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NEW MEMBERS. The following list comprises the names of those persons who became members during the month of September, 1913: Members. ANDERSON, ANDREW P., Min. Engr 908 Story Bldg., Los Angeles, Cal. ANDROS, STEPHEN 0., Min. Engr University of Illinois, Urbana, Ill. BECKETT, PERCY G., Min. Engr Globe, Ariz. BLAIR, THOMAS S., JR., Prest. Blair Engrg. Co 343 S. Dearborn St., Chicago, Ill. BOYLE, HARRY, Min. Engr S07 Lowman Bldg., Seattle, Wash. BRADEN, EUGENE B., Vice-Prest., Selby Smelting & Lead Co., Merchants Exchange Bldg., San Francisco, Cal. CHALMERS, JOHN W., Min. and Elec. Engr., Morro Velho, Villa Nova de Lima, Honorio Becalho Minas Geraes, Brazil, So. America.

Jan 10, 1913

By Hugh Steele, Brower Dellinger

U. S. mining trends for 1956 continued steadily U+ S. uphill, technique and equipment advanced with the pull, and exploration and development of once mined districts attracted more attention than new areas. Expansion of the Ambrosia Lake district in New Mexico more than doubled known uranium ore reserves, and production began from several of the large new ore discoveries. In Canada the up trend was more spectacular, especially in exploration and development. To combat increasing problems arising from high labor costs, taxes, low grade orebodies, and dwindling discoveries, manufacturers and mining companies have continued to introduce new techniques and new products-reamer bits for enlarging small holes drilled by jacklegs, whup d'whups for drift mucking, Cryderman machines and over-the-head small crawler-type machines for shaft mucking, the 20-ton TL 220 four-wheeled tractor trailer unit for underground haulage, inertia-type dust collectors, roof bolting in conjunction with chain link fencing for wall support, wooden roof bolting using compression support of ground for wall support, and new one-use carbide bits.

Jan 2, 1957

The annual report f the Secretary of the Navy for the fiscal year, ending June 30, 1917, but including operations and recommendations up to Dec. 1 of that year, contains the following remark about the activities of the Naval Consulting Board. The members of the Institute who are members f this Board are William L. Saunders, Benjamin B. Thayer, Thomas A. Edison, Thomas Robins, Lawrence Addicks, Joseph W. Richards, W. R. Whitney, assisted by 47 other members f the Institute, in the capacity of associate members of the Naval Consulting Board. During the year, the work of this board, organized and approved by Congress in 1915, has increased very materially in importance and volume, its meetings have been frequent and the work of its individual members has been such in some cases as to occupy almost their entire time in the service of the Government. Some time before the active entry of this country into war the board called a special meeting to which were invited some 50 of the leading scientists and industrial managers, whose special study fitted them to advise on the methods of meeting the

Jan 2, 1918

By William Kelly, F. H. Armstrong

The object of this paper is to describe the electric equipment at the iron-ore mines of Penn Iron Mining Co., Vulcan, Mich. and of Republic Iron Co., Republic, Mich.; to give the results of tests; and to discuss the methods in use from an operating as well as from an efficiency standpoint. Electricity was introduced at the Penn mines for pumping, hoisting, and compressing air in the spring of 1907, upon the completion of a hydro-electric plant built by that company on the Menominee river about 4 miles from the mines. This plant was described in a paper1 presented before the Lake Superior Mining Institute. A paper2 presented at a meeting of the same Institute describes some of the operating features, and the safety devices of the electric hoist at the Curry shaft were briefly described in the Proceedings of the First Co-operative Safety Congress held under the auspices of the Association of Iron and Steel Electrical Engineers at Milwaukee, Wis., Sept. 30 to Oct. 5, 1912. Generating PoweR Plants After the success of electrical operation was assured, a second set of water wheels and generator was installed at the falls, for which provision had been made in the original design and in the construction of the foundations, and later three additional wires were added to the main transmission line, doubling its capacity and reducing the line loss. The general conditions of this installation are particularly favorable for hydro-electric operation. In the neighborhood of three-fourths of the power used is for mine pumping, which in the main is regular and continuous. For air compressing, power is used for about 18 hr. a day for five days, and 9 hr. for one day in the week, though occasionally when shaft sinking is going on a very small amount of compressed air may be

Jan 1, 1915

By John E. Lanning

During the last decade, since most smelters have included Cottrell plants as standard equipment for the removal of dust from furnace gases, it has become apparent that smeltermen have had a new problem slowly developing. This problem has manifested itself in accelerated destruction of, or serious injury to, the masonry of flues and chimneys. The masonry either spalls, if the material is of low strength, or acquires large major cracks, either of which conditions attains such proportions that renewals or reinforcing become necessary to maintain the structure in satisfactory condition. This paper describes the failure of a large modern brick chimney to such an extent that its safety was vitally impaired; the investigation of its condition; the methods of restoring satisfactory strength to the structure; and the installation of an acidproof lining. Plant History The Clarkdale smelter of the United Verde Copper Co., which was put in operation in 1915, was primarily a blast-furnace plant. The smelter at Jerome had utilized blast furnaces exclusively, and in the design of the new (1915) plant, blast-furnace smelting evidently was considered of major importance, the smelting equipment consisting of four blast furnaces 48 in. by 26 ft. 8 in. and three reverberatories, each 19 by 101 ft. The latter, supplemented by roasters, were intended mainly for handling dust and fine ore resulting from the crushing operations. The original roasting equipment consisted of six six-hearth Wedge roasters, six more being added in 1917. All gases from blast furnaces, reverberatories, roasters and converters were conducted by means of suitable flues and dust chambers to one central chimney. This chimney, 30 ft. inside diameter by 400 ft. high, is a self-supporting steel structure, lined with 4-in. brick supported on steel shelf angles, riveted to the shell, spaced about 15 ft. vertically. The bricks were of local manufacture, not particularly hard-burned, and were laid in ordinary cement-fireclay-sand mortar. No record is available to indicate that any particular effort was made to secure an acidproof mortar. The same materials were employed in the construction of the reverberatory and roaster flues, and the roaster dust chamber. Parenthetically, it may

Jan 1, 1934

By J. D. Price, W. M. Bertholf

In preparing a paper on coal washing in Colorado and New Mexico, it is difficult to refrain from entering into a discussion of the historical aspects of this subject, for the story of coal washing in these states goes hack well into the last century. This phase of the subject could well make a complete paper in itself, and of necessity this present discussion must be limited to current operations. Therefore, we are taking into consideration only those washing plants which have operated for some period during the years of 1947 and 1948. Summary Of the eight million tons of coal mined in the two states in 1947. ap- proximately two million tons were washed in wet washing plants, using concentrating tables or jigs. The one table plant accounted for 70 pct of the output of washed coal, and two large Baum jig plants accounted for an additional 26 pct, leaving only a small residual tonnage to be accounted for by other types of jigs The necessity for washing coal is occasioned by the desire or necessity of reducing the ash content of the coals— sulphur is not a problem in this area. All washeries, except the table plant, are at or near the tipple, hence wash only one kind of coal. At the table plant a large number of different coals are washed. Only at the table plant is there any occasion for drying any considerable quantity of fine coal— other plants size and/or dewater on shaking screens. The results of washing at the smaller plants are judged by the number (or lack) of complaints about the quality of the washed coal. This is probably as good a system as can he devised for small, intermittent operations. The efficiency of the Baum jig ap-pears to be quite high. This is to be expected as long as the automatic control of the refuse gate operates properly. The efficiency of the concentrating table is not as high as that of the Baum jig, especially when the "difficulty" of washing is taken into consideration. When dealing with coals in which the "bone" is larger than the "coal," the table appears to be at a definite disadvantage, because of its sizing action.

Jan 1, 1950

By Frederic Benard

RECOVERY of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.1 During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. EQUIPMENT Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and. arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 3-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 lb. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1938

Jan 1, 1933

By Frederic Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 166,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1943

By Frederic Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 166,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimonial lead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1943

By A. Josefsson

The transition temperatures of 0.01 to 0.02 pct carbon steels are shown to be strongly influenced by cooling rate in the a range, quenching from A, causing a very low transition temperature even after strain aging. In a titanium-stabilized steel and in a steel with 0.05 pct C this effect is absent. NORMAL mild structural steels usually show a structure of more or less pure ferrite, as a matrix, in which cementite grains or pearlite are embedded. Of these components, ferrite is by far the most interesting one as far as ductility and brittle (cleavage) fracture are concerned. Obviously, pear-lite and carbide are by no means necessary for a cleavage crack to nucleate and grow in the ferrite, as steels with a very low carbon content (Armco iron with 0.02 pct C) have an impact transition temperature just as high as semikilled steels with 0.26 pct C.1 Although it has been argued that a very embrittling effect is to be expected from cementite, precipitated as continuous films along the ferrite grain boundaries,'. " the micrographic evidence for a direct causal connection between the brittleness and these films does not seem to be very convincing. On the other hand, it has been stated that cementite particles in ferrite are able to stop ferrite cracks.4,5 In any case, the properties of the ferrite itself seem to be of overwhelming importance to the ductility of steels, justifying a thorough study of steels consisting of ferrite of different compositions, but principally free from pearlite, which means a carbon content below 0.02 pct. Such investigations have been carried out using the impact transition temperature as a criterion of the tendency to brittle fracture and have given some rather unexpected results. One result is the profound influence of carbon on the transition temperature of the steel in normalized condition. If the carbon content is reduced from 0.02 to 0.015 pct and below, a nearly discontinuous decrease in transition temperature appears even with high percentages of such elements as phosphorus and nitrogen present. This will be reported elsewhere." The present paper deals with another effect of carbon upon transition

Jan 1, 1955

By Robert Hoy

If the reader finds that the basic information in a commodity chapter is insufficient, he can consult the appropriate sources in this chapter to find more detailed or more up-to-date information. In these days, technology develops so rapidly that this 4th edition will be somewhat out of date even by the time it is distributed. A comparison of this edition with the 3rd edition (1960) of Industrial Minerals and Rocks will clearly demonstrate how rapidly the scene changes. One of the best sources of new information, of course, is attendance at technical meetings. For example, the papers presented at the national and sectional meetings of AIME usually discuss new developments in the respective divisions of the society. Frequently this information is available in Preprints. In addition some are printed in Mining Engineering and/or the Transactions of the Society of Mining Engineers of AIME. Furthermore, other professional and trade journals contain articles pertinent to the field. A journal introduced in 1967, Industrial Minerals, published by the Metal Bulletin, Ltd., London, is an excellent source of information. The Mining Journal, Ltd., also in London, publishes a weekly journal, a Mining Magazine (monthly), and a Mining Annual Re- view. The latter covers the field from three aspects: (1) by commodities, (2) through technical developments, and (3) geographically. Other useful magazines and periodicals include Engineering and Mining Journal, Pit and Quarry, Rock Products, and World Mining, all published in the United States. In addition many new books related to industrial minerals have been published since the 3rd edition of Industrial Minerals and Rocks. Most of these, of course, are included in the bibliography of each chapter in this volume. Another excellent information source is the proceedings of the Forum on Geology of Industrial Minerals. This group, which held its 11th annual meeting in 1975, is sponsored by a state geological survey or another mineral agency on a rotational basis. The proceedings have been published by the various sponsors and are available as indicated in Table 1. Two major sources of basic industrial mineral and rock data in the United States, and also a good source for many foreign countries, are the U.S. Geological Survey and the U.S. Bureau of Mines. The two agencies publish many reports and maps on a variety of geo- logical and mining subjects. In addition, each agency has an indexed list of all their publications with a free service announcing new publications. (New Publications of the Geological Survey, U.S. Geological Survey, Washington, D.C. 20242) and New Publications-Bureau of Mines, Publications Distribution Branch, U.S. Bureau of Mines, 4800 Forbes Ave., Pittsburgh, Pa. 15213). The U.S. Bureau of Mines (USBM) publishes annually Minerals Yearbooks which provide statistical data on mineral products including production, consumption, imports and exports, as well as information on new developments. Another very useful USBM series is called Mineral Facts and Problems. Editions were published in 1960, 1965, and 1970. Three other major series of publications by the Bureau are Information Circulars, Reports of Investigations, and Mineral Trade Notes. The latter is particularly good for news of foreign developments. A new Professional Paper No. 820 of the U.S. Geological Survey, 1973, summarizes data on the mineral resources of the entire country. The USGS, in cooperation with USBM, other Federal and various state agencies, has also prepared summary reports on mineral and water resources of given areas which include

Jan 1, 1975

By J. D. Wright

INTRODUCTION The Endako deposit was first explored in 1926, but development waited until the early nineteen sixties. It first came under the control of Placer Development in 1963, and early in 1964 a decision to bring it into production was reached. The deposit is located near the geographic center of British Columbia, and is served by an east-west communication system including a paved highway, mainline railway and good telephone, teletype, and computer facilities. The plant area is shown in Figure 1. The operation is known as the Endako Mines Division of Canex Placer Limited of Vancouver. First production was achieved in June, 1965, at a nominal rate of 10,000 tons per day, but it soon was closer to 15,000 tons per day. In 1967, two new grinding and flotation, sections brought capacity to the present rate of approximately 27,000 tons per day. With mill heads of around 0.15 percent MoS2, production is about 14,000,000 pounds of molybdenum per year. A flowsheet of the operation is given in Figure 2. A legend for this flowsheet is given in Table 1. Published ore reserves are estimated at 214,500,000 tons at an average grade of 0.143 percent MoS2. PRIMARY CRUSHING The 85 or 100-ton haulage trucks dump over a grizzly into a 42 inch x 65 inch C.A.C. (Canadian Allis Chalmers) gyratory crusher. The

Jan 1, 1976

By M. O. Holowaty, C. M. Squarcy

1750 to 1850: The scene shifts westward across the Alleghenys to the young town of Pittsburgh; charcoal gives way to mineral coal as furnaces grow larger and the blast is heated; above all, Pennsylvania iron is adding strength to the new Nation and building an empire in the West. TWO names are inseparably associated with the Pittsburgh iron industry-those of George Anschutz and John Hayden. The iron ore deposits of southeastern Pennsylvania were found and developed early in the 18th century, and several forges and furnaces were built and operated. It was only after the revolution that the iron men crossed the Susquehanna River, built furnaces in the neighborhood of ore deposits of Franklin County, then along the Juniata River and its valley. Juniata Iron found a ready market in the Pittsburgh area. However, difficulty in transporting it across the Allegheny Mountains induced iron mas¬ters to seek ore and plant locations in the Pittsburgh district. One of the first to reach this area was George Anschutz, who migrated to America in 1789 at the age of 36, reaching Pittsburgh in the fall of 1790. Anschutz immediately set out to organize an iron company in Pittsburgh, and was able to interest some residents in his project. After being informed of an iron ore deposit located only three miles out of town (on the site of the present 26th St. and the Allegheny River) he decided to build there his blast furnace and foundry plant. Total cost of the installation was $300. When the furnace was put in operation, Anschutz, now known as Red George, found that the ore deposit was only an insignificant one and would last no more than a few weeks. A new deposit was found on Roaring Run, in the southeastern corner of Armstrong County. Anschutz transported some of this ore to the mouth of Two Mile Run, where it was loaded on horse wagons and transported to the furnace. In this way, he operated off and on for several months, until the furnace was blown out in 1794. After working for a year as plant manager for John Probst at Langhorntown, he built the Hunting-

Jan 1, 1961

By C. E. Abbott

The Birmingham district, Alabama, is distinctive in the proximity to one another of its deposits of iron ore, coal and flux. These three basic requisites for the making of iron and steel are found within a radius of 10 miles. Both dolomite and limestone are produced, the former for blast-furnace flux and the latter for basic open-hearth operations. The Tennessee Coal, Iron and Railroad Co., a subsidiary of the United States Steel Corporation, operates a limestone mine at Muscoda, near Bessemer, 12 miles southwest of Birmingham, served by its own railroad transportation system. The mine has a capacity of 130 tons per hour. Average analyses of a recent month's production arc as follows: Fe²zO³ SiO² Al²O³ CaCO³ MgCO³ Lump, percent............................. 0.51 0.22 98.63 0.14 Crushed and washed, per cent,................ 0.70 0.26 98.36 0.18 Lump stone, 2 1/2 to 755 in., is used in open-hearth operations at Fairfield Steel Works. Fine crushed and washed stone, 1% to 0.063 in., is calcined at the lime-burning plant and used for lime charges at the Ensley open hearths. Geology The district's deposits of hematite ore occur in the Clinton formation, and the limestone beds mined are stratigraphically 330 ft. above the ore beds worked. A cross section on the center line of the mine is shown in Fig. 1. This limestone formation, 130 ft. thick, is in the Warsaw horizon of the Lower Mississippian. It lies above 100 ft. of Fort Payne chert, which is immediately above the Clinton formation, and is composcd of layers of chert and cherty limestone, approximately 50 per cent of the material being pure chert. The chert is extremely hard, and the cost of driving raises through it is very high. Both iron ore and limestone deposits lie on the southwest limb of the Jones Valley anticline, the formations dipping from 15' to 32' to the southeast. The iron-ore seam outcrops along the crest of Red Mountain, a ridge with northeast-southwest trend rising 200 to 300 ft. above Jones and Shades valleys at the

Jan 1, 1938

By C. E. Abbott

The Birmingham district, Alabama, is distinctive in the proximity to one another of its deposits of iron ore, coal and flux. These three basic requisites for the making of iron and steel are found within a radius of 10 miles. Both dolomite and limestone are produced, the former for blast-furnace flux and the latter for basic open-hearth operations. The Tennessee Coal, Iron and Railroad Co., a subsidiary of the United States Steel Corporation, operates a limestone mine at Muscoda, near Bessemer, 12 miles southwest of Birmingham, served by its own railroad transportation system. The mine has a capacity of 130 tons per hour. Average analyses of a recent month's production arc as follows: Fe²zO³ SiO² Al²O³ CaCO³ MgCO³ Lump, percent............................. 0.51 0.22 98.63 0.14 Crushed and washed, per cent,................ 0.70 0.26 98.36 0.18 Lump stone, 2 1/2 to 755 in., is used in open-hearth operations at Fairfield Steel Works. Fine crushed and washed stone, 1% to 0.063 in., is calcined at the lime-burning plant and used for lime charges at the Ensley open hearths. Geology The district's deposits of hematite ore occur in the Clinton formation, and the limestone beds mined are stratigraphically 330 ft. above the ore beds worked. A cross section on the center line of the mine is shown in Fig. 1. This limestone formation, 130 ft. thick, is in the Warsaw horizon of the Lower Mississippian. It lies above 100 ft. of Fort Payne chert, which is immediately above the Clinton formation, and is composcd of layers of chert and cherty limestone, approximately 50 per cent of the material being pure chert. The chert is extremely hard, and the cost of driving raises through it is very high. Both iron ore and limestone deposits lie on the southwest limb of the Jones Valley anticline, the formations dipping from 15' to 32' to the southeast. The iron-ore seam outcrops along the crest of Red Mountain, a ridge with northeast-southwest trend rising 200 to 300 ft. above Jones and Shades valleys at the

Jan 1, 1938

By Daniel Hanson

FoR most of their practical applications metals are required to withstand stresses of appreciable magnitude: indeed, it id because they possess the quality of resisting stress without becoming permanently deformed that they find such extensive use in the service of man. Metals and alloys must, in service, usually behave as elastic substances—or nearly so. It is not difficult to satisfy this condition at ordinary temperatures. Iron and its alloys, especially the steels, are at normal temperatures excellent elastic bodies, capable of satisfying most of the mechanical requirements of the engineer: where electrical, chemical or other properties are impor-tant, which cannot be met by steels, it is usually possible to find a non-ferrous alloy such as nickel, copper or aluminum, which will prove satisfactory. When the metals or alloys are not inherently sufficiently elastic, cold-working or heat-treatment may develop elastic properties to a sufficient extent for practical needs. By means of relatively simple, rapid tests we can measure such properties as elastic modulus, limit of proportionality and proof stress, upon which design can be based with confidence. The case of the soft metals, such as lead and tin, is well known to be exceptional. They possess no definite limit of elasticity, and the value of proof stress or tensile strength depends to a great extent on the speed with which the test is carried out. Design here must be based on other considerations than a well-established theory of the proportionality of stress and strain. It is now generally recognized that steels and non-ferrous alloys possess at temperatures not greatly exceeding that of the atmosphere, characteristics quite different from those existing at ordinary temperatures, and that they assume qualities similar to those of the soft metals. Not only have they no limit of elasticity, but the proof stress and the ultimate stress depend on the time of application of the load. Flow under load may persist for long periods of time, possibly indefinitely, and the determination of a true maximum stress becomes a matter of great difficulty.

Jan 1, 1939

By Daniel Hanson

FoR most of their practical applications metals are required to withstand stresses of appreciable magnitude: indeed, it id because they possess the quality of resisting stress without becoming permanently deformed that they find such extensive use in the service of man. Metals and alloys must, in service, usually behave as elastic substances—or nearly so. It is not difficult to satisfy this condition at ordinary temperatures. Iron and its alloys, especially the steels, are at normal temperatures excellent elastic bodies, capable of satisfying most of the mechanical requirements of the engineer: where electrical, chemical or other properties are impor-tant, which cannot be met by steels, it is usually possible to find a non-ferrous alloy such as nickel, copper or aluminum, which will prove satisfactory. When the metals or alloys are not inherently sufficiently elastic, cold-working or heat-treatment may develop elastic properties to a sufficient extent for practical needs. By means of relatively simple, rapid tests we can measure such properties as elastic modulus, limit of proportionality and proof stress, upon which design can be based with confidence. The case of the soft metals, such as lead and tin, is well known to be exceptional. They possess no definite limit of elasticity, and the value of proof stress or tensile strength depends to a great extent on the speed with which the test is carried out. Design here must be based on other considerations than a well-established theory of the proportionality of stress and strain. It is now generally recognized that steels and non-ferrous alloys possess at temperatures not greatly exceeding that of the atmosphere, characteristics quite different from those existing at ordinary temperatures, and that they assume qualities similar to those of the soft metals. Not only have they no limit of elasticity, but the proof stress and the ultimate stress depend on the time of application of the load. Flow under load may persist for long periods of time, possibly indefinitely, and the determination of a true maximum stress becomes a matter of great difficulty.

Jan 1, 1939

US 4,132,635 -In the froth flotation beneficiation of low- grade siliceous iron oxide ore, an aqueous pulp of undeslimed ore is conditioned first with a reagent formed by incorporating a water-soluble polyvalent metal salt into an aqueous solution of sodium silicate and then with oleic acid or other anionic collector and optionally pine 011 or other frother. The conditioned pulp is subjected to flotation to concentrate Iron oxide values in the froth D. C. Yang, assigned to Michigan Technological University Jan 2, 1979 7 pp (209-1 66) Filed 1-1 3-77 (759,094) Drawing below.) [ ] US 4,133,038-In the froth flotation beneficiation of copper sulfide ore or other ores, an aqueous suspension of a mineral sample of uniform grain size and composition is conditioned with a strongly adsorbable collector in an amount which is a fraction of the amount sufficient to create a monomolecular layer on the mineral grains, and the conditioning continued until the entire amount of collector is adsorbed The conditioned pulp is subjected to flotation, the floated particles separated at timed intervals, and the flotation rate coefficient determined. By varying the degree of adsorption in repeated treatments, the dependence of the flotation rate coefficient on the degree of adsorption may be determined A Nieml Jan 2, 1979 10 pp (364-502) Filed 12-7-77 (858,353) Priority Finland, 5-26-75 (75/1,525) Same: British 1,533,723, dated Nov 29, 1978 Same Canadian 1,065,066, dated Oct 23, 1979 US 4,133,746System and method for maintaining substantially steady state conditions in the froth flotation beneficiation of copper ore, molybdenum ore, or other metal ores The mass flow of flotation concentrate from the cell is monitored continuously, and the rate of admission of aeration air into the pulp in the cell is varied inversely with respect to variations in the mass flow control of rougher flotation cells is accomplished with a single valve G W Dopson, assigned to Magma Copper Co Jan 9, 1979 6 pp (209-1) Filed 11- 23-76 (744,306

Jan 1, 1980

By F. Benard

Recovery of selenium and tellurium at Copper Cliff by the Ontario Refining Co. has been previously described by the writer.l During 1935 a new building was erected to house this operation and description of the new plant and process form the subject of this paper. The building, of modern steel and tile construction, covers an area of 5900 sq. ft. with a volume of approximately 165,000 cu. ft. The large monitored center bay is flanked by two smaller outside bays, one of which is devoted to the tellurium section. All equipment, ceilings and upper walls, are treated with aluminum paint, giving good illumination and facilitating good housekeeping, essential from a health standpoint in handling material of this nature. Equipment Layout and type of equipment conforms to the requirements of the process as described below. In the selenium section, storage tanks, neutralizing tanks and precipitators are of steel construction, lead-lined and arranged for gravity flow (Fig. 1). The neutralizing tanks are equipped with water-cooled lead coils for controlling solution temperature, agitation being accomplished with compressed air. The precipitators are provided with mechanical agitators, and sulphur dioxide is introduced into the solution through 1/2-in. lead pipes leading from a manifold attached to the cover of the precipitator. Each precipitator has internal cooling coils and an air-jet exhauster to carry off fumes. Neutralized solutions are filtered in a 29-plate wooden filter press using heavy cotton duck as a filter medium, forced feed being maintained by a Welmet centrifugal pump. Dilute solutions are concentrated by evaporation in a vacuum evaporator, constructed of cast hard lead. Heat is supplied by an outside steam chest operating under 15 Ib. steam pressure. The solution is circulated through the steam chest by a pump of antimoniallead at a rate approximating 400 cu. ft. per min. The evaporator is evacuated by a water-jet condenser that creates a vacuum of 26 in. of mercury under normal operating conditions. The capacity of the vessel is 60 cu. ft. and the rate of evaporation 25 cu. ft. per hour.

Jan 1, 1944