Search Documents

By J. R. Long, T. R. Graham, R. G. Feustel, R. S. Dean

The comprehensive study of the copper-manganese-zinc alloy system in the Bureau of Mines Laboratories has so far been principally concerned with alloys that lie within the alpha solid solution field of the system. Two regions, one centering about 65 per cent copper, 10 manganese and 25 zinc, and the other centering about 70 per cent copper, 20 manganese, 10 zinc, have been carefully examined. These have indicated that when the alloys are made with electrolytic manganese considerable amounts may be readily introduced and that the strength and hardness are increased without excessive losses in ductility. In the course of the work of establishing the limits of the alpha solid solution range,3 enough of certain of the alloys was prepared to permit determination of their- physical properties at a future date. The 60 per cent copper alloys concerned here are part of that series. They cross through the alpha field and into the adjacent alpha plus beta and alpha plus X fields, and are of interest because they offer some information on the effects of manganese on alloys lying in these fields. Composition and Fabrication of Alloys The chemical composition of the alloys involved is given in Table I. They were intended to contain 60 per cent copper with manganese increasing from 5 to 25 per cent in 5 per cent steps and zinc decreasing from 35 to 15 per cent. The analyses are so close to the intended composition that the alloys mill be referred to hereafter by their norninal compositions. They were finished into sheet by cold-rolling and intermediate annealing procedurzs calculated to produce sheet $i6 in. thick, cold-reduced by 20, qo, 60, and 80 per cent in thickness. Physical properties were determined on standard flat tensile specimens with 4-in. gauge length, although the test gauge section used was 2 in. The properties were obtained on cold-worked material and on material annealed at temperatures ranging from 700' to r500°F. after 60 per cent cold reduction. Since an annealing temperature of 1200°F.

Jan 1, 1946

By Henry M. Howe

THIS paper gives the composition of the iron and slag at different stages in the "air-furnace" process of preparing "hard metal," or white cast-iron, for conversion into malleable cast-iron by annealing. The details of the process are given in an appendix. One of us had been trying for years to work some chemist of some of our malleable-iron works up to a degree of enthusiasm which would lead him to make such au investigation. It would have had the advantage of the greater familiarity with the conditions which one habitually on the spot must have. Failing in this, he made use of an opportunity which presented itself of taking samples here represented, with such fairness as the conditions permitted, holding firmly that a rough approximation to the truth is better than the complete lack of data, or that a bird in the hand is worth two in the bush. We hope that this attempt may stimulate others effectively to duplicate this work, and thus correct or confirm it. Our results are shown in Table I. and graphically in Figs. 1 and 2. Discussion.-At the time when the first two samples were taken, the metal and slag were still too sluggish to permit fair sampling, and not until sample 6 were the conditions really favorable, because at the time of the fourth sample the metal was not fully melted, and even at the time of sample 5 it was still sluggish. Indeed, the slag was probably very heterogeneous throughout, because it took up silica and alumina rapidly from the bottom, and because it was so siliceous as to be sluggish at this relatively low temperature. This hetero-geneousness is exaggerated in the two samples of slag 8, apparently by the great viscosity due to its extraordinary acidity. Note that the manganous oxide of one sample is about two and

Mar 1, 1909

By John Mark Patek

Knowledge of the relative floatability of silicate minerals is increasing in importance as flotation is being applied to the concentration of nonsulfides. Many silicates are in themselves commercial products amenable to concentration by flotation. Moreover, the selective flotation of other nonsulfide minerals, such as cassiterite, depends largely upon the floatability of associated gangue silicates. Differences in floatability existing between the various silicates have not- been sufficiently appreciated; for example, the feldspars that differ greatly in floatability have generally been merely treated as "feldspar." It was the purpose of the work described in this paper to determine by experiment the differences in floatability between silicates; to investigate the causes for such differences, and to discover a means of predetermining approximate floatability without the necessity of experimentation. Determining Floatability The relative floatability of 20 silicates so selected as to represent all of the more common silicate types1 was obtained by flotation tests enumerated in Table 1. The mineral to be floated was crushed dry on a steel plate, and screened repeatedly during crushing through an 80-mesh screen in order to produce a sand with all grains as close to 80 mesh as possible. The sand was placed in dilute (6N) hydrochloric acid until free of soluble foreign material, and then washed with tap water about ten times in order to remove both acid and fines. The resultant product, which averaged 82 per cent plus 200 mesh, was floated in 50-gram charges in a 50-gram Denver celluloid flotation machine with 0.008 gram of terpineol, and from 0.01 to 0.05 gram of oleic acid in a solution acidified with sulfuric acid. The degree of separation of one mineral from another was determined by counting under a nlicroscope the grains of each mineral, both in the concentrate and in the tailings, and comparing their relative abundance in each. Unless the comparison showed a decided difference in amount,

Jan 1, 1935

By American Institute of Mining Engineers

David J. Mack (University of Wisconsin, Madison, Wise.)—Have the authors considered that the effects reported in their paper are readily explainable on the basis of equilibrium grain boundary segregation rather than ordering? It seems to the writer that all of their experiments and observations correlate well with known behavior associated with equilibrium grain boundary segregation. Although at first glance one would tend to dismiss such a possibility because of the similarity of the gold and copper atoms, their sizes differ by 12.8 pct which is in the range where segregation at grain boundaries would be expected. Then, too, the electrochemical differences between the copper, the Cu3Au, and the gold strongly suggest that a segregation mechanism is involved in the corrosion of the Cu-Au alloys. R. Bakish and W. D. Robertson (authors' reply)—The authors would like to thank Dr. Mack for his consideration of the problem of grain boundary segregation as an explanation of the observed phenomena. We had considered the problem in the following terms: Assuming a pure binary Cu-Au alloy and an ideal solid solution, the surface excess, T2= N25 — N2, of the second component (gold) may be expressed in the following way20 1 —exp (—da/kT) where 8 is the difference in surface tension of copper and gold, and a is the surface area per atom. In the present case, 6 is positive which implies that the component in excess at the boundary is gold. Since the only chemically active component in ferric chloride is copper, it does not appear that the segregation of gold is likely to increase the boundary activity. A small concentration of a third component could profoundly affect the situation. Analysis indicated only spectrographic traces of impurities, all of which are soluble in both copper and gold. Quenching experiments, reported in the paper, also tended to eliminate significant effects attributable to a third component.

Jan 1, 1958

By L. H. Levenson, Charles S. Barrett

Since 1925, when the preferred orientations in compressed aluminum were first determined1,2 the orientations have been described as a fiber texture in which a face diagonal, [110], of the face-centered cubic lattice is parallel to the compression axis. Subsequent experiments have seemed to confirm this texture,3-5 and a number of theories (recently summarized in references 6 and 7) have been proposed to explain it and to relate it to the behavior of single crystals during compression.3,8-11 The experiments reported in this paper prove that the orientations are not adequately described as quoted above—i.e., as a [110] fiber texture—although this is a first approximation to the actual texture. They also show that the texture cannot be thought of as a stable orientati011 that is reached and maintained after a sufficient amount of deformation. The actual texture, when studied in detail at successive stages of compression, indicates that a hitherto unsuspected range of orientations is present, both in the polycrystalline metal as a whole and in various individual grains in its interior, and that a state of dynamic equilibrium exists within this range. The reasons for the failure of previous theories to predict the actual texture become obvious when the heterogeneous nature of the flow is considered. In addition to the deformation texture, the manner of its development, and its theory, this paper presents data on the following related subjects: the identity of strain markings in aluminum; the orientation changes in aluminum single crystals during compression and a comparison of these with the conditions in individual grains of a polycrystalliile specimen; the origin of asterism ill deformed single crystals, which heretofore has been regarded as a distortion localized at the surfaces or slip planes; and the relation of plastic strain in individual grains ill all aggregate to the strain of the whole.

Jan 1, 1940

By Charles S. Barrett, L. H. Levenson

Since 1925, when the preferred orientations in compressed aluminum were first determined1,2 the orientations have been described as a fiber texture in which a face diagonal, [110], of the face-centered cubic lattice is parallel to the compression axis. Subsequent experiments have seemed to confirm this texture,3-5 and a number of theories (recently summarized in references 6 and 7) have been proposed to explain it and to relate it to the behavior of single crystals during compression.3,8-11 The experiments reported in this paper prove that the orientations are not adequately described as quoted above—i.e., as a [110] fiber texture—although this is a first approximation to the actual texture. They also show that the texture cannot be thought of as a stable orientati011 that is reached and maintained after a sufficient amount of deformation. The actual texture, when studied in detail at successive stages of compression, indicates that a hitherto unsuspected range of orientations is present, both in the polycrystalline metal as a whole and in various individual grains in its interior, and that a state of dynamic equilibrium exists within this range. The reasons for the failure of previous theories to predict the actual texture become obvious when the heterogeneous nature of the flow is considered. In addition to the deformation texture, the manner of its development, and its theory, this paper presents data on the following related subjects: the identity of strain markings in aluminum; the orientation changes in aluminum single crystals during compression and a comparison of these with the conditions in individual grains of a polycrystalliile specimen; the origin of asterism ill deformed single crystals, which heretofore has been regarded as a distortion localized at the surfaces or slip planes; and the relation of plastic strain in individual grains ill all aggregate to the strain of the whole.

Jan 1, 1940

By Russell Franks, W. O. Binder

In recent years a considerable tonnage of the 18 per cent chromium and 8 per cent nickel steels has been used in lightweight high-strength structures that must be resistant to deterioration under atmospheric conditions. These steels are austenitic in character and their strength can best be increased by cold-working. Although a marked increase in tensile strength is obtained, claims have been made that the cold-worked steels do not possess fully satisfactory elastic propertics. Under certain conditions, however, this has caused no great concern, because, as explained by Ragsdale,1,2 he cold-rolled steels have been widely applied for construction of lightweight, high-strength trains using spot welding for joining purposes. Ffield3 agrees that the ease with which thin sections of the cold-rolled 18-8 steels can be joined by spot welding is greatly in their favor, but that they would be more satisfactory if higher elastic properties and a higher modulus of elasticity could be obtained. He states that, as far as the mechanical properties are concerned, the straight chromium stainless steel is superior to the cold-worked 18-8 steel, and in order to illustrate, he prcsented the data of Fig. 1, which also give a stress-strain curve for a low-carbon 13 per cent Cr steel. Ffield† proposed that columbium-bearing or titanium-bearing cold-rolled 18-8 steels be given a heat-treatment (preferably for 1 hr.) in the range 400" to 600°C. to precipitate carbides in order to obtain better mechanical properties. Discussions by Sutton,4,5 de Ganahl,6,7,8 Krivobok and Lincoln,' Knerr,l0 and Thaden11 have given further information on the properties of the cold-rolled 18-8 steels compared with other materials used in lightweight, high-strength structures. These investigators and others point out that the ultimate tensile strength of the cold-rolled 18-8 steel can be increased to 200,000 lb. per sq. in. or higher; Krivobok et al. indicate that

Jan 1, 1940

By Russell Franks, W. O. Binder

In recent years a considerable tonnage of the 18 per cent chromium and 8 per cent nickel steels has been used in lightweight high-strength structures that must be resistant to deterioration under atmospheric conditions. These steels are austenitic in character and their strength can best be increased by cold-working. Although a marked increase in tensile strength is obtained, claims have been made that the cold-worked steels do not possess fully satisfactory elastic propertics. Under certain conditions, however, this has caused no great concern, because, as explained by Ragsdale,1,2 he cold-rolled steels have been widely applied for construction of lightweight, high-strength trains using spot welding for joining purposes. Ffield3 agrees that the ease with which thin sections of the cold-rolled 18-8 steels can be joined by spot welding is greatly in their favor, but that they would be more satisfactory if higher elastic properties and a higher modulus of elasticity could be obtained. He states that, as far as the mechanical properties are concerned, the straight chromium stainless steel is superior to the cold-worked 18-8 steel, and in order to illustrate, he prcsented the data of Fig. 1, which also give a stress-strain curve for a low-carbon 13 per cent Cr steel. Ffield† proposed that columbium-bearing or titanium-bearing cold-rolled 18-8 steels be given a heat-treatment (preferably for 1 hr.) in the range 400" to 600°C. to precipitate carbides in order to obtain better mechanical properties. Discussions by Sutton,4,5 de Ganahl,6,7,8 Krivobok and Lincoln,' Knerr,l0 and Thaden11 have given further information on the properties of the cold-rolled 18-8 steels compared with other materials used in lightweight, high-strength structures. These investigators and others point out that the ultimate tensile strength of the cold-rolled 18-8 steel can be increased to 200,000 lb. per sq. in. or higher; Krivobok et al. indicate that

Jan 1, 1940

By John Birkinbine

The experience of the past five years has furnished opportunities to study and to partially explain the operation and some of the causes of the short blast of Warwick Furnace at Pottstown, Pennsylvania, as described in the paper read at the Lake Superior Meeting, in August, 1880.* The many inquiries concerning the details of furnace operation which followed the publication of the paper, and the expressed desire of furnace managers to be informed as to future operations of this plant, have encouraged the preparation of the following data. To make the record continuous, and add to the value of both contributions, the present paper commences where the review of a short blast of Warwick Furnace ended, and includes the data of another short blast of two months, and a subsequent continuous campaign of nearly five years, which, by comparison, we shall designate as "the long blast." Frequent visits to the plant in the five years, during which its operation could be studied, and correspondence with the manager, Mr. Edgar S. Cook, have given a knowledge as to general features and details, and the courtesy of the officers of the Company which has given free access to the books of record permits the presentation of data which it is believed will be welcomed by furnace managers. Interest will undoubtedly be increased by the remarkable results which Mr. Cook has achieved chiefly with anthracite coal in a furnace whose details of construction will scarcely be generally admitted as embodying advanced ideas, its height being but 55 feet, with a bosh diameter of 15 feet 6 inches, its bosh-slope comparatively flat, its crucible smaller than the average, and the heat of the blast never reaching 1000' Fahrenheit. At present writing the credit of the best anthracite blast-furnace practice recorded in our Transactions is conceded to be that pursued by Mr. Fackenthal, at the Durham furnace, and Mr. Cook, at War-

Jan 1, 1886

By Norman Pilling

The micrographic analysis of silicon steels is possible if a dilute solution of nitric acid and methyl alcohol in nitrobenzol is used. The action of this reagent differs from that of sodium picrate in that there is no persistent deep-seated staining and the solution is used cold. THE technical difficulties hampering the metallographic analysis of silicon steels are chiefly the result of the extreme corrodibility of these alloys. The addition of silicon to iron in increasing quantities, up to about 6 per cent., rapidly increases the susceptibility of the alloy to chemical attack, not only in acid solution, but in water. This renders the preparation of metallographic sections very difficult, because of a non-selective attack upon the finely polished surface by the water used as a lubricant in polishing. This water attack masks the true structural details revealed by suitable etching reagents. It is thus necessary to use alcohol as a polishing lubricant in the last stages of preparation and to avoid all etching reagents having an aqueous base. A specific reagent for the identification of iron carbide in ferrous alloys, and the one hitherto used almost exclusively by metallurgists, is an alkaline aqueous solution of sodium picrate, which stains this constituent selectively. Its application to silicon steels has not proved successful, as its distinctive selective action is more or less completely hidden by the general attack of the aqueous solvent on the silico-ferrite, greatly accentuated by the fact that this reagent must be used at its boiling temperature (105° C.). Thus, a powerful metallographic aid to the study of the higher silicon alloys, such as transformer steels, is lost. A new reagent has been developed for the purpose of overcoming this difficulty. It is with some hesitation that the list of etching reagents, already overburdened, is increased, but the properties of this new reagent are advantageous in several ways and a definite field for it may be found in the metallography of ferrous alloys.

Jan 1, 1924

By Cyril Stanley Smith, W. Earl Lindlief

A study of the mechanical properties of the alloys of copper and silver led to the discovery that the solubility of silver in copper was greatly different from that generally supposed, therefore some work was done to determine the solubility with greater accuracy than had previously been achieved. After the work had been completed, two papers were published' giving solubility figures which agreed closely with one another and with the work described herein. A detailed comparison of that work with the present will be given later. Preparation of Allots The copper used in making the alloys was electrolytic ingot of high purity. The silver was prepared by precipitation as chloride from nitric acid solution, followed by fusion of the washed precipitate with sodium carbonate and potassium nitrate. This method gives metal containing at least 99.99 per cent silver. The copper was first melted under charcoal in a small electric resistance furnace and the silver added as pure silver, it being unnecessary to make any intermediate alloys. After thorough stirring the metal was poured into a mold of suitable form. The alloys contained between 0.008 and 0.015 per cent of oxygen. Small amounts of oxide were visible under the microscope, but it is not believed this would have much effect on the results. Copper-silver alloys are notorious for segregation, consequently a few experiments were carried out to find a form of casting with as little segregation as possible. A mold 6 in. long and 1/2-in. dia. was first used, and an alloy nominally containing 5 per cent silver was cast in it, while some of the same alloy was poured directly into water to obtain the maximum rate of cooling possible. Analyses were made both on this sample and on turnings from the top and bottom of the 1/2 in. dia. cast-ing, the turnings being separated into three parts according to the position

Jan 1, 1932

By J. L. Bray

Lead has often been suggested as a protective coating for iron and steel. Such a protective coating should possess: (1) good adhesion, (2) durability, (3) ease of application, (4) freedom from pinholes, (5) good appearance and (6) low cost, but, unfortunately, lead coatings so far produced do not have all of these characteristics. Because of the necessity of carrying out the coating process cheaply, and because lead solutions have poor plating characteristics, most of the efforts have been directed toward the hot-dipping process rather than electroplating. The hot-dipping processes using lead have not been successful chiefly because of the lack of adherence between iron and lead. In any coating process involving iron a bond can be obtained only by the formation of an intermetallic compound, the formation of a solid solution, or mechanical means. Lead forms with iron two immiscible liquid solutions, and in the solid state no intermetallic compounds or solutions. It is necessary, therefore, to employ some other element or elements as a binding agent. Tin may be used as in terneplate, or copper in the form of a thin film of electrolytically deposited metal to which the lead will adhere. Because of its physical and chemical properties, lead as a coakkg medium would undoubtedly be limited in its use to sheet and wire and then only when the article is not subject to abrasion or wear. A very large tonnage of these products is being used under such conditions and a successful lead-coating process should be a valuable contribution to the science. Two other difficulties stand in the way of successful lead coating—that of poor appearance of the weathered surface and the tendency of the lead to form pinholes during solidification. Since lead is commonly accepted as cathodic to iron, these exposed areas are ones of accelerated corrosion. Use of Zinc.—The method under consideration involves zinc as a binding agent on both the steel sheet and in the molten bath. This

Jan 1, 1937

By L. C. McCabe

This paper is a progress report on a study of the distribution of the banded ingredients (Figs. 1 and 2) in Illinois screenings and the method of determining their distribution. Proximate analyses and screen tests1 have been reported and a further report on the washability characteristics of the screenings is in preparation. The microscopic study of the screenings is not yet far enough advanced to permit a conclusive report on the effect of mining, screening and washing on the distribution of the banded ingredients in the coals of Illinois. However, considerable fundamental data have been collected as a background for the screenings investigation and for a proposed study of fuels composed of known quantities of vitrain, clarain and fusain, the three common banded ingredients of Illinois coals. These fundamental data and the preliminary information now available from the microscopic study of screenings are broadly indicative of the reaction of the coals to the physical processes affecting them in mining and preparation. Proximate analyses of samples of vitrain, clarain, and fusain from several Illinois mines have been published2, but those given in Table 1 serve to show the differences that are apparent in proximate analyses. The vitrain samples are consistently low in ash, and the unit-coal value is uniformly lower than in clarain. The average fuel ratio (F.C./V.M.) of the vitrain samples in the table is 1.57 whereas the clarain average is 1.42. The fusain analyses vary considerably in ash and moisture. In the two samples from this mine the moisture values range from 8.99 to 22.80 and the ash from 4.86 to 16.91 per cent. Fusain has higher fixed carbon than either vitrain or clarain but the percentage is erratic from sample to sample. The relative proportions of the banded ingredients in the Herrin (No. 6) coal in Illinois is reasonably well known but detailed information

Jan 1, 1936

By L. C. McCabe

This paper is a progress report on a study of the distribution of the banded ingredients (Figs. 1 and 2) in Illinois screenings and the method of determining their distribution. Proximate analyses and screen tests1 have been reported and a further report on the washability characteristics of the screenings is in preparation. The microscopic study of the screenings is not yet far enough advanced to permit a conclusive report on the effect of mining, screening and washing on the distribution of the banded ingredients in the coals of Illinois. However, considerable fundamental data have been collected as a background for the screenings investigation and for a proposed study of fuels composed of known quantities of vitrain, clarain and fusain, the three common banded ingredients of Illinois coals. These fundamental data and the preliminary information now available from the microscopic study of screenings are broadly indicative of the reaction of the coals to the physical processes affecting them in mining and preparation. Proximate analyses of samples of vitrain, clarain, and fusain from several Illinois mines have been published2, but those given in Table 1 serve to show the differences that are apparent in proximate analyses. The vitrain samples are consistently low in ash, and the unit-coal value is uniformly lower than in clarain. The average fuel ratio (F.C./V.M.) of the vitrain samples in the table is 1.57 whereas the clarain average is 1.42. The fusain analyses vary considerably in ash and moisture. In the two samples from this mine the moisture values range from 8.99 to 22.80 and the ash from 4.86 to 16.91 per cent. Fusain has higher fixed carbon than either vitrain or clarain but the percentage is erratic from sample to sample. The relative proportions of the banded ingredients in the Herrin (No. 6) coal in Illinois is reasonably well known but detailed information

Jan 1, 1936

By Albert H. Fay, William B. Plank

In practically all rock-excavation problem there is need for a careful study of the rock structure, its fault, cleavage or bedding planes, and even the texture of the rock itself. These studies should form the bases upon which an excavation method is selected and they should be carefully considered in predicting the amount and extent of the excavation. The need for such studies was forcibly illustrated in the problems involved in a cut made in 1929, along and underneath a 200-ft. high rock projection for a State highway near the City of Easton, Pennsylvania. The rock mass was badly faulted and also contained a number of cleavage planes at approximately right angles to the fault planes. Much of this structure was visible and could have been studied and analyzed before the work was begun. The State had rigid specifications as to finished grade and slope of cut, which apparently were made without reference to the geologic structure. The contractor complied with the specifications, under the close inspection of the State engineers. A tunnel blast was placed in the base of the cliff, with the result that 65 per cent more rock was broken than was intended by the specifications. About four years after the blast, the writers of this paper studied the circumstances surrounding the operation, to determine the cause of this excess excavation. Scope of Work The section of the roadway involved was about 200 ft. long and on a 6' curve. It was necessary to relocate points on the curve, from which all faults and cleavage planes were located and measured by the use of transit and clinometer. A plan (Fig. 1) showing the blasting tunnel, the roadway, and traces of the faults and cleavage planes on the level of the roadway, was prepared; also 13 cross-sections at varying intervals, showing the original face of the hill and the face after the blast. The original and final profiles of the rock face, taken from the plans of the State engineers, are shown in Figs. 2, 3 and 4.

Jan 1, 1937

By J. W. Halley

RIMMING steels derive their name from their action during solidifica-tion in the molds. As a result of incomplete deoxidation, gas is evolved during freezing, and the metal has a characteristic rolling action. The metal rises along the mold walls and descends in the center of the ingot. This action keeps the top of the ingot open and the advancing rim of solid metal can be seen. The rim grows until the rolling action is insufficient to prevent the top of the ingot from freezing or until the action is stopped by capping the ingot with a heavy plate. The violence of the reaction and its characteristics, such as growth or drop ill the molds, are deter-mined by the Composition, the furnace practice, and the deoxidation in the ladle and in the molds. Though rimming steels represent a large proportion of the amount of plain carbon steel made, they have received comparatively little attention in the technical literature. The manufacture of rimming steels has been described by Hibbard,1,2 Fleming,3 Pierce4 and Jackson.5 The reactions occurring during rimming have been considered from the theoretical point of view by Chipman and Samarin.7 The structure of rimmed-steel ingots has been discussed by Nead and one of the present authors.6 Meyer,8 in studying segregation, investigated the distribution of carbon, sulphur and phosphorus in rimmed-steel ingots by analyzing the rim and core of blooms. In their studies of segregation, the Joint Committee of the Iron and Steel Institute and the British Iron and Steel Federations studied distribution in one billet and one ingot of rimmed steel. A detailed study of the distribution throughout the ingot has not been published. The present investigation was undertaken to determine accu-rately the distribution of carbon, manganese and sulphur in normal rimmed ingots and the general distribution of other common elements present. The study included some work on the effect of pouring condi-tions and furnace practice on the distribution, though there is still much to be done in this direction.

Jan 1, 1938

By David Cole

At the time flotation appeared upon the metallurgical horizon in Arizona, the writer, under the direction of Dr. Ricketts, was engaged in remodeling and enlarging the No. 6 Concentration Plant of the Arizona Copper Co. at Morenci, and the work had been in progress nearly a year before the Inspiration experiments with flotation had disclosed the revolution in concentration that was at that time impending. The simplified flow sheet worked out for the remodeling of the Morenci plant had been based upon the removal of the freed metal in a minimum number of stages by treatment upon tables equipped with Butchart riffles, the latter being adapted to accomplish both classification of feed and removal of the metal at one operation, substantially as described in my previous paper.l The scheme of treatment for the slime was based upon the well-known fact that after copper sulphides, such as chalcocite and chalcopy-rite, etc., are reduced to a certain extremely fine state of comminution they are definitely beyond the reach of separation upon any of the concentrating devices then known. By using drag-belt classifiers (which served as conveyors as well as separators), the overflow ,would be of the usual "slimes" class. Experiment had shown that when these drag-belt overflows were properly diluted (that is, to about 5 to 7 per cent. solids in the feed under treatment) the very fine sand, and especially the very fine but still granular sulphide particles, would, if given a short distance to fall, quickly settle out in prime condition to yield an excellent recovery on vanners; a further valuable feature would be that the very fine non-separable final overflow tonnage might be discharged direct to tailing, thus conserving space requirements so as to permit within the old building, without embarrassment, the increase of capacity required. For reasons that are obvious, this kind of feed preparation for the slime could not be successfully accomplished in any form of pointed boxes or

Jan 1, 1917

By George F. Comstock

It has been reported recently1 that the hardenability and toughness of forging steels may be improved appreciably by the use of complex deoxidizers containing titanium, aluminum, and vanadium. In the light of these results, an investigation of similar deoxidizers containing various hardening and grain-refining elements was proposed. These deoxidizers included three manganese-silicon-aluminum-titanium al- loys with and without boron and calcium, three titanium-aluminum ferroalloys with vanadium, molybdenum and zirconium, respectively, an aluminum-zirconium ferroalloy, and plain ferroboron. Their approximate compositions are given in Table I, and the results obtained so far in the investigation of their effects on steel are presented in the later parts of this paper. Method of Using Deoxidizers The deoxidizers listed in Table I were used in three series of 0.40 per cent carbon steels, which were melted in a small basic-lined induction furnace and cast in the form of I7-lb. ingots about 2.75 in. square. The basic charge for each heat was 10 lb. Armco iron and 6 lb. of clean low-carbon sheet-steel scrap. When melted, this charge was deoxidized with 15 grams of ferrosilicon, then about 500 grams of pig iron was added to give the desired carbon content. After the pig iron was dissolved, nickel shot and high-carbon ferrochromium were added if required, and additions of 80 per cent high-carbon ferromanganese and 50 per cent ferrosilicon were made to provide the proper amounts of those elements. Aluminum was added to every heat 2 min. after the silicon, for grain-size control and preliminary deoxidation. One minute later the special deoxidizer was added to the clean bare surface of the molten steel, and 2 min. afterward the steel was poured into the ingot mold, using a hot-top and pipe-preventing compound after pouring to decrease the depth of the shrinkage cavity. The special deoxidizers were used mostly in the form of about ½ to¾-in. lumps,

Jan 1, 1942

By George F. Comstock

It has been reported recently1 that the hardenability and toughness of forging steels may be improved appreciably by the use of complex deoxidizers containing titanium, aluminum, and vanadium. In the light of these results, an investigation of similar deoxidizers containing various hardening and grain-refining elements was proposed. These deoxidizers included three manganese-silicon-aluminum-titanium al- loys with and without boron and calcium, three titanium-aluminum ferroalloys with vanadium, molybdenum and zirconium, respectively, an aluminum-zirconium ferroalloy, and plain ferroboron. Their approximate compositions are given in Table I, and the results obtained so far in the investigation of their effects on steel are presented in the later parts of this paper. Method of Using Deoxidizers The deoxidizers listed in Table I were used in three series of 0.40 per cent carbon steels, which were melted in a small basic-lined induction furnace and cast in the form of I7-lb. ingots about 2.75 in. square. The basic charge for each heat was 10 lb. Armco iron and 6 lb. of clean low-carbon sheet-steel scrap. When melted, this charge was deoxidized with 15 grams of ferrosilicon, then about 500 grams of pig iron was added to give the desired carbon content. After the pig iron was dissolved, nickel shot and high-carbon ferrochromium were added if required, and additions of 80 per cent high-carbon ferromanganese and 50 per cent ferrosilicon were made to provide the proper amounts of those elements. Aluminum was added to every heat 2 min. after the silicon, for grain-size control and preliminary deoxidation. One minute later the special deoxidizer was added to the clean bare surface of the molten steel, and 2 min. afterward the steel was poured into the ingot mold, using a hot-top and pipe-preventing compound after pouring to decrease the depth of the shrinkage cavity. The special deoxidizers were used mostly in the form of about ½ to¾-in. lumps,

Jan 1, 1942

By Percy Barbour

The town of Goldfield, Nevada, with the exception of six stone buildings, was burned to the ground to-day. One man is dead from causes attributed to the fire. A woman is missing and is believed to have perished and several persons were treated for burns as the result of the conflagration believed to have been of incendiary origin which started in the old Tenderloin District. The water supply was not sufficient and dynamite only scattered the frame structures and added kindling to the flames which were fanned by a forty-mile wind. Newspaper Dispatch, July 6. No former Goldfield resident could read that dispatch with unmixed feelings. About two o'clock one morning the crowded train from San Francisco landed me in Goldfield no more hours late than it habitually was. The desert air was clear and crisp and bracing but the pandemonium of cab and bus drivers did not drown out the sounds of music and merriment which floated from the blaze of light which was Goldfield about three-quarters of a mile from the station. As I stood in the ferry house, at the foot of Market Street, awaiting the Oakland Ferry, an old friend of mine, down to see who was departing for the greatest boom town of this generation, informed me that if I had made no reservation for quarters in Goldfield, I would be unable to obtain any, even chairs in the hotel lobbies were renting for $4 per night, and volun-teered the use of his room there for my convenience until his return. He described the house and location, which I identified without difficulty, but found no one to direct me to the room. I peered through a glass door into a room which seemed to be unoccupied and timorously entered and turned on the electric light., I found mail on the dresser addressed to my friend,

Jan 8, 1923