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By V. F. STANLEY

THERE is not the slightest doubt that the present recoveries of valuable minerals by the Broken Hill mills could be improved, and that further machinery would be installed for the purpose if it could be assured that a high price of metals would be maintained; but concentration, like all other com¬mercial propositions, is a question of profit and loss, and no sensible metallurgist would carry out his work in such a manner as to obtain high recoveries at a financial loss to his company. There is a point in all concentration at which the added money obtained from the higher recovery of minerals is balanced by the extra cost of obtaining the last part of the recovery; a wise metallurgist will be content with his work before his working-expenditure reaches this point. To a casual observer, the work being done by the various Broken Hill mills is identically the same. A closer investigation will show that this is far from being the case, for it is a remarkable fact that, although the larger mines extend over a length of approximately only 2 miles, such a difference in the physical and chemical properties of the ores exists that, from the first reduction downwards, special treatment is necessary in each case, and hardly any two mills are identical in operation. The details of this paper refer directly- to the work of one . particular mill in Broken Hill, for the reason that the ore from each mine presents special difficulties and requires its own special treatment. I have selected the mill referred to because it has been constructed and modified under my supervision.

Sep 1, 1909

By Bever M. B., Floe Carl F., Hung Liang

Data on the solubility of hydrogen in iron-silicon alloys are of practical interest, as hydrogen causes gas unsoundness and embrittlement in iron and steel and is also a factor in the metallurgy of cast iron. Zapffe and Simsl have recently demonstrated that in deoxidized iron and steel castings gassiness and bleeding are primarily functions of the hydrogen content of the liquid metal. These authors also suggested convincingly that ordinary melting and casting practice provides several sources of hydrogen for absorption by the metal. Norbury and Morgan2 and Boyles3 have shown that dissolved hydrogen affects the graphitization of cast iron. Schneble and Chipman4 included in a study of the effects of superheating on the properties of cast iron an investigation of the part played by hydrogen. Schwartz, Guiler and Barnett5 investigated the significance of hydrogen in the metallurgy of malleable cast iron. A complete interpretation of investigations of this kind calls for equilibrium values of the solubility of hydrogen in the liquid and solid phases. From the theoretical standpoint, the solubility of gases, especially hydrogen, may reveal some aspects of the nature of liquid metallic solutions. This was implied in the early work of Sieverts6 on the effect of alloying additions on the solubility of hydrogen in copper. Recent work by Bever and Floe7 has shown that in liquid copper-tin alloys the solubility of hydrogen changes abruptly at the composition of the intermetallic compound Cu3Sn. It is of considerable interest to determine whether liquid alloys of iron also have compositions at which the solubility of hydrogen exhibits a discontinuous or otherwise unique behavior. Among the various alloys of iron the iron-silicon system is important because of the presence of silicon in various structural alloy steels, transformer sheets, cast irons and special acid-resisting castings. The various grades of ferrosilicon, finally, cover almost the entire remainder of the composition range. Published information on the solubility of hydrogen in iron-silicon alloys is meager. The first values for pure liquid iron were reported in 1910-191 1 sieverts and Krumbhaar8 and by sieverts.9 They found that 100 grams of iron absorbs 28 c.c. of hydrogen at 1550°C and One atmosphere pressure, and 31 C.C. at 1650°C. In 1938 Sieverts, Zapf and Moritz10 published a value of 26.3 C.C. at 1550°C. Data on the solubility of hydrogen in liquid iron-silicon alloys and in liquid silicon are not available. Martin1' investigated

Jan 1, 1947

By Bever M. B., Floe Carl F., Hung Liang

Data on the solubility of hydrogen in iron-silicon alloys are of practical interest, as hydrogen causes gas unsoundness and embrittlement in iron and steel and is also a factor in the metallurgy of cast iron. Zapffe and Simsl have recently demonstrated that in deoxidized iron and steel castings gassiness and bleeding are primarily functions of the hydrogen content of the liquid metal. These authors also suggested convincingly that ordinary melting and casting practice provides several sources of hydrogen for absorption by the metal. Norbury and Morgan2 and Boyles3 have shown that dissolved hydrogen affects the graphitization of cast iron. Schneble and Chipman4 included in a study of the effects of superheating on the properties of cast iron an investigation of the part played by hydrogen. Schwartz, Guiler and Barnett5 investigated the significance of hydrogen in the metallurgy of malleable cast iron. A complete interpretation of investigations of this kind calls for equilibrium values of the solubility of hydrogen in the liquid and solid phases. From the theoretical standpoint, the solubility of gases, especially hydrogen, may reveal some aspects of the nature of liquid metallic solutions. This was implied in the early work of Sieverts6 on the effect of alloying additions on the solubility of hydrogen in copper. Recent work by Bever and Floe7 has shown that in liquid copper-tin alloys the solubility of hydrogen changes abruptly at the composition of the intermetallic compound Cu3Sn. It is of considerable interest to determine whether liquid alloys of iron also have compositions at which the solubility of hydrogen exhibits a discontinuous or otherwise unique behavior. Among the various alloys of iron the iron-silicon system is important because of the presence of silicon in various structural alloy steels, transformer sheets, cast irons and special acid-resisting castings. The various grades of ferrosilicon, finally, cover almost the entire remainder of the composition range. Published information on the solubility of hydrogen in iron-silicon alloys is meager. The first values for pure liquid iron were reported in 1910-191 1 sieverts and Krumbhaar8 and by sieverts.9 They found that 100 grams of iron absorbs 28 c.c. of hydrogen at 1550°C and One atmosphere pressure, and 31 C.C. at 1650°C. In 1938 Sieverts, Zapf and Moritz10 published a value of 26.3 C.C. at 1550°C. Data on the solubility of hydrogen in liquid iron-silicon alloys and in liquid silicon are not available. Martin1' investigated

Jan 1, 1947

By Carl F. Floe, Hung Liang, Michael B. Bever

DATA on the solubility of hydrogen in iron-silicon alloys are of practical interest, as hydrogen causes gas unsoundness and embrittlement in iron and steel and is also a factor in the metallurgy of cast iron. Zapffe and Sims1 have recently demonstrated that in deoxidized iron and steel castings gassiness and bleeding are primarily functions of the hydrogen content of the liquid metal. These authors also suggested convincingly that ordinary melting and casting practice provides several sources of hydrogen for absorption by the metal. Norbury and Morgan,2 and Boyles3 have shown that dissolved hydrogen affects the graphitization of cast iron. Schneble and Chipman4 included in a study of the effects of superheating on the properties of cast iron an investigation of the part played by hydrogen. Schwartz, Guiler and Barnett6 investigated the significance of hydrogen in the metallurgy of malleable cast iron. A complete interpretation of investigations of this kind calls for equilibrium values of the solubility of hydrogen in the liquid and solid phases. From the theoretical standpoint, the solubility of gases, especially hydrogen, may reveal some aspects of the nature of liquid metallic solutions. This was implied in the early work of Sieverts6 on the effect of alloying additions on the solubility of hydrogen in copper. Recent work by Bever and Floe7 has shown that in liquid copper-tin alloys the solubility of hydrogen changes abruptly at the composition of the intermetallic compound Cu3Sn. It is of considerable interest to determine whether liquid alloys of iron also have compositions at which the solubility of hydrogen exhibits a discontinuous or otherwise unique behavior. Among the various alloys of iron the iron-silicon system is important because of the presence of silicon in various structural alloy steels, transformer sheets, cast irons and special acid-resisting castings. The various grades of ferrosilicon, finally, cover almost the entire remainder of the composition range. Published information on the solubility of hydrogen in iron-silicon alloys is meager. The first values for pure liquid - iron were reported in 1910-1911 by Sieverts and Krumbhaar8 and by Sieverts.9 They found that 100 grams of iron absorbs 28 C.C. of hydrogen at 1550°C. and one atmosphere pressure, and 31 C.C. at 1650°C. In 1938 Sieverts, Zapf and Moritz10 published a value of 26.3 c.c. at 1550°C. Data on the solubility of hydrogen in liquid iron-silicon alloys and in liquid silicon

Jan 1, 1946

[Aase, Qlenn D., (Junior Member '40) Jr. Met.. American Smelt. & Refin. Co., Selby. Calif. Abadie, Henry G., (Junior Member '43) Petr. Engr.. Avenal, Calif. Abbott, Clarence E., (Member '04) Civil En=.. V.P.. Tennessee Coal. Iron & R.R. Co., 1542 Brown biarx Bldg.. Birminpham, Aln. Abbott. Fred E., Jr., (Member '44) Petr. Engr., C/O Arabian Anierican Oil Co.. A.P.O. 816. c/o Postmaster, New York, N. Y. Abel, Raymond L., (Member '28) Chem. Engr.. C. O., Pittsburgh Chem. Warfare Procurenlent Dist.. American Bank Bldg., Pittsburph. Pa. Abel, Walter D., (Member '32) Min. Engr.. Supvr. Engr.. RFC, Los Angeles, Calif.]

Jan 1, 1946

"Located on the Big Hole River, three miles from Divide, Montana, and 21.75 miles from Butte.Built in 1899.DAM: Rock-filled wooden crib, 512 ft. long and 57.5 feet high.SPILLWAY: Equipped with flash-boards 189 ft. long, 8 ft. 10 inches high.PENSTOCKS: Two 8 ft. diameter of steel, each branching and supplying two wheels.WHEELS: Four double horizontal, double discharge turbines, made by The James Leffel & Co., 1,000 h-p., 180 r. p. m., direct connected to generators, operating at 60 ft. head. GENERATORS: Four G. E., revolving field, 750 k-w., 180 r. p. m., 800 volt, 3 phase, 60 cycle alternators.EXCITERS: Two water-wheel driven exciters.TRANSFORMERS: 12 250-k-w. G. E. air blast, primary 15,000 volts, Secondary 800 volts.OPERATION: The plant operates essentially as a peak load plant. Except in flood period, there is insufficient water to operate at full load continually. In December its average output is about 500 k-w."

Jan 1, 1913

By AIME AIME

ALTHOUGH the present economic depression is felt in the petroleum industry, probably as much as in any other branch of American industry, the Petroleum Section of the Institute was well represented at the general sessions on Monday and at all of the seven division sessions on Tuesday, Wednesday and Thursday. The seven sessions of the Division were so arranged as not to conflict and thus permitted members to hear the programs of all sessions.* The first meeting of the Petroleum Division was held on Tuesday afternoon; a joint session on engineering research and production engineering. The following papers were presented:

Jan 1, 1931

By D. R. Mitchell

FOR the second consecutive year, attendance at the Coal Division sessions far exceeded exoectations. Those in charge were continually faced with problems of finding seats and space for attending members. 115 seats were set - II~ for the annual luncheon meeting of the Division and approximately 175 members showed un. Since the hotel management would not serve more than the 115 it meant that 60 members were forced to eat elsewhere. This created hard feelings with some members. How- ever, officials of the Division were not able to obtain in advance any indication of this overflow crowd, but are suggesting to the New York Office that some means other than ticket sales be adopted to obtain an estimate of Division luncheon and dinner attendance. Members could be circularized prior to he meeting or they could be checked when registering as to the events they expect to attend. Under the inspiring leadership of Cadwallader Evans, Jr., Chairman, the Coal Division had a phenomenal growth during the year. Reporting at the luncheon meeting, Newel1 Alford stated that approximately 190 new members had been obtained. A few more years of continuing increase at this rate will make the Coal Division one of the largest Divisions in the Institute.

Jan 1, 1944

By AIME AIME

A CORPORATION would go into bankruptcy if its affairs were conducted as are those of the state of New York, according to the Committee on New York State Government Reorganization of the American Engineering Council of the Federated American Engineering Societies, in a report to the chairman, of the Joint Judiciary Committees of the Senate and Assembly. The report, just made public, was signed by the three members of the committee who were appointed by Herbert Hoover. They were H. de-B. Parsons, chair- man, Paul G. Brown and Lewis B. Stillwell. Although the American Engineering Council is a national organization, it decided to aid in governmental reorganization in New York State because of the magnitude of the task. The Council's committee in its report urged the passage of three state reorganization amendments for consolidation of departments, an executive budget system, and a four-year term for the higher state officials. In the words of the report :

Jan 1, 1921

By Daniel R. Shawe

Large tabular beryllium deposits in waterlaid rhyolitic tuff at Spor Mountain, Utah, contain the world's largest known resources of beryllium (as bertrandite). The district also has produced fluorspar and uranium. The largest beryllium deposit is about 2.5 miles long, and known deposits contain many million tons of material with at least 0.5 per cent BeO. The beryllium-bearing tuff (Pliocene?) underlies topaz-bearing rhyolite ( Pliocene?) that contains unusually high amounts of beryllium, fluorine, and uranium, and overlies other volcanic rocks (Pliocene? or Micocene?) and marine carbonate and elastic rocks ( Paleozoic). The deposits occur in hydrothermally altered tuff only where it contains abundant carbonate pebbles eroded from the Paleozoic rocks and where the tuff was deposited as thick layers in now-buried paleovalleys. Basin and Range faults, thrust fa ults, and possibly strike-slip faults formed in this part of the Basin and Range province during the late Tertiary, and volcanic rocks were extruded. Beryllium mineralization probably occurred during this episode. Undoubtedly the beryllium deposits are related genetically to the topaz-bearing rhyolite, but the details of their genesis are not certain and probably are complex. Beryllium deposits are close to major faults, and locally the beryllium is concentrated at faults, indicating fault control of mineralization. Some elements in the deposits, such as lithium, however, are evenly distributed in certain Luff beds and perhaps were introduced prior to faulting. Still other elements, such as manganese and lead, were concentrated in the beryllium deposits and subsequently were leached along late fractures, indicating a period of metal redistribution following mineralization.

Jan 1, 1968

By WILKES BARRE

AS PREVIOUSLY announced, the semi-centennial meeting of the Institute is to be held at Wilkes-Barre, Pa., on Sept. 12, 13, 14, and 15. An interesting program of technical sessions and excursions is now being prepared by the Local Committee. At the time of going to press the program had not been completed in sufficient detail to permit its being pub¬lished in this number. The detailed program will be published in the September MINING AND METALLURGY, which will be printed in time to be distributed before the Wilkes-Barre Meeting. It may be said in advance, however, that the Com¬mittee has progressed so far in its work that we are assured of one of the -most notable meetings the Insti¬tute has held and that members will miss a rare .treat if they do not attend. The many trips and excursions, as well as the banquet, will be -given to the members as a compliment from the members of the Local Com¬mittee. . . The paper by Howard Eavenson on the Lynch Plant of -the United States Coal and Coke Co. will be illustrated by lantern slides and moving pictures. One of the most appropriate discussions will be that opened by Prof. J. F. Kemp on the Stratigraphy of the Anthracite Region; this also will be amply illustrated.

Jan 1, 1921

By R. HAYDEN, H. B. HALLOWELL, H. O. Hofman

THE object of refining copper in the reverberatory furnace is to obtain a metal which will have the highest attainable degree of malleability, ductility and electric conductivity, and present at the same time a level surface when it solidifies in the mold after casting. These desirable physical properties are governed by the character of the impurities and the forms in which they are present, by the amount of cuprous oxide retained by the copper, by the quantity of gas held in solid solution, by the casting-temperature, and by the thickness of the casting. The effects of impurities, of cuprous oxide and of gases upon the mechanical properties of copper have been studied by Hampe in his classical paper "Contributions to the Metallurgy of Copper." The most recent research into the effect of metals upon the electrical conductivity of copper is that of Addicks.2 The influence of cuprous oxide upon the electrical conductivity has been investigated by Walker' and Addicks.4 The absorption of gases has received' attention by Hampe,5 Stahl 6 and Heyn.7 The effects of casting-temperature have been noted by Stahl.8

Mar 1, 1907

By C. Law McCabe, R. G. Hudson

The Knudsen cell has been employed to determine the free energy of formation of Mn7Cs in the temperature range 800" to 950°C. A value of 66,440 cal was found for hH°o for a-manganese. Measurements of the pressure of manganese over a mixed carbide, (Fe,Mn),C, points to a power relationship between aun7cs and N.4,. RECENTLY Kuo and Perssonl have reported that the carbide of manganese which is in equilibrium with graphite at temperatures up to 1100° C is Mn7Ca. There are no published data on the thermo-dynamic properties of this compound. In order to determine the stability of Mn7Ca, it appeared that, by obtaining the pressure of manganese above 8-manganese and also above Mn,C, in equilibrium with graphite, the free energy of formation of Mn7Ca from 8-manganese and graphite could be obtained. In addition, the vapor pressure of manganese, reported by Kelley From data of Bauer and Brunner,' is subject to some uncertainty and further determinations of the vapor pressure of manganese seemed warranted. In this investigation of the pressure of manganese vapor above pure manganese and also above the carbide of manganese in equilibrium with graphite the apparatus used is the Knudsen orifice cell. The same apparatus, experimental procedure, and method of calculating the pressure was used in this investigation as in one previously reported.~ Care was taken to insure that the cells were at constant weight before using them in a run. The manganese charged in the cell was CP grade powder, carbon free, obtained from the Fisher Scientific Co. A spectroscopic analysis of the manganese after appreciable amounts of it had vaporized from the Knudsen cell showed that no element was present in sufficient quantities to contribute to a weighable weight loss or to decrease the vapor pressure of manganese to any appreciable extent. The spectro-graphic analysis was 0.002 pct Cu, 0.05 pct Fe, 0.002 pct Pb, and 0.002 pct Ni. 8-manganesea is the allo-tropic form of manganese which was present in the cell at temperatures used in this investigation. The manganese carbide, Mn,Ca, was made in the following way: In a closed graphite cell manganese powder was added to graphite powder, which was made from graphite rods for spectrographic use. The manganese powder was the same as that described previously; 5 pct excess graphite was added over that required for the formation of Mn7C,. The mixture was heated in a closed graphite cell for approximately 20 hr at 1350°K under vacuum. X-ray analysis revealed that there was no manganese present after this treatment, but that the lines due to Mn,C, were present. In order to prove that there was no volatile carbide of manganese which was effusing out of the cell, the following experiment was performed: A graphite effusion cell containing graphite power, in excess of that to form Mn,C, of a desired amount, was brought to constant weight on heating at 1228°K. The required amount of manganese was accurately weighed and then added to the graphite effusion cell. The cell was placed in a vacuum at 1228°K for one week, which was the time calculated for the manganese to have effused completely, assuming instantaneous formation of Mn,C8. The cell was then weighed again. This experiment was carried out on two different occasions and both times the weight loss of the cell came within 1 pct of the weight of manganese originally charged minus the weight of manganese left in the cell, as determined by chemical analysis. These data are summarized in Table I. This agreement is considered to be within experimental error and is taken as proof that no carbide of manganese is volatile in this temperature range. It was established, by X-ray analysis, that Mn,C, formed before appreciable amounts of manganese vaporized from the metal powder which was charged. The identification of the carbide of manganese which was present in the Knudsen cell in equilibrium with graphite and manganese vapor was carried out by Kehsin Kuo at the University of Uppsala. He established that the authors' sample, which was submitted to him for analysis, contained the phase

Jan 1, 1958

The co-operation of the members of the Institute is earnestly sought by the Committee on Nominations, recently appointed by the Board of Directors, in its work of formulating a ticket for officers and places falling vacant in the Board of Directors in February, 1916. The Committee must present the official ticket of nominations to the Board of Directors at its October meeting. Members are, therefore, urged to send promptly their nominations for officers and Directors in order that the Committee may have an opportunity to give them full consideration. The officers to be elected at the annual meeting in February, 1916, are: One officer, known as Director and President. Two officers, known as Director and Vice-President. Five officers, known as Director. The officers of the Institute whose terms expire are as follows: President, William L. Saunders (not eligible for re-election). Past President, Charles F. Rand. Vice-Presidents, Thomas H. Leggett, District 0; Fred W. Denton, District 4.

Jan 9, 1915

By GEORGE A. KIERSCH

The awesome destructive power of known and projected weapons of war presages a new need for geologists and engineers, who may be called upon to locate vital industry underground, thereby protecting it from sky-borne destruction. The Corps of Engineers is now conducting special tests to establish design standards covering the general field of underground installations as well as surveys a of construction methods and the operational hazards connected with such plants. National planning must dictate a policy that is either tactical, where surface manufactured parts; are stored underground and during art emergency assembled, or operational with both the manufacturing and assemblage completed in subsurface plants. Both plans of operation require the use of subterranean plants. Relocation of vital plants underground will probably involve only a small percentage of the production capacity of this nation. The cost of rebuilding in new location will obviously limit its adoption

Jan 1, 1949

By E. A. Holbrook

IN view of what has happened in - the past three years, it seems incredible that industrial corporations continue to write to engineering and mines schools for "promising members of the graduating class," or, indeed, that they even send representatives to the colleges to interview engineering graduates. Certainly, by this time, every company should be aware of the fact that recent engineering graduates are almost nonexistent and the number is not likely to increase within the next several years. At the February, 1945, annual meeting of the Local Section delegates of the A.I.M.E. in New York, W. B. Plank, professor of mining engineering at Lafayette College, summarized well the situation of the colleges by titling his talk "The Lost Generation of Engineers."

Jan 1, 1945

By D. B. Crouch, D. A. Poulter

The engineering and metallurgical assessment of the McLaughlin Project ore body concluded that an open-pit mine and cyanide leach mill process would be feasible, producing both waste rock and residual mill tailings. As a part of the planning and permitting process, site selection studies were conducted for the tailings and waste rock disposal. The site selection process began with a regional identification of potential disposal sites and proceeded through 1) regional screening, 2) elimination of sites with obvious fatal flaws, 3) qualitative ranking of site evaluation criteria, 4) quantitative ranking of sites, 5) field investigation, 6) evaluations of field data, and 7) selection of preferred sites. Based on this approach of site rankings and field evaluations, tailings and waste rock disposal sites were selected and recommended for the preliminary design phase of the permitting and project development process. The site selection study provided the documentation necessary to justify the use of these sites for waste disposal and enabled Homestake Mining Co. to anticipate and integrate environmental concerns with agency requirements into the planning process.

Jan 1, 1986

By M. M., Fine

In a laboratory study of grinding and classification' of silica sand, a satisfactory means of producing the medium-fine specification sand desired by producers of flint-glass containers was developed. The best procedure consisted of ball-mill grinding and double classification, which gave a properly sized sand containing less iron than the feed.

Jan 1, 1950

By Stephen G. Wright

Jan 1, 1985

Discussion of the paper Of JAMES JOHNSTON, presented at the New York meeting, February, 1914, and printed in Bulletin No. 85, January, 1914, pp. 107 to 133. CHAIRMAN E. GIBBON SPILSBURY.-I would like to call attention to the fact shown in this paper that less than five years or perhaps seven years ago nobody had thought it possible to cyanide with success silver ores. The cyaniding of silver and gold ores was first of all started in Mexico, and gradually extended to this country in the case of the silver ores alone. The average extraction, I think, for the metals in Mexico, in the case of the silver ore, is less than 85 per cent., whereas here, in the case of a very complex ore, carrying a high percentage of sulphur and arsenic, and other objectionable elements, the ore has been treated so as to extract an average of 95 per cent. of the silver contents of the ore. It is really a phenomenal revolution in the metallurgy of silver ores which has been demonstrated and worked out at the Nipissing mines. GEORGE A. PACKARD, Boston, Mass.-I would like to suggest a slight modification, perhaps, of the statement which is made that no one considered cyaniding of silver ores up to five, or perhaps seven years ago, because in 1897, when I was at Mercur, Utah, one mill near there was operating on silver ores. It did not operate very successfully from a commercial standpoint, because they did not have a great deal of ore, but the extraction, I was told, was very satisfactory, and I am quite confident that it was, because, as suggested by the name, Chloride Point, the ores were silver chloride ores, and of course very easily soluble. Some years before that, in 1892, I made some tests myself. I spent three months making tests on more or less complex silver sulphide ores at Virginia City, Mont., and while our tests on the plain sulphide ores, finely ground, were quite successful, on account of the presence of a small amount of copper we did not work out a satisfactory solution of the problem at that time; although since then a cyanide plant has been erected and for at least eight years these ores have been treated by cyaniding at Virginia City, and the mill is still in operation. The period of five to seven years should, therefore, be modified considerably, in justice to the pioneers in the cyanide processes. REGINALD E. HORE, Toronto, Ont., Canada.-I hoped that there would be metallurgists from Cobalt here to present and discuss Mr. Johnston's paper. In their absence a few remarks from me may help to make clearer to you what they have accomplished.

Jan 6, 1914