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By D. J. McAdam

Results of investigation of corrosion-fatigue of metals at the U. S. Naval Engineering Experiment Station have been presented by the author in four papers.1, 2, 3, 4 In those papers references were given to the work of Haigh in 1917.5 The investigation at Annapolis included a variety of ferrous and non-ferrous alloys. The experiments showed that even slight corrosion simultaneous with fatigue may cause failure at stresses far below the ordinary endurance limit. The experiments also showed that, for most metals, severe stressless corrosion prior to fatigue is much less damaging than even slight corrosion simultaneous with fatigue. The term "corrosion-fatigue" was restricted to mean the simultaneous action of corrosion and fatigue. The combined effect of corrosion followed by fatigue was called "prior-corrosion fatigue." A stress-cycle graph representing corrosion-fatigue is a curve approaching a horizontal asymptote, the ordinate of which may be called a "corrosion-fatigue limit." To avoid confusion in later discussion, the term "endurance limit" will be restricted to mean the fatigue limit obtained by tests in air with specimens as free as possible from stress concentration and from corrosion. The cndursnce limit as thus obtained presumably represents an inherent property of the metal.

Jan 1, 1929

By D. J. McAdam

Results of investigation of corrosion-fatigue of metals at the U. S. Naval Engineering Experiment Station have been presented by the author in four papers.1, 2, 3, 4 In those papers references were given to the work of Haigh in 1917.5 The investigation at Annapolis included a variety of ferrous and non-ferrous alloys. The experiments showed that even slight corrosion simultaneous with fatigue may cause failure at stresses far below the ordinary endurance limit. The experiments also showed that, for most metals, severe stressless corrosion prior to fatigue is much less damaging than even slight corrosion simultaneous with fatigue. The term "corrosion-fatigue" was restricted to mean the simultaneous action of corrosion and fatigue. The combined effect of corrosion followed by fatigue was called "prior-corrosion fatigue." A stress-cycle graph representing corrosion-fatigue is a curve approaching a horizontal asymptote, the ordinate of which may be called a "corrosion-fatigue limit." To avoid confusion in later discussion, the term "endurance limit" will be restricted to mean the fatigue limit obtained by tests in air with specimens as free as possible from stress concentration and from corrosion. The cndursnce limit as thus obtained presumably represents an inherent property of the metal.

Jan 1, 1929

By R. L. Doan

WHEN the Plutonium Project was started in the spring of 1942 there was no technology to produce uranium metal of the required purity. Not only was there no such metal available; no one knew how to make it or fabricate it after it was made. Since this time vast technical effort has been ex-pended in the atomic energy field. A short 15 years later the metallurgy of uranium is probably better known than that of any other metal, with the possible exception of steel. At the beginning of the 1942 drive to obtain pure uranium metal the most available raw material was black uranium oxide (U3O8) of about 92 pct purity from the Great Bear Lake region of Canada. It took only three months for the project chemists to develop a process for bringing the purity of this oxide up to 99+ pct and another three months for Mallinckrodt Chemical Co. of St. Louis to build the purification plant and get it into operation. In early summer of 1942 the purified brown oxide (UO2) started moving to the Metal Hydrides Co. in Beverly, Mass., and to the Westinghouse Research Laboratory in Bloomfield, N. J., both of which had been granted Government contracts to try to make pure uranium metal.

Jan 9, 1957

By R. E. Lund

Josephtown Smelter employs the St. Joe-developed electrothermic process for producing zinc metal and zinc oxide. The process uses resistance-type electric furnaces. Flow of current through the sintered ore and coke charge develops the energy required for smelting at the reaction sites. To produce zinc metal, the furnace off-Gases bubble through a large "U"-tube filled with molten zinc which condenses the zinc to liquid; the metal is then mechanically cast into slabs. To produce zinc oxide, the furnace vapors burn in air and the resultant powders are collected. The smelter comprises three distinct circuits. One circuit produces American Process zinc oxide and high grade metal; another circuit produces tailor-made alloys of controlled lead and cadmium content; the third circuit produces prime western zinc metal and feedstock which is refined into special High grade metal and French Process zinc oxide. The roasting circuit utilizes multiple-hearth furnaces for deleading the zinc concentrates; fluid bed and suspension roasters are employed for desulfurization. Sintering produces a hard, porous furnace feed. The flexible smelting process is adaptable to consuming various kinds of secondary material. Extensive residue treatment accomplishes high overall zinc recovery. Smelter by-products include sulfuric acid, cadmium, and mercury.

Jan 1, 1970

By Ronald F. Ayers

The basic research for this study was conducted by Battelle's Columbus Laboratories in 1974. The high-sulfur content of coal threatens to erode its competitive position in the future. The impact of sulfur removal on final costs of eastern interior coal lies at the very heart of this market analysis. An extensive market survey was conducted that considered both traditional coal markets as well as anticipated future markets. Competition for coal from this province considers low-sulfur Western coal, nu- clear power, international oil and coal trade, as well as Appalachian coal producers. Based on projections of future energy consumption under several scenarios, a comprehensive market forecast for eastern interior coal was made to 2040. The study upon which this paper is based was completed by Battelle's Columbus Laboratories for the U.S. Army Corps of Engineers in 1974. It is but part of an overall effort by the Corps to evaluate the costs and benefits to the nation of waterway improvements. This study is primarily concerned with future coal markets for production from those counties near the Wabash River in the heart of the Eastern Interior Province. An objective here is to consider a most pessimistic energy (and hence, coal) demand for planning purposes.

Jan 1, 1978

By C. F. Smart

The heat treatment of the bronze composed of 88 per cent. copper, 10 per cent. tin, and 2 per cent. zinc, has been investigated by H. S. and J. G. S. Primrose,' and also by the U. S. Bureau of Standards.2 The results obtained by H. S. and J. G. S. Primrose on dry-sand castings subjected to reheating followed by air cooling, or by quenching in water, are shown in Figs. 1 and 2. The values for tensile strength have been converted from tons per square inch to pounds per square inch. Figs. 3 and 4, have been plotted from values obtained by the Bureau of Standards on material of the same composition and treatment. Both investigations show that the ductility of the cast bronze is improved by heating to 700' C. and cooling in air, the strength not being impaired by this treatment. They are not in agreement, howevcr, as to the effect of quenching, Messrs. Primrose reporting a decrease, and the Bureau of Standards an increase, in both strength and ductility when the cast bronze is heated to 600' or 700' C. and quenched. The present investigation was undertaken to study the effect of annealing followed by different rates of cooling, and, in particular, the

Jan 1, 1921

By L. M. Johnson, C. G. Janes

INTRODUCTION In May, 1966, the General Services Administration (GSA) announced a program to encourage additional domestic production of copper in the interest of national security. Upon learning of the copper production expansion program, Duval Corporation entered into negotiations with GSA for development of the Sierrita copper-molybdenum property under the program. Agreements between the GSA and Duval Sierrita Corporation, a wholly owned subsidiary of Duval Corporation, were concluded in 1967, with the Sierrita Concentrator beginning operation in 1970 at a designed capacity of 72,000 STPD. Subsequent additions and modifications have expanded capacity to 90,000 STPD. This property, located approximately 20 miles south of Tucson, Arizona, represents an investment including working capital of about $200 million. These funds were provided from an $83 million loan from GSA, repayable in copper valued at 38 cents per pound, $48.75 million of bank loans subject to U. S. Government V-loan guarantees, and Company capital contributions. Current general operating statistics for the concentrator are listed below: [Ore Grade 0.32% Cu., 0.030"/. Mo. Daily Tons Milled 90,000 STPD Annual Copper Product ion 94,600 Tons Annual Molybdenum Production 15,000,000 Lbs. Annual Silver Production 1,135,000 Ounces]

Jan 1, 1976

By A. Donald Kelmers, Forest G. Seeley, B. Zane Egan

INTRODUCTION Coal ash, presently the fifth most abundant of the solid minerals produced in the United States, is expected to become the fourth most abundant by the end of this decade (1). The production of fly ash from the combustion of pulverized coal amounted to a total of 44 million metric tons (Mt) in 1977 and is expected to Increase to 91 Mt by 1985. Coal ash, which results from the Inorganic clay and mineral content of the coal, contains several elements and thus can be considered as a mined and crushed mineral resource rather than a waste material Furthermore, potential problems associated with fly-ash disposal ponds and the leaching of potentially hazardous elements through groundwater infiltration and/or rainfall provide additional incentive for processing fly ash for environ- mental control as well as for the recovery of certain metal values. Fly ash could provide an abundant domestic source of aluminum and several other metals Aluminum is now recovered from bauxite, and over 90% of this ore is imported since domestic sources are limited and cannot meet the U.S. demand There is a close relationship between the aluminum content of fly ash and the domestic consumption of this metal (Table 1).

Jan 1, 1981

By William P. McConnell

At the dawning of the first century of AIME, mechanical handling of bulk materials was largely confined to movement of grain and light mill products by belt and screw conveyors, but grain handling experience inevitably led to the use of the belt conveyor for coal, ore and other heavier materials. In 1891, the first major U.S. conveyor installation for heavy minerals was completed at the Edison, N.J., plant of the New Jersey & Pennsylvania Concentrating Co. Functionally, this plant revealed its grain elevator heritage. Overlooked at the time of design or, perhaps more accurately, not fully recognized, were the dramatic differences between grain and minerals in both operating conditions of the system and the physical characteristics of the material to be conveyed. This inevitably caused problems, but from the ashes of these problems rose solutions. The Edison plant became a proving ground from which came two significant developments by Thomas Robins-the first conveyor belt designed specifically for impact loading and abrasive materials and the three-roll conveyor idler. As an installation with more than 50 conveyors in widths of 20-30 in. and belt centers of up to 500 ft, the plant was a landmark, for it established the belt conveyor as a vital method of trans- porting heavy, abrasive materials.

Jan 1, 1971

By W. R. Davison, C. A. Brown, J. P. Carstens

INTRODUCTION The phenomenon of heat-weakening of rock with 10.6 micron radiation from a continuous-wave C02 gas laser has been investigated in detail at the Massachusetts Institute of Technology for over 5 years. The programs at MIT have explored the basic nature of the heat-weakening phenomena and rock fracture caused by heating (e.g., Refs. 1 and 2), and have resulted in quantitative estimates of the relationship between the amount and parer level of heating and the resulting decrease in the modulus of rupture of a rock beam in a three-point bend test (Ref. 3). Results of the tests reported in Ref. 3 indicate a greater than 90% reduction in the modulus of rupture for granite beams heat-weakened by a laser. These results prompted the U. S. Department of Transportation to seek an assessment of the expected feasibility of employing the heat- weakening concept in a full-scale tunnel boring operation. Present- day continuous rock-tunneling machines have demonstrated tunneling time and cost savings over drill-and-blast methods, when used in rock types that are easily broken by the cutters. However, cutter bits have not yet been developed which can easily penetrate very hard rock

Jan 1, 1971

By E. O. Wagner, V. F. Parry, W. S. Landers

Following investigations by the Denver Bureau of Mines on drying fine coal in the entrained state, Texas Power & Light Co. employed the fluidized technique to upgrade Texas lignite for use in power plants. Because of the rapidly rising cost of natural gas in Texas the company agreed to cooperate with the Bureau of Mines in studying further the upgrading of lignite by low-temperature carbonization, since potential value of the tar would help off- set the cost of fuel. Considerable interest was aroused, therefore, when Aluminum Co. of America decided to use dried lignite in its 240,000-kw power plant at Rockdale, Texas, operated by Texas Power & Light. Carbonization of coal before burning in a power plant is not new. Plants in Germany have been operated for many years on carbonized brown coal and lignite briquets produced in large integrated plants. Large-scale experiments in carbonizing pulverized coal with hot flue gases were made 30 years ago at Milwaukee, and many inventors have proposed other processes. In the U. S., technical and economic problems have prevented successful operation of large plants on carbonized coal, but new techniques of handling solids in fluidized beds may overcome these difficulties, particularly if the higher volatile noncoking coals are used.

Jan 1, 1956

By Linn M. Farish

The estimated production of petroleum in the Dominion of Canada for 1931 was 1,582,000 bbl., an increase of 60,000 bbl. over 1930. Nearly all of the production came from Alberta, with a small quantity from Ontario, and a very minor amount reported from New Brunswick. At the beginning of 1931 it was hoped, and predicted, that a substantial increase in production would be shown for that year, but such was not the case, since Alberta did not show the anticipated gain. The production from Ontario and New Brunswick has not varied more than a few thousand barrels during the past 10 years and aggregated 124,000 bbl. in 1930, with 126,600 bbl. estimated for 1931. Unless new fields are discovered, production in 1932 will decline, with Ontario and New Brunswick showing little change and Alberta declining appreciably. Canadian production by provinces during the past 10 years is given in Table 1. Furnished by the Dominion Bureau of Statistics. a Barrels of 35 Imperial gallons or 42 U. S. gallons. c Figures for Ontario and New Brunswick are estimated. The production of natural gas in Canada reached the record figure of 29,377,000,000 cu. ft. in 1930 and it is estimated at 26,874,600,000

Jan 1, 1932

By James E. Howard

At the request of the Council of the Institute, I have the honor to submit the following remarks upon the Program of Tests under which the current work of the Watertown Arsenal Testing Laboratory is carried on, which comprises, among other items, the tests of steel ingot metal and derivative shapes. The intended scope of the tests may be illustrated by extracts from the descriptive part of the program as submitted by the Laboratory under date of April 17,1907, and subsequently approved by the Chief of Ordnance, U. S. A. Under Item 1, Ingot Metal—Open hearth, acid and basic; Bessemer, acid and basic; crucible; fluid compressed and uncompreesed—descriptive remarks were made as follon-s: "A thorough, fundamental inquiry into the physical properties of steel necessarily begins with the ingot metal. Investigations, having for their object the improvement of steels, should also begin with the ingot. A knowledge of the ingot structure is essential for judging of the subsequent behavior or appearance of the metal. Under ordinary conditions, so little information is obtained from the ingot in individual cases that practically none of importance is acquired. These remarks have particular reference to the state of physical and structural

Jan 1, 1909

By R. N. Singh, A. S. Atkins

One of the most difficult problems associated with modern mechanised longwall mining is the lack of system flexibility to deal with local changes in geology, seam thickness and the face design parameters. As a consequence of system rigidity and the quest for increasing the coal face performance, the percentage extraction in the U.K. is currently below 52%. The paper outlines the current guidelines used in face design which permit coal to be left in situ for various purposes and discusses the strata control implications in extracting subsequent panels in the same and adjacent coal seams. The paper examines the application of strata mechanics to the design of longwall layouts for maximizing .the percentage of coal extraction. Remedial measures include optimizing pillar dimensions, reduction in roof coal left for support purposes by improving the use of available powered support technology and application of thick seam mining methods including sub-level caving and techniques of extracting coal from odd shaped pillars. Case studies are described where coal extraction has been maximized by adopting a new single heading retreat mining system; a shallow seam partial extraction system utilizing, existing heading machines and minimisin8 coal sterilization in pillars by replacing longwall access roadways by goaf scour.

Jan 1, 1984

The Industrial Minerals div. has been forging ahead in formulating a program for the February Annual Meeting in Los Angeles. Several papers have been listed and more are being worked into the program. For the cement, lime and gypsum part of the sessions, papers on Gypsum in the Aircraft Industry, Geology of San Marcos Island Gypsum Deposit, and Status of New Dry Rotary Blast Hole Drills, are expected. The Chemical Raw Materials sessions will feature a symposium on potash, with 13 papers as the anticipated number to be presented. Airborne and Ground Magnetometer Work has been suggested. Eight papers have been set for Mining Geology, Four papers, Mining Phosphate Rock, Idaho Phosphorous, and Geology of Carlsbad Potash and Geology of Pearlite will be on the program. Sessions on Dimension stone and slate have been tentatively worked out with papers on Geologic Factors Affecting the Dimension Stone Industry of California, A Quarter Century of Granite Quarrying in Massachusetts, Rock Bursting and Other Geologic Problems in the Granite Quarries of Barre, Vt., Quarry Practices in the Indiana Building Stone Industry, Stratigraphy and Composition of the Salem Limestone, and Dimension Stone in the U. S. in 1952. The Rare Minerals Committee is aiming for six papers with two papers now definitely on the program.

Jan 1, 1952

By Gordon MacVean

THE adoption of rock dusting, as a safety measure, has made notable progress in the West Virginia coal mines since May, 1925. At that time there were but two mines in the State that were thoroughly rock dusted, mines No. 2 and No. 12 of the Boone County Coal Corp., at Sharpless. Since then it is probable that 75 per cent of the coal operators in the State have given consideration at one time or another to rock dusting. This growth of interest followed the meetings of the various mining institutes all over the country, during the summer of 1925, at which papers were presented, drawing the attention of the coal mining operators to the merits of this safety measure. Yet outside of the experience with rock dusting at the Old Ben Coal Corp., of Southern Illinois, and the Carbon Fuel Co., of Rains, Utah, there had been no actual occurrence in the coal mines of the United States, which could be taken as positive evidence of the efficacy of rock dusting in the prevention of the propagation of coal dust explosions. The U. S. Bureau of Mines, however, had run innumerable tests under conditions which closely approximated actual coal mining conditions and had clearly shown that rock dusting was effective.

Jan 1, 1926

By M. R. Geer, H. F. Yancey, P. S. Jacobsen

Two growing problems confront the preparation engineer-still further restrictions on stream pollution and a greater proportion of fine coal as more and more continuous miners come into use. The dewatering screens, centrifuges, and settling ponds that sufficed a few years ago must often be supplemented by more effective equipment, and in some instances the finest solids are now being recovered by vacuum filtration, once considered too costly in many coal washeries. Unfortunately not all slurries can be readily filtered. Some are virtually unfilterable, and others do not permit the high cake rates needed to hold costs within reason. Often, however, these difficult slurries can be rendered filterable by flocculation. Starch and lime have long increased settling rate in thickeners and can also aid filtration. More recently there have been other flocculants, primarily synthetic polymers or gums. Reports of their great effectiveness prompted the U. S. Bureau of Mines to test their use in filtration as part of its program on recovering and cleaning fine coal. The object of the present work was to compare some of the newer flocculants with starch and lime and to test the reaction of different types of slurries to flocculation. Three natural slurries, three synthetic coal-clay mixtures, and five flocculants were tested, all with a laboratory filter leaf.

Jan 7, 1959

R. U. Jackson (Conveyor vs. Track Haulage, P. 866) is the author of a previous work on conveyor systems, which was presented at the Annual Meeting of the Arizona Section of the AIME in December 1951. He has worked for the Carnegie Steel Co., Koppers Co., Fairmont Mining Machinery Co., and the Hewitt-Robins, Inc., the Robins Conveyor Div., for the past 30 years, as engineer, district manager, and manager of the mining div. Jackson is a graduate of Carnegie Institute of Technology, and was born in Steelton; Pa. His present residence is in Clifton, N. J., where in his spare time he devotes himself to hiking and photography interests. F. S. White (Co-author, Solids Fluidization Applied to Lime Burning, P. 903) is a Washington University, St. Louis, Graduate, who now lives in Stockbridge, Mass. He served as a technical apprentice at Mobile, Ala., for the Aluminum Ore Co., and after four years went to Bauxite, Ark, as technical superintendent of calcination and precipitation. After a year and a half, he became technical and operating superintendent of the sintering plant. White also worked for the Dorr Co., and is now with the New England Lime Co. serving as assistant to the president. For relaxation he collects stamps and plays the piano.

Jan 1, 1952

It is desired to call the attention of young men who have had technical training and experience to the fact that their abilities can best be put at the service of the country by selecting a branch of service in which their special qualifications will be of the greatest use. The submarine force of the United States Navy requires the services, as officers on board submarines, of young men who have had technical training in mechanical and electrical engineering and who have had experience in these professions. It is intended to enroll a number of such men as provisional ensigns in the Naval Reserve Force, give then a course of instruction in deck duties at Annapolis and a course in submarine work at New London. Those who successfully pass these courses will then be sent on hoard submarines for regular duty. It is requested that any men who desire this duty and who are qualified as below outlined send their names and addresses to the Commander Submarine Force, U. S. S. Chicago, care of Postmaster, New York. Qualifications required: Desire to serve in submarines. Degree of M. E. E. E., or E. M. Two and one-half years' practical experience in profession. Not over 35 years old. Physically strong and sound.

Jan 7, 1918

By R. B. Brinsmade

The following is an attempt to form a formula by which a mine can be quickly evaluated, aft,er all pertinent physical data have been collected from observations on the ground by a competent mining engineer. Assumptions. Let Q = price to be paid for the mining property. M = cost of developing the mining property to yield y tons of ore daily. P = cost of suitable plant to treat y tons of ore daily, p = value of said plant when the mine has been exhausted. C = total fixed capital investment. W = working capital investment. Then let C + W = total capital investment. y = required yield of ore daily in tons. Y = yield of ore yearly in tons, d = number of producing days per year, u = average operating profit per ton of ore. R = rate of interest to be earned on total investment of (C + W). r = rate of interest to be earned on sinking fund annuity. v = tons of positive ore available in mine. x = tons of probable ore available in mine, z = tons of possible ore available in mine, m = fractional factor to change probable to positive ore. n = fractional factor to change possible to positive ore. Q = tons of total ore available in mine. t = time in years to exhaust mine at rate Y.

Jan 1, 1909