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By Robert Peele

TWO outstanding members of the Institute will be honored at the Annual Meeting this month: Robert Peele, who will accept his election to the small group of Honorary Members; and Clinton Hoadley Crane, president of the St. Joseph Lead Co. and William Lawrence Saunders Medalist for 1936. Eminence in the profession character, interest in Institute activities, and general recognition as a gentleman and a friend by so many people, have contributed to the election of Professor Peele. The Saunders Medal is for "achievement in mining." In awarding it to Mr. Crane the citation reads "For distinguished achievement in the successful development and operation of low-grade lead mines."

Jan 1, 1936

By G. R. Speich

The interlarnmelm spacing, growth rate, and degree of segregation that accompany cellular precipitation in four Fe-Zn alloys containing 9.7, 15.2, 23.5, and 30.5 at. pct Zn have been determined in the temperature range 400" to 600°C. The chemical free-energy change for the reaction was calculated from the available thermodynamic data and the known compositions of the phases. The fraction of the chemical free-energy change for equilibrium segregation that is converted into interfacial free energy decreases from 0.43 to 0.08 as the magnitude of this free-energy change increases from 35 to 270 cal per mole. At constant temperature the cellular growth rate is proportional to the cube of the dissipated free energy. At 600°C newly 100 pct of the equilibrium segregation is achieved during cellulm precipitation whereas at 400°C only 85 pct of the equilibrium segregation is attained. During cellular growth, mass transport of zinc occurs by grain boundary diffusion; excess zinc remaining in the a! phase after the completion of growth is removed slowly by volume diffusion. A modified Cahn theory of cellular precipitation predicts the observed interlamellar spacing within a factor of two. In cellular precipitation reactions such as pearlite formation or discontinuous precipitation, the basic problem is to predict the variation of growth rate G, interlamellar spacing S, and degree of segregation P with composition and temperature. To accomplish this we need three independent equations relating these quantities. One of these equations comes from the diffusion solution. To obtain two additional independent equations, some assumptions must be made. cahnl has suggested recently that two plausible assumptions are 1) that growth rate is proportional to the dissipated free energy and 2) that the spacing which occurs is that which maximizes the dissipated free energy. According to the first assumption, this spacing also maximizes the growth rate and the rate of decrease of free energy per unit area of cell boundary. The present work was undertaken to test these assumptions. To test the first assumption it is necessary to study a cellular reaction over a wide range of supersatura-tions to establish a relationship between G and the dissipated free energy at constant temperature. This is possible only in discontinuous precipitation reactions since in pearlite reactions constituents other than pearlite form if the composition of the parent phase deviates even slightly from the eutectoid composition. The Fe-Zn system was chosen for study because 1) discontinuous precipitation proceeds to completion over a wide temperature and concentration range, 2) the degree of segregation within the cell can be measured by lattice parameter measurements,2 and 3) the thermodynamics of this system have recently been determined by Wriedt.3 In this system the cells consisting d alternate lamellae of a and r phases form from supercooled iron-rich a phase. The a phase within the cells is bcc as is the original a phase, cia, but has a different orientation and a slightly lower zinc content than the original a phase. The r phase has a zinc content of about 70 at. pct and a crystal structure isomor-phous with T brass. EXPERIMENTAL PROCEDURE Four Fe-Zn alloys with 9.7, 15.2, 23.5, and 30.5 at. pct Zn were prepared from carbonyl-iron powder (400 mesh, 99.8 wt pct Fe) and zinc powder (200 mesh, 99.99 wt pct Zn). The powders were ball-milled together and cold-pressed under 60,000 psi to discs $ in. thick by $ in. diam. The cold-pressed discs of the alloys with 9.7 and 15.2 at. pct Zn were sealed in evacuated silica capsules and heated slowly to 1100°C over a period of 1 week (3 days at 600°C, then 3 days at 80O°C, then 1 day at 1100°C). The alloys with 23.5 and 30.5 at. pct Zn were treated similarly except that the final homogenization temperatures were 1000" and 85O°C, respectively, to prevent melting. The alloys were quenched in iced brine from the final homogenization temperature. Specimens of each alloy were subsequently aged in salt pots at temperatures of 400°, 450°, 500°, 550°, 600°, and 650°C for times that varied from a few minutes to several hundred hours. At a late stage of this work, an alloy containing 11.2 at. pct Zn was prepared by vapor-impregnation of iron foil with zinc vapor at 890°C. This alloy proved useful for electron microscope studies because it was free of porosity. The homogenization and aging conditions were based on the recent Fe-Zn phase diagram of Stadelmaier and Bridgers4 rather than the earlier diagram of ansen.5 They consist of a homogenization heat treatment in the homogeneous a field followed by an aging treatment in the two-phase a + r field. The aged specimens were metallographically polished and etched in 2 pct nital and the radius of the largest cell in the microstructure determined. This radius plotted vs time gave a straight line whose slope is the boundary migration rate or growth rate G of the cell. To determine the interlamellar spacing, specimens were examined by surface-replica and thin-section electron microscope techniques. Because of the irregular nature of the lamellae within the cell, the average interlamellar spacing S .of the cell was measured by the method of Cahn and Hagel,6 where S is defined by:

Jan 1, 1969

By Benjamin F. Merembeck

A mutispectral scanner (MSS) obtains remotely sensed data of the earth's surface in vector form, one vector element for each spectral sensing band of the MSS. Data generated by either airborne or orbiting MSS systems are organized in a lattice of scan lines and elements within scan lines. Each element, called a pixel, is represented by an observational vector and corresponds to a relatively small specific area on the ground. The total observations for a sensed scene frequently are in the millions and are composed of a number of populations, each representing a different land form category. Based on samples from the populations, the mean vectors, or spectral signatures, and the covariance matrices for the categories may be estimated. From these, an among category covariance matrix and a combined within category covariance matrix can be found. The total among category variance is the trace of the among category covariance matrix. Canonical analysis finds a linear transformation matrix such that the first transform variable accounts for the maximum possible part of the total among category variance. Similarly, the second transform variable, orthogonal to the first, accounts for the maximum possible part of the remainder of the total variance, and so on. Such transformation often results in over 95 percent of the total variance accounted for in the first three canonical variables, even though the initial number of spectral bands exceeded twenty. Transformation of bulk data into three canonical variates allows color map products to be developed by assigning each variable to a different basic color. Such color products are believed to be more useful for photo-interpretation than color products resulting from any combinations of three of the initial spectral bands.

Jan 1, 1977

By William J. Priestley

Much time has been devoted, by metallurgists, to the study of steel after solidification and remarkable strides have been made in the heat treatment of steel, but less knowledge is available of the thermophysical activity of the constituents of steel prior to solidification in the mold. It is known that certain elements added to steel produce marked changes in physical properties, also that other elements added to steel produce similar changes, but we have only meager knowledge as 'to. how these elements combine in steel under different conditions of solidification. It is not sufficient to know, from chemical analysis, that a certain element is present in steel. We should know how this element is in combination with the other elements and whether the combination is such as will give the greatest physical properties. Certain elements go into solid solution with the iron, while others segregate to the grain boundaries and combine with the impurities collected there. Until it is known where an alloy produces the most beneficial effect and a means is determined for controlling its physical location by altering solidification conditions, or otherwise, we will not obtain the maximum value from our alloys. When molten steel freezes, it forms a heterogeneous mass of various crystalline constituents; and as the transformation of steel from a liquid state to the solid crystallized state is a critical step, involving as great a transfer of heat as any other operation in the making of finished steel, a variation in the rate of this heat transfer will have much to do with the arrangement of the various constituents in the solid state. The object of this paper is to show some of the effects on steel caused by variations in the rate of cooling in the ingot mold, particularly as to ingotism, segregation, dendrites, and intergranular material.

Jan 1, 1924

Harrison W. Craver, Director The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, 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, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on 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.

Jan 5, 1917

AALL, Christian H.,(M'49), Asst Res Dir Monsanto Chemical Co Anniston, Ala AALSETH, Earl P ,(J,51), Amerada Petr Corp Geological Dept Williston N Dak AAMOT, Olav Crone, (M'29), Met Pacific N W Alloys, Inc , Box 6215, Hillyard P 0 Spokane 14, Wash AARING, Floyd D ,(J'48), Petr Engr P 0 Box 130, Calgary, Alta Canada AARCNSON, Hubert Irving, (S'47), Carnegie Inst of Tech., Pittsburgh, Pa ABADIE, Henry G ,(M'43), Asst to the Sup- of Operations, Long Beach Oil Development Co ,255 So Santa Clara Ave Long Beach, Calif ABBISS, H. J., (A'50), Min. Engr., Buchans Mining Co., Ltd.. Buchans, Newfoundland ABBOTT, Clarence Eugene, (M'04), 901 Insurance Bldg , Raleigh, N C ABBOTT, George, (S'52), Mass Inst of Tech Cambridge, Mass

Jan 1, 1952

By H. O. Hofman

PAGE Part I. Decomposition OF Zinc Sulphate by Heating in Air, . 811 I. Introduction............ 811 II. Zinc Sulphate Used,..814 III. Fumes and Pyrometers,........ 816 IV. Heating Zinc Sulphate—Dehydration,...... 817 V. Heating Zine Sulphate—Decomposition...818 (a.) Beginning of Decomposition..818 (b.) Rapidity of Decomposition,..819 (c.) End of Decomposition..823 (d.) Retardations in Heating.-Curve,..825 (e.) Formation of Basic Salts,..826 Part II. Decomposition OF Zinc Sulphate by Heating with Carbon (Reducing Roast), .830 I. Introduction,........... 830 II. Experiments and Results ,.........832 III. Summay,........... 834 Part 111. Formation of Zinc Sulphate by Roasting,... 834 I. Introduction,........... 834 IT. Description of Blende,......... 836 III. Outline of Operations,.........838 IV. Details of Experiments.......... 839 1. Decrepitation,.......... 839 2. IgnitionPoint,....839 3. Sulphatizing-Roast of Joplin Blende..840 4. Sdphatizing-Roast of Warren Blemde ,..843 5. Sulphatizing-Roast with Addition of Pyrite...848 6. Summary of Sulphutizng-Roasts,....... 854 Part IV. Appendix : Formation of Zinc Ferrate...856 Part I. Decomposition of Zinc Sulphate by Heating in Air. I. Introduction. With the exception of lead sulphate. all common metallic

Jan 1, 1905

The library of the above-named Societies is open from 9 A. M. to 10 P. M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and 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, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared, to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on 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. HARRISON W. CRAVER, Director.

Jan 5, 1919

Edward S. Simpson, Perth, Western Australia (communication to the Secretary): In 1896 the East Coolgardie gold-field was divided into three fields, viz. : Area, square miles. Officia1 Centers. (1) East Coolgardie,. . 634 Kalgoorlie. (2) Broad Arrow,. , 588 Kurawa. (3) Northeast Coolgardie,. 22,960 Kanowna. The whole of the area embraced by the eastern gold-fields is covered with late Tertiary sands and gravel, with occasional beds of clay shales. These mostly overlay granite which occasionally shows through in small round hills. At Coolgardie, Kalgoorlie and other mining centers, belts of diorite, serpentine and highly metamorphosed sedimentary rocks appear on the surface. The rainfall at Kalgoorlie in 1897 was 4.75 inches. That the climate has not always been so arid is evidenced by the recent discovery at Coolgardie (only twenty-five miles away) in the late Tertiary formations of a thick bed of brown coal, containing numerous fossil fern-leaves. As assayer and mineralogist to the Government of Western Australia I have had occasion to examine a large amount of the Kalgoorlie ores, both in Perth and at the mines at Boulder itself. The only tellurides I have been able to determine are

Jan 1, 1899

By H. O. Hofman

WITH the exception of lead sulphate, all common metallic sulphates are completely decomposed upon heating into metallic oxide, sulphur trioxide, sulphur dioxide and oxygen. Some give up their trioxide readily at a low temperature, others require considerable heat and much time to be completely freed from sulphur. Kerl in 1881 arranged the principal metallic sulphates as they are decomposed by a rising temperature in the following order: silver, iron, copper, zinc, nickel, cobalt, manganese and lead, lead sulphate being decomposed only slightly at a white heat. The researches of Bradford, published in 1903, show, however, that ferrous sulphate is decom¬posed at 590° C., cupric sulphate at G53° C. and argentic sulphate at 1,095° C. By the present investigation it will be seen that zinc sulphate is decomposed at 739° C. As far then as our present knowledge goes, the order in which the decomposition of the leading metallic sulphates takes place is the one given in Table I.

Jan 1, 1905

By H. R. Stahl

FIVE mills are operated in Southeast Missouri by the St. Joseph Lead Co.; these have a total rated capacity of 24,300 tons per day divided as follows: Federal, 12,000 tons; Leadwood, 4800 tons; Desloge, 3600 tons; Bonne Terre, 2400 tons; and Mine La Motte, 1500 tons. These concentrators are similar in a general way, differing mainly in size and type of equipment and in minor variations in flow sheet. No attempt is made rigidly to standardize procedure in the various mills in spite of a general similarity in the ores. Each mill may be regarded as a separate laboratory in which new ideas and changes may be tried. A generalized description of the process is given, noting important differences in procedure at the various plants. The concentration process may be divided into five main stages: dry crushing, wet grinding, desliming and classification, tabling, and flotation.

Jan 1, 1947

By W. P. Sykes

SINCE Honda and Murakami1 in 1918 proposed their constitutional diagram of the carbon-free iron-tungsten system, considerable effort has been expended by several investigators in attempts to define more positively the structural features of the alloys. The existence of an intermediate phase corresponding to the formula Fe3W2 (68.7 per cent W) was proposed from evidence of a purely metallographic nature by one of the present authors2 in 1926. Since that time the identity of this phase has been confirmed by Arnfelt3 and by Takeda,4 both of whom employed X-ray methods as well as the microscope and the chemical analysis of isolated microconstituents. According to Arnfelt, Fe3W2, as crystallized from the iron-rich melts at a temperature above 1450'C., contains by analysis 68.7 per cent W. The lattice of this phase is characterized by trigonal symmetry. Arnfelt, moreover, proposed a second intermediate phase formed at some temperature between 1450° and 1000° C. by a peritectoid reaction involving Fe3W2 and the iron-rich solid solution. A melt containing 25 per cent W was cooled to 1000° C. and heated for. 100 hr. The precipitated tungsten-rich constituent was separated and found by analysis to contain 62.6 per cent W. This composition agrees closely with that represented by the formula Fe2W (62.2 per cent W). Diffraction patterns from the concentrated precipitate showed a hexagonal unit cell. Takeda confirmed the data of Arnfelt regarding Fe3W2 but was unable to detect Arnfelt's second intermediate phase. While Takeda. failed to describe in detail the treatments employed, he stated that in alloys containing 40 per cent W which were quenched after heating at various temperatures between 1200° and 1450° C., no evidence of the second phase (Fe2W) was observed either in the microstructure or in the diffraction patterns of isolated residues. He therefore considered the existence of this low-temperature hexagonal compound as disproved.

Jan 1, 1932

By Cyril Stanley Smith

Although alloys of copper and silicon were examined several years ago,' and their excellent mechanical properties were shown, it was not until C. B. Jacobs 2 introduced manganese in small quantities to the alloys that they became of commercial importance. A few years ago The American Brass Company took over the patents and commenced to manufacture the alloy under the name "Everdur." The present study of the constitution of the ternary system was undertaken in order to reach a fuller understanding of the behavior of the alloy. Review of Previous WORK on the BinaRy Systems There have been no papers published dealing with the constitution of the ternary system, although some tests of the mechanical properties have been described," which indicate that there is a change in solubility with temperature. Copper-silicon System The copper-silicon system has been studied in detail by the author and is described in two papers published in 1928.V he portion of the diagram up to 8 per cent. silicon, as determined by this research, is reproduced in Fig. 1. The author's previous papers include a complete review of the work of other investigators and it is not necessary to deal further with this system here. Copper-manganese System The copper-manganese system has been investigated by several workers, notably Lewis,5 Wologdine,6 Sahmen7 and Schemtschuschny,

Jan 1, 1930

By George W. Mitchell

THE property of Eureka Corp. Ltd. is located in the approximate geographic center of Nevada, 2 miles from Eureka, the county seat. The great sources of power, the Colorado, Snake, and Salmon Rivers and the rivers of northern California, are 300 to 500 miles distant, and no lines serve areas closer than 150 miles. Fuel for diesel and steam generation is available in Utah, 300 to 400 miles to the east. Eureka's railhead is 80 miles north where two trunk lines cross the county. A spur line serves Ely, 77 miles east. Good highways connect Eureka to the railheads. Activity in the Eureka mining district began in the early 1870's. The oxidized high grade lead-sil-ver-gold ore terminated against the footwall of the Ruby Hill fault, and in 1890 the main operations ceased. In 1938 Eureka Corp. Ltd. discovered ore in the hanging wall of the fault by diamond drilling. The history of Eureka in the late 1800's indicates that there was some water at 600 to 800 ft in the old workings, probably accumulations above the water table which did not seriously interfere with mining operations. Both the Locan and Richmond shafts were sunk to a level below the table, but apparently the only serious difficulty with water occurred in the Locan. The steam pump used when the last work was done on the 1200 level in 1923, many years after exhaustion of the main orebodies, is still installed on the Locan 900 level. The capacity was about 500 gpm, lifting 750 ft to the 100 level, which connected with the surface. In addition to this. bailers were used to keep the 1200 level free of water. It is said that pumping in 1923 lowered the water in the Holly shaft, about a mile and a half away, but this seems doubtful. The pumping was of short duration because no ore was found. When work at the new Fad shaft was started in 1941 Eureka Corp. Ltd. engineers were fully aware of the probability of encountering water in large volume. Their primary exploration and development had to be carried on at the 2250 level. The first water was encountered at 300 ft. This was undoubtedly surface drainage in the bedding of the Pogonip limestone and was less than 100 gpm. The fractured, loose Hamburg dolomite at the water table was not well cemented, and relatively little water, 300 gpm, percolated through it with difficulty. At 1350 ft well-cemented dolomite containing some open fractures was encountered. These fractures produced the first water of consequence, 750 gpm. At 1700 ft the volume was 1000 gpm increasing to the maximum during shaft sinking, 1600 gpm, at the 2000 level. Secret Canyon shale, a dry formation, was entered at 2100 ft, where a concrete water ring was placed to catch all of the water. The volume decreased rapidly to a constant flow of 1200 gpm. Below 2100 ft the shaft and stations remained in the shale and water was not a problem. Several faults of moderate displacement, including the reverse Martin fault, had been intersected during the traversing of 1000 ft of wet Hamburg, but no undue quantities of water were encountered. Observations in the diamond drill holes in the ore zone area showed a rapid lowering of the water table. The shaft was flooded when it left the dry shale and entered the water-bearing Eldorado dolomite on the 2250 level, crossing a fissure which paralleled the Martin fault. High pressure water doubled the volume then being pumped. Pipe failure through a water door bulkhead was a contributing factor. Immediately following this flooding in March 1948 preparations were made to recover the shaft as rapidly as possible by increasing power and pump capacities as needed. Measurements before flooding indicated the water could be lowered at a fast rate. However, the water table did not recede as rapidly as expected and volumes required to lower the water in the shaft were higher. Obviously the size of the main water channel on the 2250 level was increasing because of erosion, allowing greater volumes to enter the workings and draining beyond the cone originally being drained during shaft sinking. Eroded material was being deposited in the shaft below the 2250 level in serious proportions. In December 1948 a second flooding of the Fad shaft was allowed for the purpose of reassessing existing conditions and studying alternate methods of attack. The detailed geology of the Eureka mining district, see Fig. 1, has been described during the past 75 years by many geologists.' Only the general features and those which seem to affect the drainage problem will be discussed. The old ore zone, mined between 1870 and 1890, is located in a wedge-shaped block of Eldorado dolomite between the footwall of the Ruby Hill fault and the underlying Prospect Mountain quartzite, see Fig. 2. Production of high grade oxidized lead ore containing high values in gold and silver has been variously estimated at $50 to $90 million. The tonnage mined was probably close to 1,500,000, nearly all of which was found above the water table. The new ore, discovered by diamond drilling in the hanging wall of the Ruby Hill fault, is a flat-

Jan 1, 1954

By W. D. Faulkner, J. E. Urbanic, R. J. Jula

The process of treating granular activated carbon for return to service in the recovery of gold in carbon-in-pulp and carbon-in-leach circuits has been investigated. Carbons from two US mines, one Canadian mine, and a South African pilot plant operation were characterized before and after regeneration. Thermal regeneration of the carbon was investigated using factorial analysis to determine the effect of interaction of furnace temperature, retention time, and use of supplemental steam. The operation of acid washing the service carbon was investigated, including a comparison of the use of nitric and hydrochloric acids. The effect of quenching regenerated carbon was also briefly studied. Prom the data obtained, guidelines are given for effective regeneration operation.

Jan 1, 1986

Thomas Haight Leggett, London, Eng. (communication to the Secretary): Mr. Hammond has given us a concise yet complete description of the Witwatersrand gold-fields, and the character of the operations which have resulted in their remarkable development.

Jan 1, 1902

By Granville S. Borden

TAXES in general are onerous and are not a pleas- ant subject for discourse. There are, however, some very cogent reasons why we should dedicate a part of our thoughts and services to the solution of our taxation problems: The happiness of every individual in the United States depends on the maintenance of a stable government. The collection of taxes is an indispensable function of a stable government, and the power to collect taxes depends in part on the question whether taxes are fair and equitable. As representatives of the mining industry it is our duty to .protect it from tax burdens that are discriminatory or- unjust, As citizens we find that taxation is incessantly endeavouring to unravel the knots in our purse-strings. Many members of the Institute may be consulted .by clients on taxation problems, especially the phases which re- late to depletion and valuation. It is the hope of the writer that the discussion of some of the current depletion and valuation problems will stimulate interest in the problems, and as a consequence of this new interest facts will be ventilated, opinions rendered and services performed, which will be a means of solving the problems to the satisfaction of all parties interested.

Jan 1, 1929

By W. R. Clark, W. W. Cotter

Jan 1, 1946

By W. W. Cotter, W. R. Clark

Jan 1, 1946

By Thomas MacFarlane

DURING the last fifteen years the progress made in the science of lithology has been of a very marked character. From being a miscellaneous collection of facts and observations regarding certain mineral aggregates seemingly incapable of systematic arrangement, it has become a most interesting and orderly department of science. The investigators who have brought about this great change have recorded the results of their labors, and placed at our service an extensive and varied literature on the subject. To this I have paid some attention, and partly from .studying it, partly from my own observations, I have wrought out a classification of original or crystalline rocks, which I venture to bring under the notice of the members of this Institute. The practical importance of the subject will be acknowledged when it is considered that rock species are not without their influence on the contents of the mineral veins which intersect them. Besides, the Institute has been doing good service in defining terms in metallurgy, and no doubt in mining and geology we might

Jan 1, 1880