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By William H. Marlowe, Thomas E. Ban, Eric Johnson

Introduction In recent years, the industries of the US have been caught between ever increasing environmental concerns and an increasing uncertainty in availability of fuel. An obvious solution is to use our vast reserve of coal by direct combustion or gasification. The problem involves development of a fuel that is environmentally acceptable for these purposes. In order to resolve this problem in the shortest period of time, it would be ideal if an existing technology could be modified to produce a clean fuel from coal. Shortly after World War II, the iron ore industry was compelled to develop a high quality ore from low grade resources. This need led to the development of the taconite industry which involved milling, concentrating, and pelletizing technologies. These technologies are now fully established and applicable to conversion of coal. This presentation introduces a process for converting high sulfur coal into carbonized composite pellets, which emit low quantities of sulfur and particulate matter and may be produced by employing proven elements of technology. The new product, a clean pellet fuel (HelifuelTM) was initially developed by McDowell-Wellman Co., a subsidiary of Helix Technology Inc., at their Dwight-Lloyd Research Laboratories

Jan 1, 1982

By I. Stapf

Systematic investigations on silver-rare earth metal systems have been extended on the Ag-Ce system in order to clarify the discrepancies reported in literature. The phase diagram has been reinvestigated on the base of thermal analyses and of microstructure examination on cast and annealed specimen. All intermetallic phases Ag4Ce, Ag3Ce, Ag2Ce and AgCe show no extended range of homogeneity, they melt congruently fm), or decompose peritectically (d) at 815 °C (d), 1030 °C (m), 855 °C (d) and 855 °C (m), respectively. The system shows eutectics at 793 °C/10 at.%, 780 °C/42 at.%, and about 505 °C/81 at.% Ce. d-Ce dissolves up to 2 at .% Ag and decomposes metatectically at 710 °C. Furthermore, the phase transformation of the intermetallics would be clarified. The phases Ag5Ce and Ag51Ce14 reported in literature could not be verified.

Jan 1, 1984

By David B. Campbell

Production of both metallurgical and thermal coal represents a significant sector of the mining economy of British Columbia. The coal measures are located in the Rocky Mountains, and the majority of the coal is produced by open pit mining. The coal seams occur interbedded with siltstones, sandstones, mudstones, and shales. Consequently, large volumes of waste rock are generated in the course of open pit mining. The waste rock is consigned to waste rock piles that of necessity must be developed on moderate to steeply sloping terrain. Some of the waste dumps currently under development will ultimately contain in excess of 500 million cubic meters of material, and some of the proposed waste piles will attain heights in excess of 300 m. These waste piles must be developed in a manner that will assure their stability through all stages of development, as well as over the long term after mining operations have been completed. This paper describes methods of waste dump development, factors affecting stability, modes of potential failure, and a simple method for monitoring movements to provide a warning of pending unstable conditions.

Jan 1, 1985

By G. E. Archie

THE usefulness of the electrical resistivity log in determining reservoir characteristics is governed largely by: (I) the accuracy with which the true resistivity of the formation can be determined; (2) the scope of detailed data concerning the relation of resistivity measurements to formation characteristics; (3) the available information concerning the conductivity of connate or formation waters; (4) the extent of geologic knowledge regarding probable changes in facies within given horizons, both vertically and laterally, particularly in relation to the resultant effect on the electrical properties of the reservoir. Simple examples are given in the following pages to illustrate the use of resistivity logs in the solution of some problems dealing with oil and gas reservoirs. From the available information, it is apparent that much care must be exercised in applying to more complicated cases the methods suggested. It should be remembered that the equations given are not precise and represent only approximate relationships. It is believed, however, that under favorable conditions their application falls within useful limits of accuracy.

Jan 1, 1942

By S. Lipson, H. W. Antes, H. Rosenthal

A study was made of the effect of ingot structure on the strength and ductility of high-strength wrought-aluminum alloys. It was found that a fine-cast structure facilitated complete homogenization which, in turn, resulted in significant increases in ductility and strength. A completely homogenized 7075-T6 alloy developed tensile properties of 85,000 psi UTS, 75,000 psi YS, with 40 pct RA. Completely homogenized 7001-T6 alloy tensile properties were 102,000 psi UTS, 99,000 psi YS, with 19 pct Ra. A method was devised for making small ingots having secondary dendrite arm spacing of less than 10 u. This method involved multiple-pass arc melting of commercial rolled plate with a tungsten electvode. This material could be completely homogenized after 3 hr at 900°F; homogenization of the original plate material was not complete after 120 hv at 900°F. Degree of homogeneity was determined by use of metallographic and electron-microprobe analyses. The electron-micro-probe study also showed the preferential segregation of solutes in the microstructure. HIGH-strength aluminum alloys, such as those of the 7000 series, usually freeze by the formation and growth of dendrites. The dendrite arm spacing (DAS) depends on the rate of solidification.' Commercial ingots are usually direct chill-cast to promote more rapid solidification, but, due to the large mass of the ingot, localized solidification times are long and a large DAS results. During solidification, solute elements are rejected by the solid as it forms, causing enrichment of the liquid and ultimately solute-rich interdendritic regions. In order to attain a homogeneous ingot, the segregated solutes must diffuse across the dendrite arms. The larger the DM, the longer the time for complete homogenization. In the case of commercial ingots, the DAS is so large that the time for complete homogenization is prohibitively long and, therefore, second phases or compounds are always present. These un-dissolved phases are carried over to the wrought material during processing, resulting in an impairment of strength and ductility. In addition, the mechanical fibering of the undissolved second phases or compounds during working results in mechanical property anisotropy. If complete homogenization could be attained, higher ductility could be expected. The realization of higher ductility at current strength levels is a desirable objective; however, if higher-strength alloys were wanted, it might be possible to sacrifice some of this ductility by adding more solute elements and produce even higher-strength alloys than are currently available. Further, if complete homogenization leads to more efficient utilization of solute elements, then more dilute alloys should have relatively high strengths with very high ductility. In all instances, it would be expected that the degree of mechanical property anisotropy due to mechanical fibering would be reduced. Therefore, it was the purpose of this investigation to produce cast structures that would facilitate homogenization and to determine the effect of homogenization on the properties of high-strength, wrought-aluminum alloys. MATERIAL CLASSIFICATION Commercial Alloys. In order to illustrate the non-homogeneous condition that exists in commercial high-strength, wrought-aluminum alloys, typical micro-structures of 7001, 7075, and 7178 are shown in Fig. 1. The chemical compositional specifications of these alloys are given in Table I. It can be seen in Fig. 1 that a considerable amount of undissolved second-phase material is present in each of these alloys. The solute elements associated with the undissolved phases were identified by electron microanalyses. Back-scattered electron images and characteristic X-ray images of the three commercial alloys are shown in Figs. 2, 3, and 4. These data indicate that the second phases are regions of high copper and high iron-copper concentrations. The second-phase material also was analyzed for magnesium, zinc, manganese, chromium, and silicon, but no significant enrichment above that of the matrix was found. Therefore, the problem of homogenization resolved itself into one of dissolving the copper-rich and the iron-copper-rich second phases. In order to accomplish this objective, two approaches were made. The first was to reduce the iron as low as possible since this element has a maximum solid solubility of 0.03 pct in aluminum. The second was to produce cast structures with finer DAS to facilitate dissolving the second phases. Commercially Produced High-Purity Alloys. A special high-purity, 2000-lb ingot of 7075 alloy was made by a commercial producer. This alloy contained the following weight percentages of solutes: 5.63 Zn, 2.48 Mg, 1.49 Cu, and 0.21 Cr. All other elements combined were less than 0.02 pct by wt including iron and silicon at less than 0.01 pct each. The ingot was cast and processed into rolled plate using standard commercial techniques. Microstructures of standard commercial 7075 and the special high-purity 7075 are shown in Fig. 5. It can be seen from this figure that the high-purity alloy has less undissolved second-phase material, but a significant amount was still present. The second phase in the high-purity material did not contain iron but it was found to be enriched with copper. The slight effects of the increased purity and de-

Jan 1, 1968

By Y. C. Liu, G. A. Alers

measurements of the anisotropy in Young's modulus produced in copper by rolling 95 pct reduction in thickness below room temperature have been carried out in order to study the dependence of the texture on rolling temperature. The results clearly show the transition from a copper-type texture to a brass-type texture as the temperature of rolling is lowered. The intermediate textures observed can be described very well as a simple mixture of the two terminal textures. These results cormbined with other texture measurements make possible afresh review of the experimental facts velating to rolling textures in fee metals and, as a consequence, a critical examination of the current theories is presented. PREVIOUS experiments have shown that the transition from the copper- to the brass-type rolling texture is clearly displayed and can be quantitatively analyzed by measurements of the anisotropy of Young's modulus.' Application of this method to the Cu-Zn alloy system showed that the description of the texture transition as a gradual rotation of the grains from the orientation characteristic of the copper texture to the {110}(112) texture of brass2 was inconsistent with the data. Instead, the data suggested that the texture within the transition region could be described as a simple mixture of the two terminal textures.5 Unfortunately, it was difficult to establish this point conclusively because of the inadequacy of corrections for the composition dependence of the single-crystal elastic constants. Since a rigorous establishment of the nature of this texture transition is essential to our understanding of the formation of rolling textures in fee metals, it is clearly important to undertake an investigation in which the composition dependence of the elastic constants would not enter. A suitable composition-independent texture transition is provided by the well-established variation in the rolling texture of copper with rolling temperature. This temperature-dependent texture transformation has been studied by smallman' in several fee alloys and by Müller5 and others"' in copper. They observed that the texture characteristic of copper rolled at room temperature changed to a brass-type texture when the rolling temperature was lowered to 77°K. Although it is not possible to decide unequivocally from the published pole figures whether or not the 77°K rolling texture of copper is entirely of the brass type,' this complication does not affect the main purpose of the present investigation. In addition to establishing the nature of the texture within the transition region, the modulus data should also provide a determination of the temperature at which the transition occurs as well as the temperature range over which the transition extends. This information when combined with the modulus data on Cu-Zn alloys would then provide a considerable body of new information on textures in fee metals. Since these modulus results and the data obtained from pole-figure studies must be internally consistent, it is appropriate to compile a brief summary of the experimental observations based on all available methods rather than on the pole-figure data alone as has been done in the past. The primary purpose of such a summary would be to yield a more precise definition of the experimental facts on the rolling textures of fee metals, and thus greatly facilitate our evaluation of various proposed theories in this field. The final section of this paper is devoted to this compilation of consistent, experimental facts and their application to the various theories. EXPERIMENTAL PROCEDURE Two 18-lb ingots of cathode copper of 99.99 pct purity were induction-melted under a nitrogen atmosphere in a graphite crucible and chill-cast into a steel mold. The ingots were repeatedly cold-rolled and annealed (I hr at 500°C) into slabs about 1 1/8 in. thick. Blocks 3 1/4 in. wide, 2 1/4 in. long, and 1.000 in. thick were machined from each slab. The rolling schedule used was the same as in the previous investigation1 and the final thickness of the sheet was 0.050 in. with a rolling reduction of thickness of 95 pct instead of 97.5 pct as in the previous work.' The compositions and temperatures of the cold baths used for the low-temperature rolling were as shown in Table I. After each pass the rolled strip was immediately immersed in the cold bath for about 1 min or until the bubbling of the bath had subsided. The modulus data were taken within 2 hr after the rolled strip was warmed to room temperature for the first time, so that effects due to recrystallization were minimized. The modulus specimens were in the shape of flat bars, 3 in. long, 4 in. wide, and 0.050 in. thick, cut with their long dimensions oriented at 15-deg intervals between the rolling direction and the transverse direction. The values of Young's modulus were deduced from measurements of the frequency at which these long narrow bars were set into longitudinal, resonant vibration as previously described.9 To excite the mechanical vibrations in the specimen, an electromagnetic drive similar to that employed by Thompson and lass" was used. The maximum in the amplitude of

Jan 1, 1968

By John D. Gill

The purpose of this paper is to invite attention away from the obvious. direct monetary costs of oil-field overdevelopment (as distinguished from "social costs") to a consideration of the role played by the exercise of freedom to create even allegedly excessive1 plant facilities in contributing to the maintenance of equilibrium in the wholc economy and in promoting material progress. The obvious and most commonly discussed effect of overdevelopment of oil fields is illustrated by the allegation that already the excessive development of the East Texas field has cost upward of $162,000,000;2 in other words, the drilling of 12,500 wells more than the number estimated as the requirement for economical recovery of the reserve has unnecessarily raised the total cost of development that amount. Many other illustrations of so-called excessive development of oil pools could be presented. Some of them, like Cushing, Powell and Long Beach, might be drawn from the era antedating widespread discussion in the trade of such matters as optimum well spacing, reservoir energy, the conservation rate of depletion of reserves, etc. Numerous other cases can he found in the records of the current era, which began with the introduction of rationalized restriction of production. Besides East Texas, there may be mentioned Oklahoma City, Centralia and. more recently, the town-lot development of Bloomingdale, Michigan.

Jan 1, 1940

By D. C. Seidel, E. F. Fitzhugh

Nickel sulfide ores lend themselves readily to concentration before smelting or pressure leaching, but neither of the major oxidized ore types-the iron-rich laterites and magnesium-rich, soft silicates-has been directly concentrated. Upgrading of crude ore in current practice is limited to cobbing lumps of the harder, lower grade rock (protore) from the softer, enriched silicate ore, because only a small percentage of the nickel in these ores occurs in discrete, contrasting mineral particles. There is no apparent mineralogical contrast in the superficial, iron-rich lateritic ores and, in fact, there is no firm assurance that the nickel atoms are within the lattices of the limonite minerals, or else irregularly adsorbed on the limonite. Within underlying, "rotten rock" silicates, occasional veinlets of garnierite and related nickeliferous silicates are found.1 The garnierite veinlets are only incidental, and the majority of the nickel atoms occur as erratic replacements of magnesium atoms in the micaceous chlorites of the ore mass.

Jan 4, 1968

By T. Egleston

Although the success of metallurgical operations depends so largely on the possibility of finding proper refractory materials, which enter so prominently into the cost of their operations, it can hardly be said that our knowledge of them is in a very satisfactory condition, or even that we know very much about them, beyond a few facts which have been gathered through their use. Experience, as a general thing, is an excellent master, but the requirements of

By W. H. Holman, J. B. Wagstaff

IN spite of considerable interest among blast furnace operators on the question of the penetration of air into the furnace, there is still uncertainty as to how far the blast does, in fact, penetrate. Moreover, it is not always clear just what is meant by the word penetration in this sense. In 1952, Elliott et al.1 showed that at the end of each tuyere of a blast furnace there is more or less of a void. In this region, coke particles are blown around by the force of the air. This explained the well-known observation reported by Sweetser2 hat if a bar is pushed into a furnace through a tuyere it will go easily into the furnace a distance of some

Jan 1, 1958

By Clarence Linville

IN an article published in the Iron. Trade Review 1 I gave a convenient arrangement for the installation of wet and dry bulb thermometers for use in making moisture determinations in the air being blown into a blast furnace, and also gave a chart for use in obtaining moisture values from the thermometer readings. The data from which this chart was prepared were obtained from the tables in use by the U. S. Weather Bureau.2 The work of Carrier 3 has shown that these tables are somewhat in error. He has recalculated the values for moisture as referred to, wet and dry bulb thermometer readings, and he has prepared a psychrometric chart from the values thus obtained. This work has priced the subject of psychrometry upon a correct scientific basis. I think it is proper that we should recognize the importance of his work and give him credit for one of the most interesting and valuable researches that have been published in recent years. Blast-furnace men are not ready to use, as he suggests 4 a value expressed in grains of water accompanying a pound of dry air. However convenient this may be for heating and ventilating work and other engineering problems, there are several reasons for preferring the use of a value expressed in grains of water in a. cubic foot of mixed air and water vapor, in connection with combustion phenomena and the effects of moisture on blast-furnace operation. Previous papers presented to the Institute have used such values and we have

Jan 10, 1913

For the first time, the attendance at the meetings of the Institute passed the thousand mark; as is shown by the following table: REGIS- AT BANQUET DID TOTAL TERED NOT REGISTER Men :..:... 703 76 806 Women 195 61 256 1062 The names of the members and guests who registered or attended the banquet but did not register are: A A. D. Beers C. A. Adams Hans Behr Thos. J. Adams Edgar G. Bell Lawrence Addicks Donald A. S. Bell H. T. Abrams W. de LeBenedict G. Aertsen G. B. Bertelli M. M. Albertson Charles P. Berkey James Aldrich Clinton Bernard D. C. Alexander, Jr. W. N. Best W. H. Alexander Robert M. Betts A. W. Allen Christopher H. Bierbaum F. D. Aller Paul Billingsley R. H. Allport R. A. Bingham F. C. Alsdorf R. M. Bird Capt. M. Altmayer John L. W. Birkinbine A.' W. Ambrose G. S. Bisey Henry M. Ami Charles W. Boise F. L. Antisell J. J. Blackmore R. S. Archer A. E. Blackwood Paul' Armitage Capt. C. K. Blatchly Andrew B. Armstrong E. L. Blossom Clifton T. Armstrong C. A. Bohn Ralph Arnold James M. Bonsall R. M. Atwater, Jr. E. E. Boon Joseph E. Aue Gail Borden A. M. Austin R. S. Botsford W. S. Ayres John M. Boutwell

Jan 4, 1919

By Sir Nathaniel Barnaby

We must not conceal from ourselves that, against the perils arising from perforation of the shells or hulls of ships, we are greatly worse off in these days of steel and iron than we were when our ships were built of oak, teak and pine. Apart from the greater

Jan 1, 1891

By R. M. Porter

The Sullivan mine of Consolidated Mining and Smelting Co. of Canada Ltd. is located one mile west of Kimberley. With its daily production of 10,000 tons, the mine is the largest in British Columbia and one of the outstanding mines of the world. The Sullivan orebody dips from nearly horizontal to 45". The ore zone is a bedded replacement de- posit in argillite with a width varying from a few inches up to 300 ft. The main sulfide minerals are pyrrhotite, pyrite, galena, and sphalerite. The chief metals produced are lead and zinc, with less important qualities of iron, silver, tin, antimony, bismuth, cadmium, indium and sulfur.

Jan 12, 1963

By W. A. Hockings, G. W. Lower, K. A. Smith

The kinetics of dissolution of metallic copper in aqueous cupric ammonium carbonate solutions were investigated. The major variables studied were temperature, agitation, and the cupric, cuprous, ammonia and carbonate concentrations. The rates of copper dissolution from rotating discs were determined by measuring the weight loss. The dissolution rate increased with the square root of the disc rpm and doubled when the temperature was increased from 20°c to 40°C.

Jan 1, 1973

By George Laird

IF IT IS true that Sir Walter Raleigh lost his head for his failure to find gold in the Guianas, the trumped up charge of "treason" might better have been "con-tributory negligence." That systematic investigation and development of the gold-bearing areas of both Dutch and French Guiana have not been accomplished is not due so much to the lack of gold as to the geo-graphical, physical and climatic conditions of the two colonies. The Dutch, as a people, are not prospectors. The French look upon "Cayenne," or French Guiana, as DJOEKA BOATS USED IN RIVER TRANSPORTATION. just what it is: a penal colony, which produces a certain amount of balata, gold and essential oils, all of which can be purchased from the natives with far less physical exertion than they can be secured from the "bush" or jungle. The colonies have had their gold "booms," and dur-ing these periods the production has increased to a considerable amount, but the hardships to be endured in reaching the fields, the cost of transporting tools and supplies, the ever-present fevers, the bite of the "57 varieties" of insects and, lastly but not leastly, the abundance of rum in the seaport towns, dampen the ardor of even the strongest; the production of gold is left to the "pork knocker" or illegal gold digger and to the comparatively few producing "mines."

Jan 10, 1922

The Library of the above-named Societies is open from 9 A.M. to 10 P.M. on all week-days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 2, 1915

By H. M. Garrett

The basic cement making process is outlined relative to the fuel but chemically sensitive suspension preheater (SP) kiln which made its debut in the early 50s. The SP history is trailed through the process disasters of the late 50s; identification of chemical sensitivities in the 60s; and resurgence of the SP together with development of its stepchild process, the precalciner (PC) kiln, in the 70s. The current energy problem and related conversions to coal re-emphasize the process chemical sensitivity. Attention is focused on the basic problem of coal sulfur and ash variations and several solutions are presented.

Jan 1, 1981

By John Bell

Aim of Rock-Crushing Experiments THE aim of the laboratory experiments described in this paper was twofold: 1. To measure as accurately, as possible the maximum amount of crushing that can be effected by 1 hp. acting for 24 hr., by the two proposed methods for measuring the amount of crushing, namely: (a) by Rittinger's method; (b) by Stadler's method, based on Kick's law. 2. To show, if possible, that by one of these methods, the amount of crushing produced by 1 hp. in 24 hr. is a constant amount throughout a wide range in the diameter of the piece crushed, and that by the other method, the amount of crushing is a variable quantity over the same range of diameter; or else show that neither of the proposed methods for measuring the amount of crushing indicates a fixed relation between power and crushing and consequently a new method for computing this amount will have to be found to permit the establishment of a law of crushing. Experimental Methods Testing machines, calorimetric methods and commercial. types of rock-crushing machines were considered with reference to their value for measuring power used in crushing. The following electrically driven crushing machines, installed and available in the McGill Ore-dressing Laboratory and which had been used in previous rock-crushing tests, on the whole seemed especially suited to the investigation: (1) Comet "A" crusher; (2) 7 by 9-in. Dodge crusher; (3) 10 by 16-in. rolls. In later tests a 3 ½ -ft. Huntington mill was used.

Jan 2, 1917

In his paper, Sastry proposes the use of flotation methods other than the "conventional flotation!' process as possible economical methods of removing mineral fines, The practice of Liquid/Solid separation employing microbubbles to assist or induce the flotation of suspended solids is common to both municipal and industrial waste- water treatment; and is also used as a separation step in some processing industries. The pretreatment (if any) of the stream prior to flotation, the source of the microbubbles, and the design of the separation vessel depend on the application. For example: a metal finishing plant would use an elaborate chemical conditioning scheme to precipitate metal hydroxides for removal by a dissolved air flotation unit operating in the effluent recycle mode, while some oily waste can be separated using a dispersed air flotation cell with no chemical conditioning. At the present time, the "conventional flotation" process employed by the mineral processing industry makes use of mechanical agitation and aeration to generate certain sizes and quantities of bubbles and to mix these bubbles with the pulp. Specific types of chemical conditioning are used to obtain the desired results. For the separation of mineral fines, the type of chemical conditioning, bubble generation and separation device needed to obtain optimum results will have to be determined through research. The point to be made is that while the principles of flotation separation can be applied to a wide variety of applications, the specifics of the flotation process may vary with each application. Sastry's paper has dealt with the many areas of research required to fully understand and utilize the flotation process for the beneficiation of mineral fines.

Jan 1, 1979