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By Clarence Zener

THEORETICAL considerations by one of the authors have led1 to the prediction that the dynamic internal friction of annealed metals has a broad maximum at a certain grain size. This prediction they have veri-fied2 for alpha brass. In the present paper the theory is extended to include the precise manner in which the internal friction varies with grain size on either side of the maximum. New experimental data are pre¬sented to test this extended theory. The physical basis for the type of internal friction that is being investi-gated lies in the interplay between stress and temperature. Just as local fluctuations in temperature give rise to local fluctuations in stress, so like-wise fluctuations in stress give rise to fluctuations in temperature. But temperature gradients give rise to necessarily irreversible thermal cur-rents, and hence to internal friction. The theory for this type of internal friction has been developed quantitatively,3 and has been experimentally verified,4,5 for the particularly simple case of the transverse thermal cur-rents accompanying transverse vibrations. Of more fundamental impor-tance are the intercrystalline thermal currents accompanying all types of vibration. The variation in stress across grain boundaries arises from the elastic anisotropy and at least partial random orientation of the individual crystallites. An exact quantitative treatment of the internal friction due to these thermal currents is of course out of the question. However, much information can be obtained from general arguments.1,6 Thus when the frequency of vibration f is low, or when the grain size d is small, adja-cent grains remain nearly in thermal equilibrium, and vibration proceeds isothermally with little internal friction. Again, when the frequency is high, or the grain size large, the heat flow per cycle is small, the vibration proceeds adiabatically with little internal friction. The internal friction will become a maximum in the transition region. The degree of adiabatic-

Jan 1, 1940

By C. Everard Arnold

The Giroux Consolidated Mines Co. is equipping a five-compartment shaft at Kimberly, Nev., which will serve the Alpha mine. The depth of this shaft, January, 1910, is 963 ft., and of this depth 948 ft. was opened by raising; 15 ft. of sinking was done so that the bearers, collar-set, and three shaftrsets might be installed and concreted, and with this done it mas possible to erect the necessary surface-equipment for resuming shaft-timbering on the completion of the raise. The arrangement of the shaft-timbering is shown in Fig. 1. At the 1,000-ft. level of the Alpha, and 750 f't. SW. from the Alpha shaft, a 14- by 18-ft. station was cut, and a 25-h-p. airhoist was installed. From here the raising commenced on July 5, 1909. The raise was cut approximately 13 by 21 ft. in area, and supported by timbering with square sets, illustrated in Fig. 2, which shows the division into four compartments. The end compartments, which were used as chutes, had the center girts heavier than in the others on account of the wear from falling rock. The chute-lining was braced by inserting 8- by 8-in. stiffeners parallel to and half way between successive caps. Similarly, the lagging on the wall sides of the cage-way and the compartment for pipes and ladder was stiffened with 4- by 6-in. timbers. In the pipe-and-ladder compartment the chute-stiffeners were reinforced with 8-by 8-in. struts, and as the cage-way was partitioned off by braced lining, there was practically no chance of rock entering the ladder-way in case a chute burst into the cage-way. Over the two center compartments the last two sets were always bulkheaded with 8- by 12-in. timbers, shown in Fig. 3, and from the lower bulkhead the cage sheave-wheel was suspended. After a round of holes had been blasted and the loose

Jan 1, 1911

By V. Lessels, D. J. Buckwalter, D. H. Rose

A cyanide leaching process developed at Michigan Technological University was tested in a 12 to 24 tpd pilot plant. Flowsheet layout and equipment are described. Cyclic operation of leaching, copper precipitation by acidification, and regeneration of the cyanide leaching solution are discussed. Copper extraction and reagent consumption were as predicted by laboratory tests, and the process was proven to be technically feasible. The White Pine Copper Co., a wholly-owned subsidiary of the Copper Range Co., produces copper in the Upper Peninsula of Michigan. Production in 1965 amounted to 138 million pounds of metal. An expansion program now under way will increase this by approximately one half. The highly mechanized room and pillar mine produces 18,000 tons of ore per day, which is treated in a flotation plant. The concentrate is smelted in a reverberatory furnace, the matte is blown in converters to blister copper, and the blister copper is further refined to a uniformly high-quality Lake copper, which is 100% conductive and has a silver content of 25 to 40 oz per ton. The run of the mine ore averages 22.5 lbs of copper per ton with the ore mineral occurring in the form of chalcocite. The nature of the mineralization is such that the sand tailings average a little over 4 lbs of copper per ton. Intensive research has improved copper recovery in the flotation operation to some extent, but at the scale of present operation about 12,000 tons of sands containing over 48,000 lbs of copper go to the tailings pond daily. When the plant expansion is completed, the loss of copper will be somewhat greater. In 1959, the White Pine Copper CO, initiated a study of the recovery of copper in the sand tailings. Inasmuch as the flotation operation was considered to be optimized, a logical approach seemed to be leaching. For various reasons ammonia, ferric chloride, acid, and biological leaching were ruled out as impracticable. This led to a consideration of cyanide leach-

Jan 1, 1968

By C. P. McCormack

THE Cuyuna manganiferous iron ores can be a principal source of manganese for the iron and steel industry in the United States, provided metallurgical methods as a whole are adjusted so as to use run-of-mine ore. The use of manganese in steelmaking is growing. Increasing amounts of impurities in raw materials call for more manganese, a constant cheap supply of which is wanted. There are few deposits of ore in the United States carrying over 35 per cent. manganese that can be mined and marketed at a profit in normal times. We are largely dependent on foreign ores. The small domestic deposits should rightly be held in reserve for an emergency, such as a war, when importation might cease. Even the production from lean ores, concentrated it may be, might not carry us through a protracted stringency. The Cuyuna district is, therefore, during normal times capable of supplying a large total of manganese. The ores are iron ores containing 5 to 25 per cent. of manganese with the inverse range of 52 to 28 per cent of iron. The manganese costs no more per unit in the ore than the iron, because cost of mining, largely by open-pit methods, is not affected by the manganese content. The manganese units should, perhaps, command a higher price, but as their value is contingent on metallurgical practice, a higher price may be justified only when a shortage in manganese occurs. Manganiferous iron ores can never entirely supplant straight manganese ores though methods are employed that will permit them to do so partly. For the manufacture of ferromanganese, ores carrying above 42 per cent. manganese are needed. Ores with manganese running between 20 and 42 per cent. are used for making spiegeleisen. But established practice in certain plants, based on the admixture of manganiferous iron ores to straight iron ores has greatly lessened the consumption of high-priced, scarce, manganese alloys with good results.

Jan 2, 1925

By C. S. Trewin

ZINC, in its wrought form, is produced commercially in rolled strip, sheet, wire, rod and tubing. Wire has been made periodically, but due to the fact that slight drafts are necessary, the cost of production is greater than for the more common non-ferrous metals which are made into wire. Notwithstanding the cost, zinc wire has certain special uses for which it is particularly adaptable. Rod has been made both by rolling and extrusion, the product, however, has not indicated great commercial value. Tubing has been made from strip from time to time by forming a strip around a mandrel and either electrically or gas-welding a longitudinal joint. Recently a tube manufacturer has succeeded in making a fair quantity of this material. Its commercial adaptability is still to be determined but anyone who desires it can obtain quantities of the smaller sizes. Inasmuch as strip and sheet are commercially the most important, this paper will be devoted to these products. In the broader sense, zinc is not alloyed. That is, there are no combinations comparable to the various copper, aluminum and nickel alloys. It has been recognized,, for some time, that the lead and cadmium occurring with commercial zinc have some effect on its properties and such alloys as may be said to exist are those made from zincs containing varying amounts of lead and cadmium with a relatively low iron content. The foreign rolled zinc will analyze higher in lead than the domestic grades. A representative foreign analysis will run 1.1 per cent. lead, 0.07 per cent. cadmium and 0.02 per cent. iron. The American grades vary from zinc approximating high grade. and analyzing 0.08 per cent. lead, 0.002 per cent. cadmium and 0.015 per cent. iron, to the lower grades in which the lead will vary from 0.3 to 1.0 per cent., cadmium from 0.10 to 0.5 per cent. and the iron in the neighborhood of 0.02 percent.

Jan 1, 1927

By M. J. Hordon, M. A. Wright

The well-defined increase in fatigue life observed o many metals cyclicly strained at vacuum levels below 10-1 to 10-3 torr has been attributed to the critical retardation of oxygen or water vapor chemisorption at the crack tip during crack propagation.1-3 In the absence of strongly adsorbed surface films, crack re-welding during cyclic compression or dislocation escape from the plastic zone around the crack tip has been proposed to account for the observed decrease in the rate of crack growth. The increase in the critical pressure required for the transition in crack growth rate with temperature experimentally determined for aluminum was found to be generally in accord with the adsorption rate model.4 However, although the adsorption mechanism would also predict an increase in transition pressure and fatigue life with increase in cyclic loading rate, and such effects were noted by Snowden5 for lead and Hordon3 for aluminum, the opposite results were reported by Kramer et al.B in studies on aluminum. The present note describes some recent measurements of the fatigue properties of 1100-H14 aluminum at low pressures to determine the specific effect of cyclic strain frequency in the transition pressure range. Flat cantilever-type specimens of 1100-H14 aluminum shaped to produce a uniform strain gradient along the gage length were tested in reverse plane bending at constant deflection amplitudes in two independent multi-specimen vacuum fatigue systems. One series of tests using 2-in. gage length specimens was conducted in an ion pumped apparatus with 107 torr and 50 cps capacity, denoted as Unit I, utilizing fixed mechanical cams to impose the strain amplitude. An independent test series using shorter 1-in. gage length specimens was conducted in a cryopumped apparatus designed for extremely low pressures below 10-10 torr, denoted as Unit II, using an electromechanical vibrator at non-resonant frequencies up to 150 cps to provide the deflection. Both vacuum fatigue units and associated test procedures have been described previously.3'7

Jan 1, 1969

While coal was undoubtedly seen by the early travellers within the state, the first mention of it was in the late 1820's when hunters put some stones from a creek bed under the logs of a large camp fire, and awoke later to find the stones on fire. The stream was later named Coal Branch; the location was at the eastern side of the present Bibbs County.1 In the Louisville Daily Journal of Feb. 11, 1831, the following short editorial note appeared: "Tuscaloosa Coal.-A small quantity of this article has reached Mobile, and has been tried in the office of the Patriot; it is said to be an excellent article. We invite such of our friends as desire economy in fuel, love a cheerful and constant fire, or would eschew a smoky room, to call and examine." On a geological map published in 1832, the "Carboniferous group" is shown and a spot near Tuscaloosa indicated as showing bituminous coal,2 and this is again alluded to in Morton's Synopsis, 1834. A brief description of the coal fields in the state in 1834 said that in winter coal was brought down the. Black Warrior River to Mobile and sold there at the same price as Liverpool coal, $1.00 to $1.50 per barrel, ($10 to $15 per ton) and that the writer was using it in his laboratory.3 At that time it was in local use by smiths and an iron foundry was using it in Shelby County.4 In 1836 some coal was mined in the Birmingham district, chiefly in the northern portion of the Coosa basin, where it was loaded on barges and taken down the Coosa Rivers.5 "William Whitman dug coal out of Wolf Creek (Walker County) in 1837," and in the same county, in 1839, the first coal shaft in the state, was sunk. This was near the mouth of Lost Creek and was known as Frierson's Shaft. It was operated by a hand windlass, using two tubs.1

Jan 1, 1942

By J. Morgan Clements

The manufacture of coke in Peru, as practiced at the coalmines of the Quishuarcancha and Goyllarisquisca districts, is intermediate between the primitive coke-heap and the bee-hive oven. The method of coking is quite simple. In constructing the coal-heap, preparatory to burning, the ground is first leveled, and a simple stack of stone and clay is built, giving the bottom, to a height of 6 ft., approximately 6 ft. of external diameter. The size of the stack varies in different districts, but is generally 9 ft. high, and slightly smaller at the top than at the bottom. The walls of the heap are from 12 to 14 in. thick, which allows an inside diameter of from 3.75 to 4 ft. These walls are pierced at intervals by three or more tiers of openings or flues, connected with the central flue. The radial flues have a diameter of about 5 in. and are built with a gentle upward slope. The stack (shown in Fig. 1) is permanent; and in this respect the practice in Peru differs from other primitive practices in which nothing is permanent except the yard. Above the permanent 6-ft. portion of the stack there is added a cap of clay, about 3 ft. high, which contracts toward the top, where it has an inside diameter of about 2 ft. This clay cap is temporary, and frequently has to be renewed after each burning. Before charging the coal, there are first built, from the lowest tier of flues upon the ground, a number of temporary flues, leading from the central stack out to the edge of the coal-heap, and constructed of blocks of coal for the greater part of the distauce, the outer edge alone being of rough stoue. The coal is then piled up over these flues and around the stack to a height of about 6 ft. The bottom flues are the only ones that

Jan 1, 1905

By N. Jaffe, J. E. Dorn

The effect of stress on the creep rate of high-purity poly crystalline aluminum in the intermediate temperature range was investigated by conducting creep tests at a series of different stresses and by decreasing the stress abruptly during the course of primary and secondary creep. Three series of decreases in stress tests were conducted: the stress was decreased in primary and secondary regions of creep at 347.5°K and the stress was decrensed in primary creep at 327°K. The results demonstrate the effects of structure and temperature on the stress dependence of the creep rate. The trends in the creep rate after a drop in stress are complicated and show that recovery takes place. The experimental results were compared with Friedel's theory for cross-slip, the experimentally determined energy for a constriction being in good agreement with the theoretical estimate proposed by Stroh. PREVIOUS investigations have shown that the ap-- parent activation energy for creep of polycrystalline aluminum, over the range from about 250° to 380°K, is approximately 27,400 cal per mole,' a value that is to a first approximation insensitive to the applied stress, the creep rate, and the creep strain. Several facts strongly support the thesis that creep, in this temperature range, is controlled by the rate-determining mechanism of cross-slip: 1) Recovery of the cold-worked state can take place by a number of mechanisms prominent among which is climb and cross-slip. Astrom2 reported rapid recovery of cold-worked polycrystalline aluminum at 340° to 370°K giving an activation energy of 28,000 cal per mole and additional recovery at the higher temperatures of 455° to 478°K giving an activation energy of 36,000 cal per mole. Whereas the latter process was clearly identified with the climb mechanism, the former process. which has an activation energy in good agreement for that of creep in the same temperature range, is most likely due to recovery by thermally-activated cross-slip. 2) Single crystals of aluminum exhibit sharp slip-

Jan 1, 1962

By Sir Robert A. Hadfield

The Hadfield method of producing sound steel ingots has been the subject of a paper read before the Iron and Steel Institute, so that it will be unnecessary to describe it fully here. The object of the method is to make poseible the production of steel ingots in which the pipe is almost entirely obliterated, and it is applicable particularly to the production of sound ingots, from which good rails could be rolled. The method in brief consists in casting the ingots on cars, usually with the small end down. Each ingot mold is provided with a sand top, rammed up in the well-known manner. After the mold is filled to the desired height with steel, a layer of slag about 0.5 in. thick is placed upon it and the balance of the mold is then filled with charcoal. Then, through suitable piping, an air blast is directed in numerous jets upon the charcoal, which is burned thereby, the combustion supplying addi, tional heat to the top of the ingot, which helps to keep the top fluid and to retard its solidification, while the lower parts are rapidly losing heat by its transfer to the mold. By one plan the ingots are cast in molds placed upon bogies, movable trucks, or platforms, in the position A, Fig. 1. The ingots are cast vertically on bogies, say four or more ingots on each bogie, as may be found most convenient, and the upper surface of the steel is maintained in a molten condition during the transit of the ingots from the casting pit to the stripper. This is effected by a series of air pipes, for example, three in number, with jets or holes on the under surface of such pipes, placed preferably horizontally, arranged in such a manner as to cause jets of air to impinge on the upper surface of the ingots. These holes or jets are made throughout the entire length of the overhead pipes, the length of such pipes being

Jan 1, 1914

By Charles R. Simcoe

The stress-strain curves in the microyield region for various Fe-C solid solutions shown by Davies and Ku are typical examples of parabolic curves defined by the expression a = kEn 111 These data, when replotted on log-log coordinates, as shown in Fig. 9, exhibit three essentially parallel straight lines. It is apparent that carbon increases the flow stresses, but does not affect the exponent n. In other words, the only factor in Eq. [1] affected by in in carbon content is the constant k. As Eq. [1] is written k is the stress at a strain of 1.0. This is unsatisfactory for examining data in the microyield region. Therefore, the equation can be altered to the form: to permit the use of the authors' microyield stress at a strain of 10-6 as k. Extrapolating the curves in Fig. 9 to a strain of 10-6 gives stress values of 2000, 3200, and 5400 psi for 0.008, 0.014, and 0.02 pct C, respectively. These values do not agree exactly with the authors' measured values, but this will not affect the following discussion. The effect of carbon content on the slopes of the stress-strain curves shown in Fig. 2 of the paper by Davies and Ku can be analyzed by differentiating Eq. [2] with respect to strain. Thus: where n is always less than 1.0. Since n is essen- tially constant as a function of carbon content for the data under discussion, the slopes of the stress-strain curves depend only on k and E. If the slopes are examined at various selected Plastic strains. i.e., 10-6, 10-5, and so forth, it follows from Eq. [3] that the dif-ferent slopes for the different carbon contents depend only on the different values of ke=10-6. Thus, the larger ke=10-6, the steeper the linear stress-strain curve will rise with increasing plastic strain. This

Jan 1, 1969

By E. P. Jennings

These unique copper-deposits occur on the top of the Kaibab Plateau, in Cocouino county, Arizona, and extend from the northern edge of the Grand Cañon of the Colorado river to near the Utah State line. The best-developed deposits are near Jacobs Lake, 30 miles south of the Utah line, where they are 16 ft. thick, of unknown width, and are more or less continuous for 5 miles. From Jacobs Lake to the edge of the Grand Cañon, a distance of 40 miles, outcrops of ore have been found, but no explorations have been made except those of wandering cowboys and hunters. The Kaibab Plateau, the highest of the Colorado river plateaus, is a great uplift, about 90 miles long from north to south, and from 10 to 20 miles wide from east to west. Its southern face is the Grand Cañon; its western boundary a N—S. fault plane, which separates it from the Eanab Plateau, lying 1,500 ft. below. Its eastern edge is a monocline which brings the horizontal beds of the high plateau to the level of the plateaucountry of eastern Utah. The elevation of the plateau near the Colorado river is over 8,000 ft., and about 6,000 ft. at the Utah line. Its structure, as shown by the western fault, consists of about 500 ft. of Aubrey limestones underlain by 1,000 ft. of red sandstones. The limestone is the upper member of the Carboniferous, and is overlaid by the marls and shales of the Permian, 25 miles to the north on the Kanab Plateau. At the town of Kanab, near the Utah line, the Permian strata pass under the magnificent redsandstone cliffs of the Triassic, that rise to heights of 1,000 ft. above the desert. The Grand Cañon exposes a section a mile deep at the southern end of the plateau, showing all the formations from the Archean to the top of the Carboniferous.

Jan 1, 1904

By R. G. Baughman

With the constantly increasing sales competition, coal to be sold today must meet the test of quality in every respect. The producers must be able to make all marketable sizes that will meet such general requirements as follows: 1. Ash content must be consistently low, depending upon the use to be made of the coal. 2. Sulfur content must be controlled accurately according to requirements. 3. All sizes must be positively free from visible impurities. 4. Free moisture of washed sizes must be reduced to a minimum. 5. The freezing of wet coal in cars must be prevented. 6. The percentage of fines in small mixed sizes must be controlled to give the uniform and proper combustion when used on various types of automatic stokers. 7. The undersize particles or degradation caused by handling must be kept to an absolute minimum in all sizes loaded. Many difficulties may be met in bringing any particular coal to meet these quality requirements, because the extent to which the quality of a coal may be controlled is determined largely by its physical characteristics. Preparation of an Impure Coal Bed The application of modern and scientific methods in the controlled preparation of bituminous coal from a bed in the mid-western field will illustrate the results that can be accomplished by adequate preparation: The bed referred to contains coal inherently excellent as to low ash and other desirable characteristics; in fact, the coal itself is one of the best in the field. It is, however, divided into four layers by dirt bands of soft shale 1 to 2 in. thick. It also contains much sulfur in the form of sulfur lenses and laminated sheets. Horsebacks or rolls varying from 6 in. to 12 ft. in width are encountered in the mining of the bed and heretofore have rendered it practically unworkable. The mines operating in this

Jan 1, 1931

By Gerhard Derge, Harold Markus

The introductory paper1 of this series described the potential behavior of tin in sodium carbonate and bicarbonate solutions whose pH ranged from 8.4 to 11.2 and demonstrated that significant and reproducible results could be obtained by proper attention to experimental technique. In examining the corrosion of tin under such conditions, it is desirable to know the effects of anions, aside from carbonate, that are likely to be present in commercial materials packaged in tin. Therefore, in this paper the potential behavior of tin in carbonate solutions to which sodium fluoride, chloride, bromide, iodide, sulphate, nitrate, monobasic phos-phate, dichromate, perborate and acetate have been added will be dcscribed. For most of the additions, solutions containing 0.001 and 0.01 moles of the added material were studied. The experimental procedure was exactly the same as that described in the first paper; the pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicar-l,ol~ate as follows: pH 0.1 M NaHC0............................................ 8.4 2 parts 0.1 M XaHCOr, 1 pa.rt 0.1 M NaZCO?................. 9.5 1 part 0.1 M NaHCOs, 2 parts 0.1 M iVa.,C03. ................ 10.0 0.1 M Na2C0............................................. 11.2 The reagents used were all of C.P. grade. The anions studied may be divided into three groups: (1) anions that had little or no effect upon the potential curves—sulphnte, nitrate, and acetate; (2) those that helped to prevent corrosion at low pH only -fuoridc, chloride, bromide, and iodide; (3) those that helped to prevent corrosion at high pH also—phosphate, pcrborate, and chromate. Potential Measurements f The time-potential curves represntative of group 1 are shown in Fig. 1. These are the curves for 0.005 M sulphate ion and their similarity

Jan 1, 1939

By Harold Markus, Gerhard Derge

The introductory paper1 of this series described the potential behavior of tin in sodium carbonate and bicarbonate solutions whose pH ranged from 8.4 to 11.2 and demonstrated that significant and reproducible results could be obtained by proper attention to experimental technique. In examining the corrosion of tin under such conditions, it is desirable to know the effects of anions, aside from carbonate, that are likely to be present in commercial materials packaged in tin. Therefore, in this paper the potential behavior of tin in carbonate solutions to which sodium fluoride, chloride, bromide, iodide, sulphate, nitrate, monobasic phos-phate, dichromate, perborate and acetate have been added will be dcscribed. For most of the additions, solutions containing 0.001 and 0.01 moles of the added material were studied. The experimental procedure was exactly the same as that described in the first paper; the pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicar-l,ol~ate as follows: pH 0.1 M NaHC0............................................ 8.4 2 parts 0.1 M XaHCOr, 1 pa.rt 0.1 M NaZCO?................. 9.5 1 part 0.1 M NaHCOs, 2 parts 0.1 M iVa.,C03. ................ 10.0 0.1 M Na2C0............................................. 11.2 The reagents used were all of C.P. grade. The anions studied may be divided into three groups: (1) anions that had little or no effect upon the potential curves—sulphnte, nitrate, and acetate; (2) those that helped to prevent corrosion at low pH only -fuoridc, chloride, bromide, and iodide; (3) those that helped to prevent corrosion at high pH also—phosphate, pcrborate, and chromate. Potential Measurements f The time-potential curves represntative of group 1 are shown in Fig. 1. These are the curves for 0.005 M sulphate ion and their similarity

Jan 1, 1939

By William M. Bowron

In the hope that a brief description of the conditions that are favorable or unfavorable to success in the practical treatment of titaniferous ores in the blast-furnace may not be without interest to the members of the Institute, the present paper is submitted. The class of ores of which I speak may be described as magnetites, with a gangue of siliceous matter, in which a portion of the silica is replaced by titanic acid. Professor Dana, in his System of Mineralogy, gives a long list of representative analyses of titanic iron ore in which the percentage of titanic acid varies from 59 down to 34. If the percentage is below the latter figure, the ore is no longer recognized as a "titanic ore;" although, according to my experience, titanic acid is present, in small quantities, in almost all ores. In the methods followed in ordinary analysis it is usually included with the "insoluble matter," unless special search is made for it. In the ores usually regarded as "titanic "the proportion of titanic acid frequently assumes quasi definite percentages, such as from 4 to 5, 8 to 9,12 to 13, and so on, in an ascending scale to those higher percentages that do not at present concern us. The proportions quoted characterize large masses of ore that are now accessible to market and are lying idle only on account of the titanic stigma. My experience with titanic acid in the furnace began in England, fourteen years ago, with my being employed as chemist by the manager of the Norwegian Titanic Iron Company, which was at that time smelting, without mixture, ilmenite from Norway in a furnace 16' X 50'. The process, regarded as a process, was a perfect success; but the enormous quantity of fuel required, the small quantity of iron in the ore, and the cost and uncertainty of importation militated seriously against its commercial success, and a few years saw the attempt abandoned. The metallurgy being successful, an at-

Jan 1, 1883

By T. O. Massalski, J. D. Ayers

A massive transformation, 0 —am, takes place in a number of copper-based systems where the ß phase field at high temperatures extends to compositions that are slightly less solute-rich than the limits of the a phase field that exists at lower temperatures. Consequently a solid-state transformation becomes possible that does not involve a change of composition. Within this narrow range of composition the massive am phase can be usually produced in two ways: by a fast quench from the ß phase through the a phase field, or by pulse heating into the a phase field of an undecomposed ß phase retained at room temperature by a prior quench. In the Cu-Ga system the occurrence of a massive am phase has been also observed in alloys whose composition falls outside the equilibrium a phase field1 but not in the Cu-Zn system.2 We have recently observed the occurrence of the ß — am transformation also in two silver-based systems, Ag-Zn and Ag-Cd. The a and 0 phase fields in these systems again slightly "overlap" in a narrow composition range. In the Ag-Zn system this range falls between 36.7 and 40.2 at. pct Zn, and in the Ag-Cd system between approximately 41 and 42.5 at. pct Cd. Alloys were prepared from high-purity materials and cast in quartz tubes under inert atmosphere. No significant change of composition occurred during casting. After homogenizing in the 0 phase field, small pieces of each alloy were reheated at the homogenizing temperatures for a few minutes and quenched into various media. There were examined metallographic-ally after removal of surface layers that may have suffered from contamination or from the loss of the solute element. In the Ag-Zn system extensive areas of the am phase (identified by selective etching, observation of the slip trace variants, and occurrence of twinning) were observed in a comparatively low-zinc alloy (37.8 at. pct Zn) for all quenching media employed: iced

Jan 1, 1969

Development: Iron Ore In Peru Utah Construction Co., of San Francisco and a Peruvian Government corporation have signed an agreement for development of a large iron orebody in Peru. Most tests show 60 pct iron or better. Most of the ore is magnetite. Although ore will be shipped mainly to Eastern U. S. blast furnaces, shipments to the West Coast may develop as the orebody opens up. The construction firm indicated three American steel companies have shown interest in the project. The orebody is located 300 miles south of Lima and about 15 miles from the coast at the same longitude as New York City. Allen D. Christensen, executive vice-president of Utah Construction noted that the distance is shorter between Peru and the East Coast. The ore deposit measures about four to five miles in one direction and 10 miles in the other. As many as 15 outcroppings within these limits have been reported. Several of the outcroppings are thousands of feet long by several hundred feet wide, Christensen said. Shipments between 100,000 and 200,000 tons of ore per month are projected by the company. Cost of opening the mine to production may go over $5 million, Christensen said. It would include building of docks for ocean going vessels, housing, and heavy duty mining and processing equipment. The contract with the Peruvian government gives Utah Construction six to eight months for additional tests and a 20 year concession for mining the orebody. Peru will collect royalties on all ore. The company will also supply about 300,000 tons per year for an electric furnace to be installed by the Peruvian Government at Chimbote. No steel is produced in Peru now. Utah Construction formed the Argonaut Mining Co. last year, and was shipping iron ore from British Columbia to Japan at a rate of more than 50,000 tons a month, before winter weather decreased operations.

Jan 1, 1952

By C. A. Heberlein

C. A. HEBERLEIN,* New York, N. Y.-The results stated by Rey and Brevers are so startling that they are of great interest, as the concentration of a low percentage of cinnabar by differential flotation yields a high-grade concentrate in the presence of either arsenical or iron pyrite. The authors say: "Cyanide can thus be used to depress arsenopyrite and make a good cinnabar-arsenopyrite separation. A cinnabarpyrite separation could probably be effected in the same way." Corrosive sublimate at the present price of mercury would be a very expensive reagent but the expense would be justifiable if a high rate of concentration could be obtained with a high extraction. On my request, special tests were made in the Punitaqui mill in Chile along the line suggested by the authors, without any improvement of either grade or extraction. As the recovery of the cinnabar in a complex sulphide of chalcopyrite and pyrite gave unsatisfactory results, I had tests made at the testing laboratory of the American Cyanamid Co. at Stamford, Conn. As these tests turned out to be highly satisfactory, not only at Stamford but later at the mine, they are presented here. [AMERICAN CYANAMID TEST FEED PER CENT Si02 66.54 A12032.08 CaO0.70 MgO 0.00 Alkalis1.78 Fe15.63 Cu0.44 S9.42 Hg0.45 OZ. PER TON Ag0.95 Au0.151 Screen Analysis of Tailings, Per Cent Plus650.0 Plus 1001.32 Plus 15020.75 Plus 20019.85 Minus 20058.08] The pulp had a density of 22 and a pH of 7.8. Total time of conditioning was one minute. The reagent added was Texas fuel oil, 0.116lb. Of 33.7 Bé. gravity containing 0.9 per cent sulphur. Frother, 0.062 lb. of No. 5 pine oil. Rate of concentration of mercury was 25.7: 1 [ ]

Jan 1, 1941

By T. M. Chance

THE necessity of adopting improved methods of bituminous-coal cleaning at. many collieries is recognized by all familiar with the requirements of the various bituminous markets, the approaching exhaustion of the relatively small areas of inherently high-grade-coal, and the difficulties encountered in maintaining a uniform grade of shipped coal. Many coals lose much of their .market value by degradation in size, and, in any event, if the cleaning process is to contemplate wetting the coal the minimum amount of fines should be produced to prevent sludge losses and the difficulties resulting from the moisture content of the wet fines. Hence, it is desirable to by-pass the finer coal dry, if this can be done without too-great increase in impurities in the final product. This procedure has given excellent results at washeries at Steelton and in the Birmingham district. If the raw fines are too impure to permit admixture with the washed coal, it may be desirable to use dry methods, such as the pneumatic table, rather than to wet an excessive amount of such fine material. The bituminous-coal cleaning plant should therefore: (1) Treat the raw coal in as large lump as possible and without sizing; (2) eliminate degradation of pure coal -in the washing process; (3) avoid wetting the fines, if possible; (4) produce washed coal practically free from mechanically included impurities; (5) crush the refuse and retreat, if much intergrown coal, and refuse are present, rather than precrush the entire feed. Ordinary gravimetric methods of concentration, whether hydraulic or pneumatic, will not meet all of these requirements, as the large lump includes those sizes. now sent to the picking tables, if it is desired to treat material of such size. I do not know of any prior commercial method, based on the falling velocity, coefficient of friction or resistance to fracture, that permits the production of clean coal varying in size from, say, 10-in. lump to 1/16 -in. mesh.

Jan 6, 1924