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It is interesting to note that during the period that has elapsed since the Institute's formation, wood charcoal, anthracite and bituminous coal, as well as beehive and by-product coke, have been used as blast-furnace fuels, that the reign of supremacy of each fuel was associated with specific periods, and that each successive era was marked by a production of pig iron greater in quantity than the one it followed (Fig 1). The transition of the manufacture of blast-furnace iron from charcoal to anthracite and then to beehive coke, and ultimately to by-product coke, is a reflection of the economic limitations of each fuel coupled with availability sufficient to meet the increased demands of each succeeding decade. It is a pattern that has been followed almost without exception in the history of pig iron in every country. CHARCOAL Colonial production of iron relied exclusively on wood char- coal as a fuel, and the iron industry of this count recognizes the important role played by this fuel. Charcoal iron has been available to consumers since the beginning of the organized iron industry in America in 1645, by John Winthrop at Saugus, Mass.,1 and although its greatest use antedates the formation of the Institute, it is still used to some extent. Until about 1840 nearly all of the pig iron manufactured in the United States was made with charcoal, and it continued as a principal smelting fuel until 1855.2 After that time, more pig iron was produced with other fuels, despite the fact that

Jan 1, 1948

By G. Sachs, S. I. Liu

Introduction In a previous investigation on the effects of repeated strains of large magnitude on the aluminum alloy 24 ST, it was found that the reduction in ductility by straining in tension was partially restored by a subsequent compression.&apos; As illustrated by the dashed line in Fig I,$ the ductility (e~) retained after prestraining in tension by a certain amount (el) and measured in a subsequent tension test is represented by a straight line sloping down under 4s°. If a compression of the same magnitude as the first tension is inserted (€2 = — €1) between prestraining and final testing in tension, such a "balanced" tension-compression cycle yields a ductility considerably higher than that present after prestraining in tension only. The results of these tests can be correlated with those of an investigation on the effects of prestraining in compression.~ As also shown in Fig I, the ductility in subsequent tensile tests decreased with com- pression, at a rate considerably slower than that after prestraining in tension. The above discussed testing conditions can be considered as special cases of a general straining cycle, consisting of first, straining in tension by an amount el, subsequently straining in compression by an amount e2, and finally determining the retained &apos;ductility, e,, in a tensile test. Prestraining in tension is then represented by el > o and e2 = o. Prestraining in compression is given by e~ = o and e~ < o. Balanced cyclic straining is defined by the condition el > o and cz = — 61. In order to obtain further information on the effects of straining cycles consisting of tension and subsequent compression, further tests were made, varying both the tension strain, el, and the compression strain, e2, within extreme limits; el varied between 0.06 and 0.28 and e2 between — 0.008 and —0.h approximately. Apparently, such tests have not been previously performed. They revealed phenomena which have not been recognized to date, The results of the investigation are herewith reported, without attempting to correlate them with internal processes within the metal structure. However, in order to assist in an analysis of this type, the results have been represented in various manners. In addition, further test data on the effects of prestraining by compression were provided by using specimens of various contours (notched specimens) in the sub-

Jan 1, 1949

By D. R. Walker, M. C. Shaw

Dimitri Kececioglu (Allis-Chalmers Manufacturing Co., Milwaukee)—The idea of applying metal cutting theory to comminution and vice versa is very impressive. Among others, the demarcation of wheel-grinding data into two regions, namely Kick&apos;s and Rittinger&apos;s, draws attention here. A study of Figs. 6 to 9 shows the following: In Fig. 6, 1 point out of 8; in Fig. 7, 4 points out of 26; in Fig. 8 only 1 point out of 13; and in Fig. 9 practically none out of 13 points fall out of curve No. 2. Also when grinding particles smaller than 5x10." in. it is difficult to measure very accurately the grinding forces, chip geometry, and particle size. In view of the above it would be difficult to make a positive and distinct demarcation of the Wheel-grinding data into two regions, namely, Kick&apos;s and Rittinger&apos;s. The idea of using machine grinding to determine the comminution properties of materials is indeed unique. The following cautions come to mind, however, regarding applicability of machine grinding data to comminution: 1—Grinding gives uniform particle size, whereas comminution gives a variety of particle sizes in the same process. The fact that grinding gives uniform particle size is not necessarily an advantage because in comminution the overall energy under actual comminution is desired and comminution invariably results in the production of a variety of particle sizes. 2—In grinding, a small particle is ground off a comparatively large surface. In comminution small bodies are broken down to smaller bodies. This makes it difficult to establish a concept of reduction ratio in machine grinding. 3—The mechanics of machine grinding involve direct shearing action under very high strain and comparatively high compression at the shear zone, whereas: comminution involves direct dynamic compression and surface friction with comparatively little strain and shear. Consequently the mechanics of machine grinding appear to be different from those involved in comminution. Hence one might arrive at erroneous con- clusions when comminution characteristics are eval-uated from machine grinding results. It is noticed also that functions other &apos;than Eq. 16 which do not involve the concept of direct proportionality of useful energy input to new surface area created (Eq. 2 and particularly Eq. 12) may be derived to fit the, data of curve No. 2. One such relationship may be u = ct-", where c is a positive constant and n is a positive constant less than unity. This, of course, is made possible because data of a very small range. of particle size are being fitted by the curves of No. 2 and the hereby suggested relationship. A sound comminution theory should be applicable to a relatively large range of particle size. George B. Clark (Department of Mining Engineering, University of Illinois)—While the experimental work of Walker and Shawin this article is of intrinsic value in revealing certain fundamental aspects of machine grinding, milling, and related processes and in adding to the store of information concerning the comminution of solid materials by this particular process, it appears doubtful that the results of their research can be employed to verify either Kick&apos;s or Rittinger&apos;s theories. Both these laws were originally developed and proposed on the basis of very simple, idealized hypotheses. The creation of parallel idealized physical laboratory conditions which would be required for either their proof or disproof appear to be well beyond the scope of human ingenuity, at least at present. One great weakness of the imputed verification is that the spread of the points plotted on the graphs is not sufficient to permit accurate &apos;curve fitting. The range of particle sizes included in the belt and wheel grinding is not extensive enough to show any general trends, particularly for the horizontal portion of the curves, said to represent Kick&apos;s laws. That the milling; grinding, and turning data obtained by Walker and Shaw for both metals and minerals happen to comply with. certain interpretations of these two theories under certain specialized conditions

Jan 1, 1955

By E. H. Jr. Dix

THE work of Merica1 and other investigators indicates that the phenomenon of age-hardening in. alloys of the duralumin type is primarily dependent upon the variation in the solubility of copper with temperature. In addition to copper, however, these alloys contain small amounts of magnesium, silicon, manganese and iron, which may affect the age-hardening either directly or indirectly. The effect of these elements on the solubility of copper and on the manner in which this solubility varies with the temperature is of considerable interest, therefore. The effect of magnesium is of especial interest because apparently it exerts a marked effect on the natural or room-temperature aging of alloys of the type described.2 A series of investigations3 has been in progress in the research laboratories of the Aluminum. Company of America to determine the functions

Jan 1, 1932

1938 ABERNATHY, G E Feb 6, 1948 Min & Met Apr 1948 1937 ADAMS, ARMY Aug 20, 1949 Min Eng Dec 1949 1946 ADDY, GEORGE E Sept 24, 1950 Min Eng July 1951 1920 ALDERSON, WILTON P Feb 1951 Min Eng Sept 1952 1896 ALDRICH, T H , JR May 24, 1950 Min Eng Aug 1950 1942 ALDRIDGE, LEONARD June 8, 1952Jrn Met Sept 1952 1919 ALLEN, ROLLAND C July 18, 1948 Min &Met Sept 1948 1950 ANDERSON, C P Unknown Min Eng Feb 1951 1937 ANDERSON, JOHN H May 10, 1950 Min Eng Aug 1950 1914 ANDERSON, L DOUGLASS Unknown Min Eng Nov 1951 1948 ANDRAU, E W K Oct 20, 1951 1936 ANDREWS, CHARLES B Apr 19, 1950 Min Eng June 1950 1918 ARMITAGE, PAUL June 28, 1949 Min Eng Oct 1949 1924 ARMSTRONG, PERCY A E Jan 23, 1949 Min Eng May 1949 1906 ARNOLD, CHARLES LE NEVE Aug 7, 1949 Min Eng Oct 1949 1945 ARNOLD, HAROLD S Aug 7, 1950 Min Eng Oct 1950 1936 ASH, JAMES E Dec 17. 1949 Min Eng Apr 1950

Jan 1, 1952

By H. H. Stout

IN the early fall of 1025, the writer was conducting, in the Ledoux and Co. labora-tory, New York, experiments directed to-ward ascertaining the effect on its impurity content when cathode copper was subjected to a current of various gases at an elevated temperature below the melting point. The apparatus consisted of a vertical I-in. dia. silica tube about 12 in. long, heated on the outside. The cathodes were broken to pass 3/8-in. mesh, and a current of various differ-ent gases was passed up through a 4-in. long column of these loose cathode particles in the vertical tube furnace. Temperature was maintained to 1500° to 1600°F. and the gas treatments lasted from 3 to 6 hr. The writer observed that whenever reducing gas (H2 or CO) was used, these cathode par-ticles stuck together at points of contact with each other. The cohesion was so marked and tenacious that an examination was made of the fractured surfaces, when cathode particles were broken from the cluster. Crystal growth was always found to have taken place across the surfaces where separate particles were in contact, but only after all oxides, sulphates, etc., had been completely removed. The idea of a possible new process was then conceived and was disclosed to A. M. Smoot (V. P. Ledoux and Co.) with intent to obtain his views. The first conception as given Smoot was "to gas-clean broken cathodes, put them in an extrusion press, solidify and extrude them at around 1500°F." Smoot&apos;s reaction, after a few moments considera-tion, was, "It looks perfectly all right to me." The writer and his assistants, W. H. Osborn and H. H. Stout, Jr., after confer-ring as to ways and means, decided to go ahead with preliminary laboratory experi-ments, which, it was thought, would move the new process from the possible to the probable. This program followed a course indicated by three basic considerations: I. Since brittle cathodes were often unin-tentionally produced, it seemed probable that the laws controlling this type of deposi-tion could be ascertained. 2. We had already proved the gas-clean-ing feature. 3. There remained to prove: whether a sound, homogeneous metal billet could be produced with crystal growth established over the entire surface of each individual particle in the billet; and, if so, what would be the physical properties? Osborn arranged with Columbia Uni-versity for conducting experiments in its research laboratory to prove or disprove the third item; Columbia assigned C. A. Phillipi, Jr. to assist in the project. A press with a cylinder 2 in. high and of I-in. dia. was used. It was surrounded and heated by a resistance coil of Nichrome wire. Broken tough cathodes were used.

Jan 1, 1940

By J. A. Richardson

J. A. RICHARDSON[t]-Mr. Stuckey&apos;s account of the geology of the kaolins of North Carolina suggests that they exhibit some features similar to those of the Malay Peninsula. About one half of British Malaya (some 26,000 square miles) is occupied at the surface by igneous rocks, of which granite and its associated derivatives constitute fully 90 pct. The average granite is a biotic variety. It is predominantly potassic but carries, in addition, notable amounts of soda and lime so that albite and albiteoligoclase are generally common constituents of the rock. The minor derivatives from granite "magma" likewise include potassic and sodi-potassic members. Decomposition of the granitic rocks has led to the formation of kaolin in many localities, but, in general, the deposits are rather small and, at present, none is exploited commercially. True primary or residual kaolins (as defined by Stuckey; p. 48 Vol. 173, p. 2 TP 2219) have been developed from feldspar veins, pegmatites and from other granitic differentiates which cut through the larger masses of granite; they are usually small and narrow. Kaolin has been derived from aplite, quartz porphyry, quartz micro-porphyry, felsites and microgranites belonging to a complex known as the Chegar Perah-Pulai intrusion in northwest Pahang and southwest Kelantan. The bulk of the component rocks has been more or less strongly sheared. Kaolin-like end products have been formed from both sheared and nonsheared varieties. Kaolin has been formed also by the complete breakdown of trondjemite flanking the northwestern and western margins of the complex Bukit Ranjut syenite intrusion in northwest Pahang. These trondjemites range in composition from essentially quartz-free albiteplagioclasites to quartz-free microcline rocks; they are, in effect, the syenitic homologues of white sodic and potassic granite-aplites. The granites in Malaya have generally undergone more or less severe surficial weathering leading to the production of a spongy and rather cellular or a soft "mealy" material (sandy clay) down to depths of about 100 ft; in places the granite is strongly decomposed down to 150 ft. There has occurred, therefore, widespread partial kaolinization, but, in general, no extensive deposits of good quality kaolin seem to have been formed by these processes of decay. Frequently, the katamorphic processes of desilicification have advanced beyond the production of kaolin towards the formation of lateritic end products. The more important Malayan kaoiins seem to be confined to the western alluvial plains, particularly in areas either where granite crops out at surface, or where it forms the bedrock of the alluvium. There are numerous excellent examples around Gopeng and elsewhere in the Kinta Valley of Perak. Such kaolins belong to Stuckey&apos;s groups of secondary deposits, and, like them, these also may be bedded. Field observations have established the existence of what for want of a better name is referred to by the Malayan Geological Survey as "granite wash." It is believed that granite, undergoing extensive deeply penetrative and probably rather rapid destruction under humid tropical weathering (temperature around 90°F; rainfall about 100 in. per annum; high humidity) "flowed," was moved by "creep" and, in addition, probably slumped in large waterlogged masses of sandy clay from topographic salients onto the adjacent flats. Either during this period of transmigration or later when the sludged granite detritus, after having more or less come to rest, was attacked by flowing water, differential sorting and erosion took place with the result that the resorted debris was moved and later deposited as bedded alluvium. In this way, banded "granite wash" was produced comprising alternating bands of clayey sand (resorted granite sludge) and white

Jan 1, 1947

By Glenn C. Waterman

THE diamond drill is a very important tool in exploration and development testing and its use is increasing. In almost all cases results of diamond drilling are analyzed on the basis of grade and tons. A proper evaluation of core and sludge assays is important if drilling results are to be acceptable as a basis for geologic and engineering appraisal. The relatively wide variation in assay averages as calculated by various well-known combining methods indicates that the engineering choice of a method may affect the outcome of the drilling in terms of ore and waste. The problem of combining assay results from core and sludge samples has been discussed many times in conference and in the literature.&apos;" Most writers agree that the field of disagreement in methods is large and that the engineer on the job must consider features unique to his drilling, pick one of several combining methods, and depart from the rules when abnormal results come in. All the discussion to date can be summed up by the admission that as yet there is no fairly simple, generally acceptable combining method that is practicable over a wide range of drilling conditions, ground conditions, and ore occurrence.

Jan 1, 1955

By Whitman E. Brown, Louis J. Erck

The installation in 1948 of a Hum-phrey~ spiral concentrator section at the Hill-Trumbull plant of The Cleve-land-Cliffs Iron Co. is the latest commercial method on the Mesabi Range being used for the recovery of fine iron ore. In two stages of concentration 84 spirals treat approximately 120 long tons per hour of minus ? in. ore. These spirals augment the production of the heavy-density plant which recovers the plus 36 in. iron from the plant crude ore. Structure of the ore is such that, when crushed, about 50 pct of the plant crude is minus ? in. size. After de-sliming in a 66 in. Akins classifier, grinding the classifier product in a ball mill and again desliming in a 78 in. Akins classifier about 15 pct of the crude ore remains to be treated in the spiral plant. Overall recovery of the ball mill feed in the Hill-Trumbull spiral plant during the 1948 season was about 53 pct of the weight and 66 pct of the total iron content. Of the actual feed delivered to the spirals from the 78 in. classifier 64.9 pct of the weight was recovered containing 73.7 pct of the total iron. The average analysis of the spiral concentrate is 55.05 pct Fe and 14.83 pct SiO2. An average of mill assays during the 1948 season is given in Table 1. The Hill-Trumbull plants treat both wash ore and jig-type ore. During the 1948 season spirals were used only on the fine sizes of jig-type ore. At times the deslimed minus ? in. size is of sufficient grade to warrant bypassing the spirals but in the main the fine size is delivered to the 48 first stage spirals and thence to the 36 cleaner or second stage spirals. In the past several years numerous Mesabi Range ores in the fine size cate- gory have been tested by a wide variety of beneficiating equipment. The prodigious amount of research devoted to the recovery of values in the fine ore reflects the dire need of the iron industry to squeeze the last possible unit of iron from the mined ore and to develop suitable equipment and processes to satisfactorily concentrate the leaner horizons as they are encountered in the process of mining. Large governmental and private appropriations have been allotted, new laboratories built, research and technical staffs increased, and operator-manufacturer cooperative agreements applied to hasten the solution of the problem. The University of Minnesota, at its Eighth Annual Mining Symposium in January 1947, dedicated as its objective the bringing to light of technological developments in iron ore beneficiation. Papers were given at that time relating to processes being developed. Specifically, these papers reviewed flotation, Baum jig, selective media concentrator, Hardinge concentrator, Dorrco sizer, heavy media concentration, Hydrotator, and the Humphreys spiral. The Cleveland-Cliffs Iron Co., after encouraging results from tests in a small pilot plant using one full size spiral, made the first commercial installation of Humphreys spirals on the Mesabi Range at their Hill-Trumbull mine, Taconite, Minn. This company

Jan 1, 1950

By Walter Miller

A surprising development during the year was the continued high demand for petroleum products and the high level of crude oil charges to the stills. Generally speaking, the petroleum industry during 1946 succeeded in producing a greater quantity of crude oil and petroleum products than in any of the war years, and considerably exceeded the production of any prewar year. Daily crude still charges averaged between 4,700,000 and 4,800,000 bbl per day for 1946 and about equaled the 1945 record, although most pessimistic 1945 guesses, predictions, or fears ranged, for 1946, from only 3,900,000 to 4,400,000 bbl per day. In spite of the high crude charge to the stills, total stock of crude oil was higher at the end of the year by some 7,000,000 to 8,000,000 bbl. A similar story holds regarding stocks of the principal refined products. Gasoline on hand at year&apos;s end was two to three million barrels lower, and was considered low for the expected demand during the coming high consuming season, while stocks of light and heavy fuel oils, although some higher than a year previous, hardly reached a comfortable level. The trend in gasoline of high octane number, which has resulted in a marked rise in. the antiknock quality by the end of 1945 (five or six numbers higher than during the war and one number higher than the prewar quality of civilian motor gasoline of 1941) was abruptly arrested by an acute shortage of metallic lead for manufacturing tetraethyl lead. Government action in the form of lead price control, rationing, and the setting of octane ceiling specifications to conform to the reduced ethyl lead compound available were enforced until abrogated at the end of the year. It will be interesting to see how rapidly the octane levels will resume the rising trend, as more metallic lead slowly becomes available for making greater quantities of ethyl lead compound. As octane quality rises over present levels the disadvantage of the refiner without catalytic cracking equipment will increase. Gasoline made by catalytic cracking, without addition of ethyl lead, approximates 77 octane by the official ASTM Motor Method test, compared with 66 for gasoline generally similar in volatility made by the older thermal cracking operation. Catalytic gasoline shows an even greater improvement in the Research octane number, the comparison being roughly 86 Research versus 71 Research octane for the thermal cracked product. This higher differential in Research octane is credited by many, although not universally so, as contributing to better road performance, and consequently resulting in a more desirable product marketwise. In some parts of the country a premium of roughly one fourth cent per gallon is now being paid for gasoline with higher Research octane made possible by including catalytic cracked product in the final blends. If such price differentials in favor of catalytic gaso-

Jan 1, 1947

By Walter Miller

A surprising development during the year was the continued high demand for petroleum products and the high level of crude oil charges to the stills. Generally speaking, the petroleum industry during 1946 succeeded in producing a greater quantity of crude oil and petroleum products than in any of the war years, and considerably exceeded the production of any prewar year. Daily crude still charges averaged between 4,700,000 and 4,800,000 bbl per day for 1946 and about equaled the 1945 record, although most pessimistic 1945 guesses, predictions, or fears ranged, for 1946, from only 3,900,000 to 4,400,000 bbl per day. In spite of the high crude charge to the stills, total stock of crude oil was higher at the end of the year by some 7,000,000 to 8,000,000 bbl. A similar story holds regarding stocks of the principal refined products. Gasoline on hand at year&apos;s end was two to three million barrels lower, and was considered low for the expected demand during the coming high consuming season, while stocks of light and heavy fuel oils, although some higher than a year previous, hardly reached a comfortable level. The trend in gasoline of high octane number, which has resulted in a marked rise in. the antiknock quality by the end of 1945 (five or six numbers higher than during the war and one number higher than the prewar quality of civilian motor gasoline of 1941) was abruptly arrested by an acute shortage of metallic lead for manufacturing tetraethyl lead. Government action in the form of lead price control, rationing, and the setting of octane ceiling specifications to conform to the reduced ethyl lead compound available were enforced until abrogated at the end of the year. It will be interesting to see how rapidly the octane levels will resume the rising trend, as more metallic lead slowly becomes available for making greater quantities of ethyl lead compound. As octane quality rises over present levels the disadvantage of the refiner without catalytic cracking equipment will increase. Gasoline made by catalytic cracking, without addition of ethyl lead, approximates 77 octane by the official ASTM Motor Method test, compared with 66 for gasoline generally similar in volatility made by the older thermal cracking operation. Catalytic gasoline shows an even greater improvement in the Research octane number, the comparison being roughly 86 Research versus 71 Research octane for the thermal cracked product. This higher differential in Research octane is credited by many, although not universally so, as contributing to better road performance, and consequently resulting in a more desirable product marketwise. In some parts of the country a premium of roughly one fourth cent per gallon is now being paid for gasoline with higher Research octane made possible by including catalytic cracked product in the final blends. If such price differentials in favor of catalytic gaso-

Jan 1, 1947

By Geo. Otis Smith

Twelve years ago, the Director of the United States Geological Survey addressed to the Secretary of the Interior a letter calling attention to the government&apos;s need for liquid fuel for naval use and pointing out that the rate of increase in demand was more rapid than the increase in production.&apos; This letter, in a way, inaugurated the policy of public oil-land withdrawals, which was well founded in its primary purpose of protecting the oil industry and highly desirable in its immediate effect of checking the over-development of that day in California. Unfortunately, however, through delays in legislation, this policy may be regarded now as having outlived both its intent and its usefulness. In 1908, the country&apos;s production of oil was 178,500,000 bbl., and there was a surplus above consumption of more than 20,000,000 bbl. available to go into storage. In 1918, 10 years later, the oil wells of the United States yielded 356,000,000 bb1.—nearly twice the yield of 1908—but to meet the demands of the increased consumption more than 24,000,000 bbl. had to be drawn from storage. Nor is this all of the brief comparison. In 1918, our excess of imports over exports of crude petroleum was nearly 33,000,000 bbl. whereas in 1908 we exported 3,500,000 bbl., which was net, as we had not begun to import Mexican oil. In this period, the annual fuel-oil consumption of the railroads alone has increased from 16,871,000 to 36,714,000 bbl.; the annual gasoline production from 540,000,000 gal. to 3,500,000,000 gal. This record may be taken not only as justifying the earlier appeal for Federal action, but as warranting deliberate attention to the oil problem of today. Need of Future Supply The position of the United States in regard to oil can best be characterized as precarious. Using more than one-third of a billion barrels a year, we are drawing not only from the underground pools but also from storage, and both of these supplies are limited. In 1918, the contribu-

Jan 1, 1921

Meeting of April 24, 1914.-President Thayer announced the appointment of the Committee on Safety and Sanitation. The Committee on Nominations for officers for 1915 was appointed, as follows: William J. Cox, Chairman; H. Poster Bain, Joseph Daniels, Charles E. Mills, R. V. Norris, E. Gybbon Spilsbury, and Herbert A. Wheeler. The request of twenty residents of Salt Lake City and vicinity for permission to establish the Utah-Nevada Local Section was granted and R. C. Gemmell was appointed Chairman of the Committee on Organization. The following resolution was adopted: Resolved: That under authority of Article V, Section 7, of the Constitution, a special Committee be and hereby is appointed, to consist of the President and six other members of the Institute, to be named by him, Who shall be authorized to appear before the proper authorities at Washington and urge that Mining Engineers be appointed upon the proposed Commission for revision of the Federal Mining Laws. Further Resolved: That the activities of this special Committee be restricted to the authority given in this resolution.

Jan 6, 1914

Jan 1, 1937

Jan 1, 1933

By Arthur Coffinberry

EVE have studied the gold-aluminum system by X-ray diffraction and by the microscope over the entire range of composition for temperatures between 300° and 500° C. Results obtained are shown in Fig. 1, com-bined with the work of Heycock and Neville1 at higher temperatures. The diagram differs in important details from that given by Hansen2 in his critical compilation of the literature of binary alloy systems. This work was, undertaken both because of the intrinsic value of a knowledge of the phase diagram of this system and because of the need of theoretical metallurgy for precise and accurate data, particularly X-ray diffraction data. Systematic studies of equilibrium diagrams, particularly by Hume-Rothery,3 have shown regularities that yield a certain insight into the nature of alloying forces. It has been shown, for example, that solid solubility depends on the concentration of free electrons in the alloy, on the relative radii of solvent and solute atones, on the forces of attraction between atoms, and on the relative stability of intermediate phases. The well-known Hume-Rothery rule states that the crystal structures and compositions of many intermediate phases depend on the electron-to-atom ratio. This has been confirmed and extended by wave mechanical calculations.4 A knowledge of the forces between atoms in alloys, even an imperfectly developed empirical one, should be a valuable guide in the preparation of technological alloys of desirable properties. Furthermore, such informa-tion is basic in such problems as rate of diffusion, age-hardening, phase transformations, and others. The most valuable data for this purpose are furnished by X-ray diffraction studies. Unfortunately, work has been

Jan 1, 1938

By W. M. Peirce

WITH the supply of zinc, like that of most other nonferrous metals, inadequate to meet the demand, efforts to increase domestic ore supplies and production capacity have been of primary interest. No major sources of new ore have been disclosed during the year but improvements have been reported in facilities for mining and concentrating ores from existing mines. The American Zinc, Lead and Smelting Co. has announced its intention of erecting a new mill in the Ouray district of Colorado. The Consolidated Mining and Smelting Co. of Canada is reported to be planning improvements costing $3,000,000 to its Sullivan mine and concentrator at Kimberley, B.C., where the sink-float process is to be used for preliminary ore treatment. In the reduction field, the St. Joseph

Jan 1, 1947

By James A. Barr, R. B. Burt, I. S. Tillotson

DISCUSSION Howard Howie (Knoxville, Term.)—The authors are to be congratulated on the presentation of a paper containing so much valuable information on the pipeline transportation of phosphate, as there is very little literature on the subject. The writer is especially interested in the paper, as he conceived the arrangement of the Akin and Godwin plants and was in charge of the design work and the engineering incident to their construction. The Akin and other phosphate deposits in the Tennessee phosphate area lie on beds of limestone that are very irregular. The limestone beds, after the phosphate matrix has been removed, are similar in appearance to land severely eroded by the action of water and denuded of top soil. Depressions in the limestone, called cutters, are irregular in depth with vertical or overhanging walls, having the general appearance of cracks in dried clay. They change abruptly in direction, width, and depth, and vary on the Akin tract from 1 to 25 ft in depth and from 1 to 50 ft in width. Pinnacles of limestone commonly occur in the cutters which appear, when exposed, like small clifflike islands in a river. Limestone floats also occur. The phosphate matrix fills the cutters and covers the uncuttered areas, the thickness of the cover varying continually and sometimes rather abruptly. It occurs generally as stratifications of phosphate rock and clay of varying thickness. The phosphate rock in the matrix varies in hardness and in percents of silica, lime, iron oxides, and fluorine, and the clay varies in toughness. In some places the deposit consists of narrow strata of rock almost devoid of clay streaks. In other nearby locations the clay will predominate. When it is excavated, the phosphate rock breaks into thin irregular lumps, locally known as plate rock. Limestone lumps are also excavated with the matrix. Akin plate rock is generally much softer than that occurring in other deposits in the area. Because of the above described physical and chemical variations of the excavated material, the resultant slurry varies in size distribution, specific gravity, and percent of slimes. When the rock is soft or when there is an increase of clay, the slime fraction is greatly increased as it passes through pumps and pipelines, resulting in reduced pipe friction. It is obvious that the longer the pipeline the greater the reduction of coarse fractions into fines, causing a decrease in pipe friction that cannot be accurately evaluated. The matrix is mined with a dragline that drops it into a hopper with a grid composed of 9-in. parallel bar spacings located above the hammer mill. The matrix on, and passing through the grid, is subject to the action of powerful sprays which wash it down to the hammer mill, together with any limestone lumps that are not removed before passing through the grid. The hammer mill reduces the feed to lumps of plate rock and clay, most of which will pass through the 8-in. pump suction. The mixture discharges into a pool containing the pump suction pipe. Water from a hydraulic nozzle moves the mixture to the pump suction intake. The pump, driven by a variable speed motor, is the same size as the pumps mentioned on p. 279. Provision is made to remove any lumps that lodge in a bend in the suction pipe in a manner similar to that used in the Florida phosphate fields. The hammer mill and pump units are mounted on wide steel skids so that they can be moved as the mining operation progresses. The discharge from the pump flows through an abrasion-resistant spiral welded steel pipe 8 1/4 in. actual inside diam, 8 in. nominal diam, for a maximum distance of 2200 ft, which is the limiting pumping distance for one pump. This pipeline, referred to hereafter as pipeline A, discharges into a ball mill without balls, which in turn discharges into a rotary screen attached to it that separates the slurried matrix into 11/4-in. oversize and undersize fractions. The oversize is returned to the mill for further reduction; the undersize is pumped to a Dorrco washer and then flows into a hydroseparator 160 ft in diam. In spite of the size reduction in the hammer mill and the blunging and washing of the slurry in its passage through the pump, pipeline, mill, and washer, the discharge to the hydroseparator frequently contains mud balls almost perfectly spherical. Sometimes the discharge from the 16,000-ft pipeline at Godwin contains mud balls the size of bird shot and smaller. This pipeline will be referred to subsequently as line B. Liquid caustic is added to the slurry at the Akin plant before its passage through the hydro-separator, which decreases the size of particles in the overflow by dispersion. In passing through pumps 1, 2, and 3 and pipeline B, the slime fraction in the underflow is increased by abrasion and blunging and also by continuing dispersive action of the caustic. The matrix for use in the experimental tests referred to on p. 279 was obtained from three small surface openings on the Akin tract that were made previous to the purchase of the tract by the Authority. Matrix used in the 2 and 4-in. experimental pipeline tests was taken from the three openings and proportioned to obtain a sufficient quantity that would be fairly representative of the average in the Akin deposits. Prospecting samples of matrix had been obtained from drill holes which showed no small variation in physical and chemical properties. Some of the physical variation is evident from the size distribution of solids in samples taken during the tests covering line B flows so thoroughly made by the Authority under the direction of Mr. Burt, see Table V, p. 280. Hydraulic gradients for a pipe of 8-in. diam were derived from the 2 and 4-in. pipeline tests using the so-called representative matrix as above described, and plotted on the profile of pipeline B. Gradients of other materials in slurry form passing through pipelines that bore some similiarity to the Akin matrix slurry were also plotted. After a study had been made of the hydraulic gradients plotted on the profile and the varying slurry flow that would probably occur during actual operation, three pumps were ordered, referred to as No. 1, 2, and 3 on p. 279. No. 1 and 2 pumps were installed and the third kept in reserve should the operation of 1 and 2 pumps prove satisfactory, since installation of the third pump would require an attendant, as well as the laying of 5400 ft of pipe to supply it with seal-water from the Akin plant. Subsequently, it was found desirable to install the third pump to maintain capacity when the slime fraction was low and the coarse fractions were large. Reference to Fig. 6 will show that the flow in B line goes upgrade in three locations. At the outlet at Godwin, the slurry flows between two 45" bends for an approximate distance of 18 ft to rise above the ground a sufficient height to discharge into a launder feeding the first classifier. This condition requires extra energy, which is taken care of by keeping the hydraulic gradient a sufficient distance above the high points. Although there are rather heavy upgrades in the line, the choking condition that might occur at the

Jan 1, 1953

By J. A. Barr, R. B. Burt, I. S. Tillotson

DISCUSSION Howard Howie (Knoxville, Term.)—The authors are to be congratulated on the presentation of a paper containing so much valuable information on the pipeline transportation of phosphate, as there is very little literature on the subject. The writer is especially interested in the paper, as he conceived the arrangement of the Akin and Godwin plants and was in charge of the design work and the engineering incident to their construction. The Akin and other phosphate deposits in the Tennessee phosphate area lie on beds of limestone that are very irregular. The limestone beds, after the phosphate matrix has been removed, are similar in appearance to land severely eroded by the action of water and denuded of top soil. Depressions in the limestone, called cutters, are irregular in depth with vertical or overhanging walls, having the general appearance of cracks in dried clay. They change abruptly in direction, width, and depth, and vary on the Akin tract from 1 to 25 ft in depth and from 1 to 50 ft in width. Pinnacles of limestone commonly occur in the cutters which appear, when exposed, like small clifflike islands in a river. Limestone floats also occur. The phosphate matrix fills the cutters and covers the uncuttered areas, the thickness of the cover varying continually and sometimes rather abruptly. It occurs generally as stratifications of phosphate rock and clay of varying thickness. The phosphate rock in the matrix varies in hardness and in percents of silica, lime, iron oxides, and fluorine, and the clay varies in toughness. In some places the deposit consists of narrow strata of rock almost devoid of clay streaks. In other nearby locations the clay will predominate. When it is excavated, the phosphate rock breaks into thin irregular lumps, locally known as plate rock. Limestone lumps are also excavated with the matrix. Akin plate rock is generally much softer than that occurring in other deposits in the area. Because of the above described physical and chemical variations of the excavated material, the resultant slurry varies in size distribution, specific gravity, and percent of slimes. When the rock is soft or when there is an increase of clay, the slime fraction is greatly increased as it passes through pumps and pipelines, resulting in reduced pipe friction. It is obvious that the longer the pipeline the greater the reduction of coarse fractions into fines, causing a decrease in pipe friction that cannot be accurately evaluated. The matrix is mined with a dragline that drops it into a hopper with a grid composed of 9-in. parallel bar spacings located above the hammer mill. The matrix on, and passing through the grid, is subject to the action of powerful sprays which wash it down to the hammer mill, together with any limestone lumps that are not removed before passing through the grid. The hammer mill reduces the feed to lumps of plate rock and clay, most of which will pass through the 8-in. pump suction. The mixture discharges into a pool containing the pump suction pipe. Water from a hydraulic nozzle moves the mixture to the pump suction intake. The pump, driven by a variable speed motor, is the same size as the pumps mentioned on p. 279. Provision is made to remove any lumps that lodge in a bend in the suction pipe in a manner similar to that used in the Florida phosphate fields. The hammer mill and pump units are mounted on wide steel skids so that they can be moved as the mining operation progresses. The discharge from the pump flows through an abrasion-resistant spiral welded steel pipe 81/4 in. actual inside diam, 8 in. nominal diam, for a maximum distance of 2200 ft, which is the limiting pumping distance for one pump. This pipeline, referred to hereafter as pipeline A, discharges into a ball mill without balls, which in turn discharges into a rotary screen attached to it that separates the slurried matrix into 11/4-in. oversize and undersize fractions. The oversize is returned to the mill for further reduction; the undersize is pumped to a Dorrco washer and then flows into a hydroseparator 160 ft in diam. In spite of the size reduction in the hammer mill and the blunging and washing of the slurry in its passage through the pump, pipeline, mill, and washer, the discharge to the hydroseparator frequently contains mud balls almost perfectly spherical. Sometimes the discharge from the 16,000-ft pipeline at Godwin contains mud balls the size of bird shot and smaller. This pipeline will be referred to subsequently as line B. Liquid caustic is added to the slurry at the Akin plant before its passage through the hydro-separator, which decreases the size of particles in the overflow by dispersion. In passing through pumps 1, 2, and 3 and pipeline B, the slime fraction in the underflow is increased by abrasion and blunging and also by continuing dispersive action of the caustic. The matrix for use in the experimental tests referred to on p. 279 was obtained from three small surface openings on the Akin tract that were made previous to the purchase of the tract by the Authority. Matrix used in the 2 and 4-in. experimental pipeline tests was taken from the three openings and proportioned to obtain a sufficient quantity that would be fairly representative of the average in the Akin deposits. Prospecting samples of matrix had been obtained from drill holes which showed no small variation in physical and chemical properties. Some of the physical variation is evident from the size distribution of solids in samples taken during the tests covering line B flows so thoroughly made by the Authority und&apos;er the direction of Mr. Burt, see Table V, p. 280. Hydraulic gradients for a pipe of 8-in. diam were derived from the 2 and 4-in. pipeline tests using the so-called representative matrix as above described, and plotted on the profile of pipeline B. Gradients of other materials in slurry form passing through pipelines that bore some similiarity to the Akin matrix slurry were also plotted. After a study had been made of the hydraulic gradients plotted on the profile and the varying slurry flow that would probably occur during actual operation, three pumps were ordered, referred to as No. 1, 2, and 3 on p. 279. No. 1 and 2 pumps were installed and the third kept in reserve should the operation of 1 and 2 pumps prove satisfactory, since installation of the third pump would require an attendant, as well as the laying of 5400 ft of pipe to supply it with seal-water from the Akin plant. Subsequently, it was found desirable to install the third pump to maintain capacity when the slime fraction was low and the coarse fractions were large. Reference to Fig. 6 will show that the flow in B line goes upgrade in three locations. At the outlet at Godwin, the slurry flows between two 45" bends for an approximate distance of 18 ft to rise above the ground a sufficient height to discharge into a launder feeding the first classifier. This condition requires extra energy, which is taken care of by keeping the hydraulic gradient a sufficient distance above the high points. Although there are rather heavy upgrades in the line, the choking condition that might occur at the

Jan 1, 1953

By R. B. Burt, J. A. Barr, I. S. Tillotson

DISCUSSION Howard Howie (Knoxville, Term.)—The authors are to be congratulated on the presentation of a paper containing so much valuable information on the pipeline transportation of phosphate, as there is very little literature on the subject. The writer is especially interested in the paper, as he conceived the arrangement of the Akin and Godwin plants and was in charge of the design work and the engineering incident to their construction. The Akin and other phosphate deposits in the Tennessee phosphate area lie on beds of limestone that are very irregular. The limestone beds, after the phosphate matrix has been removed, are similar in appearance to land severely eroded by the action of water and denuded of top soil. Depressions in the limestone, called cutters, are irregular in depth with vertical or overhanging walls, having the general appearance of cracks in dried clay. They change abruptly in direction, width, and depth, and vary on the Akin tract from 1 to 25 ft in depth and from 1 to 50 ft in width. Pinnacles of limestone commonly occur in the cutters which appear, when exposed, like small clifflike islands in a river. Limestone floats also occur. The phosphate matrix fills the cutters and covers the uncuttered areas, the thickness of the cover varying continually and sometimes rather abruptly. It occurs generally as stratifications of phosphate rock and clay of varying thickness. The phosphate rock in the matrix varies in hardness and in percents of silica, lime, iron oxides, and fluorine, and the clay varies in toughness. In some places the deposit consists of narrow strata of rock almost devoid of clay streaks. In other nearby locations the clay will predominate. When it is excavated, the phosphate rock breaks into thin irregular lumps, locally known as plate rock. Limestone lumps are also excavated with the matrix. Akin plate rock is generally much softer than that occurring in other deposits in the area. Because of the above described physical and chemical variations of the excavated material, the resultant slurry varies in size distribution, specific gravity, and percent of slimes. When the rock is soft or when there is an increase of clay, the slime fraction is greatly increased as it passes through pumps and pipelines, resulting in reduced pipe friction. It is obvious that the longer the pipeline the greater the reduction of coarse fractions into fines, causing a decrease in pipe friction that cannot be accurately evaluated. The matrix is mined with a dragline that drops it into a hopper with a grid composed of 9-in. parallel bar spacings located above the hammer mill. The matrix on, and passing through the grid, is subject to the action of powerful sprays which wash it down to the hammer mill, together with any limestone lumps that are not removed before passing through the grid. The hammer mill reduces the feed to lumps of plate rock and clay, most of which will pass through the 8-in. pump suction. The mixture discharges into a pool containing the pump suction pipe. Water from a hydraulic nozzle moves the mixture to the pump suction intake. The pump, driven by a variable speed motor, is the same size as the pumps mentioned on p. 279. Provision is made to remove any lumps that lodge in a bend in the suction pipe in a manner similar to that used in the Florida phosphate fields. The hammer mill and pump units are mounted on wide steel skids so that they can be moved as the mining operation progresses. The discharge from the pump flows through an abrasion-resistant spiral welded steel pipe 81/4 in. actual inside diam, 8 in. nominal diam, for a maximum distance of 2200 ft, which is the limiting pumping distance for one pump. This pipeline, referred to hereafter as pipeline A, discharges into a ball mill without balls, which in turn discharges into a rotary screen attached to it that separates the slurried matrix into 11/4-in. oversize and undersize fractions. The oversize is returned to the mill for further reduction; the undersize is pumped to a Dorrco washer and then flows into a hydroseparator 160 ft in diam. In spite of the size reduction in the hammer mill and the blunging and washing of the slurry in its passage through the pump, pipeline, mill, and washer, the discharge to the hydroseparator frequently contains mud balls almost perfectly spherical. Sometimes the discharge from the 16,000-ft pipeline at Godwin contains mud balls the size of bird shot and smaller. This pipeline will be referred to subsequently as line B. Liquid caustic is added to the slurry at the Akin plant before its passage through the hydro-separator, which decreases the size of particles in the overflow by dispersion. In passing through pumps 1, 2, and 3 and pipeline B, the slime fraction in the underflow is increased by abrasion and blunging and also by continuing dispersive action of the caustic. The matrix for use in the experimental tests referred to on p. 279 was obtained from three small surface openings on the Akin tract that were made previous to the purchase of the tract by the Authority. Matrix used in the 2 and 4-in. experimental pipeline tests was taken from the three openings and proportioned to obtain a sufficient quantity that would be fairly representative of the average in the Akin deposits. Prospecting samples of matrix had been obtained from drill holes which showed no small variation in physical and chemical properties. Some of the physical variation is evident from the size distribution of solids in samples taken during the tests covering line B flows so thoroughly made by the Authority und&apos;er the direction of Mr. Burt, see Table V, p. 280. Hydraulic gradients for a pipe of 8-in. diam were derived from the 2 and 4-in. pipeline tests using the so-called representative matrix as above described, and plotted on the profile of pipeline B. Gradients of other materials in slurry form passing through pipelines that bore some similiarity to the Akin matrix slurry were also plotted. After a study had been made of the hydraulic gradients plotted on the profile and the varying slurry flow that would probably occur during actual operation, three pumps were ordered, referred to as No. 1, 2, and 3 on p. 279. No. 1 and 2 pumps were installed and the third kept in reserve should the operation of 1 and 2 pumps prove satisfactory, since installation of the third pump would require an attendant, as well as the laying of 5400 ft of pipe to supply it with seal-water from the Akin plant. Subsequently, it was found desirable to install the third pump to maintain capacity when the slime fraction was low and the coarse fractions were large. Reference to Fig. 6 will show that the flow in B line goes upgrade in three locations. At the outlet at Godwin, the slurry flows between two 45" bends for an approximate distance of 18 ft to rise above the ground a sufficient height to discharge into a launder feeding the first classifier. This condition requires extra energy, which is taken care of by keeping the hydraulic gradient a sufficient distance above the high points. Although there are rather heavy upgrades in the line, the choking condition that might occur at the

Jan 1, 1953