Search Documents

By Zay Jeffries

It has been known for centuries that iron and steel could be hardened by cold hammering and that the metal could be restored to the normal condition by heating to a red heat arid cooling, either rapidly or slowly with nearly pure iron, but slowly with steels containing considerable carbon. The art of tempering steels is also very old. When a medium- or high-carbon steel is quenched from a cherry-red heat, the hardness is increased; this hardness can be reduced by heating to various temperatures below the lower thermal critical point,, which is near 700" C. The present paper will not consider these old and well known changes in iron and steel below the thermal critical range but will confine itself to the more unusual changes, some of which have been studied recently. Stromeyer,1 for example, In 1886, reports that both working steel and heat treatment of steel in the blue-heat range arc highly injurious. Recently, however, some metallurgists believe that the straiglltening of warped steel forgings at a blue heat produces a beneficial effect on the metal2 The Engineering Division of the National Research Council has constituted a committee on Physical Changes in Iron and Steel below the Thermal Critical Range, which has the following personnel: K. R. -Abbott, H. C. Boynton, William Campbell, J. V. Emmons, F. B. Foley, H. J. French, H. M. Howe, Zay Jeffries (chairman), F. C. Langenberg, J. A. Mathews, P. D. Merica, A. H. Miller, J. H. Nelson, G. A. Reinhardt, W. E. Ruder, H. F. Wood. This committee is studying several aspects of the physical changes in iron and steel. The results, reported in the literature and obtained by recent experimentation, will be given; this will be followed by a general theoretical discussion of the more important

Jan 1, 1922

By Zay Jeffries

It has been known for centuries that iron and steel could be hardened by cold hammering and that the metal could be restored to the normal condition by heating to a red heat arid cooling, either rapidly or slowly with nearly pure iron, but slowly with steels containing considerable carbon. The art of tempering steels is also very old. When a medium- or high-carbon steel is quenched from a cherry-red heat, the hardness is increased; this hardness can be reduced by heating to various temperatures below the lower thermal critical point,, which is near 700" C. The present paper will not consider these old and well known changes in iron and steel below the thermal critical range but will confine itself to the more unusual changes, some of which have been studied recently. Stromeyer,1 for example, In 1886, reports that both working steel and heat treatment of steel in the blue-heat range arc highly injurious. Recently, however, some metallurgists believe that the straiglltening of warped steel forgings at a blue heat produces a beneficial effect on the metal2 The Engineering Division of the National Research Council has constituted a committee on Physical Changes in Iron and Steel below the Thermal Critical Range, which has the following personnel: K. R. -Abbott, H. C. Boynton, William Campbell, J. V. Emmons, F. B. Foley, H. J. French, H. M. Howe, Zay Jeffries (chairman), F. C. Langenberg, J. A. Mathews, P. D. Merica, A. H. Miller, J. H. Nelson, G. A. Reinhardt, W. E. Ruder, H. F. Wood. This committee is studying several aspects of the physical changes in iron and steel. The results, reported in the literature and obtained by recent experimentation, will be given; this will be followed by a general theoretical discussion of the more important

Jan 1, 1922

By Beall, John V.

THIS is not simply the story of how a water filled shaft was developed into a million-ton- a-year producing mine in the space of four critical years, although it is reason enough for telling it, but it is also the saga of an engineering achievement in which knowledge nurtured by years of experience in coal and ore mines was blended together and the best from each type of mining selected. The entire system of mining was detailed on maps by the mining engineering department before the shaft was unwatered, and subsequent development followed these plans nearly to perfection. The selection of machinery was particularly critical as it was necessary to push production from only a few headings in the early stages of development and metal mine machinery was being used in a coal panel-system of mining. At the start of World War I1 the demand for iron ore to supply Woodward blast furnaces, and rapid exhaustion of the main source of Wood- ward ore, No. 3 Red Ore mine, necessitated speedy opening of the Pyne mine. The mine is three miles southwest of Bessemer and is responsible for 80 pct of Woodward ore, the rest coming from the Songo mine. The Woodward Iron Co. is one of the old producers of the Birmingham district. S. H. Woodward, an iron-master of Wheeling, overheard two Union soldiers conversing about ore and coal lands in Alabama, which lead to the acquisition of the first ore lands of the Woodward Co. in 1869. Development was not begun until after the death of S. H. Woodward; his two sons, W. H. Woodward and J. H. Woodward, formed the Woodward Iron Co. in 1881 and purchased a tract of land midway between the ore vein on the southeast and the coal field on the northeast about 12 miles southeast of Birmingham for the

Jan 1, 1950

By Louis D. Huntoon

SHORTLY after publication of the article in the July, 1924, issue Of MINING AND METALLURGY, entitled "Canada as a Gold Producer," requests were received to determine the ownership of production. Advices have also been received that considerable discussion has taken place on the same questions both in Canada and Great Britain. The author is indebted to R. H. Coates, Dominion Statistician, and George C. Bateman, Secretary, Ontario Mining Association, for the following figures and takes this opportunity of expressing his appreciation. There have been no statistics compiled as to ownership of production. Statistics were compiled as of Dec. 31, 1921 relative to the distribution of stocks, bonds and "other securi¬ties" in industrials, agriculture excepted, throughout the Dominion, and "distribution of ownership of securities issued by mining companies incorporated and operating in Ontario" for the same year. Stock registration does not necessarily represent actual ownership' as large blocks may be endorsed and not transferred; neither does registration actually represent production. When the charts are studied individually and collectively one cannot help but be impressed with the fact .that in the mineral industry of Ontario and the Dominion at large, Canadian registration predominates, the United States registration is about half that of Canada, and Great Britain is about half that of the United States. When the nickel-copper industry is excepted the British registration falls to a very low percentage. Since Dec. 31, 1921, British capital has commenced to flow into mining enterprises in Ontario and it has been already rewarded by the discovery of valuable ore deposits.

Jan 1, 1925

By R. L. Moment

The anisotropic elastic behavior of rolled beryllium sheet has been measured, using a pulse echo technique, and compared with X-ray diffraction data. Calculated elastic stiffness constants compared favorably with published values for beryllium single crystals which were attributed to the strong (0002) rolling plane texture. Variations of Young's modulus in the yolling plane could be associated with the velative distribution of (0002) planes out of their ideal position in the rollitzg pkule. WHEN a metal is subjected to cold working such as drawing, forming, or rolling, a crystallographic texture develops which can significantly alter its physical properties. One method for detecting this texture is X-ray diffraction, but Alers and Liu' have recently pointed out how the prediction of anisotropic physical properties from pole figures alone is not always accurate due to differences in interpretation. Variations in Young's modulus with orientation or, more completely, the values of the effective elastic constants of the worked metal, also serve to indicate the presence of a texture. In fact, as Alers and Liu' pointed out, calculated variations in Young's modulus for assumed orientations, when compared with experimental data, can be used to eliminate some of the uncertainty in interpretation of X-ray pole figures. Thus, elasticity measurements can serve not only to clarify any unusual elastic behavior of worked metal, but also to detect and in part determine the nature of its texture. X-ray determination of the texture of rolled beryllium has been reported by Smigelskas and Barrett,2 who found a strong texture of (0002) in the rolling plane with (1070) planes normal to the rolling direction. In the case of metal rolled at room temperature, they reported that [1010] directions also appeared at positions 60 and 120 deg from the rolling direction in the rolling plane, while in more recent work Keeler3 found these directions were also tilted towards the rolling plane. The texture for beryllium rolled at 80O0C, however, only showed (1010) planes normal to the rolling direction and the spread of (0002) planes out of the rolling plane was less. In looking for elastic anisotropy one might consider unidirectional rolling of a metal as introducing an or-thorhombic symmetry through reorientation of the grains, since the three deformations, compression, extension in the rolling direction, and extension in the cross direction, are orthogonal to each other and unequal in magnitude. Thus the rolled sheet could be treated like an orthorhombic single crystal and the nine stiffness constants of the elasticity tensor used to calculate the anisotropy of Young's modulus, the shear modulus and Poisson's ratio. In this case we could write: which is symmetric about its diagonal. Borik and Alers4 have recently used this approach on rolled die steel with very good results. They found, however, that instead of displaying orthorhombic elastic symmetry their specimens could be considered tetragonal in which case Cr1 = c22, c13 = Ca, and c44 =cjj. This conclusion was made solely on the basis of the measured tensor elements, and serves to point out the advantage of this method for studying the anisotropy of rolled metals. Their calculated values for Young's modulus as a function of angle in the rolling plane also checked very well with direct measurements made on different specimens using the resonance technique. In the present study, cross-rolled beryllium was used which had been unidirectionally rolled about 11 pct for the final reduction. This imparted a slight anisotropy in the rolling plane which was detected both by X-ray techniques and elasticity measurements. For purposes of discussion in this paper, the rolling direction is that direction in which the most reduction passes were made and cross direction is the normal to the rolling direction in the rolling plane. It was also decided to consider the rolled sheet as displaying orthorhombic symmetry for the purpose of obtaining elasticity samples with the direction defined as in Table I. Any change in the final symmetry attributed to the sheet would then be made on the basis of the measured elastic stiffnesses. The final data would then be compared with that expected from the X-ray study and that reported for beryllium single crystals. EXPERIMENTAL PROCEDURE Rolling Schedule. The samples used in this study were taken from a large sheet which, because of its size, had to be unidirectionally rolled for the final reduction. The resulting texture was that of cross-rolled metal with a slight unidirectional texture superimposed. A cast beryllium ingot, 9.500 in. sq by 3.325 in. thick, was cross-rolled to 81 pct reduction followed by unidirectional rolling for an additional 11 pct to give a total reduction of 92 pct. The thickness of the final sheet ranged from 0.265 to 0.280 in. Reduction up to 67 pct was done at 980°C and the final 25 pct at 870°C. Analysis for metallic impurities showed aluminum 0.06 pct, iron 0.19 pct, and silicon 0.11 pct, giving a beryllium purity of 99.64 pct.

Jan 1, 1968

By W. B. Price

AT the New York meeting of the American Institute of Mining and Metallurgical Engineers held in February, 1926, W. H. Bassett and J. C. Bradley presented a paper entitled "Exudations on Copper Castings."' The purpose of the present paper, as the title suggests, is to call attention to somewhat similar phenomena which the authors have encountered in brass and bronze. From a study of the examples given, a more-or-less speculative theory of "inverse segregation" is advanced. Protuberances on Admiralty Brass In the rolling mill of the Scovill Manufacturing Co., there have been found quite commonly bars of certain alloys which had a sort of shaggy roughness on the surface due to slight metallic protuberances. No special attention was paid to these until some bars were found on which these protuberances were heavy enough at the bottom of the bars to produce a blistered appearance. A sample of the protuberances was milled off the surface of the bar illustrated (Fig. la) and upon analysis was found to contain 66.66 per cent. copper, 4.02 per cent. tin and 0.03 per cent. lead, whereas the average composition of the bar was 70.21 per cent. copper, 1.21 per cent. tin, and 0.01 per cent. lead. A sample of the shaggy-rough protuberances at the very top of a bar was also analyzed and was found to contain 2.45 per cent. tin, indicating that it was probably of the same origin as the blistered areas. These results were not entirely unexpected for previous analyses of this alloy had revealed that the surface was richer in tin than the rest of the bar. This, of course, is contrary to what we would expect from a consideration of the equilibrium diagram and has been called "inverse segregation." Fig. 16 is a cross-section of a bar through the protuberances on the surface. It reveals that there is a decidedly different structure through the raised areas and seems to indicate that the bar originally solidified

Jan 1, 1927

By AIME AIME

ATER the preliminary registration at which approximately 380 members and guests were registered, the 138th meeting of the Institute was opened in the Concert Room of the Palace Hotel. E. A. Hersam, chairman of the San Francisco Section, voiced a brief welcome and introduced F. W. Bradley, president of the Institute, who presided over the remainder of the morning session. After expressing the welcome of the Institute to the members and guests, he read a telegram from Secretary H. Foster Bain, extending the best wishes of the eastern staff and members for a successful meeting. He next introduced Theodore J. Hoover, dean of the School of Engineering, Stanford University, who read an address by the Secretary of the Interior, Ray Lyman Wilbur, briefly outlining California's part in the mining industry and giving the welcome of California to this meeting of the Institute.

Jan 1, 1929

By David J. Dunn

At a time when mill availability is at a premium, production costs are rising, and lead time for mill liner casting is a year or more, mill liner design is an important factor in ore grinding. Testing and selection of the optimum liner profile for a given set of mill operating conditions can improve mill capacity, reduce liner wear rate, and lengthen liner life. The mill liner that grinds best, lasts the longest, and costs the least is a necessity for economic mill operation. After testing four mill liner profiles for 3.96 X 3.65-m (13 x 12-ft) overflow ball mills, Climax Molybdenum Co. found that an improved design increased mill tonnage by 2.72 t/h (3 stph) while reducing finish grind by 1.7% minus 100-mesh, reduced liner wear rate, and almost doubled liner life.

Jan 12, 1976

E. K. Landis, Philadelphia, Pa. (communication to the Secretary) : Mr. Firmstone's paper is of great interest; but he has unfortunately otnitted to state the most important point, viz., the percentage of sulphur in the two materials he compares; and this omission vitiates the conclusions which he draws. Comparing by grade, instead of silicon-contents (as in his Table III.), the iron made using limestone with that made using dolomite, we find for gray-forge the average of four analyses under limestone to be, Si, 0.644; S, 0.089 ; while one analysis under dolomite gives Si, 0.508 ; S, 0.070. For No. 2 iron, the limestone flux gives, as an average of 19 analyses, Si, 1.107; S, 0.051; while the average of 4 analyses made with dolomite flux gives Si, 0.630; S, 0.056. It will be observed, that no No. 1 pig is given under limestone, while 14 analyses appear under dolomite, averaging Si, 0.950 ; S, 0.028. As nothing is said about changed conditions, it is Fair to presume that the ore and fuel, as well as the blast-temperature (which is stated to have been uniform at about 750' F.) remained practically the same; and since the sulphur in the two fluxes is not given, it is impossible to know whether the lower sulphur for equal silicon-contents is due to the use of dolomite or to other conditions. The use of dolomite would produce a more fusible cinder, and the furnace would be hotter than when using limestone; therefore, we might expect to see a grayer iron. The amount of So. 1 iron made with dolomite seems to confirm this supposition; and, under these conditions, we might expect more of the sulphur to be volatilized, and to pass off in the gases. The easier fusibility of the cinder would also permit more rapid driving; and this should reduce the amount of silicon and sulphur in the iron, as the amount of reduced metalloids in the pig is directly proportional to the length of time it remains in the reducing-zone.

Jan 1, 1895

By E. A. Anderson

THE copper-zinc phase equilibrium diagram has been the sub-ject of many investigations. Until recently, however, the boundary of the terminal solid solution of copper in zinc (eta) has not been thoroughly investigated. This paper reports determinations of the solid solubility of copper in zinc at temperatures from 100° to 400° C., the course of the liquidus and solidus for the eta solid solution and determinations of the peritectic temperature and peritectic point for the reaction between epsilon and the melt to form eta. The liquidus of the eta phase was determined by thermal analysis and the solidus by the microscopical examination of specimens quenched from temperatures above and below the solidus. The temperature of the peritectic horizontal was obtained by thermal analysis and the com-position at the peritectic point was determined by extrapolation of the solid solubility boundary of the eta phase to the peritectic horizontal. The solid solubility boundary of the eta solid solution was investigated very carefully. Particular care was used to achieve equilibrium in the alloys at each temperature selected. The X-ray, electrical con-ductivity and microscopical methods were used in determining the solid solubility limits. The X-ray method measures the changes in the solvent lattice with increasing solute content and in this manner locates the composition of the alloy at which no further change in the solvent lattice takes place, the limit of solid solubility. The method of electrical conductivity measures the conductivity of the alloys of a graded series of compositions, whereby the solubility limit is indicated by a discontinuity in the conductivity-

Jan 1, 1934

By T. A. Rickard

Our Transactions contain two notable papers descriptive of the stamp-milling practice of the Black Hills and of Grass Valley, namely, the elaborate and complete treatise of Prof. H. 0. Hofman, on " Gold-Milling in the Black Hills,"" and the paper describing the North Star mill, by E. R. Abadie, its superintendent. Having visited and examined the stampmills of both localities, I venture to offer here such comment as more recent information or a different point of view has suggested.†

Jan 1, 1896

By T. A. Rickard

MILLING is one of the metallurgical arts whereby the extraction of the largest possible proportion of the value in an ore is effected at the least possible expense. Stamp-milling* is that particular process in which a heavy body of iron is caused to fall upon the ore so as to disintegrate it and thereby induce a separation between what is valuable and what is worthless. The latter is usually less in specific gravity, and is therefore, by the further aid of water, removed from the former, which is then collected by the use of mercury. Several similes have been employed to describe this process. The stamp has been likened to a hammer of which the stem is the handle and the die the anvil. The ore upon which the stamp falls has been compared to a nut awaiting the descent of the hammer whose blow is to separate the valueless shell, the quartz, from the valuable kernel, the gold. When we begin to pursue our inquiries, however, we find that the analogy is just sufficiently true to emphasize the departures from it. The hammer falls, the anvil is fixed; so with the stamps and the mortar. The anvil is made of softer metal than the hammer; so also the die is often, and should be always, of steel or iron less hard and more tough than that of the shoe. The movement of the hammer and the drop of the stamp are both intermittent. In regard to their intermittent action, as in many other respects, stamp-mills arrange themselves under two types, which, though apparently contradictory, have both been evolved from a common original, and are united by a great variety of intermediate modifications. The slow speed and the high drop of the mills of Gilpin county Colorado, appear to have very little in common with the fast speed and short drop of those of the main gold belt of California; yet the practice of the one was largely derived from that of the other,

Jan 1, 1894

By W. E. Howlett, R. L. Slobod

Jan 1, 1965

By Sherwin F. Kelly

THE principal interest in the meeting sings arranged by the Geophysical Committee this year centered around the many papers dealing with the practical applications of geophysical methods to solving geological problems in many other parts of the world. The program Wednesday morning dealt with work in South Africa, Poland, and South America. Rudolph Krahmann's first paper gave a perspective of the geophysical investigations upon mineral deposits in South Africa. A striking point in his story was the tremendous increase in magnetic work during the last two or three years. This is largely accounted for by the intensive exploration for the extension of the Witwatersrand gold mining area. The author mentioned many surveys in which other methods were used for the search for ores of copper, lead, and zinc, and in the study of water-bearing and oil-bearing structures.

Jan 1, 1935

ALABAMA Anniston.-Bretz, J. A. Carrington, F. G. Gerber, A. B. Klugh, B. G. Semple, R. A. Ashland.-Barton, .J. Bessemer.-Abbott, C. E'. Ball, T. L. Beaver, J. J. Ferguson, V. Salmon, H. S. Sehaber, C. F. Whatley, W. J.

Jan 1, 1923

By W. J. Parton

THE efficient recovery and preparation of small sizes of anthracite called No. 4 Buckwheat (3/3 2 by 1/3 2 in.) and No. 5 Buckwheat (1/3 2 in. by 0), present a difficult problem to the anthracite operators. In many instances preparation of these sizes, particularly No. 5 anthracite, is extremely inefficient. In many of the older preparation plants, inadequate facilities, and often none at all, were provided as an integral part of the plant for cleaning this fine anthracite. Consequently, much of the material smaller than s, 32 in. was discarded. As the demand for these sizes increased, facilities for preparing the fine sizes were often crowded into existing structures with consequent sacrifices of capacities and efficiency. In addition to this condition, the methods of preparing the finest sizes are being developed in an attempt to improve their efficiencies. Because the demand for small sizes of anthracite still is increasing, many operators would benefit by investigating and improving the cleaning equipment employed on these sizes.

Jan 1, 1949

Aalde, Kaare, (S'40) Box 827, Socorro, N. M. Aase, Glenn D., (S'40) Engr. Experiment Sta., Univ. of Utah, Salt Lake City, Utah. Abadesco, Enrique A., (S'39) Student. College of Engrg., Univ- of the Philippines, Manila, P. 1. Abbott, John L., (S'40) Met. Engr., Engr. Trainee. Wright Aeronantical Corp., Paterson, N. .J. Abbott, Robert H., (S'42). Agricultural & Mech. College of Texas, College Sta., Tex. Abreu, Ovidio M., (S'38) Dept. of Geol., Compauia Cousulidada de Petroleo, Caracas, Venezuela. Acomb, Allen, (S'41) 3921 Chestnut St., New Or¬ leans, La. Adam, Howard W., (S'41) Montana School of Mines, Butte, Mont. Adams, Charles E., (S'42) Uuiv. of California, Los Angeles, Calif. Adams, Charles W., (S'39) Student, Michigan Col¬ lege of Min. & Tech., Houghton, Mich. Adams, H. Travis, (S'39) 310 South 5th St., Bur¬ bank, Calif. Adams, John W., (S'42) Univ. of Texas, Austin, Tex. Adams, Rob L., (S'40) Lt., B. 0. C. No. 12, Fort Sill, Okla. Adamson, Charles R., (S'41) Uuiv. of Utah, Salt Lake City, Utah.

Jan 1, 1942

By Nicholas M. Short

Many a geologist or driller has wished he could somehow climb into a borehole to see for himself what fractures looked like. Or why recovery was poor. Or how the bit was actually lost. Now it is possible to do the next best thing to climbing into the hole. TV cameras are being used for a close-up look at borehole conditions. Ever since television was invented, geologists and others interested in subsurface conditions have wanted a TV camera that could be used in the narrow confines of a borehole. But development of such a camera was slow, mainly because of the need for compact size. Not until the late 1950's did the technology of electronic miniaturization develop to a point where a camera satisfactory for the purpose could be put together.

Jan 1, 1963

[NORTH AMERICA UNITED STATES ALABAMA ADAMSVILLE U. S. Steel Corp. Neason, James E. ALBERTVILLE Thompson Floral Co. Loudermilk, E. L. ANNISTON No Data Supplied Bonnichsen, Bill BESSEMER U. S. Steel Corp.-TCI Div. Beck, Adolph W., Jr. Boyle, James R. Cofield, William H. *Evans, James D. F., II *Guyton, Jesse C. Johnson, Leland H. Tetley, Albert L. No Data Supplied Crockard, F. H. Fisher, Joe T. Griffin, Joseph M. McFarland, E. A. Mohr, Henry E. Neal, George M. Walker, Wilber D.]

Jan 1, 1961

By Arthur Notman

TO present some idea of the magnitude of the gold-mining industry of Canada and the world, the records of 106 gold-mining companies currently paying dividends have been studied. Forty of these are in Canada, and 37 on the Rand in South Africa, these being all the straight gold-mining companies that paid dividends in the two areas in 1938. None of the base-metal companies that produce gold as a by- product, or even as a major fraction of the value of their total product, have beezl included. In addition, a group of 29 similar companies from Southern Rhodesia and the Gold Coast in Africa, India, Australia, Manchuria, Philippine Islands, the

Jan 1, 1939