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By T. L. Joseph

A study is made of the amount of solution loss necessary to maintain the reducing power of the gas stream in the blast furnace. Curves are presented to show the effect of solution loss, moisture in the blast, and carbon dioxide from the flux on the nitrogen in the THE blast furnace process is based upon the counter flow of gases and solids. As CO, N, and H, flow upward from the combustion zones, oxygen is acquired from the descending charge. In the reduction of iron ore, a portion of CO is converted to CO, and similarly a portion of H, is converted to water vapor. The inert N,, from the air used in combustion, passes through the furnace with little change. Its concentration is, however, decreased by reactions such as direct reduction and solution loss which increase the volume of CO in the gas stream; Similarly the evolution of C02 from the limestone also dilutes the nitrogen. he purpose of this paper is to illustrate an idealized and simplified method of studying furnace processes by following changes in the gas phase between the tuyeres and the stock line. A more specific objective is to evaluate the effect of solution loss upon the CO/CO, ratio in that region of the furnace in which FeO is reduced to metallic iron. This last stage of reduction requires relatively high CO/CO, ratios to exceed the equilibrium requirements. Solution loss or the reaction of COZ with C to produce CO has a pronounced effect upon the ratio of the carbon gases and is necessary to maintain the reducing power of the gas stream if the consumption of coke is low. It will be explained later that indirect reduction followed by solution loss is stoichiometri-cally equivalent to direct reduction. Calculations will be made to show how the composition of the gas in the region of the mantle varies with coke consumption and with different amounts of solution loss. Such calculations show the condi- tions under which gasification of C with oxygen in the charge is needed to maintain the reducing power of the gas. Equilibrium conditions for FeO and the carbon gases will be used to establish a minimum CO/CO, ratio below which reduction will not proceed. The manner in which carbon is gasified in the furnace, at the tuyeres with oxygen in the air or above the tuyeres with oxygen from the charge, will be a basic feature of all calculations. It is hoped that greater interest in the use of top gas as a means of following furnace reactions will be aroused by the calculations and generalized curves which are presented. Bosh Gas Equations Subject to some alteration by the amount of moisture in the blast and by direct reduction, the gas leaving the combustion zones of a blast furnace has a definite composition. Because a relatively small amount of oxygen is acquired from the charge in the bosh and in the crucible, the products of combustion undergo little change until they enter the shaft. Bosh gas is, therefore, essentially the products of combustion of carbon in a deep fuel bed with air. The relative weights and volumes of reacting materials are expressed by the equation: 2~ + 0? + 3.76N, = 2C0 $ 3.76NZ [I] Air Bosh Gas -air = 79% N? = 3.76) 21% 02 Starting with a known mass of C consumed largely by air, Eq 1, but partly by water vapor, Eq 2, the volume and C + H2O = CO $ H? [21 composition of the bosh gas can be calculated and subsequent changes followed as reactions take place at various elevations in the furnace. As shown in

Jan 1, 1952

By Hans Lundberg

In order to comprehend the help and information that may be expected from electrical prospecting, it is necessary to have at least a general knowledge of the methods and principles involved in preparing and interpreting results obtained in the field. Electrical prospecting is rather complicated, both in theory and practice, and in order to make a brief description clear to the practical mining man it has been necessary to idealize and generalize the problems, at the risk of having such simplification criticized by the theoretical man. This simplification must not be misinterpreted as showing a lack of theoretical knowledge. For its operation, electrical prospecting mainly depends on the fact that most metallic ores conduct an electric current much more readily than barren rocks. If an electric current flows through a block of ground within which a body of chalcopyrite is enclosed in country rock of schist, the current will find less resistance to its passage through the chalcopyrite than through the schist, even though the passage through the latter be much shorter. This is because the longer path through the chalcopyrite offers less resistance, owing to the superior electrical conductivity of the chalcopyrite (Fig. 1). The good conductor, chalcopyrite, in the poor conductor, schist, thus attracts the current and deflects the normal flow far outside the conduct-

Jan 1, 1929

By W. H. Bassett

THE subject assigned is rather a broad one but it, is doubtless expected that it will be dealt with as applying to metals and alloys and not to the ob-taining of metals from their ores. The liberty will further be taken of confining the matter discussed to copper and some of the copper alloys. Everyone is familiar with copper, at least everyone who attends the meetings of the A. I. M. E., so no gen-eral description of the metal is necessary. There are still to be recognized two classes of copper and each of these has some sub-divisions. The two general classes are electrolytic and fire-refined copper. Since there is some misunderstanding about these materials, definitions are in order. Electrolytic is just what the name implies. It may and it should be very pure but with high current densi-ties or very impure anodes, or both, impurities such as antimony, tellurium and lead may be carried over to the, cathode. Any one of these, or a combination in which they occur, are alike fatal to good working quali-ties in the resulting metal. Of course, these metals are not supposed to be deposited with copper, but slimes containing them may be 'occluded. in the deposited cop-per or held in rough cathodes if not washed with suffi-cient thoroughness.

Jan 5, 1927

The Sixty-fifth Congress was a "War Congress." Perhaps nothing else than war work should have been expected of it, but it had time and opportunity to do much more. Engineers have good reason for sorrow over the engineering legislation that died merely because there was no opportunity for a vote. The mineral resources of the public lands of the United States are, except the precious metals, locked away from development. For more than eight years there has been an attempt by both the executive and legislative departments of the nation to secure legislation which, under proper conditions and without detriment to the public interest, will open up these lands for development. After eight years of study, argument, conciliation, and compromise, Congress agreed in conference of the two Houses upon a measure satisfactory to it and to the Executive Department and the final draft was passed by the House of Representatives, but in the Senate it was talked to death by Senator LaFollette of Wisconsin. Some of its proponents plan to, reintroduce the bill identically as agreed to in conference into the 66th Congress, where it is hoped that by reason of its peculiar fate in the 65th Congress it will be regarded in the nature of unfinished business and thus receive early consideration and passage.

Jan 5, 1919

By W. H. Bassett

One of the difficulties for many young engineers is the acceptance of responsibility. Even though they start as assistants to older men, they hesitate to offer positive opinions. They often make reports of observations and leave the boss to draw his own conclusions. If they happen to be in a position where they are not reporting to a senior engineer, and it is necessary to take the final responsibility for a decision, they try to get someone to help out and either assume or share such responsibility. Generally this is the result of want of confidence in one's self and fear that something may happen to go wrong and bring about criticism. Frequently diffidence is the principal factor. Young men come to me with reports on work that has been well done and well written up, who are evidently laboring under an intense desire to drop through the floor or to make a rapid' exit in some other way because of want of confidence. In my own early experience a consulting job came in that required considerable investigation. The man who was handing his place over to me mentioned my good fortune and I replied that the work would be interesting and I could handle it all right but feared the responsibility, which seemed considerable. He was an

Jan 1, 1932

The greatest single obstacle in the path of constructive action in making conservation a reality is the inherent discord in the hearts of men. A perfect society doubtless is many millenniums removed from the present generation, but it must be admitted that progress toward a conservative use of our natural heritage with the altruistic concept of the greatest good for the greatest number for the greatest time can be attained only by a society in which discord is reduced to a minimum compatible with the limitations of human nature. Daily industrial discord is witnessed between management and labor which passes the bounds of arbitration and results in stoppages of production, waste of productive capacity, idle capital, idle labor, and the complete loss of the most unrecoverable element of all-time. The conservation of material things cannot progress independently of the conservation of the efforts of the human worker, and the results of these efforts are proportional to life itself as measured in hours and years. Unfortunately discord passes international boundaries, and the story of war is as old as the story of mankind. Our recent attempts of international control of nations appear to be dismal failures. The prestige and power of the League of Nations and the present United Nations declined rapidly after they were unsuccessful in stopping the first outbreak of hostilities after their or-

Jan 1, 1950

By George W. Lower, William A. Hockings, Donald A. Kaczynski

The rate of dissolution of polycrystalline metallic copper in aqueous cupric ammonium nitrate solutions in the non-film-forming region was investigated by the rotating disc method. The investigation was performed in solution concentration ranges applicable to hydrometallurgical processes. This investigation was an extension of a study on the cupric ammonium carbonate system previously reported by Smith, Lower and Hockings, in which the following kinetic model was proposed: (1) Diffusion of cupric ammine ions to the copper surface; (2) Forward reaction - first order reaction of cupric ammine ions with metallic copper; (3) Reverse reaction - disproportionation of cuprous ammine ions to metallic copper and cupric ammine ions ; and (4) Diffusion of cuprous ammine ions from the copper surface. The nitrate system was selected for this study because it simplified the determination of the ionic composition of the solutions. The variables studied were stirring speed and cupric, ammonia, and nitrate concentrations. The dissolution rate increased linearly with at low values of but exhibited increasingly negative deviations from linearity at higher values of m. The rate also increased with increasing cupric concentration but decreased with increasing ammonia and nitrate concentration. Good agreement was obtained between the experimental rate data and the proposed model. Further verification of the model was indicated by the close agreement of the diffusion coefficient calculated from the data and comparable literature values.

Jan 1, 1974

By Nicholas J. Grant, W. Michael Yim

The creep-rupture properties of nickel, in as-prestrained or prestrain-polygonized condition, were studied at 1300°F and 4000 psi, and also at 700°F and 26,000 psi. An improvement of strength was noted in both the as -prestrained and the prestrain-polygonized tests at each temperature. The as-prestrained tests, however, showed superior creep resistance to the prestrain-polygonized ones. From the results of X-ray and etch-pit studies, the strengthc gain was interpreted in terms of dislocation density and the stability of preformed substructures. COLD work is known to improve the strength properties of metals at low temperatures. At high temperatures, however, the strength improvement is often lost if gross structural changes, such as re-crystallization, take place prior to or during the test. Even in the absence of recrystallization, a prestrained metal may undergo structural changes— polygonization and the formation of well-defined subgrains—which importantly effect the resultant properties. The relationship between substructure and creep properties has received considerable attention in recent years. The work of wood1 indicated that the creep strength of aluminum and its alloys was closely related to the subgrain size. Hazlett and Hansen,2 and Ancker, Hazlett, and parker,3 working with nickel and nickel alloys, had shown that small amounts of prestrain at room temperature followed by a recovery anneal at 800°C (1470°F) improved the strength at both low and high temperatures. The strength gain was attributed to an increase in the number of subgrain boundaries as a result of the prestrain-polygonization treatment. More recently Coldren and Freeman4 studied the effect of substructures on the creep rate of nickel at 1550°F. Their conclusions indicated that the substructure size as measured by the number of boundaries was the factor that controlled the creep rate. In addition, the perfection of the subgrain boundary has been indicated to have an important role on the strength.' On the other hand, there are data which disagree with the above observations. Grant, Chaudhuri, Silver, and Ganow6 found no creep strength improvement by a prestraining treatment. In reviewing the role of subgrains on high-temperature creep, Shepard and Dorn7 concluded that the contribution of the subgrains to high-temperature creep strength was a minor one. Guard,8 in a recent study on poly-gonized nickel, has cast doubt on the validity of the postulate that subgrain size controls the creep rate. In the majority of the previous studies, the subgrain boundaries have been singled out as the most important factor in determining creep strength; however, there is no firm theoretical ground for the postulate that the subgrain boundaries act as effective barriers to dislocation motion.B910 Little effort has been directed toward the study of the relationship between creep strength and other structural variables, such as dislocation density, lattice strain,

Jan 1, 1963

By L. A. Walker

DURING the past twelve years the underground shaft of the United States mine at Bingham has been sunk an additional 2000 ft. with stations and pockets cut every 200 ft. without interrupting the mining of 600 tons of ore per day and the advancing of 1500 ft. of development per month. Following is a brief description of the way the joint work is conducted. The vertical underground shaft is a three-compartment shaft with outside dimensions of 6 ft. 4 in. by 15 ft. 6 in., and inside dimensions for each compartment of 4 ft. 2 in. by 4 ft. 8 in. The manway compartment of the main shaft is used as the hoisting compartment in sinking operations; it is partially lined with 2 by 12-in, lagging and a bucket is used without guides or crosshead. Preparatory work includes the placing of a bulkhead in the manway compartment, 60 ft. above the lowest station or level, the installation of a hoist, a head sheave, a fleet sheave, a-signal system, air and water lines, and a trap door for handling waste.

Jan 1, 1937

By W. T. Cardwell, R. L. Parsons

This paper discusses the practical problem of estimating a single equivalent permeability for an oil reservoir, or a portion thereof, whose actual permeability varies in an irregular manner. Limiting averages for general types of permeability variation are developed, and illustrated by examples involving important, specific types of variation. Introduction The theory of the flow of fluids through porous media1"4 is becoming increasingly important in predictions of oil-reservoir behavior. In practical applications, however, reservoirs are seldom found to which simple theory strictly applies. Actual reservoirs have complicated shapes and nonuniform permeabilities and porosities. This paper discusses the problem of estimating a single equivalent permeability for an oil reservoir, or a segment of an oil reservoir, whose actual permeability varies in an irregular manner. The equivalent permeability of a reservoir segment is defined as the permeability of a homogeneous segment of the same dimensions that would pass the same flux under the same pressure drop- It is the permeability value that can be used in simple theoretical formulas to calculate the reservoir behavior. To the authors' knowledge, previous theoretical calculationst on systems of nonuniform permeability have been carried out only by Muskat'"; and he has not dealt with irregular variations, except in writing down the general differential equation for the pressure in variably permeable systems.lb In practical work, many calculations necessarily have been made to estimate equivalent permeabilities from the permeabiiity profiles obtained by core analyses. Regarding such calculations, Johnston and Sherborne6 say: Simple arithmetic and weighted averages have been tried on many wells and it has been found that, where frequent sampling has occurred, the arithmetic average is as satis- factory as a weighted average. It is possible that the application of statistical methods to the analysis of permeability data as recently presented by Law8 may prove fruitful. L,, has made a valuable contribution in showing how statistical analyses may aid in picturing the characteristics of a reservoir from those of a necessarily limited number of core samples. It is believed however that the particular problem of the estimation of equivalent permeabilities can be most directly approached from a fluid dynamical viewpoint as given in the present paper. An example is presented of the use of the conclusions herein in conjunction with Law's method. Theory In order to approach the problem of heterogeneity simply, it is interesting to consider a square block composed of four smaller, homogeneous, square blocks of porous medium, two of which have a

Jan 1, 1945

By O. H. Banes

The electrolytic zinc plant of the American Zinc Company located at Sauget, Illinois started operations in April 1941. The plant had a designed capacity of 45(T) per day. The original flow sheet was quite simple, incorporating the low density process. Through the years the capacity of the plant has been increased to the current design of 214(T) cathodes per day. This paper describes the current operation along with typical metallurgical data.

Jan 1, 1970

By H. M. Howe

The chief purpose of this note is to call attention to the triaxial diagram as a convenient means of illustrating the properties of slags, and by this example of its use to commend it to those inclined to graphical studies having other possible applications. Explanation.—In the common or di-axial diagram, the properties corresponding to any point are determined by its perpendicular distance from each of two axes. For example, in an ordinary stress-strain diagram the properties of a given point in the curve are, first, a stress cd so many pounds per square inch, because its perpendicular distance from the horizontal axis of the diagram corresponds by the vertical scale to that stress; and second, a strain or elongation of so many per cent., because its perpendicular distance from the vertical axis corresponds by the horizontal scale to that elongation. It happens that, as a matter of convenience, we habitually place these two axes at right angles to each other; so that our measurenieilts happen to be made not only at right-angles to

Jan 1, 1899

By Henry N. McCarl

[The Construction Materials section contains the following Chapters: Aggregates Cement and Cement Raw Materials Crushed Stone Dimension and Cut Stone Lightweight Aggregates Gypsum and Anhydrite Sand and Gravel Insulating Materials-Thermal and Sound Slag Roofing Granules] Mineral aggregates are those natural and manufactured industrial mineral and rock materials that provide bulk and strength in portland cement concrete, bituminous concrete mixes, and plaster or stucco surfaces. They may also provide special characteristics such as thermal and acoustical insulation, weight, surface textures, abrasion resistance, and impermeability to various concrete products and mixes. Most aggregates are relatively inexpensive materials, but despite their low unit value, the tonnages consumed each year in the United States and throughout the" world make mineral aggregates by far the leading industrial mineral and rock materials both in terms of volume (tonnage) produced and value consumed. The major use of mineral aggregates is in concrete. The low cost, high bulk aggregates tend to keep concrete construction costs at levels competitive with other building materials. Other major uses of aggregates include highway and railroad base or ballast materials, graded fill, and various industrial uses such as metallurgical and chemical fluxes and raw materials-these latter uses are often considered nonaggregate uses of mineral aggregate materials. The per-ton value of mineral aggregate materials at the production plant in 1980 and 1981 varied from $2 to $5 for most sand and gravel and crushed stone, $3 to $6 for air-cooled slag, $7 to $20 for expanded slag and expanded clay or shale aggregate, to as much as $165 to $320 for expanded perlite or vermiculite. The expanded lightweight aggregates have been dramatically affected by increasing fuel costs. It is ironic that the specialized aggregates used as insulating materials to conserve energy cost so much more to produce due to the high proportion of energy consumed in their production. The first four parts of "Construction Materials" deal with the utilization of four major mineral aggregate types: Crushed Stone, Lightweight Aggregates, Sand and Gravel, and Slag. While the focus will be on the use of these industrial minerals and rocks, there will also be some coverage of sources, mining and production, especially in those cases where they are not discussed in the Commodity section of this book.

Jan 1, 1983

By Wayne Loel

THE application of aerial photographs to all phases of geologic mapping is set forth, indicating the advantages to be gained in different types of country and under varying climatic conditions, Methods of field and office procedure are given from a geological point of view, as well as suggestions regarding the best methods of aerial mapping for different uses and under varying field conditions, including the study of submarine geology. Aerial photographs with accompanying geologic maps are shown to illus-trate the appearance from the air of different geologic features under varying climatic and topographic conditions.

Jan 1, 1938

By Harold Markus, Gerhard Derge

THE first paper1 of this series described a technique of careful surface preparation by means of which reproducible results may be obtained from potential measurements of the behavior of tin in carbonate solutions with a pH range from 8.4 to 11.2. It then went on to establish the behavior of pure tin electrodes under these conditions and showed that the metal remains active at all times, though the steady potential attained after several hours decreases from I.I2[t] volts at a pH of 12.6 to 0.6 volts at a pH of 8.4. This behavior may serve as a norm with which all other data can be compared. In the second paper,2 small amounts of other anions were added to the carbonate solutions and the conclusion was reached that the common impurities encountered in alkaline materials packaged in tin do not increase corrosion. In fact, in some cases these anions may actually promote the formation of protective films. The present paper rounds out this survey by presenting data on the influence of cations added to the carbonate solutions, as well as the effect of alloy additions to the tin. In many cases the potential data are supplemented with weight-loss measurements. Information is also presented on the effects of some additional anions, the influence of gases above the electrolyte, the behavior of high-purity tin, and the effect of atmospheric oxidation on the corrosion resistance of the above-named alloys. Analysis of the entire body of data discloses some general rules applicable to corrosion in carbonate solutions. The experimental methods used are the same as those previously described. EXPERIMENTAL DATA Cations.-The carbonates of the cations K+, Li+, NH4+, which are soluble, were studied in the same way as the anions, by adding 0.01 mol of the metal carbonate to one liter of 0.2 M sodium carbonate solution, pH 11.2, or to 0.1 M sodium bicarbonate, pH 8.4. The other metallic carbonates are only slightly soluble, of the order of 0 7-3 mols per liter or less, and the sodium carbonate solutions were saturated by adding excess reagent several days before the experiment, shaking frequently, and filtering just before use. The chemicals were c.p. grade in each case except the indium salt. This salt was prepared by solution of the metal in hydrochloric acid and precipitation by addition of Na2CO3. These cations may be divided into two classes, according to their effect on the potential behavior of the tin: (I) normal, (2) passive. To offer a basis of comparison, curves I of Figs. I and 2 are given to illustrate the behavior of tin in carbonate solutions saturated with CaCO3. These curves are the

Jan 1, 1941

By K. P. Gupta, P. A. Beck, N. S. Rajan

By determining the a phase boundaries in the following ternary systems: V-Fe-Si (at 1175oC), V-Co-Si (at 1175°C), V-Ni-Si (at 1175oC), Cr-Mn-Si (at 1000°C), Cr-Co-Si (at 1175°C), Cr-Ni-Si (at 1175°C), V-Fe-A1 (at 1175°C) and Cr-Co-A1 (at 1175°C), it was found that Si exerts a stabilizing effect on these a phases, while A1 tends to destabilize them. Si atoms in solid solution occupy sites D in the a structure, The co/ao ratio increases with increasing Si-, Mn- or Fe-content. The volume of the unit cell decreases with increasing Si-content. THE stabilization of certain metal silicides (the Nowotny phases) by the addition of relatively small

Jan 1, 1961

CONTENTS PAGE FULTON, CHARLES H., and READ, J. BURNS-A New Roasting Furnace for Zinc Flotation Concentrate. Discussed by Charles H. Fulton, Arthur S. Dwight, B. M. O'Harra, Kurt Stock 1 STOCK, KURT.-Redistillation of Zinc. Discussed by G. E. Dalbey, Kurt Stock.. 3 BEASLEY, F. E.-High Zinc in Lead Blast-furnace Slags. Discussed by R. C. Canby, R. L. Lloyd, C. R. Haywood, G. E. Dalbey, A. S. Dwight, E. P. Mathewson, A. L. Walker, B. M. O'Harra, and C. P. Linville 4 STEELE, E. W.-Application of Pulverized Coal to Copper Refinery Furnaces. Discussed by F. R. Pyne, E. P. Mathewson 11 LINVILLE, C. P.-Recovery of Arsenic and Other Valuable Constituents from Speiss. Discussed by C. R. Hayward, C. P. Linville, G. E. Dalbey, A. S. Dwight, Edward F. Kern, Karl Eilers, E. P. Mathewson 12 A New Roasting Furnace for Zinc Flotation Concentrate Discussion of the paper of CHARLES H. FULTON and J. BURNS READ, presented at the New York Meeting, February, 1925, and issued, as Paper No. 1362-D, with MINING AND METALLURGY,. October, 1924. G. E. DALBEY, East Berlin, Conn. What would be the, effect on the formation of sulfates of an increased water vapor content in the roasting gases? CHARLES H. FULTON.-I cannot answer that from our experience. The question of the formation of sulfate in the roasting of zinc is mainly one of temperature and the concentration of S02 and S03 in the gases. We found we could roast almost completely to sulfate if the concentration was kept at the proper point. We, however, did not care to do this because we wished to make a 5 to 6 per cent. S02 gas for sulfuric-acid work. The sulfating of the zinc oxide in the proper concentration of gases goes on very rapidly. There are certain places in the furnace system such as the Cottrell and in a part of the dust chamber in which the roasted

Jan 6, 1925

By Robert A. Rapp

The standard molar free energy of formation of MOO,was determined between 750o to 1050o C in galvanic cell measurements involving the solid electrolyte Zr0.85 Ca0.15 O1.85. Use of the reference electrodes Fe + FexO and Ni + NiO Provided two independent determinations of FoMoo2. The data may be represented by the equation FMoO2 = -137,500 +40.0T(°K) which is in good agreement with previous CO/CO, gas equilibrium measurements of Gleiser and Chipman. The standard molar free energy of formation of molybdenum dioxide has recently been reported over a large range of high temperatures from the calorimetric experiments of King, Weller, and christensen.' Gleiser and chipman2 have also recently determined ?FmoO2 from 926o to 1068oC in CO/CO2 gas equilibrium measurements. Earlier gas equilibrium studies have been made and reviewed by Gokcen.' Over the temperature range studied by Gleiser and Chipman their values for ?FoMoO2 differed from the calorimetric data by about 700 cal. This investigation was undertaken to resolve this difference and thereby establish the two phase mixture of Mo + MOO, as an electrode of well-known oxygen potential for galvanic cell applications at very high temperatures. The galvanic cell technique involving the Zr,.,, Ca,0.15 01.85 solid electrolyte was introduced for the

Jan 1, 1963

Jan 1, 1938

Jan 1, 1938