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By H. Foster Bain

Jan 1, 1910

By R. P. Rothwell

THE milling of silver ores has arrived at a great degree of perfection in the mining districts of our Western States and Territories, and I have thought the record of the practical results obtained at the present time, in a few of the principal districts, would prove of value and interest to many of our members, both at home and abroad. An American silver mill is composed, in descending order from where the ore is dumped, of: 1st. A rock-breaker, usually of the Blake or Alden pattern ; 2d. The battery of stamps, the number of which varies from 5 to 120, generally in batteries of 5 or 10 heads, so arranged that a single battery may stand while the others are running; 3d. The tanks where the crushed ore settles (if it is a wet stamping-mill), or of a drying-floor if the crushing is done dry; 4th. Amalgamating pans ; 5th. Settling pans ; 6th. Agitators or pans in which mercury escaping in the tailings is caught; 7th. Blanket sluices, over which the tailings run, and where mercury and unamalgamated sulphides are saved. A reference to the engravings (see plate), which show one of the latest forms of an 80-stamp silver-mill run by a turbine water-wheel, will show clearly the arrangement of the several parts. THE ONTARIO, UTAH, SILVER MILL. One of the best examples of a silver-mill, and at the same time one of the most successful concerns in the West, is the mill of the Ontario Silver Mining Company, near Salt Lake, in Utah. This mill treats the ore from the Ontario mine, ore which at present is very base, being composed of zinc, lead, and silver sulphides and silver chloride in a quartz gangue. This ore has become baser as the mine attained greater depth, though the vein holds its own, or rather increases, both in thickness and richness. The mill is man¬aged in a skilful and economical manner, though the necessity for * Read at the Montreal meeting, September, 1879.

Jan 1, 1880

By William G., Pariseau

There are important phenomena in rock and soil mechanics that cannot be explained in terms of theories of homogeneous, isotropic materials. Subsidence of strata about mine openings is an example. In-situ stress measurements in nonisotropic sedimentary, and metamorphic rocks is another. Patterns of joints, faults, fractures, and similar geologic features impart directional mechanical properties to rock masses that are locally isotropic or anisotropic. On the geologic scale, the non-homogeneity of composite rock masses may, in certain instances, be dealt with as homogeneous anisotropy. The mechanics of large rock masses can, therefore, be expected to involve considerations of anisotropy. The source of the anisotropy is not relevant. Once the scale of observation is selected and the material is defined accordingly, the analysis of stress and deformation proceeds without regard to the numerical values of the material constants. There are also important phenomena in rock and soil mechanics that cannot be explained in terms of linear elasticity, theory. For the mechanical description of anisotropic geologic materials capable of de- forming beyond the limit of purely elastic strains, a plasticity theory is required.

Jan 1, 1972

By J. C. Yannopoulos, N. J. Themelis

Ah electronic thermogravirnetric balance was used to measure the veductioiz rule o single cirpric oxide particles suspended in a stream of hydrogen. Very jzne thermocouples embedded in lie center and at the surface of the sphere recorded the variation of terw perature during reduction. In contrast to iron oxide reduction, where in most instances the rate of interface reactiokl is controlling, the heat- and mass-transfer phenotnena play a predolrinant role in the reduction of cupric oxide. The correlation of experitnental data or tnass lransfev lhrough the boundary layer at Reynolds nunlber 0-4 50 was as jollocs: ThE reduction of cupric oxide by hydrogen is represented by the equation: It is a highly exothermic reaction and the amount of heat released varies only slightly with temperature (-21,430 cal per g-mole at 400°C). Most of the published studies on this system have been conducted at temperatures in the range of 34 to 280c.l-&apos; The concensus of opinion has been that at temperatures below 200°C the reaction is preceded by an induction period during which there is very little or no reduction. The length of this period diminishes as the temperature of the reaction is increased1l5 and aseawa found that at 280°C reduction starts practically immediately when the oxide is exposed to hydrogen gas. The existence of an induction, or incubation, period has led experimenters to believe that the reduction of CuO by hydrogen is catalyzed by metallic copper.&apos; Boldurev and rmolaev found that mechanical additions of powdered copper to oxide did not affect its reduction, although metallic copper produced during the reduction seemed to have a catalytic effect. At least three other authors2&apos;5&apos;7 have reported that addition of copper had no effect on the rate of reduction. Pease and alor&apos; observed that water vapor had a strong inhibiting effect on the reduction at 1503C, but its effect was greatly diminished at 200 C. Pavlychenko and Rubinchik5 studied this reaction at 159 to 235 C and found that, once the reaction had been initiated, there was no inhibiting effect due to the introduction of water in the hydrogen stream; at temperatures above 183°C there was no inhibiting effect due to water vapor, either before or during reaction. The same authors noted that the rate of reduction was independent of pressure in the range of 200 to 700 mm Hg. aseawa investigated the kinetics of the CuO-Hz system at 160 to 280°C and estimated the apparent activation energy at 14,000 cal per g-mole. A similar value (13,500 1200 cal per g-mole) was reported by ond&apos; in the temperature range 148 to 216°C. Bond also reported that there was no incubation period and that water vapor had no inhibiting effect on reduction at temperatures above 190 C. The above studies have been conducted at temperatures below 280°C and the physical configuration of the system under investigation has not been defined adequately. However, it is well-known that the mechanism of gas-solid reactions depends on a number of in series physical and chemical rate prcesses.&apos;&apos; It is, therefore, essential to include among the experimental factors the geometry of the solid system and the mass-transport characteristics of the reducing gas. Scott studied the reduction of packed beds of cupric oxide cylinders by Hz-He streams of very low hydrogen concentrations at temperatures 400 to 600 C, pressure of 10 to 30 atm, and gas velocity from 0.18 to 5.8 ft per sec (3 < Rep < 30). The reduction rate was found to be mainly controlled by diffusion through the boundary layer and through the pores of the reduced copper phase. The following correlation was proposed: Scott in an earlier work studied the reduction of fixed beds of cupric oxide wire and found that the rate of flow of the gas stream through the bed had a controlling effect on the rate of reduction. The same mass-transfer phenomenon was observed by Bond and clark13 on a similar reduction system. The analogy between mass and heat transfer through the boundary layer which exists between a solid surface and the bulk stream stems from the similarity of the differential equations representing these phenomena

Jan 1, 1967

By J. T. Ryan

SAFETY practice or the elimination of accidents in our coal mines is specifically a problem of management. It cannot be delegated to any governmental agency except that the various coal-producing states do and should have some minimum safety standard laws. However, the legislative method of attempting to control mine accidents is ineffective because of the delay between the necessity and the action. It will always be impossible to keep our various state mining laws up to date; and when the law says you must do a certain thin there is a tendency to do this and no more. Unless the scheme for setting up state regulations is so flexible that when a new hazard develops it can be immediately and adequately covered and the whole responsibility for accident elimination placed undivided on the

Jan 1, 1937

By W. O. Philbrook, L. D. Kirkbride

IN the normal operation of the iron blast furnace, reduction of the iron oxides is accomplished almost entirely above the tuyeres.&apos; Blast furnace slags usually contain less than 0.5 pct FeO, although higher values may occur with abnormal operation. There is reason to conjecture, however, that incompletely reduced ore may sometimes reach the hearth and enter the slag as a result of heavy slips or, perhaps, even from cores of excessively large lumps of a charge material of poor reducibility. The possibility of reoxidation of iron droplets falling in front of the tuyeres has been considered by several writers. It would be of interest, to know how rapidly iron oxides reaching the slag for any of these reasons could be reduced by reaction with coke or with the high carbon liquid iron in the hearth. In comparison with the hundreds of papers that have appeared on various aspects of the reduction of solid iron oxides by gases and in the presence of several forms of carbon, little work has been published on the reductioin of liquid oxides or slags. Dancey measured rates of reaction of the pure liquid oxides, both FeO and Fe,O,, with molten iron containing about 4.3 pct C. The oxide was dropped into the cup formed in the upper surface of the iron by rotating the crucible and melt. Under these conditions, reduction of either FeO or Fe,O., was completed in less than 10 sec. The present study was concerned with the reduction of FeO from blast furnace-type slags containing less than 5 pct FeO and melted over carbon-saturated iron in stationary graphite crucibles. The results were considerably different from those found by Dancey, as will be discussed later. Although this work is of interest in relation to hearth reactions in the blast furnace, interpretations must be made with caution because the experimental conditions do not duplicate those within a furnace and may not even lead to the same reaction mechanism. The authors were motivated in undertaking this work by an additional interest—the part played by FeO reduction in the mechanism of de-sulphurization of iron by slags under similar experimental conditions. Derge, Philbrook, and Goldman eveloped detailed experimental evidence to support a three-step mechanism for desulphurization like that originally proposed by Holbrook and Joseph&apos; (These reactions are written in molecular form for convenience, but this is not intended to imply the existence of molecules of FeS in the bulk metal phase nor to deny the likelihood of ionic reactions in the slag.) Earlier work by Chang and Goldman" had shown that the overall reaction follows first-order kinetics with respect to sulphur and that the rate of reaction is proportional to the slag-metal interface area, which observations have been confirmed by subsequent work. Later studiese,&apos; have established the influence of al.loying elements on the first and last steps of the reaction. This paper reports a study of step 3 alone, uncomplicated by the simultaneous process of sulphur transfer. Apparatus and Procedure The experiments were made in a conventional high frequency induction furnace powered by a 35 kva Hg spark gap converter. The graphite crucibles used for most of the runs were 14 cm (5.5 in.) deep and 4.8 cm (1.9 in.) ID with 0.75 cm (0.3 in.) wall. An insulating cover with a small opening for withdrawing samples was used to minimize heat loss and infiltration of air into the furnace. The crucible was charged with 300 g of carbon-saturated iron and either 65 or 100 g of prefused slag analyzing 38.0 pct SiO,, 15.4 pct A10 and 47.1 pct CaO. To obtain the cleanest possible interface at the start of the reaction, the metal and slag were brought to temperature together to prevent the rejection of kish graphite that would have been caused by the chilling effect of a large addition of cold slag to carbon-saturated iron. After temperature control had been established, the desired amount of iron oxide was added in the form of a prefused slag of composition 73.6 pct FeO, 7.7 pct AWX and 19.0 pct SiOl. This slag addition was observed to be molten in somewhat less than 1 min, and a very vigorous reaction proceeded for 1 to 2 min after its introduction. Zero time was taken as 2 min after the ferrous silicate slag addition. Slag samples weighing about 0.5 g each were taken periodically by a copper chill sampler." The weight of the initial slag was large relative to the weight of samples removed, so that the slag weight never varied by more than 5 pct during any run. Temperature was measured by a calibrated W/Mo thermocouple immersed in the metal, with a graphite tip cemented over the fused silica protection tube to prevent attack by slag and metal. After some difficulties with uncertain temperatures during the first two runs, the practice adopted to position the thermocouple for reproducible results was to lower the protection tube to touch the bottom of the crucible and then raise it 0.5 cm. The apparent temperature gradient between the bottom of the crucible and the top of the slag was found to be 15°C (27°F). but much of this spread was probably the result of inadequate immersion of the protection tube to off-set conduction losses along the graphite tip when the thermocouple was inserted only into the slag. The temperature of the bath was controlled within 25°C (9°F) during a run.

Jan 1, 1957

By R. D. MacDonald, John Dasher, A. M. Gaudin

ION exchange is a widely used unit operation in water treatment and elsewhere in chemical industries. It has occasionally been used in hydro-metallurgy for treating plating, pickling, and rayon wastes Concerning ion exchange in extractive hydrometallurgy—for treating ore leach solutions— the literature prior to the Geneva Conference has given only hints."-" Yet most of the ore leach plants now being built or completed in the last three years use ion exchange for this purpose. Most of these plants are used for extracting uranium. The overall process for leaching low grade uranium ores and the history of its development have been given in the authors&apos; previous papers.&apos;,&apos; The object of this paper is to discuss certain engineering aspects of the new application of ion exchange to recover dissolved values from ore leach solutions. Necessarily the illustrations will be taken from the first application—to uranium metallurgy. Although ion exchange processes have been devised in which separation of spent residue from pregnant liquor is not required, as in the RIP process,"-&apos;I only ion exchange operation, in which the resin is contacted with a clear solution, will be discussed in this paper. Uranium exists in acid leach liquors mainly as the cation UO," and can be adsorbed completely by cation exchange resins, but the adsorption is not selective as other cations such as Fe++, Fe+++, Al+++, Mg++, Mn", and Ca++ are also adsorbed. Uranium, however, forms complex anions with sulfate, phosphate," Carbonate"~"~ and even with chloride if the solution is strong enough.15 These anions can be adsorbed by anion exchange resins. The strong base anion exchangers have a very strong preference for these complexes and hence this adsorption is very selective. In this paper, the examples concern acid sulfate leach liquors from which uranium is adsorbed as UO,(SO,),-% and UO,(SO,),". Materials and Equipment Ion Exchange Material—Ion exchange materials include natural and synthetic; organic and inorganic; cationic and anionic; and weak, intermediate, and strong varieties. They consist of fragments or beads normally in the size range —16 to $50 mesh. The newer varieties have been developed to have greater stability, chemical strength, and/or capacity than earlier varieties. The resin used for uranium recovery is a strong base anion exchanger.* To make * Such as Rohm and Haas Amberlite IRA-400 series, British Permutit DeAcidite FF. Permutit lonac SE. and Dow Nalcite SAR. this resin, styrene plus a few percent divinyl benzene are polymerized into long chains with occasional cross links. This resin in bead form is then reacted to introduce quaternary amine groups onto most of the aromatic rings.&apos; These resins are water-avid gels of specific gravity of about 1.1, which shrink and swell by osmosis when the ionic content of the surrounding solution is changed. The beads which are shown in Fig. 1 can be broken like an onion by rapidly replacing 15 pct H,SO, with water. This organic gel can also be broken by mechanical handling as by a centrifugal pump. Otherwise it is remarkably stable. It is unharmed by fairly strong acid or alkali, oxidizing or reducing agents, and heat up to 70°C. The strong base resin when completely in the chloride form (with a chloride anion on each quaternary amine group) holds over 107 g of C1- per dry kg. As all these chloride ions can be displaced by other anions, the resin has an exchange capacity of over 3 g equivalents per dry kg. However, the resin is sold and used by moist volume. The moist resin contains about 50 pct water, weighs about 43 lb per cu ft, has 40 pct voids, and an exchange capacity of over 1 g equivalent per liter of bed volume. Ion Exchange Equipment—Ion exchange equipment used for recovery of uranium from leach solutions is substantially identical to that developed for water treatment and other applications.&apos;" The resin beds are held in closed tanks or columns which, in the uranium plants, have been standardized at 7 ft diam and 12 ft high. The resin bed

Jan 1, 1958

By S. C. Hollister

An evaluation of the function of the engineer, so that means whereby education can best serve his needs can be adopted.

Jan 2, 1950

By R. J. Grissom

PHOSPHATE deposits have been worked in many countries of central and south central Tennessee, but only ht ebrown rock deposits of Maury and Giles Counties will be discussed at any length in this articles, as all of the major opeations are now located there. They are: Mt. Pleasant District-Federal Chemical Co., Hoover and Mason Phosphae Co., International Minerals and Chemical Corp. (Maury and Giles Counties), Virginia-Carolina Chemical Corp. (formerly Charleston Mining Co.), and Victor Chemical Co. Columbia District-Armour Fertilizer Works and Monsanto Chemical Co. In the near future, the well-known, extensive deposits of blue rock in Lewis and Hickman Counties,also the brown rock in Hickman, Willamson, Summer and Davidson Counties, will again come into production. Certain physical peculiarities of the Tenessee deposit have played an important part in the design and use of mining and milling equipment.

Jan 1, 1944

By E. T. Turkdogan, W. L. Worrell

The rate of reaction of hydrogen sulfide with ferrous sulfide was studied by measuring the initial rates of sulfidation of iron strips in hydrogen sulfide-hydrogen-argon mixtures at 670°, 800°, and 900" C. The time-dependent surface sulfur activity is derived from the instantaneous rate of sulfidation with the assumption that diffusion in the sulfide layer is in a pseudo-steady state with the gas-sulfide chemical reaction. The rate of sulfur transfer from hydrogen sulfide to the surface of iron sulfide is proportional to the partial pressure of hydrogen sulfide and inversely proportional to the activity of sulfur at the surface of the sulfide layer. The derived rate equation is based on the assumption that most of the surface sites on the chemisorbed layer of iron sulfide are occupied by sulfur atoms and that the slow rate-controlling reaction is the dissociation of hydrogen sulfide on the chemisorbed layer. The experimental results are in reasonable accord with this reaction model. 1 HE slow approach to parabolic growth rate in the sulfidation of iron in hydrogen sulfide-hydrogen mixtures is a manifestation of slow approach to surface equilibrium between the gas and the surface of the sulfide layer. For example, at 800°C and Fig. 7 in Part I, the parabolic growth rate begins after approximately 1 day of sulfidation time. With decreasing temperature and decreasing partial pressure of hydrogen sulfide, the time necessary to reach gas-sulfide surface equilibrium is much longer. These observations are similar to those reported previously by Turkdogan et al.&apos; on the oxidation of iron to wustite in hydrogen-water vapor mixtures. The slow approach to gas-sulfide equilibrium is well-demonstrated by the results in Fig. 1 where the square of the weight gain per unit area, ( g S per sq cmI2, is plotted against time for gas mixtures having PH g//>H = 1.0 with 0, 25, 50, and 67 pct Ar at 800°C. The value of 1.5 X lo-&apos; (g S per sq cm)&apos; corresponds to almost complete sulfidation of the iron strip (- 0.05 cm thick) to iron sulfide. The points fall on S-shaped curves. If the inflection parts of the curves are considered to be linear, thus indicating parabolic growth rate and the establishment of gas-sulfide equilibrium, their slopes would have to be the same for a fixed ratio in the gas mixture. Such is not the case, and the slopes for the "linear" parts of the S-shaped curves are lower than the value when gas-sulfide surface equilibrium is established. The subject matter of this paper is the kinetics of the surface reaction of hydrogen sulfide with iron sulfide during the early stages of sulfidation of an iron strip. EXPERIMENTAL RESULTS The apparatus and materials used were the same as those discussed in Part I. In the present experiments of relatively short duration, a purified iron strip, 5 by 2 by 0.05 cm, which was suspended in the uniform hot zone of a vertical zircon tube, reacted with a flowing gas mixture of hydrogen sulfide-hydrogen-argon. The sample was suspended from a gold chain attached to a calibrated silica spring. The amount of sulfur picked up by the iron, which formed a layer of iron sulfide, was determined by measuring the displacement of a reference point on the silica spring, using a cathetom-eter. In all cases, the degreased sample was first annealed in a stream of oxygen-free dry hydrogen for several hours to remove any impurities such as oxygen, nitrogen, or carbon which might have been present on the surface of the sample.&apos; The rate measurements were carried out at 670°, 800°, and 900° C in hydrogen sulfide-hydrogen-argon mixtures with pH2 s/Ph2 ratios from 4 to 0.1. In a few experiments of short duration no sulfur deposition was observed in gas mixtures with (comments concerning sulfur deposition at high pH s/ph ratios were made in Part I.) Typical examples of the results obtained are shown in Fig. 2 for two temperatures and two gas compositions. With the present experimental technique, reproducible rate data could be obtained only after a uniform

Jan 1, 1969

By W. C. Ellis, E. S. Greiner

Metallic titanium has been prepared in small quantities since the beginning of the century. Hunter1 reported in 1910 that he obtained a malleable product of 99.9 pct purity by the reduction of the tetrachloride by sodium in a closed container. Later Van Arke12 and Fast prepared small quantities of malleable titanium by thermal decomposition of titanium iodide. Another method for producing malleable titanium from tetrachloride was reported by Kr0ll4 who used magnesium as the reducing agent. More recently Dean, Long, Wartman, and Anderson5 working at the U.S. Bureau of Mines have reported the preparation of the metal on a pilot plant scale by the reduction of titanium tetrachloride by magnesium in an atmosphere of helium. Their product, which is malleable, was used in the present investigation. Early in 1948 after the work of this paper was completed Campbell, Jaffee, Blocher, Gurland, and Gonser6 described the strength and working characteristics of pure titanium which was prepared by the iodide method on a scale producing 300 to 600 g per run, in the form of 0.3- to 0.4-in. diam rods. Their product is characterized by low hardness and large capacity for cold work which they attribute to a high degree of purity with respect to oxygen, nitrogen, and carbon. Titanium has a melting point of about 1725 C," it may be classed as a light metal since the specific gravity is 4.5 g per cc-I. The crystal structure is close-packed hexagonal from room temperature to 885°C. Above this temperature the structure is reported7 as body-centered cubic. The change in crystal structure has been associated with discontinuities in specific heat,8 electric resistanceg and theimoelec-tric force10 at temperatures near 890°C. It is reportedll that annealed titanium has a tensile strength of 78,700 psi which can be increased by cold-work to 123,000 psi. In the present investigation, the lattice constants at room temperature, the thermal expansivity between 30 and 800°C, as well as the electrical resistivity and thermoelectric force against platinum between — zoo and I000 C have been determined. Materials For the measurements, two series of specimens were prepared from titanium furnished by the U. S. Bureau of Mines. The first was made from an annealed sintered compact, 0.38 in. thick. Sections of the compact were cold-swaged with intermediate anneals in vacuum to the sizes used. Sizes over 0.25-in. diam were annealed at I000°C and smaller sizes at 800°C. Specimens originating from the sintered compact are designated in this paper as A. The second series of specimens was made from a rod of titanium, 0.19 in. in diam, which was cold-swaged with the necessary intermediate anneals to the required sizes. This series of specimens is designated B. The impurities in the specimens of titanium, determined by chemical analysis, are given in Table 1. Oxygen and nitrogen which Were not determined by analysis, are probably present although in small quantities in view of the ductility of the material.

Jan 1, 1949

By AIME AIME

Russell B. Paul, Chairman of the Special Committee on Divisional Relationships, presented the interim report of his Committee which was published in the September, 1945, issue of MINING AND METALLURGY and a copy of which is incorporated in the official minutes of this meeting. The following specific actions were taken by the Board of Directors in relation to the six recommendations in the Summary of the Report as published: (1) Mr. Haider, Chairman of the Petroleum Division, presented the formal request of his Executive Committee that the headquarters of the new Secretary of the Petroleum Division be established in Dallas, Texas. After lengthy discussion in which the point was made that the success of this program would depend upon effective co-operation between the Chairman of the Division, the Secretary of the Petroleum Division, and the Secretary of the Institute, the request was approved. The new secretary will be selected by the Division and will be employed by the Institute in the capacity of an Assistant Secretary. (2) The following item in the report was approved:

Jan 1, 1945

The following is an incomplete list of members and guests who called at Institute headquarters during the period Feb. 10, 1918 to Mar. 10, 1918: W. G. Anderson, St. John, N. B., Canada. Charles E. Locke, Boston, Mass. L. M. Banks, Camp Meade, Md. E. T. Lednum, Joplin, Mo. P. E. Barbour, Albany, N. Y. C.&apos; K. McDonald, Washington, D. C. Alan M. Bateman, New Haven, Conn. C. T. Malcolmson, Chicago, Ill. Graham Bright, Pittsburgh, Pa. Stuart B. Marshall, Badin, N. C. J. F. Callbreath, Washington, D. C. T. C. Merriman, New Haven, Conn. J. E. S. Clark, Riverside. Cal. Arvid E. Nissen, Gary, Ind. G. H. Clevenger, Palo Alto, Cal. Herbert G. Officer, Conway, S. C. George C. Crossley, Trenton, N. J. J. E. Parker, Bulawayo, Rhodesia, S. Afr. R. H. Eagles, Palmerton, Pa. Francis R. Pyne, Elizabeth, N, J. Charles Enzian, Pottsville, Pa. Alfred Hull Ramage, Joplin, Mo. Albert H. Fay, Washington, D. C. H. H. Stoek, Urbana, Ill. David B. Gemmill, Crown King, Ariz. G. M. Taylor, Colorado Springs; Colo. Ronald Harris, London, Ont., Canada. Charles Tubby, St. Paul, Minn. Wm. J. Hayes, Colombia. So. America. J. B. Tyrrell, Toronto, Canada. B. B. Hood, Chrome, N. J. Edmund W. Westervelt, Ymir, B. C. 0. P. Hood, Pittsburgh, Pa. Carl Zapffe, Brainerd, Minn. H. M. LaFollette, LaFollette, Tenn. W. S. Boyd, formerly superintendent of mines of the Ray Consolidated Copper Co., has been appointed assistant general manager. William Campbell, Professor of Metallurgy, at Columbia University, is acting as metallurgist at the New York Navy Yard.

Jan 4, 1918

By Walter W. Bradley, OLAF P. JENKINS

IN April of this year the California State Division of Mines (formerly known as the State Mining Bureau) observed its 50th anniversary. The Division serves as a bureau of information and, an encyclopaedia of California&apos;s economic minerals. Its primary function is to make economic surveys of the mineral resources of California, their development and utilization. Geological studies also constitute a related part of the work as being necessary in tracing and out- lining ore deposits and the most likely areas in which to find them. The results of the Bureau&apos;s data-gathering are published in the form of annual reports of the State Mineralogist, and in bulletins on specific substances. The Division is just completing a series of reports on the mineral resources of the State arranged by counties.. It is now starting .a new series of reports arranged according to substances particularly the so-called non- metallic commercial groups. Of these the following are now available: clays, barite, and mineral paint. These will be followed by reports on feldspar and silica, diatomaceous earth, limestone and others

Jan 1, 1930

By Edward Keller

(New York meeting, February, 1912.) IN a paper, entitled A Uniform Method for the Assay of Copper Material for Gold and Silver,1 A. R. Ledoux invited the assayers of this country to contribute to a symposium, in which the results of their assays of given samples of copper-matte and metallic copper would be made comparable. This symposium 2 appeared about one year thereafter; and through it and its discussion, first became generally known the fact that the ,gold-yield by the all-fire method of assaying is usually higher than by the so-called combination (wet and dry) method, in which nitric acid is employed as a solvent for the copper. In the publication alluded to, the supposed cause of gold-losses in the latter method was declared to be the solvent action of copper nitrate, or of the reduction-products of the nitric acid, upon the gold. Up to a very recent date, gold has been held to be insoluble in pure nitric acid. (The solvent action of any chlorine present in the nitric acid must here properly be disregarded as belonging in the realm of carelessness. Among later allusions to this topic, W. R. Tan Liew 3 ascribes the solution of the gold in the combination-assay entirely to the action of nitrous acid at the high reaction-temperature of copper and nitric acid ; F. B. Flinn 4 a believes the low result in gold to be due exclusively to mechanical losses-finely-divided gold penetrating through the filter-paper-but presents no experimental data confirmative of this belief; and 0. Pufahl 5 attributes the solubility of the gold in some coppers to the presence of selenium-a view which appears to be shared by many as- 1 Trans., xxiv., 575 (1894). 2 Trans., xxv., 250 (1895). 3 Engineering and Mining Journal, vol. lxix., No. 16, p. 469 (Apr. 21, 1900). 4 Engineering and Mining Journal, vol. lxxxvii., No.11, p. 569 (Mar. 13, 1909). 5 Lunge, Chemische Technische Untersuchungs Methoden, vol. ii., p. 229 (1900).

Jul 1, 1912

By G. D. Rieck, G. H. G. Vaessen, D. L. Vogel

Both doped and undoped tungsten single crystals exhibit hardness anisotropy with respect to the direction of testing in each of the crystallographic phes investigated. The hardness anisotropy of undoped single-crystal tungsten is rather pronounced in (001) and (110) planes but very minor in (111) planes. The anisotropy in (122) planes of the doped and drawn tungsten after recrystallization is in accordance with a previously published concept of a stringlike distribution of the doping material in the metal. ANISOTROPY in mechanical properties of single-crystal tungsten was investigated by Rose et al., Garlick and Probst,2 and Beardmore and Hull. 3 Although data on the Vickers microhardness of tungsten have been published (see, e.g., Boosz 4 and the references cited by him), no data on the microhardness anisotropy are available. We report, therefore, some of our own results on the microhardness and its anisotropy. The microhardness has been determined of the following samples. A) Polycrystalline tungsten samples taken from: 1) powder metallurgical tungsten "normally" doped with potassium-silicon-aluminum oxides (final contents inppm: K, 100; Si, 100; Al, 20; Cr, 20; Fe, 50; Mo, 400; Ni, 10) and in the form of: a) a 10-mm-diam swaged ingot annealed at 1600°C, the grain sizes varying between 15 and 250 p; b) a sheet rolled at about 800°C and recrystallized at 2000°C7 the grain sizes varying between 15 and 150 p; c) a 2-mm-diam swaged rod, as-worked, with elongated grains (average diameter of about 25 , lengths up to 1 mm); 2) undoped electron-beam-melted tungsten with very large grains (contaminations in ppm: K < 10; Fe < 20; Cr < 10; Cu < 0.1; Ni not detectable; inter-stitial~ not determined). B) Single-crystal samples taken from: 1) pure tungsten grown on a Pintsch wire by the van Arkel procedure (main contaminations inppm: Mo, 100; Si < 10; Cu and Fe, 2; A1 < 2; interstitials not determined); 2) zone-melted undoped tungsten (analysis as under A2); 3) large crystals in secondary recrystallized tungsten

Jan 1, 1969

By John H. Hollomon

A REVIEW of the steps which have been made to increase knowledge in the field of ferrous physical metallurgy during the closing period of World War II brings both pleasure and disappointment. Contributions of great value have been made, to be sure. However, due partly to the stress of the times, researchers in this field have been in the main directing their attention toward the short-range problems involved in the development and production of materiel for war. Furthermore, publication of the results of a great number of studies has had to be delayed. Much of the German work may, indeed, be lost entirely, owing to the efficiency of our bombers, which managed to account for most of the famous Kaiser Wilhelm Institut of Dusseldorf, not to mention the other large laboratories and manufacturing plants throughout that country. It would seem safe to assume, however, that fundamental research in Germany had been forced to give way to the shallow, but more pressing, engineering problems of a country trying to avoid defeat. In Russia the picture has been clouded by the limitations imposed upon comunication; but this much does seem clear: Russia alone among the great nations of the world has maintained her long-range view and has continued to foster research of the most fundamental type. English workers; on the other hand, appear to have been able only to meet the demands of the pressing problems of war, and their studies have been of the short-range variety. That metallurgical research of any sort should have continued in France during this chaotic period in her history would seem impossible, but, amazingly, a small handful of scientists did manage to carry on their work, and it is to be hoped that more will be heard from them in the future.

Jan 1, 1946

By J. Chipman, M. N. Dastur

The importance of dissolved oxygen as a principal reagent in the refining of liquid steel and the necessity for its removal in the finishing of many grades have stimulated numerous studies of its chemical behavior in the steel bath. From the thermodynaniic viewpoint the essential data are those which determine the free energy of oxygen in solution as a function of temperature and composition of the molten metal. A number of experimental studies have been reported in recent years from which the free energy of oxygen in iron-oxygen melts can be obtained with a fair degree of accuracy for temperatures not too far from the melting point. Certain discrepancies remain, however, which imply considerable uncertainty at higher temperatures; also several sources of error were recognized in the earlier studies. It has been the object of the experimental work reported in this paper to reexamine these sources of uncertainty and to redetermine the equilibrium condition in the reaction of hydrogen with oxygen dissolved in liquid iron. The reaction and its equilibrium constant are: H2 (g) + Q = H2O (g); K1 _ PH2O / [1] Ph2 X % O Here the underlined symbol Q designates oxygen dissolved in liquid iron. The activity of this dissolved oxygen is known to be directly proportional to its concentrationl,2 and is taken as equal to its weight percent. The closely related reaction of dissolved oxygen with carbon monoxide has also been investigated:3,4,5 co (g) +O = CO?(g); K _ Pco2___ [2] K2= pco X % O [2] The two reactions are related through the wat,er-gas equilibriuni: H2 (g) + CO2 (g) = CO (g) + H2O (g); K2 = PCO X PH2O [3] PH2 X PCO2 and with the aid of the accurately known equilibrium constant of this reaction, it has been shown5 that the experimental data on reactions [1] and 121 are in fairly good, though not exact, agreement. Experimental Method Great care was taken to avoid the principal sources of error of previous studies, namely, gaseous thermal diffusion and temperature measurement. The apparatus was designed to provide controlled preheating of the inlet gases and to permit the addition of an inert gas (argon) in controlled amounts, two measures found to be essential for elimination of thermal diffusion. A known mixture of water vapor and hydrogen was obtained by saturating purified hydrogen with water vapor at controlled temperature. This mixture, with the addition of purified argon, was passed over the surface of a small melt (approximately 70 g) of electrolytic iron in a closed induction furnace. After sufficient time at constant temperature for attainment of equilibrium the melt was cooled and analyzed for oxygen. GAS SYSTEM A schematic diagram of the apparatus is shown in Fig 1. Commercial hydrogen is led through the safety trap T and the flowmeter F. The catalytic chamber C, held at 450°C, was used to convert any oxygen into water-vapor. A by-pass B with stopcocks was provided so that the hydrogen could be introduced directly from the tank to the furnace when desired. From the catalytic chamber the gas passed through a water bath W, kept at the desired temperature by an auxiliary heating unit, so that the gas was burdened with approximately the proper amount of water vapor before it was introdvced into the saturator S. All connections beyond the catalytic chamber were of all-glass construction. Those connections beyond the water bath were heated to above 80°C to prevent the condensation of water vapor. After the saturator, purified argon was led into the steam-hydrogen line at J, and finally the ternary mixture was introduced into the furnace. THE SATURATOR The saturator unit comprised three glass chambers, as shown in Fig 1, the first two chambers packed with glass beads and partially filed with water and the third empty. Each tower had a glass tube with a stopper attached for the purpose of adjusting the amount of water in it. The unit was immersed in a large oil bath, which was automatically controlled with the help of a thermostat relay to constant temperature, ± 0.05ºC, using thermometers which had been calibrated against a standard platinum resistance thermometer. The performance of the saturator over the range of experimental conditions was checked by weighing the water absorbed from a measured volume of hydrogen; the observed ratio was always within 0.5 pct of theoretical.

Jan 1, 1950

By William B. Plank

FOR the third consecutive year, I have collected the data on enrolment and employment of graduates from the schools in. the United States and Canada that grant degrees in mineral technology. The data were collected in the same way as formerly; namely, by questionnaire, dated Jan. 5, 1935, and are therefore comparable with the figures reported for former years. This year, along with the names of the 48 schools in the United States and the six in Canada, are listed the courses offered and the degrees granted by each, school, together with the names of the professors in charge. The names and addresses of the four schools in Mexico are also given. The list is on pages 450-1, which should he valued as a directory by those interested in mineral technology education. So far as is known, this is the most complete and up-to-date list that has ever been published.

Jan 1, 1935

By W. C. Ellis, E. S. Greiner

METALLIC titanium has been prepared in small quantities since the beginning of the century. Hunter1 reported in 1910 that he obtained a malleable product of 99.9 pct purity by the reduction of the tetrachloride by sodium in a closed container. Later Van Arkel2 and Fast3 prepared small quantities of malleable titanium by thermal decomposition of titanium iodide. Another method for producing malleable titanium from tetrachloride was reported by Kroll4 who used magnesium as the reducing agent. More recently Dean, Long, Wartman, and Anderson5 working at the U.S. Bureau of Mines have reported the preparation of the metal on a pilot plant scale by the reduction of titanium tetrachloride by magnesium in an atmosphere of helium. Their product, which is malleable, was used in the present investigation. Early in 1948 after the work of this paper: was completed Campbell, Jaffee, Blocher, Gurland, and Gonser6 described the strength and working characteristics of pure titanium which was prepared by the iodide method on a scale producing 300 to 600 g per run, in the form of 0.3- to 0.4-in. diam rods. Their product is characterized by low hardness and large capacity for cold work which they attribute to a high degree of purity with respect to oxygen, nitrogen, and carbon. Titanium has a melting point of about 1725°C5 it may be classed as a light metal since the specific gravity is 4.5 g per cc-1. The crystal structure is close-packed hexagonal from room temperature t0 885°C. Above this temperature the structure is reported7 as body-centered cubic. The change in crystal structure has been associated with discontinuities in specific heat8 electric resistance9 and thermoelectric force10 at temperatures near 890°C. It is reported11 that annealed titanium has a tensile strength 0f 78,700 psi which can be increased by cold-work to 123,000 psi. In the present investigation, the lattice constants at room temperature, the thermal expansivity between 30 and 800°C, as well as the electrical resistivity and thermoelectric force against platinum between - 200 and 1000°C have been determined. MATERIALS For the measurements, two series of specimens were prepared from titanium furnished by the U. S. Bureau of Mines. The first was lade from an annealed sintered compact, 0.38 in. thick. Sections of the compact were cold-swaged with intermediate anneals in vacuum to the sizes used. Sizes over 0.25-in. diam were annealed at 1000°C and smaller sizes at 800°C. Specimens originating from the sintered compact are designated in this paper as A. The second series of specimens was lade from a rod of titanium, 0.19 in. in dial, which was cold-swaged with the necessary intermediate anneals to the required sizes. This series of specimens is designated B. The impurities in the specimens of titanium, determined by chemical analysis, are given in Table I. Oxygen and nitrogen which were not determined by analysis, are probably present although in small quantities in view of the ductility of the material.

Jan 1, 1948