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By I. Iwasaki, R. Titi-Manyaka

Thermogravimetric analyses were used to formulate the chlorination and chloridization behaviors of such metals as iron, manganese, copper, tin, nickel, and zinc and their oxides; of lime and magnesia; and of such minerals as calcite, siderite, rhodochrosite, rhodonite, and apatite- all commonly encountered in ironmaking raw materials. Complexities of the reaction steps involved were indicated by plotting thermogravimetric analysis curves and the possible mechanisms were discussed based on the theoretical weight changes and thermodynamic considerations. The relative effectiveness of chlorine and hydrogen chloride as chloridizing agents was considered in the light of the experimental results.

Jan 1, 1973

By P. Somasundaran

Adsorption of a nonionic polyacrylamide (PAM), an anionic polyacrylamide with sulfonate functional groups (PAMS), and a cationic polyacrylamide with amine functional groups (PAMD), on hematite was investigated as a function of different solution conditions. Adsorption results indicate that the major mechanisms of adsorption of polyacrylamides on hematite is through hydrogen bonding, with electrostatic forces playing a secondary role. All the polymers exhibited irreversibility of adsorption upon dilution. Also, entropic effects were determined to be important in adsorption. Surface chemical properties of hematite and solution chemistry of the polyacrylamides are considered to explain the polymer adsorption behavior on hematite.

Jan 1, 1985

By William E. Ford, Edward Salisbury Dana

239, Contact-Gwiorneters. - The interfacial angles of crystals are measured by means of instruments which are called goniometers. The simplest form is the contact- or hand-goniometer one form of which is represented in Fig. 377. This contact-goniometer consists of a card on which is printed a semi- circular arc graduated to half degrees at the center of which is fastened a celluloid arm which may be turned to any desired position. The method of use of the goniometer is illustrated in Fig. 377. The bottom of the card and

Jan 1, 1922

By A. M. Hall

SULPHUR, even in small amounts, may often be harmful to nickel and high-nickel alloys, causing impairment of mechanical strength and destruction of malleability and ductility, as shown by Merica and Waltenberg.1,2 It may act. either in the form of nonmetallic inclusions produced in the liquid state during furnacing or as reaction products resulting from its diffusion into the solid metal. In recognizing the action of this element, ability to identify its various forms by means of the microscope is often of considerable importance, especially when direct quantitative methods are inapplicable. [ ] Of the sulphur compounds associated with nickel and high-nickel alloys, the sulphides that may be found in malleable nickel, Monel? and Inconel? are an important group. These sulphides were investigated by metallographic methods in order to provide descriptive data by which to identify them. The nominal compositions of malleable nickel, Monet and Inconel are given in Table I. The term "sulphide" is employed here in a very general sense, to designate a substance in which sulphur and one or more metallic elements are combined. The term includes any combinations of compounds and solid solutions. METHOD OF INVESTIGATION Three groups of small laboratory melts were made, one group to represent each of the three types of alloy under investigation. Within each group, a number of ingots with a sufficient variety of chemical analyses were prepared so that the effect of each of the elements entering the complete commercial alloy could be isolated and observed. In most cases, to facilitate metallographic study by exaggerating the number and size of the resulting sulphides, somewhat greater amounts of the minor elements were added than are present in the commercial alloys. Likewise, considerably more sulphur was added than is normal, but not enough to complicate the system. Transverse sections were cut at a point one third of the distance from the butt to the head of each ingot, polished and examined with an inverted stage metallograph equipped with a combination polarizing-analyzing vertical illuminator. The light source was a tungsten-mercury vapor arc lamp.

Jan 1, 1943

By George A. Jr. Dornin

A TRULY sound ingot can be made only from steel that is completely deoxidized. Given this condition, there is one further basic requirement-the steel in the ingot must solidify progressively from the bottom to the top. Any method of making the ingot that produces this type of solidification will yield sound products. Since a big-end-down ingot will not satisfy this condition, all sound steel today is produced in big-end-up ingots, the standard tool being the big-end-up mold fitted with some sort of refractory hot top. No one uses hot tops from choice, be cause of the bother and expense involved and because of the low yield resulting from their use-they are used because there has been no alternative where sound steel was required.

Jan 1, 1947

By Harlan Walker

ROCK-DRILL steel has an important bearing on costs in many mining operations, both directly and indirectly. Direct factors include such items as shop expense, steel consumed per ton of ore produced, cost of distribution and the dust hazard. The latter, although no specific amount may be assigned to it, is an ever-present problem, and is receiving increased attention as the science of mining progresses. Indirectly drill-steel performance affects consumption of compressed air, mainte-nance of drills and drilling speed. The latter, in turn, increases or retards the tempo of mining and development. These factors, while not all inclusive, are preponderant in their importance. Thus it is evident that in an extensive operation drill-steel expense may run to many thousands of dollars and that thoughtful research leading toward more efficient practice is warranted.

Jan 1, 1940

By John F. Burst

Nanafalia aged bauxitic kaolins which straddle the Chattahoochee River in a NE-SW trending line anchored by Eufaula, Ala., and Andersonville, Ga., apparently derive from the same Piedmont source. A genetic interpretation is offered which describes the Nanafalia as a shoreline deposit in which the blanket elastics of the Andersonville area represent an ancient freshwater swamp and the lenticular Eufaula bauxites represent meander fills in an ancient tidal flat or barrier island. Mining operations in both areas are described and economic forecasts are presented.

Jan 1, 1975

By J. J. Pavlica, I. Iwasaki

Grinding in steel milk adversely affects the flotation removal of pyrrhotite from magnetite ores. To elucidate the effect of grinding media on the floatability of pyrrhotite, rest potential and galmic current measurements were made on electrode combinations of pyrrhotite-mild steel and pvhotite- stainless steel. Galvanic contact of pyrrhotite with mild steel increased the rate of surface reactions on pyrrhotite in air-exposed and oxygenated solutions. It was postulated that the formation of an iron hydroxide coating on the pyrrhotite adversely affected its floatability. Its formation was minimal when pyrrhotite was contacted with stainless steel. Fine magnetite particles cawed slime coating on pyrrhotite surfaces by magnetic interaction and impaired the flotation of pyrrhotite.

Jan 1, 1983

By M. R. Stauffer, Z. Hajnal

Seismic velocity determinations over Precambrian outcrops near Flin Flon, Manitoba, indicate that several different rock types have sufficient velocity contrast to make reflection mapping possible. Stratigraphic and fault contacts between metasedimentary and metavolcanic rocks have been mapped at some depth. A mu1ti-fold reflection survey attempted to trace the depth extension of an ore-bearing (Pb-Zn) rhyolite horizon within the metavolcanic rocks. A synthetic seismogram has been produced from a 10,000-ft sonic log and provides means of comparing seismic records with the local geology. From this the optimum frequency spectrum and the maximum resolution of the seismic signals were estimated.

Jan 1, 1978

By R. P. Steijn

IT has been observed by a number of investigators that under certain conditions metals freeze into an aggregate of small hexagonal strands, parallel to one another and with their axes approximately in the direction of growth.'" This structure has been termed "cellular structure" and is explained in various ways by different workers, notably by Rutter and Chalmers." These investigators attribute the phenomenon to the presence of minute quantities of solute atoms which induce constitutional supercooling. However, if this is true, observations of the cellular structure in extremely pure substances, like frozen distilled water' and germanium of less than 0.0001 atomic pct metallic solute,' are difficult to comprehend. The purpose of this communication is to describe several observations made of the prismatic structure in zinc of 99.99 pct purity. Zinc single and bicrystals grown in a constant gradient electrical resistance furnace exhibit the cellular structure after etching in 15 pct HC1. (See Figs. 1 and 2.) It is noticed that the hexagonal substructure sometimes continues unbroken across the bicrystalline grain boundary.

Jan 1, 1956

Wabush Mines is the largest single supplier of iron ore to the Canadian steel industry, with 42% of its 6 million tpy of iron ore production going to the company's two Canadian owners-The Steel Co. of Canada and Dominion Foundries and Steel Ltd. Six other companies hold interests in Wabush Iron Co. Ltd. These are Lykes-Youngstown, Inland Steel Co., Intrerlake Steel Corp., Wheeling-Pittsburgh Steel Co., Finsider of Italy and Pickands Mather & Co. Field work on Wabush began in mid-1957 when a long-range program of economic, geologic, and metallurgical investigations started. This work was followed in 1959 by the construction of a temporary camp and a 700-tpd pilot plant. At the same time, work was also started on a 38-mi railway connection to Ross Bay, Newfoundland.

Jan 1, 1970

By Leon Merker

Flame fusion growth of strontium titanate crystals was undertaken to obtain large transparent crystals on which physical data could be gathered. The fact that strontium titanate is a cubic crystal and probably has a high index of refraction indicated that it might be useful in optics. No large boules* of strontium titanate had been synthesized previously, and none have been found as natural occurrences. The flame fusion process, invented by Verneuil in 1904, was first applied to grow large crystals of ruby and has since been used extensively to grow crystals of corundum and spinel on a commercial scale. Only during the past nine years has this technique been applied to the growth of large single crystals of other high melting compounds such as rutile, mullite and ferrites.

Jul 1, 1955

By N. A. D. Parlee, E. M. Sacris

OXYGEN solubility in liquid silver has been well studied.1-6 It has been established that the solubility follows Sieverts' law reasonably well5'6 up to po2

Jan 1, 1968

By John H. Stewart, Daniel R. Shawe

Major transverse structural zones in the western U.S. such as the Lewis and Clark line, Walker Lane, Texas lineament, and Colorado mineral belt, have localized important mineral districts. In Nevada and Utah the alinement of Cretaceous and Tertiary mineral deposits, such as in the Pioche, Eureka, Manhattan, and other mineral belts, may be related to similar tectonic features. All the mineral belts in Nevada and Utah have produced precious and base metals and tungsten; the Manhattan belt in addition has produced magnesite and brucite; and the Pioche belt, uranium, fluorspar, and alunite. Specific types of ore deposits seem related spatially to major belts of the Paleozoic Cordilleran geosyncline and compositionally to the intrusive bodies with which they are associated.

Jan 1, 1977

By Wallace Thorneycroft

This paper by Mr. Thorneycroft, Past President of the Institution of Mining Engineers (Great Britain), and chairman of its Subsidence Committee, is a valuable contribution to the assemblage of data on ground movement and subsidence from coal mining. It deals with the effects of advancing longwall, a method almost universal in Europe but as yet little used in the United States outside of Northern Illinois and in a few scattered places elsewhere in thin coal beds, as in the Lexington field, Missouri. Canon City field, Colorado, and the Birmingham field, Alabama. Although by advancing lougwall, a maximum recovery of coal is obtained and it has to be employed where there are weak shale roofs, especially in deep mines, it is a more expensive method of operation unless the mining conditions are suitable, which is unusual in the United States. On the other hand, there is a growing use in this country of what is essentially retreating longwall, with an approximately straight break-line as described by Rayburn.1 With this method, in which the pillars are substantial, it was shown that the ground movement effect is practically identical with that of advancing longwall, hence the value to mining engineers of the precise data given by Mr. Thorneycroft. His study is unusual in several respects; it deals with conditions connected with the mining of a coal bed 20 in. thick, about 490 ft. below the surface, over a mined-out area in a 5-ft. bed about 90 ft. below, which had been mined about 12 years earlier. Both mines passed under Plean House, a building of massive cut stone construction built over a century ago, in which Mr. Thorneycroft resided throughout the under-mining period. Slight cracks opened in the walls as the longwall face approached the house in mining the upper seam, and closed after the face passed and subsidence took place. In the northwest wall, the last wall the face passed under, some stone blocks were broken, which was attributed to a strike period when the advance of face came nearly to a standstill. Other than this there was no perceptible permanent damage, as indicated by the photographs taken by the undersigned in 1923 (Figs. 1 and 2). Mr. Thorneycroft used a novel means of studying the successive positions of the corners of the building: he hung plumb bobs from the eaves and traced the paths of the respective plumb bob points on level surfaces. The angles made by the house walls with the plumb bob lines gave measures of the slope of the subsidence wave at the respective points. A slight upward wave was indicated by the surveys ahead of the subsidence, which would appear to be due to a tilting over of the massive sandstone stratum in the roof measures near the surface, the edge of the coal face acting as the fulcrum.

Jan 1, 1931

By K. B. Nowels

The attainment of efficient flooding to a large extent depends upon a knowledge of fluid movement through porous media and the pressures used in controlling this movement. Little has been understood con-cerning the fundamental principles involved in the forced drive of water-flooding and an attempt will be made to present some data which may be of interest. Considerable data and technical information pertaining to natural and artificial water-flooding have been presented in the past by Torrey, Umpleby, Fettke, Panyity and others. Their papers have thoroughly covered the description of past and present-day methods of oil recovery by flooding in the Bradford field, especially an article by Torreyl in the Petroleum Engineering Handbook. A bibliography of papers devoted to watcr-flooding, published in Mr. Torrey's article, is appended to this paper. No attempt has been made, therefore, to describe the installations and procedure necessary in flooding, thus permitting the writer to deal exclusively with the mechanics of water movement in flooding operations and its relationship to well spacing. Artificial water-flooding will probably always be the most successful in oil fields described by Herold as being under "capillary control"" and will probably be useless in fields naturally under hydraulic or volumetric control. The natural water drive in an oil field under either of these two controls may give efficient recoveries, as a result of the regulated encroachment of edge water. Such a "natural flood" resulting from the influence of edge water must not be confused with the term as used in this paper, however. Any reference to "natural flood" will here refer to the old method of flooding formerly used in the Bradford field. This was discovered largely by accident and utilized the hydrostatic pressure created by a column of water standing in a watered-out oil well in forcing the oil to an adjacent producing well. The same principles are involved in either natural or artificial flooding, and the latter method simply

Jan 1, 1933

By L. J. Howell, H. H. Kellogg

AN a previous paper' the phase diagram and vapor pressure of melts in the systems NaC1-ZrCl,, KC1-ZrCl,, and NaC1-KC1 (1:1 molar)-ZrC1, were reported. This note supplements the earlier paper with the results of electrical conductivity measurements on NaC1-ZrC1,and NaC1-KC1 (1:l molar)-ZrC1, melts. The design of the conductivity cell is shown in Fig. 1. Tungsten electrodes, A, were sealed into the Pyrex cell, C. That portion of the electrodes in contact with the melt was covered with a tight-fitting platinum cap. The electrodes were sur-

Jan 1, 1960

J. L. McK. YARDLEY,* Pittsburgh, Pa. (written dlscussion ?) .-It is interesting to observe how closely Mr. Hansen agrees with other investigators to the effect that the art of electrolytic zinc has left the realm of mystery. In his introduction, lie has said practically what Thomas French said in his paper "The Future of Electrolytic Zinc. "1 The successful electrolysis of zinc from sulphate solutions has not been an easy matter, and it is only within recent years that the difficult problem of depositing high-grade zinc has been satisfactorily: accomplished on a commercial basis. The principal requisite is. that the electrolyte shall be quite free from certain impurities. The methods by which freedom from these impurities is assured are now very well understood, and with experienced superintendents there is little difficulty in obtaining a high efficiency in that part of the process. When certain underlying principles are recognized, the difficulty encountered in dealing with the filtration of the acid and slimy solutions also largely disappears, although it has been a very serious one to the uninitiated. In the dissolving of the zinc from the roasted ore, there is nothing which any competent chemical' engineer cannot undertake, and any other operations connected with the electrolytic process are either of little or no difficulty, or are common to the retort process. Mr. Hansen also agrees with R. G. Hall's statement in " Some Economic Factors in the Production of Electrolytic Zinc:"2

Jan 10, 1918

By J. R. Mihalisin

THE application of electron-microscopic techniques to the study of high-temperature alloys has met with considerable success.' This is due, in part, to the submicroscopic nature of the phases present in this type of alloy making high resolution methods necessary. Among the newer electron-microscopic techniques, the extraction replica technique' has proven to be of great value. This method allows phases to be examined in situ in the microstructure and permits their identification by means of electron diffracticn. This technique eliminates the main disadvantage in using electrolytic extraction of residues as a means of phase identification; that is, the uncertainty of relating constituents identified in the residue to what is observed microscopically. In the course of work relating microstructure to physical properties in high-temperature alloys, it was found that the formation of grain-boundary carbide phases and intragranular precipitation of an age-hardening phase greatly influence strength and ductility at high temperature. In particular, it was found that the formation of a unique type of precipitate in Nimonic "80" (a nickel-chromium-aluminum-titanium type superalloy), termed cellular or discontinuous precipitate, at grain boundaries generally results in poor ductility at high temperature. However, this mode of precipitation can be avoided by proper heat-treatment. It was assumed that this precipitate was either a carbide or age-hardening type of phase. Using various etching procedures with the extraction-replica technique, it was found to be possible to extract the carbide and age-hardening phases preferentially in this type of alloy. Previous work has shown that the age-hardening phase can be extracted from superalloys merely by

Jan 1, 1959

By R. L. Frantz, R. W. Bouman

The authors investigated the comminution of quartz and limestone mixtures in a ball mill, showing that the distribution modulus of a comminuted material is the same whether it is ground separately or as part of a mixture. Analysis of the ground products indicates that quartz and limestone consume energy during ball milling in proportion to their mass fraction in the mixtures. Recently Schuhmann' made a significant contribution to comminution theory by proposing that complex comminution operations comprise the summation of many individual comminution events. By means of the single comminution event hypothesis, Schuhmann derived the Charles energy-size reduction relationship by considering that fragments of every particle crushed during a single impact have a size distribution characterized by the Schuhmann size distribution. In this paper, the size reduction of mixtures of solids in ball mills is analyzed by considering that size reduction occurs as many single comminution events. If a mixture of two materials is being ground in a ball mill, each successful impact of a ball with a particle of one material should yield an assembly of particles whose size distribution is characteristic of that material. Considering both materials to follow the Schuhmann size distribution equation, the size distribution of material 1 in the product is

Jan 1, 1962