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By L. F. Pett

ALTHOUGH Kennecott's orebody has long been outlined, it is still necessary to define further its limits. This mine, long an advocate of churn drill methods, recently supplemented its practice by using a diamond drill. So far, the diamond drill holes have been along the main canyon floor which traverses the mine area. This zone, highly fractured, is cut by numerous friable quartz veinlets encountered within the porphyry. These veinlets, formed by filling contracted porphyry fractures with hot, siliceous, mineral-bearing solutions, are often more highly mineralized than adjacent porphyry. They pulverize on contact, yielding only slight amounts of core.

Jan 7, 1951

By A. W. Schlechten, R. F. Doelling

Parkes' process crusts were vacuum distilled using a shortened Pidgeon retort. Zinc was effectively removed below 800°C and recovered as a zinc sheet easily stripped from the furnace liner. Lead dasdistillationazinc required about 950°C and the resulting lead condensate tillationtended to stick to the thin metal liner. Final purity of residue is limited only by nonvolatile metals such as copper. THE successful commercial application of vacuum distillation for the removal of zinc from lead, as described by W. T. Isbell,' raises the question of whether or not a similar method can be used for other metal separations. Preliminary laboratory experiments on the vacuum distillation of Parkes' crusts by one of the authors' gave such encouraging results that it was decided to make a series of tests with large scale equipment to determine the results that might be expected in plant operation. The pilot-plant test results are reported in this paper. The great advantages of vacuum dezincing are its simplicity, the relatively low temperature of operation, and the fact that the zinc is recovered in the metallic state ready for use again in the desilveriza-tion of lead bullion. These same advantages and others would be realized from the vacuum distillation of the zinc-lead-silver crusts made in the Parkes' process. Zinc readily will distill over at temperatures of 800" to 900 °C as contrasted with the 1200°C or more used in the Faber du Faur furnace. Furthermore, the recovery of zinc as metal is practically perfect since there is no loss by oxidation or fuming. If the vacuum distillation is continued and hastened by raising the temperature to around 1000°C, the lead will distill over at an appreciable rate and deposit in a warmer zone of the condenser. This lead will contain a small amount of silver, but it can be returned to the desilverizing kettles and there is not the chance of loss that there is in disposing of the rich litharge from cupelling. The lower temperatures required will mean a saving of fuel and less wear on the equipment. One further point is that the vacuum distillation could be run on a small scale practically continuously, so as to avoid the accumulation of large amounts of silver-rich material and the need of assembling a large crew for special cupellation runs. It should be pointed out here that the final purity of the silver residue will depend on the copper or iron content of the crusts, as these and other metals with low vapor pressure will not be eliminated. The idea of treating the silver-zinc-lead crusts from the desilverization of lead bullion by vacuum distillation is not a new one, but such experiments have not been reported, as far as can be determined. In 1912, T. Turner presented a paper3 before the Institute of Metals on the vacuum distillation of brass, and a member of the audience suggested that he try his method on Parkes' crusts. In 1935, W. J. Kroll, noted for his discovery of debismuthiz-ing lead by calcium additions, published a paper' on vacuum distillation of metals and pointed out possible applications in the lead industry. Principles of Separation The successful separation of two or more metals by distillation depends upon an appreciable difference in the effective vapor pressures of the metals in the alloy to be treated. The vapor pressures of the common metals have been determined with considerable accuracy; for example, at 800°C the vapor pressures of the individual metals which are of particular interest in this paper are about .as follows: Zn, 241 mm; Pb, 0.0553 mm; and Ag, 0.0000276 mm. Unfortunately,, data are not available on the activities of the components in the ternary system Zn-Pb-Ag, but it can be estimated that on the basis of the vapor pressures of the individual metals a good separation can be made by distillation. The preliminary laboratory tests previously mentioned' supported this assumption. The pilot-plant size vacuum distilling furnace is shown in Fig. 1. It consisted of an abbreviated Pidgeon retort, 5 ft long with an ID of 8 in., heated by six silicon carbide elements placed symmetrically

Jan 1, 1952

By A. Eilers

A number of the copper refineries in this country have lately separated some of the rarer metals from the slimes in the refinery tanks. One of these has furnished me the following table of recoveries from given amounts of blister. I publish this to show the proportions, to gold and silver and to each other, in which these rarer metals may be expected to occur in copper from certain localities. GarFIeld, Utah :—The blister copper comes principally from the Bingham porphyry copper mines. Steptoe, Nev. :—All the blister copper is produced from the Nevada Consolidated mines. (Also porphyry deposits.) Omaha, Neb. :—Blister copper comes principally from concentrated copper-lead mattes shipped from the different lead-silver plants of the Rocky Mountain region to the converters at the Omaha lead refinery. Mountain, Cal. :—Ores occur in connection with diorite (?).

Jan 1, 1914

By AIME AIME

JOHN LIVERMORE CHRISTIE belongs to that group of metallurgists who entered the industrial field during World War I and have been responsible for many of the important metallurgical developments since that time. He was born in Montclair, N. J., on Jan. 31, 1894. After graduating from Montclair High School he attended Sheffield Scientific School, Yale University, received his Ph.B. degree in chemistry in 1915 and that same year was employed by the Bridgeport Brass Co. in its laboratory. Among his first duties was the return to Sheffield Scientific School for two years of graduate work in metallography under C. H. Mathewson; receiving his M.S. degree in 1917. Thus we see him becoming one of that group of eminent physical metallurgists who, with Dr. Mathewson's teaching as a foundation, have done outstanding work in metallurgy.

Jan 1, 1945

New York Meets first Wednesday after first Tuesday of each month. Chairman. PERCY E. BARBOUR, Vice-Chairman. A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN,.Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. W.. E. C. EUSTIS. Chairman. R. L. AGASSIZ. Vice-Chairman. E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting n September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON. S. SHEDD. Puget Sound Meets second Saturday of each month SIMON H. ASH, Chairman. I. F. LAUCKS, Vice-Chairman. CHARLES SIMENSTAD, Secretary-Treasurer, 425 Lyon Bldg., Seattle, Wash. GLENVILLE A. COLLINS, JOHN N. POTT

Jan 5, 1917

C. Q. PAYNE, New York, N. Y. (written discussion*).-The method adopted by Mr. Lennox is a very interesting test of the practical application of Mr. Gates' crushing-surface diagram to a greet variety of gold and copper ores. His method of dealing with the material below 200-mesh is also a distinct contribution to the subject, although, as he suggests, it seems likely that some microscopic measurement of this material may be advisable before the mesh reciprocals of its group particles can be dealt with as accurately as can those coarser than 200-mesh. In examining the general results shown in Table 3, it is somewhat puzzling to perceive why Calumet &, Hecla jig tails should show a crushing resistance 3 - times greater than that of the ore from the Ray Consolidated copper mine. The latter is, I believe, an altered. Pinal schist

Jan 10, 1918

By Joseph H. Allen

Commercial coke is made to-day in the United States chiefly from the Appalachian, the Illinois and the Colorado coal-fields. The measures of the great Appalachian coal-fields furnish by far the largest proportion, only about 1 per cent. coming from those of Illinois and Colorado. This is not due, however, to a corresponding difference in area. The Illinois field covers about 47,000 square miles in Illinois, Southern Indiana and Western Kentucky. The coal is high in both ash and sulphur, and on this account nearly all the attempts which have been made from time to time to coke it have resulted in failure, so far at least as the requirements of ironmasters are concerned. Nevertheless,. I am able to say from a practical knowledge of this field that the physical structure of the coke is perfect, and

Jan 1, 1893

By S. H. Chauvenet

Jan 1, 1882

By C. K. Leith

CERTAIN ideas on iron and steel sanctions to follow originated in a series of conferences held under the joint auspices of the War Department and Brookings Institute in Washington last spring. The views presented may be regarded as those of substantial segments of the steel industry. In view of the fact that steelmaking capacity can be so quickly converted to the production of armament, any effective control must necessarily include the entire steel industry and not solely the parts devoted to the production of implements of war. It must also be exercised all the way from production and shipment of raw materials through their ultimate conversion into finished products and use. Control will be dis- cussed under two main headings: (I) control of raw materials at the source; (2) control of steel capacity within the Axis countries.

Jan 1, 1944

Few people in the industry today are competent to comment on the O.G. system for vessel covers, but with papers as well prepared as Mr. Bradley's we will soon be well informed. I would like to direct these comments to Mr. Klaes of Ford Motor Company. Mr. Klaes' description of their steaming hood agrees with our experience at Weirton. We have been able to stay within design limits and, as a result, have had few problems with our auxiliary equipment. Our main problem, as with Ford, has been thinning of our vessel cover tubes. At Weirton, controlled circulation, high pressure boilers are in use as heat recovery units above the BOP vessels. The boilers are provided with "off cycle' oil firing equipment. A Venturi type wet gas scrubber follows the boiler to complete the vessel draft system.

Jan 1, 1972

By William P. Blake

In a former paper read at the Washington meeting of the Institute, February, 1881,' I presented a general view of the geology and veins of Tombstone as then developed. Considerable additions have been made to our knowledge of the oredeposits since that date, nearly all the mines having been worked down to the general wster-level of the district. This water was a bar to further progress in depth and costly pumps were erected at the Grand Central mine and at the Contention. By the united action of these pumps the water was gradually lowered, not only in these two mines, but in all the important mines of the district. Pending a consolidation of interests, or an equitable distribution of the cost of unwatering, both pumping-plants were destroyed by fire, and the mines were closed

Jan 1, 1904

The Committee on a Standard Gauge have been constantly engaged, since their appointment, in the duties assigned to them.§ They have corresponded with different persons interested in the manufacture and use of gauges in this country, and have received from several of them important information. They have also entered into correspondence with the governments of England, France, Gerniany, and Russia through their Consuls, ant1 with Austria directly. The Consuls of Germany and France

Jan 1, 1879

By K. H. Nimerick, B. E. Scott, F. J. Beafore

A unique freeze conditioning agent (FCA) which functions by forming structurally weak ice rather than suppressing the freezing point of water has been successful in alleviating frozen coal problems. Frozen coal treated with FCA has been quickly unloaded at temperatures below -17.8°C (O°F). Other applications of FCA include deicing: conveyor belts, idler, idler arms, and other moving parts that have been impeded by ice.

Jan 9, 1979

(Members are, urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during the period April 10 to May 10; I. N. Knapp, Ardmore, Pa. E. P. Mathewson, Anaconda, Mont. Herbert B. Cox, New York, N. Y. H. B. Barling, New York, N. Y. A. McLintock, Brooklyn, N. Y. M. M. Thompson, Morsemere, N. J. Heinrich Ries, Ithaca, N. Y. Howland Bancroft, Denver, Colo. R. M. Catlin, Franklin Furnace, N. J. John H. Adams, Birmingham, Ala. Percy E. Barbour, Candor, N. C. Henry D. Boddington, London, England. A. D. R. Galloway, Qruro, Bolivia. William J. Cox, Denver, Colo. M. K. Rodgers, Westgate, Cal. W. J. Morrison, Toronto, Canada. W. J. Richards has been elected President of the Reading. Coal & Iron Co., succeeding the late George F. Baer.

Jan 6, 1914

V. R. GARFIAS,* Palo Alto, Cal. (written discussion?).-Regarding the statement of Mr. Ordoñez, on page 1007, concerning the synclinal curving of sedimentary beds caused by the extrusion of volcanic necks, that "this phenomenon might occur, but it is not fully proved in our fields," I beg to reply that the funnel and anticlinal-ring structure is actually associated with igneous intrusions in the Mexican oil fields, as we were able to ascertain by plotting an underground contour map and making a structural model of the oil-bearing beds of the Ebano field. E. DE GOLFER, New York, N. Y. (written discussion?).-The paper under discussion is not only of interest in connection with its subject but it is a contribution of considerable importance to our knowledge of the possible effect of igneous rocks upon the accumulation of petroleum in the Mexican fields.

Jan 10, 1918

THERE is at least one concrete indication that Soviet Russia's two most important iron ore producing centers are seriously depleted. While keeping in mind Russia's penchant for reverse propaganda, one piece of evidence indicates that Magnitugorsk in the southern Urals and Krivoi Rog in the Ukraine have been mined to a point where lower grade ores are being recovered. An article in Pravda, Soviet newspaper, by I. P. Bardin. a Russian metallurgist, says that ore presently mined must undergo an expensive enriching cycle before it can be used in blast furnaces. Com- pounding Russian metallurgical troubles is the low quality of coking coals. High ash and sulphur content typifies the coal Badin talks about. Coal from the Ukraine, Eastern Siberia, Kazakhstan, and the Far East requires extensive treatment before it can be used, according to the article in Pravda.

Jan 7, 1953

By Eugene P. Pfleider, Jared Scofield

During the past ten years, the trend on the Mesabi Range has been toward the establishment of integrated operations which mine, concentrate, and pelletize the large reserves of magnetic taconite. However, since the supply of open-pit ores of acceptable quality is by no means inexhaustible, it has been proposed that it be supplemented by developing the magnetic taconites that extend down dip past the economic limits for open-pit methods. In Phase I of a long range study, Pfleider and Yardley1 collected information on the general character of the Mesabi iron formation at depth and proposed that an underground lane-and-pillar mining system be considered to extract those high grade layers where they might exist over a considerably areal extent. An approximate cost estimate was included initially, with the thought of later developing a feasibility study as time permitted.

Jan 9, 1967

Stripping of the Exotica open-pit mine, which is proceeding at about 120,000 tpd, is dwarfed by its proximity to the 500-million-ton Chuquicamata tailing pile. The excavating work is being carried on smoothly and efficiently and, as of the end of October, accounts for the removal of 77 million tons of total material of which some 200,000 tons is stockpiled ore. Diamond drilling has outlined an orebody 5900 ft long and 3400 ft wide containing an estimated 153 million tons of ore at 1.35% recoverable copper based on 80 % extraction.

Jan 11, 1969

By Thomas T. Read

AT this time of the year, engineering schools are releasing a group of young men who probably are, on the average, in much the same attitude of mind as a person arriving at the terminal station of a railway journey; namely, of having a general idea of his objective, but having to make a decision as to just where he is going and how best to get there. The man leaving the train can at first follow the crowd, but it soon breaks up, as one goes one way and one another, until he has to choose his own course. The recent graduate may do the equivalent of following the crowd by accepting the first position offered, but this only postpones a decision as to where he is going and how best to get there. So many young engineers ask for advice as to what to do that the following statement has been prepared as an attempt to make a general answer to such queries. The engineer taking his first job should realize two fundamental relations. The first is that in electing to be an engineer he has elected to be a hired man. A consulting engineer has more freedom than a man on a regular pay roll, but he is also a hired man; hired for briefer periods at a relatively high rate, but under the necessity of simultaneously doing his consulting work and developing new retainers. There is nothing derogatory in being a hired man (all doctors, lawyers and clergymen are hired men), but the tardy realization that he is one seems to give many an engineer a mental jolt that can be avoided if he accepts it from the beginning.

Jan 1, 1926

By Fred D. Gustafson

With the postwar emergency for new housing and for new industrial buildings, much research has been done on lightweight aggregates for use in concrete and plaster. The trend toward lighter weight aggregates to relieve the dead load on the higher, steel frame- work buildings started toward the end of the last century. Progressively the requirements be- came more stringent, crushed bank slag, weighing 80 lb per cu ft as com- pared to 100 lb for crushed rock, was supplemented in some sections by foamed slags and expanded shales weighing from 40 to 60 lb per cu ft. In other sections cinders were used weighing from 40 to 50 lb, including sand. Sections favored with more recent vulcanism turned to pumice weighing from 30 to 60 lb, whereas other localities made use of diatomite, from 28 to 40 lb. Exfoliated vermiculite weighing from only 6 to 10 lb per cu ft came into use. As the search for lighter weights in aggregates continued so did the search for other desirable properties such as nailability, ease of cutting or channeling, and good insulation to both sound and heat. This search eventually led to a widespread interest in the expansion of perlite, or similar volcanic glasses, with the result that in 1946, the Office of the Housing Expediter' listed eleven firms reporting the operation of processing plants either on pilot or commercial scale producing aggregates weighing from 2 to 16 lb per cu ft.

Jan 1, 1949