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By Alfred F. Brainerd

There has been no enterprise undertaken in this and adjoining States which has attracted so much interest, or has been watched so closely as this, the first successful attempt to convert our ordinary high-phosphoric pig-iron into steel from native material. Our iron-masters have noticed intently every attempt to convert high-phosphorus pig-irons into steel by the Clapp-Grifith process in this country, and the basic process on the Continent, and studied the various patents aiming to accomplish the same purpose, and the various litigations arising among various patentees over their rival claitns; but up to August, 1887, nothing was done, and no move had been made to introduce any process for making steel. At the time above named, Mr. James Henderson, of New York, came to this place with a view of introducing his patent furnace and other metallurgical processes and appliances. After some delay and personal interviews between parties interested and the inventor, a party of gentlemen, all of moderate means, and entirely unacquainted with the manufacture of either steel or iron, decided to form themselves into a body corporate, known as the Henderson Steel and Manufacturing Company, with a capital stock of $20,000,

Jan 1, 1889

By S. G. Valentine

BLAST-FURNACE blowing engines are broadly of two main types: either steam- or gas-driven reciprocating engines, or turbine-driven rotary engines. Some results of experience with a furnace blown by an engine of the latter type may be of sufficient general interest to relate. The first engine of this type was installed at Oxford Furnace, New Jersey, before the writer's connection with this plant, in March, 1910. This furnace uses chiefly New Jersey magnetites and had been in blast seven months on its old engines when the turbo blower was started. It was 80 ft. high by 17 ft. 6 in. bosh and 11 ft. hearth diameter. It is of interest to see from the records what happened when the turbo engine was put to work. But of course, as the old blowing equipment was rather antiquated, consisting of two I. P. Morris engines with air cylinders 72 by 72 in., in good running order, however, it is evident that the comparison between their work and that of the turbo blower cannot be interpreted as being between machines that were respectively of equal excellence as representatives of their types. Still the results were gratifying and -interesting. The records show that, with the old engines blowing 13,630 cu. ft: of air per minute, measured by piston displacement, the furnace was working up about 480 tons of stock per 24 hr. and producing an average of 132 tons per day and a maximum of 166 tons. The rotary blowing engine installed was a General Electric Co. machine, the driving end being a Curtis steam turbine and the air end a six-stage rotary compressor, all running at about 1,500 to 1,600 rev. per minute, and having a capacity of 25,000 cu. ft. of air per minute up to 25 lb. pressure, and equipped with an automatic constant-volume variable-speed governor. After running this blower, for a period equal to that covered above by the old engines, at an average rate of 15,000 cu. ft. of air per minute, the furnace worked up an average of about 592 tons of material and produced an average of 170 tons per day. Thus, on an apparent increase of 10 per cent. in the air volume there was an increase of about 23.5 per cent. in the materials worked up and of about 28.8 per cent. in the product. For the first calendar month's operation of the turbo blower, on an average of 15,040 cu. ft of air per minute, there is

Jan 2, 1914

By C. G. Brehm

The anthracite-producing region is in the northeastern section of Pennsylvania, and has an area of approximately 484 square miles. It is divided geographically into three separate fields, known as the Northern, Middle and Southern. The Northern field, with Wilkes-Barre approximately at its center, is a basin about 60 miles long and almost 6 miles wide at its greatest distance across. Generally speaking, it may be said that the coal measures in this field lie horizontally, or on slight pitches, and consist of from 11 to 19 veins of coal, varying in thickness from several inches to several feet. The intervening strata between veins may be composed of slate, clay, rock or shale, or a combination of several, and are sometimes very thin. This condition often causes a treacherous roof, therefore roof support and the attending hazard of mining are problems of concern. The Middle field is made up of a number of small basins of not very great depth, and the measures, which are in like number to those of the Northern field, are varying inclinations running from nearly flat to steep pitches. The Lower, or Southern field, is made up of basins of great depth, some being 4000 ft. deep, and its measures are mostly on very steep pitches. In certain sections this Southern field is being mined at an elevation of 1300 ft. below sea level, on a pitch ranging from 50' to practically vertical, and because of the tremendous pressure and the inherent gas in the seams, outbursts of coal frequently occur at the face, locally known as "bumps." These outbursts are accompanied by a rumbling noise, after which gas is usually found. This condition makes mining a difficult and extremely hazardous undertaking, and unusual skill is required on the part of the miner to drive and maintain openings necessary to the production of coal. Miners working in such seams on the heavy pitch must carry face batteries (Fig. 1) to afford proper protection while working at the face, because of the outbursts and free running coal. To drive haulageways or gangways in this field it is

Jan 1, 1940

By C. G. Brehm

The anthracite-producing region is in the northeastern section of Pennsylvania, and has an area of approximately 484 square miles. It is divided geographically into three separate fields, known as the Northern, Middle and Southern. The Northern field, with Wilkes-Barre approximately at its center, is a basin about 60 miles long and almost 6 miles wide at its greatest distance across. Generally speaking, it may be said that the coal measures in this field lie horizontally, or on slight pitches, and consist of from 11 to 19 veins of coal, varying in thickness from several inches to several feet. The intervening strata between veins may be composed of slate, clay, rock or shale, or a combination of several, and are sometimes very thin. This condition often causes a treacherous roof, therefore roof support and the attending hazard of mining are problems of concern. The Middle field is made up of a number of small basins of not very great depth, and the measures, which are in like number to those of the Northern field, are varying inclinations running from nearly flat to steep pitches. The Lower, or Southern field, is made up of basins of great depth, some being 4000 ft. deep, and its measures are mostly on very steep pitches. In certain sections this Southern field is being mined at an elevation of 1300 ft. below sea level, on a pitch ranging from 50' to practically vertical, and because of the tremendous pressure and the inherent gas in the seams, outbursts of coal frequently occur at the face, locally known as "bumps." These outbursts are accompanied by a rumbling noise, after which gas is usually found. This condition makes mining a difficult and extremely hazardous undertaking, and unusual skill is required on the part of the miner to drive and maintain openings necessary to the production of coal. Miners working in such seams on the heavy pitch must carry face batteries (Fig. 1) to afford proper protection while working at the face, because of the outbursts and free running coal. To drive haulageways or gangways in this field it is

Jan 1, 1940

By D. A. Bailey, F. L. Kadey

During recent years, expanded perlite has found extensive use in a wide variety of commercial applications. Specifications for a range of uses call for aggregates having different physical properties and requiring various types of processing. The mitre scopic examination of expanded aggregates in specially prepared thin sections has yielded important information regarding internal structure and can be a useful aid in evaluation of the product. Perlite is an acid volcanic glass containing from 2 to 5 pct combined water. When crushed and rapidly raised to a temperature of 1500° to 2100°F, the volatilization of the combined water, coincident with softening of the siliceous glass, causes the particles to expand or pop. Expansion of perlite to densities as low as 1-1/2 lb per cu ft has been achieved, although the normal range is from about 2.5 to 10 lb per cu ft. Low-density materials of this nature have found application in cryogenic insula- tions, insulating tile and board, plaster and lightweight concrete, soil conditioners, filter aids after comminution, and a host of other uses. The expansion of perlite may be controlled by a number of variables. Some of these are ore milling, furnace design, expanding temperature, use of preheating techniques, screen size distribution, and feed rate of the crude. For the specific intended uses, the art of perlite expanding has developed to the point that much is known about the effect of these variables on the end product. The requirements, however, for an aggregate to be used in plaster are different from those for an expanded perlite to be used in lightweight concrete or for cryogenics. In the study of perlite, many practical questions remain unanswered. One of the most important is, "why do some perlites make hard aggregates while others cannot resist crushing or compaction?" The usual tests and methods for evaluation of nonmetallic substances have been tried and have contributed their share to our knowledge. But chemical analyses, compaction resistance tests, screen analysis, etc., will reveal only a limited amount of information. The answers to these complex questions may well be found in an examination of the intemal structure of the expanded particle. Such questions and the ex-

Jan 1, 1962

By G. E. McElroy

MUCH attention has been directed to mine-air flow in recent years, more especially in Great Britian where there is frequent reference to a theory of fluid flow developed by English engineers. Briefly stated, this theory is that for similar passages of the same relative roughness, in which fluid flow occurs, the conditions of flow are exactly the same for equal values of the product W D V/ µ, where W = density of the fluid, D = diameter of the passage through which flow occurs, V = mean velocity of flow, and µ = absolute viscosity of the fluid flowing. This, the "Reynolds Criterion" of fluid flow, had its origin in the work of Prof. Osborne Reynolds' more than 40 years ago. Later, Lord Rayleigh amplified the theory2 which has been conclusively proved for small pipes by the experiments of Stanton and Pannel3 over a large flow range, and by Lacey4 over a somewhat more limited range. Concordant results on small pipes have also been obtained by numerous other investigators with single fluids over more or less limited ranges of flow. According to this theory results in one medium, such as water, are immediately applicable to another, such as air; and experimental results on models are (theoretically, at least) applicable to full-scale designs. This is of great importance in aeronautics and can be of considerable value in mine ventilation research. Hodgson, in a recent paper,5 has outlined the application of this theory to mine-air flow and recent English experiments" on the resistance of a timbered mine airway have been expressed in this form.

Jan 10, 1926

By Joseph Singewald

I. THE GENESIS OF THE DEPOSITS THE ore deposits at Firmeza have been worked continuously since 1884; those at Daiquiri since 1895. It is surprising, therefore, that they have not been the object of careful geologic study until quite recently. It is true that considerable attention was paid to these deposits by A. C. Spencer, in 1901, in the report on the geology of Cuba, by Hayes, Vaughan, and Spencer,1 but this was only incidental to a hasty general reconnaissance of the Island. As far as the Daiquiri deposits are concerned, this gap has been filled by the appearance of the two papers by Prof. James F. Kemp2 and by Prof. Waldemar Lindgren and Clyde P. Ross respectively.3 Max Roesler, first holder of the Emmons fellowship, made a detailed study of the Firmeza deposits during the past summer, so that soon we can expect a full description of them. Consequently, there is no. demand at the present time for a description of the deposits from other sources, rind that is not the purpose of this paper. The papers on Daiquiri, however, leave unsolved problems in regard to the age of the rocks of the district and certain phases of the genesis of the deposits, and it is with the. hope of aiding in the solution of some of these problems that this contribution is offered. Kemp, and Lindgren and Ross agree in assigning these deposits to the type of contact metamorphic deposits. They disagree in part on the question of their localization. The deposits occur in an extensive area of diorite which includes numerous blocks of limestone, and some-

Jan 3, 1916

By Kermit Allen

Historically, major natural gas transmission companies have been faced with the problem of meeting peak demands when the source of natural gas is located hundreds of miles away from the marketing area. Transcontinental Gas Pipe Line Corp.'s position was further complicated when offshore gas supply wells were shut-in during hurricane alerts. Transco's solution to this problem was the construction of salt storage wells adjacent to their pipeline near Eminence, Miss. Storage caverns were constructed using conventional solution mining methods. Two 13 3/8-in.-diam cased wells were completed and a 1,000,000-bbl cavern was leached at an interval of 5700 to 6700 ft at the base of each well. The two caverns have a usable storage volume of 2.0 billion cu f t and each well has a deliverability rate of 375 million standard cfd. The caverns are unique in that brine is not used for product displacement-all brine has been removed from the caverns. Natural gas is stored at a maximum pressure of 4000 psia. During withdrawal the cavern pressure drops to a minimum of 1225 Asia-the volume of gas between these two pressures becomes "usuable or top gas." The Eminence storage terminal is located on the Eminence salt dome about 30 miles north of Hattiesburg, Miss. Construction began in July 1968 and was completed in October 1970.

Jan 1, 1972

Transactions of the Royal Canadian Institute, Vol. 12, Part 1, 1919, includes "The Reign of Law," by Dr. J. Murray Clark; "The Northern Interior of British Columbia and its Maps," by Rev. A. G. Morice, 0. M. I., M. A.; "Educational Reform: its Relation to a Solution of the Industrial Deadlock," by C. G. Corless, M. Sc. (McGill); "The Growth of the Scales on Fishes," by A. G. Huntsman, B. A., M. B.; "Intellectual Consequences of the War," by Franklin H. Giddings, Ph. D., LL. D., and "Industrial Research," by F.. B. Jewett, Ph. D."

Jan 7, 1919

By W. L. Phillips

Stress-strain data are reported for sodium chloride, lithium fluoride, and magnesium oxide tested in compression at diffevent strain rates in the telrlperature range from 70° to 873°K. Quantitative equations are given for the stvain-rate dependence of the critical resolved shear stress and the initial rate of work havdening. The properties so determined are compared with results previously reported for metals. ALTHOUGH the effects of strain rate and temperature on the stress-strain characteristics of metals have been extensively investigated1,2 these effects have not been studied in detail in ionic crystals. In the only previous investigations on the effect of strain rate on the deformation of ionic crystals. Gilman and gohnston3 and Hulse and pask4 have shown that the yield stress of lithium fluoride and magnesium oxide at room temperature is proportional to the ninth or tenth root of the strain rate. CRYSTAL PREPARATION Lithium fluoride, sodium chloride. and magnesium oxide single crystals were purchased from the Har-shaw Chemical Co. The compression fixture and sample preparation have been described in detail previously.5 The detectable impurities in MgO were eight parts in 105 of Fe and six parts in 105 of Si; in LiF, six parts in 105 of Mg; and in NaC1, two parts in 105 of Fe and four parts in 10&apos; of Mg. The cleaved samples measured - 0.1 in. by 0.1 in. by 0.3 in. Prior to testing all samples were annealed at -0.8 of their melting point and cooled to room tempera- ture at 50 C per hr.&apos; Samples were strained at rates (<) of 0.1, 0.01, 0.002, and 0.0002 in. per in. per min. EXPERIMENTAL RESULTS Fig. 1 is a plot of the critical resolved shear stress a,. (extrapolation of slope of easy glide region to zero strain) of sodium chloride, lithium fluoride, and magnesium oxide tested at different strain rates as a function of temperature. In all crystals at all strain rates a, decreases with increasing temperature according to an equation of the type397 where uo is a stress constant, K is a constant, and T is the absolute temperature. The points in Fig. 1 are the average of six tests. It is evident that there is a break in the log 0,- temperature plots at a characteristic temperature T,. The constant K of Eq. [I] is dependent on strain rate, Fig. 2. The relationship

Jan 1, 1962

By T. P. Papazoglou, N. A. D. Parlee, W. C. Phelps

PRACTICAL designs for good "home made" molybdenum furnaces are hard to find in the literature. The one described briefly below left something to be desired but was good enough to operate as a rather long (30 in.) two-zone furnace for periods of over 2 months at temperature (1400° to 1600°C) without shutdown. The principal problem in our application was to establish a temperature profile with two distinct constant-temperature zones and no dip between the zones. This and other problems mentioned below would not arise, however, if both zones were operated at the same temperature and if a shorter furnace were acceptable. Since molybdenum windings oxidize very rapidly when heated in air, impervious refractory tubes were used for both the furnace core and the outer jacket tube shown in the accompanying figures. A protective atmosphere of forming gas (10 pct H2, 90 pct N2) was continuously passed through the gas-tight annular volume between the core and outer jacket. The water-cooled copper ends shown in Figs. 1 to 3 sealed the ends of the tubes. Annealed molybdenum wire (40 mil) was wound on the recrys-tallized alumina core (35.5 mm OD by 28.5 mm ID by 30 in.) at a spacing of 0.36 in. The spacing was reduced to 0.29 in. close to the ends to partially compensate for end heat losses. Fig. 2 shows two molybdenum-ground lead taps off the center of the winding to produce the two independect temperature zones. The ground lead was insulated with 1/4-in. alumina tubing and connected to the grounded copper end by passing the wires through the gas port tube and crimping each wire into notches cut at the mouth. To prevent sagging of the core at high temperatures, refractory "troughs" were cut from alumina and mullite tubing to cradle the core. The support "troughs" which were 6 in. long and located about 5 in. from each end of the annular volume also served as radiation shields. In view of the different expansion coefficients and operating temperatures of the core and outer jacket (3.5 in. OD by 3 in. ID by 30 in.), the ends of the tubes were smoothed and squared to produce good sealing surfaces, and the core was ground 1/32 in. shorter than the outer tube. The power terminals were passed through their respective conductor ports which were internally lined with alumina tubing and sealed with Armstrong adhesive A-6 leaving about 1 in. of protruding lead wire for external connections. (Adhesive A-6 is a two-component system consisting of an epoxy-type resin with a mineral fibrous filler and an amine catalyst.) Figs. 1 and 3 show the entire assembly of concentric refractory tubes, copper ends, and sealing o rings, held together with two brass flanges and 3/8-in. bolts with heavy springs for dimensional flexibility. The furnace shell (19 by 19 by 30 in.) consisted of a steel frame with sheets of transite forming a box. The copper ends protruded through two 3.75-in. circular holes cut at the center of each transite square end. Thermal insulation next to the transite exterior was effected by K-23 B&W bricks alld in a central volume of approximately 9 by 9 by 30 in. a row of K-30 bricks was lined up to support the hot assembly. The rest of the volume around the outer

Jan 1, 1965

By J. A. Eisele, D. J. Bauer, L. E. Schultze

Approximately 100 million mt of magnetic reject tailings, which contain apatite and about 1% yttrium and rare-earth elements, exist in the eastern U.S. as a result of iron ore mining operations. At the present time, no economic process is available for recovering yttrium from this material. The U.S. Bureau of Mines (USBM) studied the problem to determine if an effective low-cost method could be found, thereby increasing our domestic yttrium reserves. [Fig. 1] is a line drawing of a photograph taken during microprobe analysis of a sample of the tailings, and shows the distribution of yttrium. Typical analysis of this material is 0.14% yttrium and 1.1% rare-earth elements (mainly lanthanum through neodymium). Over half of the yttrium is present as a hydrated Ca-Y silicate deposited along interfaces in the grain structure; whereas, the remainder of the rare-earth elements occur as Ca-Fe-RE silicates. The remaining yttrium and rare-earth elements are in solid solution with the

Jan 1, 1977

By Charles Locke

IT will soon become apparent that the Conference Committee&apos;s choice of the title for this presentation is a fortunate one for the speaker; since if it had read "Review of Known Facts Controlling Slag Volume" he would best step down right now. There is a dearth of facts in a quantitative sense on this subject, especially in regard to the effects of slag volume on the acid electric practice for steelmaking, as borne out by a library search involving some 175 references from 1915 to date. Even the opinions in these references on any phase of slag volume are meager. This, then, leads to a report that is candidly based on private observations, on readings and on conjectures gleaned from gossiping with fellow practitioners. Perhaps the subsequent papers, which, as I understand it, are substantiated by actual measurements, of slag volume versus specific contributing factors, will be able to acclaim or disclaim my remarks.

Jan 1, 1947

By R. V. Mrazek, F. E. Block, S. B. Knapp

The mixed homogeneous and heterogeneous kinetics of the thermal decomposition of tungsten hexacarbonyl were studied by employing a batch reactor. The system was such that a sample of tungsten hexacarbonyl could be injected into the preheated reactor, and the progress of the reaction followed by a simple pressure measurement. Both the homogeneous and heterogeneous reactions were found to be first order, and approximate activation energies were determined for each reaction. It is shown that the dis-proportionation of carbon monoxide to give carbon and carbon dioxide cannot be the source of carbon in tungsten deposits prepared by this reaction. The kinetics of the thermal decomposition of tungsten hexacarbonyl have been investigated as part of a continuing study by the U.S. Bureau of Mines on the decomposition of organometallic compounds. Reactions involving the thermal decomposition of metal carbonyls have a potential application in the preparation of pure metals and fine metal powders. Indeed, it was these applications which provided the impetus for much of the early work involving the carbonyls of nickel1 and iron.&apos; The relative lack of study of other metal carbonyls can be traced to the comparative difficulty in synthesizing these compounds. The most common use for tungsten hexacarbonyl has been as an intermediate in vapor-phase plating.7&apos;8 However, attempts to obtain a carbon-free deposit of tungsten by this method have not been successful, and some investigators have taken advantage of the carbon contamination and used this process to form tungsten carbide deposits.lo Other investigators have studied the thermodynamic properties11"14 and molecular structure of tungsten hexacarbonyl. However, very little is known about the kinetics of this thermal decomposition, the mechanisms involved," or the source of carbon in the resulting plate. In contrast, studies have been made of the kinetics of the thermal decomposition of nickel tetracarbonyl, iron pentacarbonyl, and molybdenum hexacarbonyl.&apos;l It has been found that these thermal decompositions occur by a mechanism which is partially heterogeneous in nature. Information available on the equilibrium constants for the decomposition of tungsten hexacarbonyl was used to determine a temperature range, 500" to 560°K, in which the reaction could be expected to be essentially complete. APPARATUS The apparatus used allowed the injection of a sample of tungsten hexacarbonyl into a preheated batch reactor and the use of a simple pressure measurement to follow the progress of the reaction in the sealed reactor. The pressure was sensed by means of a pressure transducer (Consolidated Electrodynamics Corp., 0.3 pct)* capable of operating at the *Reference to specific products is made to facilitate understanding and does not imply endorsement of such brands by the Bureau of Mines._______ reaction temperature. This type of sensing element was chosen to avoid the problem of condensation of the sublimed carbonyl in the capillary tubing leading to any type of remote pressure-sensing device. stirring was provided by rotating the entire apparatus. Glass beads placed in the reactor provided a pulsating agitation. To minimize thermal gradients in the reactor walls, the reactor was constructed of aluminum. The support tube which held the reactor in the furnace was thin-walled stainless steel to minimize heat conduction out of the reactor. As a result of these measures, a nearly uniform temperature (°C) was maintained throughout the reactor. Fig. 1 is a schematic diagram of the apparatus. The small gear motor rotated the entire apparatus at about 200 rpm. The bearings shown at the ends of the air cylinder were perforated to allow air to be fed to the charging piston and to allow inert gas to be fed to the reactor during the preheating period. The sample was simultaneously injected and sealed inside the reactor by operation of the air piston. Fig. 2 shows a cross section of the air cylinder and the adjoining portion of the support tube leading to the reactor. The sample carrier is shown in place at the right-hand end of the injection rod extending from the air piston. The piston is shown in the retracted position, as it would be prior to the start of an experiment. The small Teflon gasket which encircled the sample carrier at the end of the injection rod sealed the reactor when the sample was injected. This seal was maintained throughout the test by maintaining air pressure on the piston. The sample carrier was a 2-in. section of thin-walled, -in.-diam nickel tubing with an internal blank about 1 in. from the base and with the base end sealed.

Jan 1, 1969

By Vittal S. Bhandary, B. D. Cullity

Swaged iron wire has a cylindrical {001} <110> texture. The texture is also cylindrical after re-crystallization in the absence of a magnetic field, but <111> and <112> components are added to this texture when recrystallization occurs in a field. The mecizanical properties in tension and in torsion are not greatly altered by these changes in texture. AS shown in a previous paper,1 cold-worked wires of the two fcc metals copper and aluminum can be made relatively strong in torsion and weak in tension, or vice versa, by proper control of preferred orientation (texture). The deformation texture can be controlled by selection of the starting texture (texture before deformation), because certain initial orientations are stable during deformation. The present paper reports on similar work performed on bcc iron. In this case it was clear at the outset that there was no hope of controlling the deformation texture, which is one in which <110> directions are aligned parallel to the wire axis. (1t has usually been regarded as a fiber texture, but Leber2 has recently shown that it is a cylindrical texture of the type {001} <110>. In either case, <110> directions are parallel to the wire axis.) There is general agreement on this texture among a large number of investigators, which in itself suggests that the starting texture has no influence on the deformation texture. More direct evidence was produced by Barrett and Levenson,3 who reported that iron single crystals of widely varying initial orientations all had a single <110> texture when cold-worked into wire. Thus <110> is a truly stable end orientation for iron and probably for other bcc metals as well. Under these circumstances attention was directed to the possibility of controlling the recrystallization texture. This texture is normally <110> in iron,4 just like the deformation texture. However, it is conceivable that this texture could be modified by a proper choice of the time, the temperature, and what might loosely be called the "environment" of the recrystallization heat treatment. In the present work the environmental factor studied was a magnetic field. The effect of heating in a magnetic field ("magnetic annealing") on recrystallization texture has been investigated by Smoluchowski and Turner.5 They found that a magnetic field produced certain changes in the recrystallization texture of a cold-rolled Fe-Co alloy. The texture of this material is normally a mixture of three components, and the effect of the field was to increase the amount of one component at the expense of the other two. Smoluchowski and Turner concluded that the effect was due to magnetostriction. With the applied field parallel to the rolling direction, the observed effect was an increase in the amount of the texture component which had <110> parallel to the rolling direction. In the Fe-Co alloy they studied, the magnetostriction is low in the <110> direction and high in the <100> direction. Thus nuclei oriented with <110> parallel to the rolling direction will have less strain energy than those with <100> orientations and will therefore be more likely to grow. In a later paper on the same subject, Sawyer and Smoluchowski6 ascribed the effect to magneto-crystalline anisotropy and made no mention of magnetostriction. In the papers of Smoluchowski et al. the intensity of the magnetic field was not reported but it was presumably large, inasmuch as it was produced by an electromagnet. In the second paper6 it is specifically mentioned that the specimens were magnetically saturated. But if magnetostriction has a selective action on the genesis of stable nuclei during recrystallization, that selectivity must depend only on differences in magneto-strictive strains between different crystal orientations and not on the absolute values of those strains. Thus the saturated state does not necessarily produce the greatest selectivity, because the relative difference in magnetostrictive strains between different crystal directions may be larger for partially magnetized crystals than for fully saturated ones.7 In the present work the specimens were subjected to relatively weak fields (0 to 100 oe) produced by solenoids. MATERIALS AND METHODS Armco ingot iron rod (containing 0.02 pct C and 0.19 pct other impurities) was swaged from 0.25 in. in diam. to 0.05 in., a reduction in area of 96 pct. The mechanical properties in tension and torsion were measured as described previously.&apos; Textures were measured quantitatively with chromium or iron radiation and an X-ray diffractometer,8,1 and

Jan 1, 1962

By B. M. Loring, W. H. Baer, G. M. Carlton

It is a well known fact that age-hardening alloys remain in a supersaturated, or partially supersaturated, condition only for limited periods of time at temperatures below the solvus. In order to develop optimum properties by subjecting the quenched alloy to precipitation or age-hardening treatment at a specified temperature, it is necessary that the cooling rate be sufficiently high to maintain the required degree of supersaturation of the solid solution. In practical applications the size and shape of the specimens obviously have considerable influence on the rate of cooling and there is need for more information on the effects of various rates of cooling. Cooling rates of quenched aluminum alloys generally have been established by the type of quenching medium, the temperature of the medium and the dimensions of the specimen. Except for the work of Roth3 little quantitative information is available on the measurement of cooling rates of aluminum alloys and the significance of the influence of various cooling rates upon the mechanical properties. The purpose of the present investigation was to study the use of the Jominy test for aluminum alloys (Table I). The material for this investigation consisted of extruded rods 1 1/4 to 136 in. in diam. The chemical compositions were as follows: The modified L-type Jominy specimen with dimensions shown in Fig I was selected as the most convenient means for obtaining a wide range of cooling rates. The standard Jominy specimen was not satisfactory because its cooling rate was not sufficiently high. The four flat surfaces machined at right angles along the length of the L-type specimen to a depth of 0.015 in. facilitated the hardness measurements. The specimens were machined from the extruded stock with no intermediate forging. New specimens were used for each aging experiment. The specimens were given solution treatments of 2 hr duration at recommended temperatures in a Hoskins furnace (Table 2). The temperature of the furnace was maintained constant to 3°C. No protective atmosphere was necessary because the thin film of oxide that formed on the surface of the specimens had no effect on the hardness measurements. AT

Jan 1, 1949

By R. J. Armstrong, J. J. McKay

The Montana Phosphate Products Co. is currently operating three underground phosphate mines in Powell County, MOnt. † In this area the Phosphoria formation is from 35 to 50 ft thick and contains a bed of phosphate rock varying in thickness from 2 1/2 to 5 ft, overlain by 12 to 30 ft of cherty quartzite, and underlain by about the same thickness of quartzite and shaly to cherty beds. In general, the phosphate bed has a reasonably hard quartzite footwall, as well as a hard cherty hanging wall, both of which greatly facilitate the mining operation. Folding has deformed the phosphate bed to a considerable degree in the area. It is carried to surface by several of the anticlines and lowered to considerable depths in some of the syn-clines. The main structural features affecting the mining operations of the company are the Garrison anticline and the adjoining syncline and succeeding limb of a second anticline on the east (Fig I). The axis of the folding strikes roughly northwest-southeast. The three mines, namely, the Anderson, Graveley, and Luke are on different limbs of the above folds. Accordingly, the dip of the bed, and consequently the mining method, in each mine differs to a considerable degree from that of the others. For this reason, each operation will be dealt with separately. Anderson Mine LOCATION AND DEVELOPMENT Topographically this mine is in a narrow valley, the bottom of which has an altitude of 5200 ft. The phosphate bed outcrops near the ridge on the east and dips towards the valley floor at an angle of from 25 to 30°,

Jan 1, 1950

Four generations ago, the Mount Morgan ore deposit sustained the hurly-burly of frantic development common to the finding of a rich discovery. In this case, it was gold discovered in gossan capping on one of the hills of the Dee Range. The bonanza ore, like the flush of youth, has been spent. Today, one recognizes in this operation the orderly manner of the senior citizen, keeping up with the times and husbanding resources. As mining towns go, Mt. Morgan has an enviable situation. The approach is from Rockhampton, Qld, a peaceful, affluent agricultural and cattle center near the sea. To reach the mine, one goes 22 miles, first across farming country, passing orange groves and occasional children on horseback. The ascent into the Dee Range is winding and rapid. In the winter, the hills are green and Bougainvillaea and flowering yellow bracken grow wild on the hillsides. Around a bend, the brown waste terraces of the mine come into view, rising above the surrounding country. The top of the mountain has been sawed off and a deep pit sunk into the core. A little further on, around a few more curves, the town of Mt. Morgan is seen nestling comfortably in the hollows, reaching up the slopes.

Jan 10, 1964

By N. B. Hoffman

Much of the drill steel produced in America is manufactured into hollow rods. After all forging has been finished the entire bar should be thoroughly annealed and heat treated before the point is hardened and tempered, at least where the drill has heavy duty, such as working in deep holes and hard rock. A large number of tools of like character and doing work requiring similar properties are now being made of alloy steels; for instance a steel with a carbon content of 0.75 to 0.85 per cent., manganese 0.25 to 0.35, phosphorus under 0.020, sulfur under 0.030 and vanadium 0.18 to 0.23 has proved very satisfactory for chisels. A steel of this type properly manufactured will be far superior to the ordinary carbon steels, while at the same time is one whose price range should not prove prohibitive. Much of the cutting efficiency of a drill depends on proper heat treatment. This vanadium steel has a far greater safe hardening and forging range than ordinary carbon steels, making it more nearly foolproof. It will harden nicely at 1400" I?. but will also harden well and satisfactorily at 1550" F. retaining its quality of hardness and toughness in either case.

Jan 1, 1922

By D. D. Homer, R. H. Cromwell

The Minas de Matahambre No. 2 shaft, vertical, four-compartment lined with steel sets and hardwood lagging, has been sunk 2057 ft. On account of rock structure, over-all cross-section dimensions are 23 by 6 ft. Certain sections have been concreted. Two compartments are for handling ore and men, one for supplies and men, and one for manway, cables and counterweight. Two 250-ton capacity skip pockets with air-operated gates and steel cartridge pockets have been installed underground. A steel "A" headframe, a 250-ton steel receiving bin, and skip-to-man-cage changing equipment have been provided. Skip capacity is 102½ cu. ft. The hoist is a Nordberg double-drum 10 ft. by 6 ft. 6 in. geared, electrically driven, with parallel grooving for 1-?in. cables. Maximum hoisting speed is 1600 ft. per minute. The motor-generator set, control panel, slip regulator and hoist accumulator are housed in the basement of the hoist house. The electrical equipment is General Electric. The direct-current hoist motor is 800 hp. Control is of the Ward-Leonard-Ilgner type. The motor-generator flywheel set, normal speed 720 r.p.m., consists of an 800-hp. induction motor, a 22-ton flywheel (dia. 117 in.) and a 650-kw. generator.

Jan 1, 1934