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Jan 1, 1938

By R. D. MacDonald

The search for metalliferrous deposits in the Labrador-Ungava Trough of Canada dates from 1929 when non-ferrous minerals were the main quest of prospectors in this area. Many gossans, resulting from the oxidation of sulfides, were located and examined but none of these led to any orebodies of commercial value. However, such investigations did much to arouse interest in this area and fostered further mapping and prospecting. Since this early period in the history of prospecting in the Trough, the presence of iron ore deposits and potential iron producing sites has commanded the center of attention of exploration personnel. The iron-bearing rocks of southwestern Labrador have in recent years come into prominence as possible sources of iron ore of the beneficiation type. Exploration and development work has been carried on in concession areas granted by the Newfoundland Government to the Labrador Mining and Exploration Co. Ltd. and to the Newfoundland and Labrador Corp. In the course of evaluating its holdings in the Wabush Lake area (Fig. l), Labrador Mining and Exploration Co. has conducted geological, geophysical and diamond drilling programs.

Jan 10, 1960

Conquista, the uranium mining and milling complex owned jointly by Continental Oil Co. and Pioneer Nuclear, Inc., has begun operations in Falls City, Texas. The mill has been designed to produce 1.5 million lb of U3O, from 600,000 tpy of ore mined. Currently, the plant processes a maximum 2000 tpd of ore. Mine Planning Texas ore deposits are small and scattered in comparison to other uranium mining districts. Those to be mined at Conquista range from a few acres to more than 100 acres in size. Ore thickness ranges from a few inches to over 15 ft, and depth from less than 20 ft to more than 170 ft below ground surface. Distance from the mill ranges up to 35 mi.

Jan 8, 1972

By A. P. Young, L. I. Marsh

HE relationship between microstructure and *- fracture is of interest in many metals and alloys. This relationship is sometimes established by examining the fracture surfaces and the flat surfaces near the fracture path in tensile samples. However, it is often difficult to tell from examining the fractured sample whether the fracture is intergranular, intra-granular, or a mixture of both. Also, it is often of interest to follow the progress of slip, twinning, or crack formation along the fracture path before fracture occurs. The ambiguity concerning the type of fracture generally can be resolved if the area along the path of ultimate fracture can be photographed at inter-

Jan 1, 1959

By D. L. King

The San Francisco Chemical Co. has been actively interested in phosphate mining since 1908. It was, in fact, the first company to make claims on properties in the western phosphate belt. From the period of 1908 to 1947, the company's phosphate operations were centered at their Waterloo property, five miles east of Montpelier, Idaho. A small tonnage of phosphate rock was shipped annually from their underground mines in that area. In 1945, the company started the first western open-pit phosphate mine on the slopes of Waterloo Hill. In 1947, they obtained an option and lease on the Beckwith Hills' deposits in southwestern Wyoming, some 25 miles south of Cokeville. While the operations at Montpelier and the Beckwith Hills are both open pit, there are many differences which suggest separate treatment in this paper. Structurally, the Waterloo Hill is the west slope of an anticline. The beddings dip from 20" to 35" to the west. Erosion has caused the footwall exposures (Well's formation) to appear in the upper areas as a series of apices, giving the outcrops a festooned arrangement. Dip faulting with subsequent erosion has induced gullies normal to the strike and resulted in eroded areas which separate the remnants of the

Jan 1, 1950

By A. H. Tousley, L. H. Gee

Until comparatively recently, the gypsum industry has been slow to change, often clinging to old processing methods developed a generation ago. Now, however, a highly competitive market has forced gypsum companies to concentrate on devising methods to reduce material and operating costs and improve product quality. In one such effort, Kaiser Engineers recently designed and constructed two modern gypsum plants for Kaiser Gypsum Co., Inc., incorporating centralized control, automatic sequence starting, mill amperage control of the roller milling systems, automatic calcining in kettles, and rapid mechanical stucco cooling. Fig. 1 shows the control panel for the calcining departments at wallboard plants located in Jacksonville, Fla., and Delanco, N. J. In each instance the calcining department (commonly known as the "mill") sets the basis for the quality control for the entire gypsum plant.

Jan 12, 1966

International Trade in Metals. By J W FURIES AND E W PEHRSON (Man &Met, Oct 474 to 477 900 words) Five world charts are presented in this article showing the production, consumption and principal trade relations of bauxite, aluminum, iron ore, pig iron and the platinum group metals in 1932 They are part of an original study conducted by the U S Bureau of Mines covering 15 of the principal metals and metallic ores Text accompanying the charts indicates the broad features of the respective industries in 1932 and the major changes that have occurred since 1932

Jan 1, 1937

By Hans Lundberq

IINDUSTRY'S attention is now focused on the production of munitions thereby creating a demand for certain minerals which in prewar days were produced only in limited quantities. Now production of these minerals must he increased from the known deposits and new deposits must be found. Can geophysics help? "War minerals" such as tin, vanadium, tungsten, antimony, manganese, chromium, and cinnabar have no physical characteristics sufficiently different front the country rook to permit their direct location by ordinary geophysical methods. As already demonstrated in work on gold and oil, useful information may be obtained indirectly, however, outlining structural features or geological conditions favorable for the deposition of such ores or the accumulation of oil. Recently, more direct and truly qualitative methods have been brought into a useful and practical stage, and by the combined application of old and new methods a technique has been developed which, it is hoped, will be of importance in the search for these vital minerals.

Jan 1, 1941

By John Birkinbine

FOR two years past the Warwick Furnace, at Pottstown, Pa., has attracted attention by the remarkable work done in it, and a statement giving details of its operation and the unexpectedly short blast of 1880 will be acceptable to every member who studies blast-furnace practice. There are so many interesting features in con¬nection with this blast, and so much to be learned from investigating it, that the results of a thorough examination are offered to the Institute sans theories. In collecting the information, the courtesy of the various officers of the Warwick Iron Company was of material advantage, every facility for investigation being extended and an inspection of records being kindly permitted. In the following description these authoritative data are given in full where practicable, without making the paper too prolix, and the

Jan 1, 1881

By E. Morgan Massey

Located in virgin coal acreage near Gilbert, W. Va., Massey Coal Mining Co.'s Ben Creek No. 2 mine afforded the company's engineers the opportunity of designing and laying out the entire mining operation from the mine faces to the railroading loading site. However, the topography of this region posed difficult problems in haulage of coal for, in this extremely rugged terrain the uppermost coal seams lay in the mountain-top ridges, approximately 1400 ft above the valley floor. The decision for mining equipment naturally leaned to the new high-capacity continuous miners where seam conditions permitted: otherwise, to the new super-high capacity conventional cutting and loading machines. Since the coal seams lay in ridges and points of considerable outcropping, the decision was to keep the transportation on the surface and mine the coal with multiple entries into the outcrop. This way, the major problems of underground haulage, drainage, and ventilation are eliminated, and the opportunity to take advantage of a-c underground power becomes a much simpler proposition.

Jan 10, 1960

Surface mining of coal is widely condemned as a despoiler of the countryside and wastrel of land and natural resources. Yet the fact has been as widely ignored that the ingenuity of those engaged in developing the methods and equipment utilized in surface mining have made several hundred million tons of coal available for utilities and industry which could never have been mined by any other method. While doing this, the surface mining companies have recovered nearly 100% of the coal in the mining area instead of approximately 50% as is common in underground methods. Efficiency has been increasing constantly, thereby maintaining low cost to the customer. Mining has provided economic health in many areas by virtue of the direct payrolls and by the attraction of other industries to enjoy low cost, dependable fuel supplies. Surface mining of coal generally falls into two categories: contour mining, which is the result of mining in hilly or mountainous terrain where the hillside or slope limits the width of the area which can be surface mined; and area mining, which results from the surface of the land being approximately parallel with the coal seam so that a wide area may be mined in a succession of pits or open cuts.

Jan 10, 1972

The banquet Wednesday evening was attended by about 700. The list of speakers was unusually brilliant and each one proved to be so interesting that it was nearly midnight before the dancing began. Capt. Robert W. Hunt was toastmaster. Captain Hunt is about to celebrate his eighty-first birthday but is blest with unusual vigor and it was a great pleasure to all his friends to honor him at this time. His selection is toastmaster was a happy one. The guest of the evening, if among so many stars one could be selected from the rest, was Charles M. Schwab, who said nothing but the urgent telegram from his dear old friend, Captain Hunt, could have drawn him away from his seclusion on his Pennsylvania farm to attend the meeting in Chicago. Mr. Schwab's address was, as usual, scintillating with wit and humor; and while lie did not directly or indirectly allude to the steel strike lie did at the end of his talk discuss serious things and gave it as his opinion that any effort to legislate or control the high cost of living would be futile until this country got down to a basis of an honest day's work for an honest day's wage.

Jan 11, 1919

NAME AND OBJECT. SEc. 1. This Institute is incorporated under the Membership Corporations law of the State of New York ; its corporate name is American Institute of Mining Engineers; and its objects are such as are stated in its Certificate of Incorporation. ARTICLE II. MEMBERS. SEC. 1. The membership of the Institute shall comprise four classes, namely 1. Members ; 2. Honorary Members ; 3. Associates ; 4. Junior Members. All members shall be equally entitled to the privileges of membership, except¬ing that Honorary Members, Junior Members, and Members and Associates whose residences shall be outside of the United States, Mexico, and Canada shall not be entitled to vote. Members and Associates residing within the United States of America, Mexico, and Canada, and not in arrears for dues, shall be entitled to vote in person at the meetings of the Institute, or, as hereinafter provided for, by letter ballot. SEC. 2. The following classes of persons shall be eligible for membership in the Institute, namely : as Members, all professional mining . engineers, geologists, metallurgists, or chemists, and all persons actively engaged in mining and metal¬lurgical engineering, geology, or chemistry ; as Associates, all persons desirous of being connected with the Institute who in the opinion of the Board of Directors are suitable.

Jan 1, 1923

By F. A. Schaufelberger

METAL can be recovered from a leach solution either indirectly by precipitation as a compound that is later reduced or directly by electrolysis, cementation, or chemical reduction, for example, with hydrogen. The widely used electrowinning processes suffer from the inefficiency of converting fuel to low voltage dc and from low current efficiency when complete recovery is attempted. With the batch hydrogen reduction methods outlined here, a unit of fuel converted to hydrogen in modern gas reform plants will make two to three times as much metal as can be obtained with electrolysis. With continuous hydrogen reduction, four to six times as much metal is obtained. Precipitation by reducing a metal salt solution with H, has been known for almost 100 years.' Commercial use of the process, however, awaited the research and development program initiated by Chemical Construction Corp. Within the last few years this program has brought about construction of commercial plants, listed on page 545. Ideal hydrogen reduction will precipitate a pure metal from a solution obtained by commercial leaching methods at a rapid rate without excessive temperatures and pressures. The metal precipitate will be of desired size and density, less than a percent left in the vessel being deposited on the wetted parts. The present discussion will outline Chemical Construction Corp.'s early development program and will discuss the chemistry and mechanics of reducing copper, nickel, cobalt, and cadmium from solution by H2. Work on selective reduction of nickel from cobalt has been described earlier.' The article is not concerned with precipitation of copper by disproportionation of cuprous solutions where yield is limited3 to 50 pet.* It does not discuss use of gaseous reducing agents other than hydrogen, such as SO2,4 which may lead to contamination with sulfur, or C0,5 which is considerably more expensive than hydrogen and produces a gaseous reaction product, CO2.† The article does not include use of other nongaseous reducing agents,7 which are far more expensive than CO. Also, notes on the history, engineering design, and performance of commercial plants have been given elsewhere.' It will be shown that a pure metal can be precipitated by reduction with hydrogen from solutions obtained by commercial leaching methods when the solution composition is controlled and proper acidity, proper metal ion concentration through controlled complex formation and hydrolysis, and adequate agitation for suspension of metal and for transfer of reducing gas are maintained. Reasonable temperatures and pressures are used which are less excessive than those used by previous workers, although they are maintained at above equilibrium values because of process kinetics.' It has also been found necessary to induce nuclea-tion and to control growth and agglomeration in order to get a powder product of suitable physical properties. Review of the Literature Muller, Schlecht, and Schubardt of I. G. Farben10 claimed a successive reduction of silver, copper, nickel, cobalt, and zinc from ammoniacal solution by applying progressively higher temperatures and hydrogen pressures. Metals produced by this technique were not pure, since no attempt was made to adjust the solution composition between the different reductions. It is doubtful that the zinc product contained any metallic zinc. The major contribution to the literature" was made by the Ipatiews,12 who prepared platinum, iridium, copper, nickel, cobalt, lead, tin, arsenic, antimony, and bismuth at often extreme conditions, up to the critical temperature of water (373ºC), at 1500 to 7500 psi, for as long as several days. Even cadmium and zinc were claimed to have been observed in trace quantities precipitated together with basic salts. In the early experiments solutions were not stirred. Extensive formation of oxides and basic salts occurred, probably long before sufficient hydrogen could be supplied in the unstirred liquid to decrease the metal concentration in solution by reduction. The importance of hydrogen pressure was

Jan 1, 1957

By Stuart S. Forbes

Changes and additions made to the Canadian Copper Refiners Ltd. electrolytic refinery between 1949 and 1955 are reviewed. The effect of high current density on current efficiency and section work is discussed. OPERATING and physical changes which have been made to the electrolytic tank house of Canadian Copper Refiners Ltd. suggest a review of present conditions. Previous papers1 a have described the general arrangement. Since then, expansion, closer anode spacing, and higher current densities have increased annual cathode capacity from 112,000 to 182,000 tons. A recent extension to the tank house, begun in the spring of 1954 and completed in August 1955, was undertaken to handle the monthly production of about 3,000 tons of anodes from Gasp6 Copper Mines. The anticipation of these additional receipts and large stocks of unrefined copper caused by the increase in custom smelting at Noranda made it necessary to increase production without immediately available additional cell capacity. Accordingly, from December 1954 through March 1955, the tank house was operated successfully at a current density of 24.0 amp per sq ft. Again, as of September 1955, one of the two tank house circuits is being operated at this high density. Although other refineries may operate at current densities higher than 24 amp per sq ft, none is doing so with anodes which contain silver and gold content as high as those being refined at Canadian Copper Refiners Ltd. General Arrangement The original building consisted of two parallel bays, each 660 ft long and 60 ft wide, with a 24 ft pump bay extending along the west side of the building. A previous expansion, completed in 1939, was to the west of the original building and consisted of two 60 ft parallel bays 240 ft long. The length of these two bays was extended in 1954 to 540 ft, adding one stripper and 12 commercial sections to No. 2 electrical circuit. Space is still available for an additional six commercial sections and one stripper section. Construction on these seven sections started in September 1955, and will be completed early in 1956. The tank house capacity will then be 206,000 tons of cathodes per year. In the two tank houses there is a total of 900 cells distributed as follows—commercial, 468; stripper, 36; total, 504 in the No. 1 tank house (No. 1 circuit): commercial, 360; stripper, 36; total, 396 in the No. 2 tank house (No. 2 circuit). Section arrangement consists of nine cells to a tier and two tiers or 18 cells to a section. Anodes, weighing 620 lb each, are cast with a Baltimore groove and are refined by the multiple system. Solution enters each cell through a bottom inlet at one end and overflows at the top of the opposite end. Rate of solution flow through the cells is controlled by valves at each section to 4.5 gpm. Electrical power to the tank house is now provided by nine 675 kw motor generator sets. Each set consists of a 135-12 v 5000 amp dc generator, driven by a 980 hp 2300 v synchronous motor. When No. 1 circuit is operated at 22,000 amp, five sets, at 4400 amp each, are connected in parallel. As the maximum allowable current on No. 2 electrical circuit has recently been set at 18,000 amp, only four sets are connected in parallel on No. 2 circuit. A tenth set, now being installed, will be reserved as a spare, for use in either circuit as required. Recent Changes In 1949, the annual capacity of the tank house was increased from 112,000 to 132,000 tons by closing the

Jan 1, 1957

By R. W. Armstrong, P. C. Jindal

TABOR1 has indicated for a number of polycrystal-line materials that their hardness should be directly related to their yield strength. For a material showing zero work-hardening, the Meyer hardness, MH, may be calculated in terms of the yield stress, sy, by utilizing slip line theory and the result is: The Meyer hardness corresponds to indenting the surface with a spherical indenter and specifying the ratio of load and projected area of the indentation. The correlation indicated by Eq. [I] is not well-established. It has been verified to some degree by performing hardness tests on materials strained to the maximum nominal stress and taking this stress as the (new) yield stress of a nonwork-hardening material. The dependence of hardness on yield strength for an annealed material capable of showing work-hardening has not been theoretically evaluated but, presumably, the hardness should be greater than that specified above. Marcinkowski, Fisher, and szirmae2 measured the dependence of the Vickers Diamond Pyramid hardness, H,, on yield strength for an annealed Fe-Cr alloy which shows work-hardening and found:

Jan 1, 1968

By W. P. Blake

The mining district and the town of Tombstone are situated in Cochise County, Arizona Territory, at the northwest end of the Mule Pass range of mountains, in longitude 110°, and latitude about 31 40' N,, upon the right bank of the San Pedro River, from which the town is distant 9 miles east.. It is also 24 miles south of Benson station on the Southern Pacific Railroad of Arizona, and about 40 miles north of the Mexican line. Its altitude above the sen is 4600 feet. The Dragoon Mountains rise across a valley to the northeast, and the Huachuca Range similarly upon the southwest. The country is open, without timber, and the surface, where the mines are opened, is in general gently rolling, and accessible to wagons by. natural roads. The first locations were made in the pear 1878 by the Scheffelin brothers and Richard Gird, the latter being well known among the pioneers of Arizona as a surveyor and miner, who contributed largely to our knowledge of the geography of the Territory in early days,

Jan 1, 1882

By William Fink

MANY investigators have attempted to determine the true nature of the internal changes taking place during aging. Merica, Waltenberg and Scott1 were the first to propose a theory of age-hardening. They attributed the age-hardening of duralumin to the precipitation of minute particles of the compound CuA12. Later Zay Jeffries and R. S. Archer2 augmented the above theory by suggesting that the small CuA12 particles acted as "keys" causing "slip interference." Many other investi-gators3 have devoted much time to the mechanism of age-hardening, some corroborating the "precipitation" and "slip interference" theory, others coming to different conclusions because of effects that to them seemed unexplainable by the early theories; e.g., the increase of electrical resistance upon aging, the fact that no change in lattice parameter could be detected during the early stages of aging even at elevated tempera-tures, and the fact that the density did not change as would be predicted. In 1932, Merica revised4 his earlier precipitation theory to take care of these presumably anomalous effects. This revised theory, the "knot" theory, assumes that substantial age-hardening occurs before actual precipitation of solute as discrete particles. The assumed mechanism is one of diffusion of solute atones into groups forming distorted regions which act as "hard" spots and cause slip interference. These "knots" are assumed to have approximately the same lattice arrangement as the solvent.

Jan 1, 1936

By J. J. Egan

ADVANCES in the production of quality steel have emphasized the need for greater knowledge of the amount and distribution of oxygen in the steel. Control of inclusion content and quality is largely dependent on such knowledge. While many analytical methods have been de-vised for the accomplishment of this end, few are without serious limita-tions in accuracy, convenience, or skill required in application. Usually at least two methods are necessary to determine total oxygen and constituent oxides. Because of the great importance of this problem and the specific interest in the application of such methods of analysis, the various procedures were carefully reviewed at the Union Carbide and Carbon Research Laboratories, with the view of developing a method free from the limitations mentioned above. Intensive experimentation finally led to an improved iodine extraction analysis described by Cunningham and Price. I After this had been thoroughly checked from the standpoint of the analytical chemist, it was rechecked from that of the metallurgist. This involved preparation of a number of small heats of varying composition with determination of total oxygen in the molten metal by the alumina method2 and an analysis of the solidified material without the aluminum addition by means of iodine extraction; the oxides of iron, manganese, silicon and aluminum also being determined by the iodine analysis. The report of this work constitutes the subject of this paper.

Jan 1, 1933

By Ihor A. Kunasz

Lithium minerals occur predominantly in pegmatites which contain mineral assemblages derived from the crystallization of postmagmatic fluids or from the metasomatic action by residual pegmatitic fluids. They have been the traditional sources of raw materials for ceramic and chemical industries. However, with the discovery of Searles Lake, brines became new sources of lithium. Indeed, the 1960s may well be referred to as the "brine decade" because several brine bodies of significant economic importance were discovered. In the United States, the brines of Clayton Valley, Nevada, presently exploited by Foote Mineral Co., and the Great Salt Lake of Utah, to be exploited by the Great Salt Lake Chemicals Corp., have been defined as major sources of lithium. Also a lithium-bearing brine has been discovered in Chile. Following the termination of the AEC purchase program in 1959, several companies such as Maywood Chemical Co., American Lithium Chemicals, and Quebec Lithium Corp. were forced to close down their operations. Nevertheless, with the development of new applications in glass ceramics, air conditioning systems, synthetic rubber, and metallurgy (aluminum potlines), the lithium industry grew steadily, and with the potential application of lithium metal in batteries and nuclear reactors, a healthy growth can be foreseen. New products and new applications are likely to stimulate exploration for expanded reserves as well as the search for new sources from which lithium could be extracted economically. Geochemistry of Lithium Lithium is the third element in the periodic table. It is the lightest of all the metals, having an atomic weight of 6.938. Its ionic radius is 0.60A and its charge is + 1. The geochemistry of lithium has been extensively studied and has been summarized by Rankama and Sahama (1950), Goldschmidt (1937), and Hortsman (1957). The distribution of lithium in igneous rocks is controlled by its size and its charge, and by the (MgO+FeO)/Li2O ratio. In the early stages of crystallization of a magma, that ratio is very large. Consequently, both magnesium and iron are removed by ferromagnesian minerals in preference to lithium which is then concentrated in the residual magma. This results in an enrichment of lithium in silicic rocks and pegmatites (Strock, 1936). Pegmatites are coarse-grained igneous rocks formed by the crystallization of postmagmatic fluids. Minerals within pegmatites may also form by metasomatism (Jahns. 1955). Genetically, the pegmatites are associated kith neigh- boring intrusives. Mineralogically, granitic pegmatites contain feldspar, quartz, and mica as the main constituents and a variety of exotic elements such as lithium, beryllium, tantalum, tin, and cesium, which may or may not occur in economically significant concentrations. Detailed studies by numerous investigators (Cameron et al., 1949, 1954; Hanley et al., 1950; Jahns, 1953, 1955; Page et al., 1953) indicate that pegmatites often exhibit an internal zonal arrangement, with each zone containing a specific suite of minerals. The lithium minerals are usually found in the intermediate zones, and although as many as 13 zones have been recognized by Cameron, a complete zonal arrangement is rarely found. Zoning of pegmatite bodies has also been observed on a regional basis. The regionally zoned pegmatite sequences exhibit mineral assemblages and complexity according to their respective distance from the granitic bodies to which they are genetically related (Mulligan, 1965). Lithium is also found in small proportions in a variety of rocks. The average lithium

Jan 1, 1975