homestake Mining Company. HISTORY Shallow workings found on the Santa Rosa vein were probably made by the Spaniards during colonial times in their search for

Jan 1, 1977

By Kenneth L. Clifford, Thomas G. White

Many changes have occurred in lead-zinc milling in the U.S. since the 1970 Lead and Zinc Symposium. New mills have been built, novel flowsheets devised, and the use of process control techniques is increasing. The Missouri concentrators produced in 1976 more lead and zinc concentrate than those in any other state. The Tennessee mills produced nearly as much zinc concentrate in 1976 as Missouri and with some very highly developed flowsheets. Progress in the Western U.S. is centered around new operations in Colorado and Utah. New mills in New York and Missouri incorporate many of the newer control concepts. Most of the older concentrators have undergone flowsheet changes to accomodate different ore types or because of the availability of new and better equipment.

Jan 1, 1977

By Gardner F. Williams

These mines are situated in Griqualand West, which is now a part of the Cape Colony. The town of Kimberley is in latitude 28o40' South, longitude 25o10' East, about 640 miles northeast of Cape Town and 450 miles from Port Elizabeth on the east coast. It is connected with these towns by a railroad, which has been completed during the present year. The mines are located in a desert country, resembling the desert portion of Arizona. The elevation above sea-level is about 4000 feet. The climate is exceedingly hot during the summer months. Diamond Deposits.—There are four large diamond-bearing deposits at Kimberley, all lying within a radius of one and one-half miles, having the De Beers mine as the center. These are named the " Kimberley," " De Beers," " Du Toit's Pan," and " Bultfontein " mines. There is, also, directly west of the Kimberley mine, a small deposit, called " St. Augustiue," which has been prospected only, and

Jan 1, 1887

By Oliver Ralston

DURING experimental study on the separation of a zinc concentrate from the heavy sulfide ores of Jerome, Ariz., a great deal of attention has been given to proper activation of the sphalerite content of the ore. The sphalerite at Jerome contains enough iron to class it as a marmatite, as picked specimens have only about 60 per cent. zinc, whereas pure zinc sulfide contains 67 per cent, zinc. This marmatite in large pieces is black in color, but in dry powdered state is brown. A flotation froth made from it has a silvery black luster in comparison with a brassy luster caused by chalcopyrite which occurs in the same ores. The sample used in most of the experiments described below consisted of about 3000 lb. of diamond-drill core from the zinc-bearing orebodies of the United Verde mine, and had the following analysis: PER CENT. PER CENT. Oz. PER TON Cu 0.695 A1203 0.83 Ag 1.30 Zn 6.17 S...:: 43.35 Au 0.02 Fe 36.23 CaO 0.46 Si02 9.27 Mineralogically, this analysis is calculated to the following, which is in agreement with the microscopic examination: PER CENT. PER CENT. Chalcopyrite 2.0 Schist 3.2 Marmatite 10.32 Quartz 8.2 Pyrite 73.0 Calcite 0.9 All samples were ground in a laboratory ball mill in order to leave about 3 per cent. on a 200-mesh sieve, fine grinding being essential to liberate the minerals in the ore. Most of the Jerome ores are so intimately crystallized that reasonably complete unlocking by grinding does not take place until 800 mesh is approached. Therefore, the 200-mesh grind adopted contains a considerable amount of locked mineral grains, but not so much as. to render impossible the preparation of commercial grades of concentrate:

Jan 1, 1929

By J. C. Mertz, C. H. Mathewson

Accurate knowledge of the solid solubilities of the elements that dissolve in the important base metals is needed for guidance in the preparation and heat-treatment of the alloys derived from these components. While there is still difference of opinion concerning the merits of the X-ray and microscopic methods of determining such solubilities, it is certainly true that the recent extensive use of X-ray diffraction to review the existing constitutional data has revealed many glaring inaccuracies and has brought about a much improved knowledge of phase-boundary locations, which will inevitably come to include all of the important alloy systems. When the work is done with all necessary precautions it appears that in the majority of cases where the solubilities extend beyond a few tenths of a per cent the X-ray back-reflection technique is capable of furnishing the best of information in this field. For the most prolonged and thorough studies it is obviously advisable to combine the results of several methods, in particular, to obtain an agreement between X-ray and microscopic data. This paper reviews the work previously done on the solubilities of phosphorus, arsenic, antimony and bismuth in copper and, in consideration of the uncertainties thus made apparent, presents new X-ray data obtained with the first three members of this group. Copper-phosphorus System Heyn and Baurl found that in slowly cooled alloys phosphorus forms a solid solution with copper up to about 0.175 per cent. Huntington

Jan 1, 1937

By Foster Fraas

MOST commercial electrostatic separators utilize the electrical property of conductivity, but although based on the same principles, they are constructed in a variety of forms, a common one being the simple roll type. Some information obtained during an investigation of that type of separator, and which indirectly is applicable to other types, is presented here. NUMERICAL RELATIONSHIP In Fig. I material discharged from hopper 6 is fed onto grounded rotating roll 2. Electrode 3 is at a high electrical potential with respect to roll 2, and any conductive particle in contact with roll 2 therefore acquires an electrical charge of such polarity that, when present in the electrical field, the force on it is in the direction of electrode 3. A detailed description of the charging by conductance as utilized in electrostatic separators may be found in a previous publication.1 As a result of this force, the path of the projected particle is changed in increasing amounts in the direction toward region C as the magnitude of the charge is increased. With the dividing edge 4 the projected particles may be divided into two fractions -those in region C designated as "deflected" or " deflectant " and those in region B designated as "residue." [ ] When material is passed over the roll only once, a complete separation is seldom obtained, therefore most commercial separators contain several roll-separator units in series, and some practical machines use as many as 12. In this paper a "pass" means the passage of material over a single-roll unit. The procedure is to repass either residue B with a low potential on electrode 3 or deflectant C with a high potential on 3. Most electrostatic separations follow a flowsheet of roughing and cleaning either the concentrate or the tailing, on both. In a specific instance, a dry, heated mixture of wet cleaned chromite and garnet from an

Jan 1, 1942

Book Notices CATALYSIS IN INDUSTRIAL CHEMISTRY. By G. G. Henderson. Lond. and N. Y., Longmans, Green and Co., 1919. 202 pp., cloth, 9 X 6 in., $3.25. This, the latest volume of the series of Monographs on Industrial Chemistry which is being published under the editorship of Sir Edward Thorpe, is intended to present broadly, our present knowledge of the phenomenon of which it treats. The hook reviews the existing literature on catalysis, paying particular attention to the many applications now used in industry. COMMERCIAL OILS-VEGETABLE AND ANIMAL. With special reference to Oriental Oils. By I. F. Laucks. 1st edition. N. Y., John Wiley and Sons, Inc.;, Lond. Chapman and Hall, Ltd., 1919. 138 pp., cloth, 8 X 5 in., $1.25. Intended to give to men in the oil trade, who have not had technical training, the technical data and information required in every-day dealings, in concise form. The various commercial oils are listed, together with their sources, uses, and phys-ical and chemical characteristics. The values have been collected from the standard texts, supplemented, particularly in regard to oriental oils, by the results obtained in the author's laboratory. FIFTY YEARS OF IRON AND STEEL. By Joseph G. Butler, Jr. Cleveland, The Penton Press, 1919. 145 pp., por., 10 X 6 in., leather. (Gift of author.) This volume is one of a special edition, of 100 copies, of an address delivered before the American Iron and Steel Institute in 1917, in which the author gives his personal reminiscences of the development in iron and steel making, as observed during an active participation in the industry in eastern Ohio, which began in 1857. To this are added some brief data on the early history of iron and steel, and a chapter on the activities of the American iron manufactures during the great war. The volume is profusely illustrated with portraits of men of note in the industry.

Jan 12, 1919