Search Documents

By Walter Crafts

Tests carried out at the Union Carbide and Carbon Research Laboratories, Inc., on the effects of grain-refining deoxidizers are in substantial agreement with the data presented by Mr. Comstock. Notable is the observation that, although boron and aluminum increased hardenability, the steel was of poor quality in comparison with the other boron-treated steels to which at least two grain refiners were added. The effect of zirconium in improving the ductility of the chromium-nickel steel is in agreement with our experience that zirconium is specifically beneficial to chromium steels. In order to amplify Mr. Comstock's results and to indicate some of the basic principles of special deoxidation, the primary observations of our study have been summarized. The effect of boron in increasing hardenability was described by R. Walther, U. S. Patent No. 1519388, Dec. 16, 1924, but effective amounts in incompletely deoxidized steel are sufficient to harm hot workability and room-temperature ductility. Work at the Union Carbide and Carbon Research Laboratories, Inc., has shown that in order to obtain deep hardening without using such large amounts of boron as to result in impairment of ductility, the steel must be thoroughly deoxidized. This may be accomplished by a high silicon content or a grain-refining addition of strong deoxidizers. The degree of grain refinement and hardenability are inclined to be erratic when only one grain-refining element is used, although aluminum, zirconium, titanium, and vanadium have been used singly and resulted in increased. although somewhat erratic, hardenability. The ductility likewise was inclined to be inconsisterlt when only one grain-refining deoxidizer was added. By combinations of grain-refining elements, it was found possible to combine the specific virtues and counteract some of the defects of each clement. In addition, the complex deoxidizers gave more consistent grain refinement and hardenability. When used in combinations, each element adds its own specific influence as well as modifying the character of the other elements. The function of aluminum is primarily to give consistent results and to minimize abnormalities resulting from too

Jan 1, 1943

By Walter Crafts

Tests carried out at the Union Carbide and Carbon Research Laboratories, Inc., on the effects of grain-refining deoxidizers are in substantial agreement with the data presented by Mr. Comstock. Notable is the observation that, although boron and aluminum increased hardenability, the steel was of poor quality in comparison with the other boron-treated steels to which at least two grain refiners were added. The effect of zirconium in improving the ductility of the chromium-nickel steel is in agreement with our experience that zirconium is specifically beneficial to chromium steels. In order to amplify Mr. Comstock's results and to indicate some of the basic principles of special deoxidation, the primary observations of our study have been summarized. The effect of boron in increasing hardenability was described by R. Walther, U. S. Patent No. 1519388, Dec. 16, 1924, but effective amounts in incompletely deoxidized steel are sufficient to harm hot workability and room-temperature ductility. Work at the Union Carbide and Carbon Research Laboratories, Inc., has shown that in order to obtain deep hardening without using such large amounts of boron as to result in impairment of ductility, the steel must be thoroughly deoxidized. This may be accomplished by a high silicon content or a grain-refining addition of strong deoxidizers. The degree of grain refinement and hardenability are inclined to be erratic when only one grain-refining element is used, although aluminum, zirconium, titanium, and vanadium have been used singly and resulted in increased. although somewhat erratic, hardenability. The ductility likewise was inclined to be inconsisterlt when only one grain-refining deoxidizer was added. By combinations of grain-refining elements, it was found possible to combine the specific virtues and counteract some of the defects of each clement. In addition, the complex deoxidizers gave more consistent grain refinement and hardenability. When used in combinations, each element adds its own specific influence as well as modifying the character of the other elements. The function of aluminum is primarily to give consistent results and to minimize abnormalities resulting from too

Jan 1, 1943

By AIME AIME

WHEN a local man has attained high position in business and civic affairs at home, his fellow citizens feel elated if his attainments are given recognition in the form of election to office in an organization of national scope. Eugene Ainsworth White, a new Director of the Institute, is one of the must prominent citizens of Tacoma, where for the past thirteen years he has managed the Tacoma Smelter of the American Smelting and Refining Co. A list of the civic duties he has carried with distinction would be a long one; for recent years it would show that he has been chairman of the Community Chest, vice-president of the Chamber of Commerce. and a member of the Pierce County Taxation Bureau.

Jan 1, 1945

By Karl F. Peterson, H. K. Najarian, Robert E. Lund

R. E. Powers (Mellon Institute of Industrial Research, University of Pittsburgh, Pittsburgh)—Several of the processing methods at the Josephtown smelter might well be considered by plants producing iron blast furnace sinter. In making blast furnace sinter the objectives are much the same as at Josephtown: To produce a strong yet porous agglomerate which has a size consist in a preferred range. The emphasis however is on production rate rather than on the size or other quality characteristics of the sinter. Therefore the technique is entirely different. Blast furnace sinter plants attempt to make their product in one pass with a minimum recirculating load and without sizing treatment after the sinter leaves the machines. Many plants are beginning to feel that more attention paid to quality characteristics would make the product a more desirable blast furnace material. The pelletizing of very fine material before placing it on the bed is not deliberately done at iron sinter plants, although the installed equipment sometimes gives a simila; action. Such pelletizing seems to be a promising way of accommodating the down-draft sintering Drocess to very fine materials. he recirculating load at Josephtown is extremely high. Two plants' producing blast furnace sinter from raw material of comparable size have a recirculating load of about 100 pct of production. At Josephtown it is notable that the size and the rate of feeding of return fines are under control. This is not the case in most blast furnace sinter plants. The sinter slicer appears to be a worthwhile aid in effecting such control. It is similar in action to rakes and plows used at a number of plants, but it has the advantage that the sinter dislodged is positively removed and not left to the inefficient action of a stationary grizzly screen. Blast furnace size specifications for sinter are not at present so rigid as the Josephtown specifications. If the sizing of blast furnace sinter does become important, then the Josephtown crushing practice, in which a large recirculating load is maintained on the crusher in order that minimum fines be produced, may be of interest. H. K. Najarian (authors' reply)—We note that Mr. Powers appreciates some points that we tried to emphasize in our paper as being of importance in making zinc sinter of good quality and which may well be applied to iron blast furnace sinter. Fig. 2 shows the pelletized nature of the feed going on to a Dwight-Lloyd type sintering machine in our plant. Practically, the entire feed consists of more or less rounded particles which permit more uniform air passage through the charge, while the larger particles in the charge roll on to the surface of the grate, which helps to keep the grate openings from being clogged by excessive fines. An agglomerated charge of this character may preferably be made by rolling action while being mixed in a rotating drum and wetted by water sprays to bind the fine particles together and give the charge the desired moisture content. From our observations of several iron ore and blast furnace flue dust sintering operations, we believe that if the fines from the sinter discharged from the machines were to be recirculated and agqlomerated with the new feed, not only sinter of better quality but larger capacity from the machines may be realized.

Jan 1, 1952

HONORARY Membership in the Institute is limited to twenty and the roster is now only fifteen, so Dr. Reynders becomes a member of a select circle. All of his life, following graduation from Rensselaer Polytechnic Institute in 1886 at the age of twenty, lie has been connected with the steel industry. For about thirty years he stayed with the same company, the Pennsylvania Steel Co., until it was acquired by the Bethlehem Steel Corp., in 1916. For many years he had been vice-president and general manager. Before he attained that position, Dr. Reynders organized and remained in charge of the bridge-building department of the company, and during his professional life he has directed the construction of many

Jan 1, 1938

Jan 1, 1956

Jan 1, 1953

By F. X. Tartaron

The comparison of actual energy of comminution with theoretical surface energy presents a wide gap. On the other hand, Solid State Theory presents a viewpoint that places actual energy of breakage in understandable relationship with the theoretical strength of materials. Therefore the physical background of comminution theory favors Kick's Law. A11 discussions of comminution theory appear farfetched when comparison is made of the actual energy of crushing with the energy input called for by thermodynamic theory. Quoting Taggart:' "The work required to crush halite was of the general order of 0.10 kg cm per sq cm of new surface produced (based on air percolation) whereas the theoretical energy of this new surface, based on thermodynamic calculation by a number of investigators is 1 x 10'4 kg cm per sq cm or the work expended was 1000 times the new surface energy — an indicated crushing efficiency of 0.10 pct." It is frustrating to probe into comminution theory with the prospect that the energy one is measuring is 99.9 pct waste energy. Do the laws of comminution deal with energy consumed by mineral breakage or with waste heat energy? There seems to be something wrong. Solid State Theory may provide the answer. The following statement is particularly apt to the situation: "The fundamental fact about metals and indeed all materials, is that they are much weaker than they should be. By this, we mean that if the stress required to cause a given plane of atoms to slip past a neighboring plane is calculated from basic atomic and Solid State Theory, the resulting number is some 1000 times too large to be accounted for by errors in approximations or assumptions. We know now that this is due to dislocations, and we even have a fair understanding of the details of the process by which dislocations make a crystal weak. An intriguing possibility which suggests itself, results from the discovery of very minute metallic crystals which are apparently free of dislocations and which have a strength approaching the ideal value for a perfect crystal." Here we have an extraordinary reversal of the situation. The actual energy for breakage is only one-thousandth the theoretical instead of 1000 times as given by Taggart. But the theoretical energy presented by Solid State Theory is the binding energy between atoms (or ions) in a crystal lattice. This is the kind of energy envisaged by Kick's law. The surface energy or the other hand corresponds to Rittinger's law. Comparison of theoretical with actual, on the basis of surface or on the basis of Rittinger's law, seems to present an absurdity; yet Rittinger's law is confirmed by an impressive array of experimental evidence. Comparison of theoretical and actual on the basis of Solid State Theory or, in other words, on the basis of Kick's law seems reasonable; yet there is not a scrap of evidence to verify Kick's law. The situation appears paradoxical, but the developments in the next section of this paper show that the paradox is a hint to a strange turn of events. ENERGY-WEIGHT FRACTION FUNCTION charles3 has presented a final equation showing the relation of energy consumed in comminution to size of product n{-1) a-n + 1 E is energy, C is proportionality constant, a and n are constants and k is the coarsest size in the ground product (size modulus). In the course of study of a large amount of experimental evidence, Charles discovered that in the general case, a-n + 1 approximated zero. For some reason, a and n differed only by unity. But if a—n + 1 = 0 within experimental error, then it is obvious that Eq. 1 states that it requires an infinite amount of energy to grind any sample to any size. This is a case where nature gives an absurd answer to a man-made mathematical equation, hence something is wrong with the equation. An adjustment must be made to fit the equation with experience. TO reveal the nature of the adjustment, the differential equation preceding the second integration in Charles' group of equations is given When Charles integrated the quantity xa-n it was almost impossible for him to realize that he was dealing with a special case of integration and that

Jan 1, 1962

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members. ) Member, age 33, single, desires position as null superintendent or charge of mine and mill. Twelve years' milling, cyaniding and flotation in the southwest and Mexico. Will go anywhere. No. 458. Member, mining engineer and geologist, graduated, from- mining college, age 27, single, exempt, with practice in metal mining, surveying of any kind, field geology and ore testing, desires to .engage as geologist or mining engineer with a reputable concern in the west or east of. U. S. Hard worker and reliable. No: 459.

Jan 6, 1918

By P. Barnes

The tabular statement accompanying this note shows the money cost in each of the three departments of manufacture, of 17 leading items, and also the proportion (expressed in a clecimal fraction) which each of these items bears to the total cost. The statement can hardly be taken for more than an average illustration of the clear showing of ratios and of results which may be made by such an arrangement, for not only will these items vary from month to month in any given works, but the methods themselves of manufacture differ widely in different works. It is obvious that such a statement, however useful it may be, must be submitted with but exceedingly little explanation or discussion, or with none at all, for the reason that to enter at any satisfac-

Jan 1, 1879

By Wang Yongjia, Steven L. Crouch

This paper describes a numerical method for computing time- dependent displacements and stresses in linear viscoelastic media. For such materials, the correspondence principle can be used to obtain the time-dependent solution directly from the solution to an associated elastic problem in Laplace transform space. The elastic solution, in turn, can easily be obtained by boundary element methods. The work presented in this paper is based on the displacement discontinuity method, adapted for the case in which the region of interest consists of two half-planes bonded together. A practical example of the method is given for a problem involving a panel of rooms and pillars in a thick layer of salt that is overlain by limestone. Viscoelastic behavior of the salt causes time-dependent displacements and stresses in both rock types.

Jan 1, 1982

By R. T. Gallagher

FOLLOWING recent precedent, the Mineral Industry Education Division opened its first session on Sunday afternoon at the Columbia University Men's Faculty Club with an unexpectedly large attendance. The first session was presided over by the Division Chairman, A. F. Greaves-Walker. The first paper, a preliminary report on college enrollments in mineral technology curricula, by W. B. Plank, though incomplete, pointed to a general over-all reduction of 38 per cent in enrollment in mineral industry curricula. Following that, A. C. Callen's paper elicited many comments. It presented the results of a survey (no direct questions asked) addressed to officials in the mining industry. J. L. Bray spoke on war production drive methods and results and his slides gave visible evidence (and much laughter) of the success of the drive. C. L. Wilson's able presentation covered not so much present status but the future status of accelerated mineral technology programs after the war. The last paper of the first session by Edward Steidle, was handed out in mimeographed form.

Jan 1, 1943

Jan 1, 1950

By H. I. Ashby

INITIAL development of the south orebody at San Manuel is being carried out from the No. 1 and No. 2 shafts. The haulage and grizzly levels are being driven to develop the upper one third of the massive hydrothermally altered and fractured monzonite orebody. This first haulage level has been placed at the 1475-ft level with a grizzly level 60 ft above. The grizzly level will be connected to all service shafts so that men and supplies can come down to the grizzly level and go to working places without congesting the haulage level. These connections are also a vital part of the ventilation plan. The haulage level is being advanced along the north and south fringes of the orebody and connections are being driven to the three shafts now under construction. The No. 1 and No. 2 shafts will serve the development work with supplies, skip hoisting, and ventilation at each shaft and the two shafts are connected on both the grizzly and haulage level.

Jan 7, 1954

By T. Sterry Hunt

THE essential principle of this new process, now in operation in Chili and in North Carolina, for the extraction of copper from its ores, is the dissolving of the oxides of copper by a hot solution of protochloride of iron and common salt. In the action which takes place, the protochloride of iron is converted into peroxide, while the oxides of copper are changed into protochloride and dichloride, the latter of which, though insoluble in water, is readily soluble in a hot strong brine. From the solution thus obtained, metallic iron throws down the copper in a metallic state, regenerating the protochloride of iron; which is then ready for the treatment of a fresh portion of oxidized copper ore. In the case of slimy ores, the contact of the bath with the ore is effected by agitation in tubs; but when the ores are granular, lixiviation in large vats is equally efficient and simpler. The hot solutions, charged with chlorides of copper, are digested in tanks with scrap-iron, or better, are made to flow through covered channels containing the scrap-iron, and in their passage lose the whole of their copper; the reaction at the same time evolving so much heat as to keep up the temperature of the liquid. In order to prevent a certain loss of chlorine, which otherwise takes place from the production of some basic ferric chloride in the reaction between the ferrous chloride and the oxides of copper (both protoxide and dinoxide being generally present in calcined ores), a portion of sulphurous fumes from the roasting is made to pass through the regenerated bath before adding it to fresh ore. This has hitherto been effected by injection, with the aid of a jet of steam.

By C. L. HUSTON

MY ANCESTRAL connection with the manufacture of boiler plate runs back through four generations, and my personal acquaintance with the practice reaches back to the time, in my ,boy- .hood days, when iron plates' were made in a mill operated entirely by water power. -The mill originally was driven by an old-fashioned "'breast" water wheel 20 ft. in diameter and with a20-ft. face, geared direct to the roll train. When the mill slowed up and there was danger of its stalling, the men would jump upon the rim and help the wheel around with their weight, to prevent a "sticker." Later, as large plates were called for, a flywheel was set out of line so that it could' be speeded up by gears from the water wheel and connected back again,. by reducing- gears, to the roll train. The flywheel, with its cast-iron rim and wooden spokes, made 90 r.p.m. and the roll train 45 r.p.m. In 1870, our company installed our first steam-driven plate mill two-high rolls, 84 in. long. In these early mills the hot metal was manipulated by hand.

Jan 1, 1920

By D. S. Fuerstenau, S. Chander

The results of a preliminary investigation undertaken to explore the possibility of treating potential in sulfide mineral flotation systems as an external variable are reported in this note. Two different methods were used to assess floatability. One involved measurement of contact angles at a mineral electrode in reagent solutions, and the other involved direct measurement of flotation recoveries in a Hallimond tube flotation cell that had been modified such that mineral particles were in electrical contact with a gold electrode. Fairly good correlation between the contact angles and flotation recoveries has been obtained.

Jan 1, 1976

By M. A. Mallinger

A series of laboratory tests was conducted to determine the limits of practicability in regulating the weights of various cement slurries. It was found that slurry weights of 12 to 19 lb per gallon could be obtained by adding bentonite to decrease the weight and barytes ore to increase the weight. It was also found that barytes ore was not usable in all cements. LIGHTWEIGHT CEMENT SLURRIES INTRODUCTION During the drilling and completion of oil wells the magnitude of the hydraulic pressures exerted on certain formations is critical. In many cases considerable care must be exercised to prevent drilling mud weights from becoming too high, and in those wells where loss of circulation is a problem, the use of normal weight cement slurries will generally result in lost returns during casing cementing operations. While mud weights can easily be controlled, it is necessary to exercise care in the selection of weight reducing additives for cement slurries in order that slurry weights may be reduced sufficiently to prevent the loss of a large portion of the cement to the thief formations without seriously affecting the setting properties of the cement. EXPERIMENTAL RESULTS An extensive search revealed that a large number of materials .that might have been otherwise practicable as a weight reducing additive were not acceptable for use with oil we cements because the imposition of pressure on the slurries caused the additive being tested to be compressed or to absorb water from the slurries, resulting in negligible decrease in the slurry weight. This search for lightweight additives disclosed that bentonite, a material very commonly used for reducing the weight of drilling muds and cements, produced the best results without undue harmful effects on the properties of oil well cements. It was found that there was a limit to the amount of benton-

Jan 1, 1950

By John B. Miles

The present period of depression in the iron industry, with the resultant close approximation of the cost of production to the selling-price of pig-iron, should make the discussion of this subject at this time not only interesting but profitable. It is possible that it may result in the collection of data, which when added to those set forth in this paper will clearly indicate the influence of the rate of driving a blast-furnace upon its fuel-economy. The question is not whether an excessive rate of driving (meaning a rate definitely in excess of the average rate in the United States) results in an increase in the fuel-consumption, but rather whether a rate considerably less than the average does not result in a marked decrease in the fuel-consumption. The commercial and metallurgical sides of this problem must be kept separate. With a large margin between the cost of production and the selling-price of pig-iron, and a plant already in operation, it is frequently profitable to sacrifice a couple of hundred pounds of fuel per ton of pig-iron in order to secure the greater gross profits resulting from a larger tonnage. When this margin decreases with a plant in operation, or when the determination of the size of a new furnace intended for a certain production confronts the management, a clear understanding of the effect of the rate of driving upon fuel-economy becomes necessary. If it be granted that slow driving leads to low fuel-consumption, it should be borne in mind in the design of a new plant for the production of a certain tonnage that the adoption of an economical rate of driving increases only the size of the furnace proper, whereas, due to the decrease in quantity of blast required on account of the decrease in fuel burned, the stoves, the blowing-engines, the boilers and the piping may be de-

Jan 1, 1909

By R. M. Briney

A RETURN to nonwar conditions characterized the year 1946. The acquisition and forced use, under Government auspices, of low-grade and uneconomic ores, both foreign and domestic, ceased in 1945, but there was some carry-over into the early months of 1946. The world shipping situation delayed the procurement of some foreign ores, but conditions were improving by the end of the year. No actual shortage of any important alloy was experienced, hence the industry was able to make prompt shipment of orders placed. Price levels of ferroalloys, which had remained virtually constant through the war years, were forced upward, with increases on specific products as conditions necessitated. Standard ferroman-ganese and low-carbon ferrochrome were notable exceptions in that their price did not change. No new ferroalloy smelting plants were constructed. The Defense Plant Corp.. sold the works at Ashtabula, Ohio, to the Electro Metallurgical Co. A new type of ferroalloy furnace was described at the Birmingham meeting of the Electrochemical Society. Known as the "Elkem Rotary Furnace" it is distinguished by a rotating shell. The whole furnace, including shell, refrac-

Jan 1, 1947