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By A. H. Lindley, Fraizer M. Stewart

For many years large mining companies were able to finance nearly all of their capital requirements from internally generated funds. However, during the last decade, funds needed for capital expenditures, dividends, and scheduled debt retirement have grown faster than cash flow. As a result the minerals industry has had to rely increasingly on other sources of funds. Getting the capital for new mining projects is a challenge, particularly for smaller companies. New methods of financing and new variations to old methods have been developed and more are needed. Commercial banks are short-term lenders. By policy their loans are limited to low risk loans-those made solely on the borrower's general credit, and secured loans where cash flow is sufficient to provide repayment within a comparatively short term. To maintain liquidity, banks prefer to make loans of less than seven years' term. If a longer loan is needed an insurance company or pension trust may take the long-term part.

Jan 1, 1971

By Carmine D. &apos, Lemuel Tarshis, Joel Hirschhorn, Antonio

Vapor-deposited nickel films in the thickness range 700 to 4360A were tested in uniaxial tension utilizing a microtester designed specifically for this study. Contrary to the findings of some investigators, a definite thickness-strength relationship was observed below 3000 A with a four-to sevenfold increase in strength over that of bulk nickel. The films were characterized by high elastic strains and little plasticity. On the basis of these and other reported data, it is suggested that the high strength level in metal films is related to the manner in which they are produced. Vapor deposition, owing to its severe quenching effect. is believed to promote the formation of point defects which inhibit dislocation movement. IN recent years it has been reported that metals, when in the form of thin films, exhibit extraordinarily high strengths. The data published to date have been primarily concerned with silver and gold because of the ease with which these metals can be vapor-deposited and their high resistance to surface oxidation. Previous investigations into the mechanical strength of thin films has uncovered an apparent dichotomy of view on film behavior. Beams and his co-workers have reported a definite dependence of strength on film thickness. Other workers,"-'6 however, in separate studies on the strength of poly crystalline and single-crystal films have found no such thickness-strength relationship. The study of thin-film strength is extremely difficult because of the many variables associated with film preparation, handling, and testing. Moreover, the manner of test employed by different investigators has varied quite radically, ranging from simple uniaxial-tension to biaxial-bulge testing. The work reported herein was conducted in order to determine the mechanical behavior of a structural metal when in the form of a vacuum-deposited thin film and to gain some insight into the reasons for the high strengths exhibited by metals having such a con- figuration. In this study a method of test was chosen which would yield results which are easily interpreted and lend themselves to comparison with properties of the same material in bulk form. Moreover, specimen-preparation parameters and film-handling techniques are set forth so that other investigators can properly compare their findings with ours. EXPERIMENTAL PROCEDURES A) Film Preparation. Vacuum deposition was performed in an 18 by 30 in. bell jar using a standard New York Air Brake Co. vacuum station with a 6-in. oil-diffusion pump. Before evaporation the system was pumped to a pressure of less than 2 x 10"5 torr. A shield was employed to protect the substrates from the emission of contaminants during the critical melting and outgassing of the evaporant. The source consisted of from one to six filaments (0.020 in. diam). The length of each filament was about 5 in. and was placed 6 to 8 1/2 in. from the substrate in such a manner that the substrate face was at 90 deg incidence with respect to the evaporant beam. The temperature of the source was 2000"~ during evaporation. The films were deposited onto a substrate arrangement which was composed of four basic components, that is: 1) a 3 by 1 in. glass slide; 2) a 22-mm sq micro cover glass on 1); 3) a 22 by 50 mm micro cover glass coated with collodion on 1); and 4) a stainless-steel sheet mask containing twelve rectangular openings of 1-mm and 2-mm widths and lengths of 5 mm laid over 3). Thus, test specimens of 1-mm and 2-mm widths are deposited onto a collodion substrate which precludes epitaxial effects in the specirnens. 17-le The rectangular cover glass and square cover glass were positioned in such a manner that a strip of film would be evaporated along the length and across the width of the large glass slide. This boundary of evaporated film was used to determine the film thickness by multiple-beam interferometry. The square cover glass was used for X-ray and chemical analyses. Thickness of the deposits was varied by changing the number of filaments used (one to six). The duration of evaporation was 30 sec for each filamgnt which resulted in a deposition rate of 8 to 20A per sec. Evaporations were all performed at room temperature; however, radiant heat from the source raised the substrate temperature to 40" to 60°C. All substrates were cleaned by ultrasonic agitation in a solution of spectranalyzed isopropyl alcohol. Collodion was deposited on the micro cover glass by immersion in solution of collodion in amyl acetate. B) Thickness Control and Measurement. Film

Jan 1, 1963

NOTHING makes the run-of-the-hall Congressman feel quite so secure as to be on an investigating committee. It's sure fire publicity for one thing and is a convenient excuse for absence from Congressional sessions when controversial issues are being balloted. The minerals procurement program has just had a thorough investigation by Congressmen of the House Interior and Insular Affairs Committee who heard valuable testimony from men like John D. Morgan, director of materials procurement, DPA. He listed over 40 government agencies concerned with mineral affairs. Testimony disclosed the justification for many of the agencies but Congressmen and mine operators have been regarding the defense minerals program in the same light as did the mining student who remarked to the descriptive geometry prof "it's not the intrinsic difficulty of the problem which gives me trouble; it's the multiplicity of detail."

Jan 9, 1951

By R. D. Nelson

The purpose of this technical note is to briefly present some data on a phenomenon—recrystallization with concurrent deformation—that has been found to occur in a plutonium. This phenomenon is unusual because a plutonium is considered brittle, not easily deformed, and not easily recrystallized; the a phase is simple monoclinic having 8 atoms per unit cell and it is stable below about 115°C. The properties of the recrystallized metal were different from the as-cast metal. Even though a plutonium is difficult to deform, Ianniello successfully rolled it' and he also observed some recrystallization at 120°C.2 Pavlick and Hanson3 detected some recovery at 109°C but they observed no recrystallization. Gardner4 and Bronisz5 studied the compression properties up to 100°C but they did not report having seen recrystallization. In the present deformation studies of electrorefined plutonium pronounced recrystallization took place concurrently with plastic deformation in compression between 24" and 115°C. The metal contained less than 300 ppm total impurities with the major impurities being 100 ppm Am, 30 ppm C, 40 ppm W, and 25 ppm U; all other impurities totaled less than 100 ppm. The compression specimens were machined to dimensions of 1.2 cm long and 0.8 cm diam from as-cast rods having a density of 19.65 g per cu cm. They were heated to the test temperature in a high-temperature silicone fluid that was evacuated to 10-4 Torr. With this procedure the specimens oxidized a negligible amount, and the temperature was maintained within ±0.2°C for times up to 3 weeks. Deformation and recrystallization

Jan 1, 1969

By C. H. Li, R. J. Stokes, T. L. Johnston

Dislocation half-loops, artificially introduced by sprinkling with carborundum, were subjected to stress using three-point loading. The different stages of loop expansion and multiplication were then correlated with the macroscopic stress-deflection curve. Loop expansion started at approximately one-third of the "yield stress," defined here as the motivation stress. Above one-half of the "yield stress" simple multiplication commenced while about two-thirds of the yield stress gross multiplication developed short slip-line segments. These values were not affected by the age of surfaces exposed to both dry and wet air. Slip was not detected on unsprinkled crystals below two-thirds of the "yield stress." Thus the stress to activate intrinsic sources, defined here as the activation stress, was approximately twice the motivation stress. This relationship was independent of the strain rate used. It is concluded that lattice resistance takes the form of a viscous drag rather than a static type of force. THE importance of surface condition and environment as one of the more significant factors controlling the mechanical properties of ionic solids has recently received renewed attention.1-4 In some materials, notably the alkali halides, exposing freshly cleaved specimens to the atmosphere results in a progressive hardening and embrittlement of the crystals. This has been attributed to the surface layer becoming "aged," thereby restricting the motion of dislocations in such a way that pileup and eventually fracture results. It is necessary therefore in studying the mechanical properties of ionic crystals to inquire first into the density and distribution of dislocations in the normal cleaved surface and to understand the role these dislocations play in the onset of plastic flow. Knowledge of the effect of environment on this behavior will then assist in understanding the mechanism of embrittlement on aging. In the work reported here a method is described for studying the initiation of plastic flow from dislocation sources in the surface of magnesium oxide crystals. Preliminary results are described of the influence of surface age on this behavior. EXPERIMENTAL TECHNIQUES The magnesium oxide used in this investigation was obtained from the Norton Co. and had a nominal purity of 99.5.pct. Single-crystal specimens, having dimensions typically 1/4 by 1/8 in. cross section and 1 in. in length, were prepared by cleavage over (100) planes from the parent crystal. They were deformed under three-point loading with 3/4 in. spacing between the two end supports and a constant rate of deflection at the center of 0.001 in. per min. The maximum strain rate therefore was 1.5 X 10-5 sec-1. Reasons for choosing this particular form of loading will become apparent in a later section. In addition, a number of confirmatory type tests have been performed at higher loading rates where the maximum strain rate was increased to 1 x 10-3 sec -1. Following deformation the crystals were etched to reveal the dislocation distribution. In a previous paper5 we described a satisfactory etching solution consisting of 5 parts of saturated ammonium chloride, one part of sulfuric acid, and one part distilled water. Immersion of the crystals for 1/4 hr at room temperature developed reproducible conical etch pits at the points where dislocations emerged through the surface. It should be mentioned that dislocations freshly introduced by room temperature deformation gave sharply pointed etch pits which generally distinguished them from the almost flat-bottomed pits obtained on "grown-in" dislocations. The distinction is obvious in the photomicrograph included in Fig. 5(b). Annealing crystals at 1000°C for 12 hr on the other hand gave sharper etch pits on the grown-in dislocations and the distinction was no lower -possible; a similar observation has been reported for lithium fluoride. We have succeeded furthermore in chemically polishing magnesium-oxide crystals. Boiling in fresh 85 pct ortho-phosphoric acid for only 1 min resulted in a microscopically smooth surface which could again be etched to reexamine the dislocation distribution. This boiling time was sufficient to remove the surface damage introduced by cleavage (see next section). SURFACE DISLOCATION SOURCES There are a number of ways by which dislocations may be introduced into cleaved surfaces to act later

Jan 1, 1960

By C. F. Tolman

In February 1913, Prof. L. C. Graton and Dr. Joseph Murdochl presented to the American Institute of Mining Engineers a notable contribution to economic geology under the title The Sulphide Ores of Copper. The value of the work was recognized by mine operators, and Mr. Graton was assisted in his plan to extend his investigations, by the organization of a commission to undertake a "secondary enrichment investigation." In this work he secured the cooperation of the Geophysical Laboratory of the Carnegie Institution of Washington. The report2 on the chemical phascs of the investigation has just been published. Incidental to investigations3 carried on in our laboratory of Economic

Jan 1, 1916

POSITIONS VACANT A steel manufacturing company is desirous of securing an assistant superintendent for its plant. Experience in open-hearth plants and in rolling mills particularly desirable. No. 112. Opening as assistant superintendent of a non-ferrous smelting plant. Man with metallurgical experience preferred but chief essential is ability to handle men. No. 114. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, aged 41, mining engineer, manager or general superintendent, 20 years' experience, 10 years in Mexico, 5 years Western States, 5 years abroad. Guarantee results, fluent. Spanish, excellent references. New York interview. No. 282. Member, technical mining graduate, 10 years' experience, especially in design, erection, construction and purchase of power and mining equipment and supplies, desires position in purchasing department. Married, aged 32, employed at present, references furnished. No. 295.

Jan 7, 1916

By Clarence Zener

THE heat-treatment of steels will not pass from the stage of an art into that of a science until the mechanism of the phase transformations associated therewith is thoroughly understood. Such an under- standing will involve two distinct types of inquiry: (I) the direction of the trans- formation, (2) the speed of the transformation. The first type of inquiry, which involves only the equilibrium relations between the various phases in steel, is the subject of the present and of a succeeding article; the second type, which involves the kinetics of transformations, will be the subject of a later article. In order that a theory of equilibrium relations may give useful information, certain experimental data must be put into the theory. It is customary for these data to be of a thermal nature. In the system discussed here in steel such thermal data are very scarce. In medium-alloy steels another type of data might possibly be used. In these steels the concentration of solute is so low that it may be possible to use the approximation of dilute solutions, an approximation that leads to linear relationships. The unknown functions, or constants, may then be determined in some cases from the binary iron- alloy system and in other cases from the ternary iron-carbon-alloy system. From the functions, or constants, so determined may then be computed the equilibrium relations in more complex medium-alloy steels. In the present article this second approach is used, the necessary experimental data being obtained from the simple binary and ternary equilibrium diagrams. FUNDAMENTAL EQUATIONS In this article are derived the equilibrium relations between the gamma, alpha and cementite phases. In these three phases all important alloying elements except carbon form substitutional solutions, each alloying atom occupying a potential site for an iron atom. Carbon, on the other hand, forms an interstitial solution. In the face-centered cubic gamma phase, the interstitial positions are at the center of the unit cube and at the centers of the cube edges. There are therefore four interstitial positions per unit cell, or one per iron atom. In the body- centered cubic alpha phase, the interstitial positions are probably at the face centers, and also at the centers of the edges, which are crystallographically equivalent to the face centers. There are therefore six interstitial positions per unit cube, or three per iron atom. In cementite, (Fe, Alloy)3C, the carbon atoms may be regarded as filling all the lattice positions of a given type. The introduction of the fundamental equations of equilibrium has presented the author with a quandary. These equations are formally so similar to other equations that have been derived1,2 for related systems that they may appear to some readers

Jan 1, 1946

By H. H. Kellogg

Equations representing the standard free energy of formation as a function of temperature, for thirty metallic chlorides, are presented and plotted on a free-energy vs. temperature diagram. The use of these data for calculations on reduction of metallic chlorides, refining of metals with chlorine, and chlorination of metallic oxides and sulphides is illustrated. CHLORINE metallurgy' has attracted metallur- gists for more than a century because the unusual properties of the metallic chlorides—low melting point, high volatility, and ease of formation from the oxides—make possible many useful extractive processes. Interest in chlorine processes is undergoing a renaissance due to present availability of chlorine at relatively low prices, and to recent advances in technology. During the present century there have accumulated a considerable number of reliable values of the thermodynamic constants for the metals and their chlorides. These data permit the calculation of free-energy equations for many metallurgically important reactions. Consideration of free-energy values makes possible certain predictions of the direction and extent of a given reaction, as well as the effect of temperature, pressure, and composition upon the result. Reaction rate, although not predictable from free-energy data, is usually sufficiently great at elevated temperatures that diffusion of the reactants and products to and from the zone of reaction determines the actual rate. Thus, if the free-energy indication is favorable, the chances are good that a high temperature metallurgical reaction will proceed at a reasonable rate, if adequate provision for rapid diffusion has been made. This paper presents standard free-energy equations for a number of metallic chlorides, based on data which are scattered throughout the literature. The equations are presented in a form that simplifies their use, and typical examples are given of the application of free-energy data to metallurgical processes. Free Energy of Reaction The free-energy change (AG) of a reaction is the true measure of the "driving force" of the reaction under a given set of conditions, and this is related to the standard free-energy change (AGO) of the reaction as follows: For the reaction: bB + cC = dD + eE ?G = ?G°+RTln ADd. AEA / ABb. ACc where A, = activity of constituent (i) T = absolute temperature, OK R = gas constant The criterion of a spontaneous reaction from left to right, at constant temperature and pressure, is a negative value for the free-energy change (?G). The standard free energy of the reaction is equal to the free energy of the reaction when all the reactants and products are at unit activity, since under these conditions the second term on the right-hand side of eq 1 is equal to zero. The concept of activity is treated fully in many textbooks on chemical thermodynamics1 and in a recent article by Chipman.2 Briefly, the activity (A,) of a constituent (i) is a measure of the reactivity of this constituent relative to its reactivity in some arbitrary standard state. For liquids and solids the standard state most often used is the pure liquid or solid constituent. Thus the activity of a pure liquid or solid in a metallurgical reaction is equal to unity. Gases under moderate pressure and at elevated temperatures behave very nearly as 'idea1 gases,' and the standard state is chosen as the gas at 1 atm pressure. The activity of an ideal gas is therefore equal to its partial pressure, and this relation is sufficiently exact for real gases in most metallurgical reactions. For a liquid or solid solution there is in general no simple way to express the activity of a constituent as a function of its concentration, and activity must be determined by experiment. A few solutions follow a so-called 'ideal' behavior, and if the pure constituent is chosen as the standard state, the activity of a constituent in an ideal solution becomes equal to its mol fraction. When a reaction reaches a state of thermodynamic equilibrium at constant temperature and pressure, AG becomes equal to zero and eq 1 reduces to: [ADd . AEe ?G°=RTln Abb ¦ Ac c equilibrium [2] The brackets surrounding the activity term are used to emphasize that each of the activities is an activity under equilibrium conditions—not just any arbitrarily assigned value. The bracketed term is the equilibrium constant (K) of the reaction. Eq 2 makes possible the calculation of equilibrium activities for a given reaction, if AGO is known at the desired temperature. The standard free-energy equations presented in this paper were calculated from the fundamental thermodynamic values of enthalpy of formation at 298°K (AH°,), standard entropy at 298°K (So298), heat capacity as a function of temperature (Cp), and enthalpies of transition, fusion, vaporization, and sublimation for the various constituents. Where possible the data reported in the recent "Selected Values of Chemical Thermodynamic Properties," published by the Bureau of Standards," were used. A large number of data came from the publications

Jan 1, 1951

By C. F. Jr. Tolman

IN February 1913, Prof. L. C. Graton and Dr. Joseph Murdoch1 presented to the American Institute of Mining Engineers a notable contribution to economic geology under the title The Sulphide Ores of Copper. The value of the work was recognized by mine operators, and Mr. Graton was assisted in his plan to extend his investigations,. by the organization of a commission to undertake a "secondary enrichment investigation." In this work lie secured the cooperation of the Geophysical Laboratory of the Carnegie Institution of Washington. Their report 2 on the chemical phases of the investigation has just been published. Incidental to investigations 3 carried on in my laboratory by advanced

Jan 2, 1916

By John M. Kelly

New Mexico produced 31,913,816 bbl. of oil in 1942, the lowest annual production since 1936, and dropped one place to rank eighth among oil-producing states. This production decreased 7,838,052 bbl., or 19.71 per cent, from the 1941 figure is the result of transportation difficulties caused by the dislocation of tanker sailings to east coast ports. The average per-well allowable in New Mexico on Jan. I, 1942, was 43 bbl. and at the end of the year was 38 bbl. Allocations as set by the New Mexico Oil Conservation Commission followed the recommendations of the Petroleum Administrator for War. After setting the daily outlet, however, the average daily pipe-line runs were 87,545 bbl.—11.06 per cent short of these allocations. Production for Lea County was 26,812,949 bbl., Eddy County 4,624,578 bbl., northwestern New Mexico 473,609 bbl., Chaves County 2,680 barrels. Drilling activity for New Mexico in 1942 was approximately 84 per cent of that in 1941 with 339 completions. Of these completions 254 were oil wells, II gas wells, and 74 dry holes. Proven fields accounted for 55 of the dry holes and 19 were wildcats. Three new oil fields and one new gas field were discovered as the result of wildcat drilling. Extensions were made to one oil field and one gas field. By the close of the year, the New Mexico Oil Conservation Commission had designated 59 areas as proven for oil and/or gas. Southeastern New Mexico Lea County Monument was again the largest producing field in the state, with 5,729,336 bbl.; Eunice was next, with 5,217,965; Vacuum produced 3,295,624 and Hobbs 2,973,488. The Hobbs field has the largest accumulated production, which at the close of 1942 totaled 100,381,417 bbl. The 100-million-barrel mark for Hobbs focused attention on the fact that this is the first field in the state to attain this figure, and also that, as Hobbs has been under continuous proration since July 1930, or approximately the entire life of the field, this 100-million-barrel recovery was obtained with 86 per cent of the wells in the pool still flowing and having a drop in bottom-hole pressure of only 3.5 Ib. per million barrels recovered. Hobbs stands out as perhaps the best regulated major oil field in the world. Two new oil fields were discovered in Lca County, the most inlportant being the area designated as East Lusk, consisting of the south 4 tiers of Sections in T. 19 S., R. 32 E. The discovery well was drilled in the SW. SW. 1/4 of sec. 21, T. 19 S., R. 32 E., by Culbertson and Irwin, Inc., and others. It was completed at a total depth of 2751 ft. in the Seven Rivers formation of Permian age. The initial potential of the well was 237 bbl. per day on pump. The oil produced has a gravity of 24.10 A.P.I., with sulphur content of 0.9 per cent. This oil has an asphaltic base and because

Jan 1, 1943

By John M. Kelly

New Mexico produced 31,913,816 bbl. of oil in 1942, the lowest annual production since 1936, and dropped one place to rank eighth among oil-producing states. This production decreased 7,838,052 bbl., or 19.71 per cent, from the 1941 figure is the result of transportation difficulties caused by the dislocation of tanker sailings to east coast ports. The average per-well allowable in New Mexico on Jan. I, 1942, was 43 bbl. and at the end of the year was 38 bbl. Allocations as set by the New Mexico Oil Conservation Commission followed the recommendations of the Petroleum Administrator for War. After setting the daily outlet, however, the average daily pipe-line runs were 87,545 bbl.—11.06 per cent short of these allocations. Production for Lea County was 26,812,949 bbl., Eddy County 4,624,578 bbl., northwestern New Mexico 473,609 bbl., Chaves County 2,680 barrels. Drilling activity for New Mexico in 1942 was approximately 84 per cent of that in 1941 with 339 completions. Of these completions 254 were oil wells, II gas wells, and 74 dry holes. Proven fields accounted for 55 of the dry holes and 19 were wildcats. Three new oil fields and one new gas field were discovered as the result of wildcat drilling. Extensions were made to one oil field and one gas field. By the close of the year, the New Mexico Oil Conservation Commission had designated 59 areas as proven for oil and/or gas. Southeastern New Mexico Lea County Monument was again the largest producing field in the state, with 5,729,336 bbl.; Eunice was next, with 5,217,965; Vacuum produced 3,295,624 and Hobbs 2,973,488. The Hobbs field has the largest accumulated production, which at the close of 1942 totaled 100,381,417 bbl. The 100-million-barrel mark for Hobbs focused attention on the fact that this is the first field in the state to attain this figure, and also that, as Hobbs has been under continuous proration since July 1930, or approximately the entire life of the field, this 100-million-barrel recovery was obtained with 86 per cent of the wells in the pool still flowing and having a drop in bottom-hole pressure of only 3.5 Ib. per million barrels recovered. Hobbs stands out as perhaps the best regulated major oil field in the world. Two new oil fields were discovered in Lca County, the most inlportant being the area designated as East Lusk, consisting of the south 4 tiers of Sections in T. 19 S., R. 32 E. The discovery well was drilled in the SW. SW. 1/4 of sec. 21, T. 19 S., R. 32 E., by Culbertson and Irwin, Inc., and others. It was completed at a total depth of 2751 ft. in the Seven Rivers formation of Permian age. The initial potential of the well was 237 bbl. per day on pump. The oil produced has a gravity of 24.10 A.P.I., with sulphur content of 0.9 per cent. This oil has an asphaltic base and because

Jan 1, 1943

By L. D. Tracy

On Aug. 5 and 6,1918, and Mar. 26, 1919, the writer made an investigation of the mine-water neutralizing plant at the Calumet mine of the H. C. Frick Coke Co. The object of this plant is to develop a process of treating the water pumped from the mines so that it may be rendered suitable for use at the power plants of the mines and also at the coke ovens; at the same time, eventually producing a byproduct which will have enough commercial value to provide a sufficient revenue to place the plant on a self-sustaining basis. The Calumet mine is situated in Mt. Pleasant Township, Westmoreland County, Pa., on a branch of the southwest branch of the Pittsburgh Division of the Pennsylvania Railroad. It is about 6 mi. (9 km.) southeast of Greensburg, the county seat of Westmoreland County. The coal, which is the Pittsburg or Connellsville seam, lies at a depth of about 200 ft. (60 m.) and is brought to the surface by means of a shaft. The output of the mine averages 200,000 tons of coal annually, all of which is made into coke, either at the ovens, at the mine, or at byproduct ovens. There are 260 coke ovens at the mine. The continued development of the coal fields of Pennsylvania and the increased use of electric power in the operation of the mines has brought the problem of an increased water supply for the plants to the attention of the coal operators. This is especially true in the Connellsville coking region, where large quantities of water are used in quenching the coke at the ovens. Many of the streams receive the drainage from the mines; and as this water is highly acid and contains sulfur in various forms, some method of treatment is necessary to render it suitable for use at the plants of the mines. With this end in view, the H. C. Prick Coke Co., about 4 years ago, installed at its Calumet mine a plant for experimental purposes, in an endeavor to develop a process that would provide a maximum amount of suitable water at a minimum cost. From a purely technical point of view, the result of these experiments has been encouraging. The company is now endeavoring to place the plant on a commercial basis.

Jan 1, 1922

By W. A. Thomas

Steam is, and doubtless always will be, the basic power in the anthracite industry, either directly applied through engines and pumps or electrically. The rapidity with which electric power is being applied to the mining and preparation of anthracite leaves little doubt as to its utility and economy. There is practically no operation, except possibly the drilling of hard rock, that has not been successfully electrified and the matter of drilling is handled economically with electrically driven compressors and the standard compressed-air drills. Conservation and the seemingly ever-increasing cost of production, justify careful consideration of the possible results of the more extensive use of electric power in the industry. It is not planned to discuss, herein, the relative economies of individual applications but to consider the relative economy and flexibility of steam and electric power. The reports available for the year 1920 indicate a production of slightly over 80,000,000 tons of anthracite, of which 8,843,500 tons were used for power and heating purposes; in other words, over 11 per cent. of the production was used at the mines. Some of this was used to generate electric power at the mines, about 160,000,000 kw-hr., while 150,000,000 kw.-hr. was purchased from the public utility companies. One large producer, who is buying some electric power and generating some, used over 13 per cent. of the production for power and heating at the mines. Another producer, where considerable electric power is generated on the properties, is using less than 9 per cent. of the output for power and heating. One of the largest producers has a fuel consumption of over 15 per cent. of the output, besides which considerable power is purchased. A careful study of the field indicates that steam-operated plants use upwards of 13 per cent. of the production for power and heating, while electrically operated plants use about 1 per cent. for heating; so that, for steam-power purposes at least 12 per cent., or 268.8 Ib., are used for power out of each ton produced. In the complete electrification of anthracite mining operations, no set rule can be given for the power requirement, in kilowatt-hours per ton, as conditions vary widely in the matter of pumping, ventilation, and transportation, but the following cases are given as a basis of determining a range and a possible average power requirements:

Jan 1, 1922

By H. E. Lee, P. C. Feddersen

Greenockite is the only known cadmium mineral of importance. It occurs rather universally, in minor concentrations, as a secondary mineral in sphalerite deposits. The world's cadmium output is obtained through the processing of metallurgical by-products, largely from the treatment of residues from electrolytic zinc, retort zinc and lithopone plants. These sources are supplemented by the processing of fumes from lead and copper smelting operations. The development of modern selective flotation practice in the decade 1920-1930, which permitted the economical mining of complex lead-zinc ores, resulted in significant increases in the quantities of cadmium entering lead smelting systems. Being closely related to zinc as to occurrence, properties and production, most detailed description of cadmium recovery methods are to be found recorded in connection with zinc metallurgy. Other than occasional articles pertaining to particular operational procedures, literature offers but little in the nature of a balanced survey of lead smelter cadmium recovery practices. While many of the basic operations described for the recovery of cadmium from zinc by-products are applicable to the treatment of lead plant products, the inherent problems involved differ widely. In general the cadmium content of related by-products from routine lead smelting operations is present in lower concentrations, exists in a less soluble state and is associated with both a greater quantity and a greater variety of detrimental impurities. To cope with these problems, lead smelter practices are found to follow the general outline: Preparatory Processing 1. Concentration operations 2. Sulphation operations Cadmium Plant Processing 1. Leaching operations 2. Purification operations 3. Sponge precipitation operations 4. Metal recovery operations 5. Refining and casting operations As in the case of related zinc plant operations, cadmium recovery practices at lead smelters are not standardized. They not only vary as to type, but also extent. Depending upon prevailing conditions, lead smelter cadmium operations range from simple concentration campaigns, for the purpose of sufficiently "up-grading" products for shipment elsewhere, to complete processing steps for the production of refined metal. Preparatory Processing The cadmium content of lead smelter receipts is low and, as a rule, proportionate to the zinc content; the usual range of cadmium contained being of the order of 0.01-0.05 pct. Were it not for the low boiling point of cadmium, such small concentrations would, no doubt, be lost in the large tonnages of slag, metal and other smelter end products. However, the ready volatility of cadmium and its compounds at prevailing lead smelting temperatures results in its concentration in fractional portions of fume collected. This collected fume comprises a circulating load within the smelter system. Thus, the cadmium content of blast furnace fume* increases with each successive circulation until an equilibrium value is reached when the sum of the cadmium losses, due to handling and in slag, waste gases and other end products, becomes equal to the intake as ore. With ore receipts averaging, say 0.03 pct cadmium, the concentration value obtainable, through fume circulation in a routine manner, approaches 10-12 pct. In such operations, cadmium concentrations in blast furnace fume of from 3-5 pct are readily .attainable. However, the concentration gain beyond this range, with each additional circulation, is progressively decreased as a result of mounting losses occurring through handling and in end products. Therefore, to avoid excessive cadmium loss and to enhance the ultimate concentration anttainable, it is customary practice to isolate blast furnace fume at some intermediate cadmium content for special concentration procedure. The most common type cadmium concentration "campaign" involves special smelting operations wherein a relatively high portion of blast furnace fume at 3—6 pct cadmium is incorporated into the sinter charge. This type practice is roughly illustrated by the diagram on p. 111. Cadmium fume collected from lead blast furnace operations is not amen-

Jan 1, 1950

By R. N. Kust, J. C. Agarwal, H. E. Barner, N. Beecher, D. S. Davies

Kennecott Copper Corp. has developed a new hydro-metallurgical process for extracting nickel, copper, cobalt and molybdenum from manganese nodules. This process (KCC Cuprion Process) utilizes a reduction leach operating at atmospheric pressure in the temperature range of 45 OC to 50°C and has been successfully demonstrated in a continuous pilot plant processing 350 kg/d of nodule ore. The chemistry, basic flowsheet and operating characteristics are presented and discussed.

Jan 1, 1980

By Ralph Hultgren

FEW phase diagrams of alloys composed of two transition metals have been adequately studied, probably because of the high melting points involved. Transition metals are the elements that have inner shells incompletely filled with electrons. They comprise groups IIIa to VIIIa of the periodic table, including more than half of all metals. We have chosen to study two systems whose comparatively low melting points allowed the alloys to be melted in a molybdenum resistance furnace. The nickel-palladium system proved to consist of a simple series of solid solutions, but iron-palladium manifested several remarkable features. The main characteristics of the latter diagram were decisively established, but lack of time prevented precise determination of phase boundaries. The gamma to alpha transformation in this system is unusual and warrants further study. Grigorjew1 determined the liquidus and solidus of the iron-palladium system by thermal methods. He found a minimum melting point, but no eutectic. He also found that palladium lowered the gamma to alpha and raised the gamma to delta transformation temperatures of iron, with a complete series of solid solutions existing between gamma iron and palladium. His measurements also indicated a compound or super-lattice near the composition FePd3. Jellinghaus2 found that annealing at 500° C. greatly increased the magnetic coercive force of an alloy of composition FePd. X-ray dif-fraction photographs showed that a tetragonal ordered phase had formed during the anneal.

Jan 1, 1939

By T. C. Atchison, W. I. Duvall

Over the past ten years a series of investigations have been conducted to determine some of the pnysical processes involved in breaking rock with confined concentrated charges. Detailed discussions of many of these investigations have been published elsewhere.1-6 Laboratory experiments made by other investigators using Hopkinson pressure-bar techniques have shown that solid materials are fractured in tension by the reflection of an incident compressive stress pulse at a free surface.7-12 In these tests a small charge of explosive is placed in contact with one end of a bar. Detonation produces some plastic flow and crushing of the bar near the charge and generates a compressive stress pulse that travels along the length of the bar. At the free end of the bar the compressive stress pulse is reflected back into the bar as a tensile stress pulse. If the tensile strength of the bar is exceeded during this reflection process, a tensile fracture normal to the length of the bar is produced, and the broken end of the bar moves forward with a constant velocity equal to the average particle velocity trapped in the broken fragment. The new surface formed by the fracture becomes the new free end of the bar that reflects the remaining portion of the incident compressive stress pulse. This process is repeated any number of times until all of the incident stress pulse is reflected. Hino has demonstrated this kind of breakage for three rock types—marble, granite, and sandstone." He has defined a blastibility coefficient, B, as the ratio of compressive strength, C, to tensile strength, T, thus: C The quantity B is the maximum number of slabs that can be produced by reflection breakage. Normally fewer slabs are produced because of loss of energy as the stress pulse travels through the rock. Fig. 1 illustrates reflection-type fracture for a triangular compressive stress pulse. The number of slabs produced by the reflection breakage process is the first whole number less than the ratio of the peak stress of the incident pulse to the tensile breaking stress of the solid. Thus the number of slabs is given by the thickness of each slab is given by and the total length of rock broken is given by N = number of slabs S - peak stress in incident pulse T = tensile strength of the rock F = fall length of incident stress pulse h = thickness of each slab D = total length of rock broken During the reflection process the particle velocity at the free surface is twice the particle velocity in the incident stress pulse. Thus the velocity with which the broken fragments move forward is given by where v, = velocity of broken fragment, and v = average particle velocity contained in that portion of the incident pulse trapped in the broken fragment. Results of these laboratory experiments cannot be applied directly to rock blasting where the explosive charge is placed in a drillhole. In laboratory tests the charge is unconfined and in contact with the rock in only one direction. In a drillhole additional confinement is offered by the rock surrounding the charge and by the stemming placed above it. This additional confinement may be enough to allow the explosive gases to do additional work on the rock during their expansion. Other writers have discussed possible effects of gas expansion'on rock breakage.13-10 However, very few experimental data are available to determine to what extent expansion of the gases is responsible for rock fragmentation. The USBM has studied the physical processes involved in breaking rock with confined concentrated charges by using simple crater tests breaking to one free surface. Crater tests have been performed in four rock types: granite, sandstone, marlstone, and chalk. Table I gives some physical properties of these rocks. Fig. 2 shows plan and section drawings of two typical crater tests and illustrates some of the test variables measured. For these tests the charge was placed at the bottom of the drillhole and primed with an electric cap. The hole was stemmed to the collar with sand and the charge detonated. Size and shape of the crater were measured after it was cleared of broken rock. As a given charge size was buried deeper in a drillhole, the crater depth usually was equal to or

Jan 1, 1960

By F. L. Robertson, C. H. Bacon, J. W. Till

A description is given of the development of a process for making low sulphur steel on furnaces fired with 2 1/2 pet sulphur oil. Slag and metal are analyzed at melt. Slag weight is estimated. A simple method for calculating necessary lime additions for making 0.025 and 0.035 pct sulphur steel is given. DURING the last 15 years John Summers & Sons have been confronted increasingly by the problem of producing a low sulphur steel from high sulphur materials. The principles adopted, the processes used, the data collected on a furnace specially set aside to study this problem, and speculation on future developments are dealt with in this paper. This study is limited to two melting shops which make sheet steel only, of the following analysis: C, 0.06 pct; Mn, 0.33; S, 0.04, 0.035, 0.03, and 0.025; and P, 0.02 and 0.015. All the processes described have reference to the manufacturing of this steel and are not necessarily applicable, without modification, to other steels. The raw materials used are given in Table I. Development of Process About 1934, Schenck's work on phosphorus was applied to frame quantitative rules for the removal of phosphorus, with great success. We could however, neither in our own work nor in the voluminous literature, find any assistance to frame quantitative furnace rules to remove sulphur. Perhaps, we should have persevered with Schenck's outstanding chapter on sulphur in The Physical Chemistry of Steelmaking, but we missed the importance of one (Ss) sentence on p. 478. "Evidently this ratio -------- is [S] the important quantity to be considered from the point of view of chemical reaction; it is clear that the sulphur content of the steel alone, as frequently given in the literature cannot suffice for judging the success of the reaction unless special details are given regarding the sulphur charge and the amount of slag."' We were not however very successful in getting values for Schenck's "n" that agreed with (S) arrived at by our direct analysis. [S] In addition to Schenck's work much attention was given to V value. The formula selected for V was: (SCaO) — 1.57 (2 P2O5) (S SiO2) After plotting many charges a curve was obtained, based upon the relationship between the percentage sulphur in the finished steel and V value, Fig. 1. For a long time this was used as standard with about a 60 to 70 pct success on producer-gas fired furnaces, if all uprising scrap was used and no bought scrap used. An inspection of this curve shows clearly that it is not a quantitative manufacturing process, and that it was not sure enough to go to the trouble and expense of doing stage analysis for P,O,,

Jan 1, 1952