Search Documents

By W. W. Little

At the United Verde mine the 9-2D stope on the 4050 ft level is located within the north sulphide mass lying some 800 ft north of the main sulphide ore body. In 1948 it was estimated that this block contained 85,000 tons of ore at 4% copper and 9.2% zinc. The north ore body is a lenticular replacement deposit in the black schist, extending from about 100 ft above the 3750 level to a distance below the 4500 level yet to be determined. Although the mineralized zone approaches 1000 ft in length, only 300 ft is of economic importance. In width it varies from a maximum of 60 ft to about 3 ft at the north end, and is characterized by pinching and swelling in the ore zone. One of these larger swells is being mined as the 9-2D stope. Mining costs at greater depth, together with the expected grade of ore after dilution, necessitated a low cost mining method to permit profitable stoping operations. Based on the results obtained in a number of Canadian mines, it was decided to develop the ore body for stoping by the Aldermac or bench method of diamond drill blastholes; however, this plan was subsequently changed and the radial or ring method adopted. Such a method seemed to offer the advantage of large tonnages at low cost, and obviate the necessity of waste fill. This latter point was of particular importance, since the present waste system does not extend below the 3000 level.

Jan 4, 1950

By A. T. Schwennesen

(Wilkes-Barre Meeting, June, 1911.) EVERY engineer has occasion to trace or copy a map, plan, or other drawing on paper too thick for the ordinary way of using tracing-cloth or tracing-paper. When the figure is small and simple a copy may be made by holding the original against a window-pane, covering it with the paper, and tracing direct by the aid of the strong sunlight from outside. The need of utilizing this principle on a larger scale and in a more convenient position led Dr. J. C. Branner to plan the table of which the following is a description: This table was first made in the form of an adjustable glass-top table with a mirror beneath, in 1887, while Dr. Branner was State Geologist of Arkansas. Later it was modified as experience suggested until the form as here described was evolved. The device consists essentially of a drafting-table with a plate-glass top, upon which the original drawing and the paper are laid, and a mirror mounted underneath to reflect the light of the sky up through the drawing. The glass top is hinged and fitted with two arms and thumb-screws, so that it can be raised and fixed to any position, either inclined or horizontal. The mirror is pivoted and revolves about a horizontal axis, so that it may be tilted to any angle. The hood of cardboard or black cloth prevents the reflection of light from the tracing, and may or may not be attached to the table. The apparatus is set up before a window through which part of the unobstructed sky is visible. The mirror is then adjusted like the reflector of a microscope, so that the skylight is reflected up through the drawing. If the mirror can be so located that the direct rays of the sun are reflected through the drawings, thicker paper can be used. The map or drawing may be held in place by clips screwed

May 1, 1911

By Frederick Laist

THE ore from the Butte mines of the Anaconda company is quite siliceous; that is, it contains considerably less iron than is needed for the fluxing of the silica. The direct smelting of this ore, therefore, requires the addition of considerable fluxing material. The only flux available in sufficient quantity at Anaconda is limestone containing no metallic minerals. This necessarily makes the direct smelting of the ore so expensive that it is more profitable to subject the ore to a preliminary treatment by concentration. However, as the losses in the concentrator were very high, compared with the losses in the blast furnaces, it was found, by calculation, more profitable to send ores containing more than a given percentage of copper to the blast furnaces, in spite of the higher costs of treatment. The dividing point was dependent on various factors, the chief of which was the prevailing market price of -copper. It was customary, therefore, to segregate the ore as mined into two classes. Ore in the first class generally contained 5 per cent. or over of copper;: this was sent directly to the blast-furnace department. Second-class ore contained less than 5 per cent. of copper, and averaged around 3 per cent.; it went to the concentrating department. With the introduction of the flotation process, it was found possible to maintain an average recovery, as concentrates, of 96 per cent. At the same time, the cost of reverberatory smelting was very materially decreased by the use of pulverized coal. These two changes in practice made the blast furnaces unable to compete with the reverberatory furnaces on a cost basis. The distinction between first-.and second-class ore was therefore abandoned, and the ore was treated by concentration. Obviously, on ores as high in iron as the Butte ores, the concentrator, produces a product that is self-fluxing; in fact, it is possible to produce a

Jan 1, 1920

By Wm. C. Coffin

THE refractory linings of open-hearth steel furnaces above the bath line are subject to severe wear not only from the heat caused by the combustion of the fuel and the reactions of the bath, but also from the melting action of the gases when not controlled and directed, and from the scouring of the oxides, etc. with which the products of combustion are charged. The framework that encases or binds the furnace is made up primarily of an iron or steel pan in which the furnace proper is built, side and end buckstays, and tie-rods. The expansion and contraction are so great and variable that the bindings may be subjected to severe stresses unless the tie-rods are carefully adjusted in heating up the furnace, but they are most affected by direct heat and usually become deformed from that cause when the lining is worn thin and, sometimes, when sections of the lining fall in and expose some of the framework. A deformed framework displaces the skewback of the roof arch and tends to distort or crush the roof. Bent buckstays deform the front wall, causing the door frames to stand away from the lining so that the gases burn between the lining and the frames, destroying both of them. Frequently the frames are attached to the buckstays; then when the latter bend the frames usually break. Preventing the distortion of the framework and maintaining the economy of the refractories are real factors in the cost of steel making. Not only does the cost of general repairs and reconstruction add directly to the cost of steel produced, but the time lost in making repairs cuts clown the steel production and increases the overhead expense of both the furnace shop and its allied foundry or mills. Many years ago water-cooled equipment applied to iron blast furnaces made it possible to increase greatly not only the size and production of the furnaces but also the life of the lining. It also cut down the loss from frequent repairs. The open-hearth furnace is a much later invention, especially as a commercial factor; for though it dates from the Fred Siemens patent of 1856, much more progress was made in the Bes-

Jan 2, 1919

YEAR OF ELECTION 1913. FRANK DAWSON ADAMS Montreal, Canada. 1935. GUILLAUME DANIEL DELPRAT Melbourne, Vic., Aust. 1920. HENRY STURGIS DRINKER Merion Station, Pa. 1933. KARL EILERS New York, N. Y. 1922. FEDERICO GIOLITTI Trino,Italy. 1906. SIR ROBERT A. HADFIELD London, England. 1921. FRANK WILLIAM HARBORD London, England. 1917. HERBERT HOOVER New York, N. Y. 1931. WALDEMAR LINDGREN Cambridge, Mass. 1921. C. MCDERMID London, England. 1913. EZEQUIEL ORDOAEZ Mexico City, Mexico. 1935. ROBERT PEELE New York, N. Y. 1937. GEORGE S. RICE Washington, D. C. 1911. ROBERT H. RICHARDS Cambridge, Mass. 1934. T. A. RICKARD..... Victoria, B.C., Canada. 1933. ALBERT SAIVEUR CAMBRIDGE, MASS.

Jan 1, 1937

PROF RICHARD ÅKERMAN Stockholm, Sweden DR. FRANK DAWSON ADAMS Montreal, Canada PROF RICHARD BECK Friberg, Germany ANDREW CARNEGIR New York, N.Y. DR. JAMES DOUGLAS New York, N.Y. PROF HATON DE LA GOUPILLIERE Paris, France SIR ROBERT A. HADFEILD London, England PROF HANS HOFFER Leoben, Austria PROF HENRI LOUIS LE CHATELIER Paris France EZEQUIEL ORDONEZ Mexico City, Mexico ALEXANDRE POURCEL Paris, France DR. ROSSITTER W. RAYMOND New York, N.Y. DR. ING H. C. EMIL SCHROEDTER Dusseldorf, Germany JOHN E. STEAD Middlesborugh, England JAMES M. SWANK (Associate) Philadelphia, Pa. PROF DIMITRY CONSTANTIN TSCHERNOFF St Petersburg, Russia PROF TSUNASHIRO WADA Tokyo, Japan CHARLES D WALCOT Washingtion D.C.

Jan 1, 1917

CURRENT MATTERS Page Page New York Meeting : v 27th Engineers xl Year Book, 1918 v Professional Classes War Relief. x1i Minutes of Meeting, Board of W. S. S x1i Directors vi American Engineering Standards xlii President's Report vi Hadfield Prize xlv Local Section News: Members in Military Service... xlviii Columbia xiii Personal li San Francisco xiv Positions Vacant liii New York xvi _ Engineers Available liv Southern California xxxi Forthcoming Meetings 1v United Engineering Society xxxii Library...% lvi Engineering Council xxxv Membership lix Other Societies: Institute Committees lxxviii Mining and Metallurgical Soc- Officers and Directors lxxxvi iety of America xxxix

Jan 3, 1918

YEAR OF ELECTION 1913. FRANK DAWSON ADAMS, Montreal, Canada. 1938. HENRY CORT HAROLD CARPENTER, London England 1933. KARL EIKERS New York, N. Y. 1922. FEDERICO GIOLITTI Torino, Italy. 1906. SIR ROBERT A. HADFIELD London, England. 1921. FRANK WILLIAM HARBORD London, England. 1917. HERBERT HOOVER Washington, D. C. 1931. WALDEMAR LINDGREN Cambridge, Mass. 1921. C. McDERMID London, England. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico. 1935. ROBERT PEELE New York, N. Y. 1938. A.M. PORTEVIN Paris France 1937. JOHN V.W. REYNDERS, New York, N. Y. 1937. GEORGE S. RICE Washington, D. C. 1911. ROBERT H. RICHARDS Cambridge, Mass. 1934. T.A. RICKARD Victoria, B.C., Canada

Jan 1, 1939

[Trans. No,PlaceDate Vol. Page1 1. Wilkes-Barre, Pa*May, '71 13 2, Bethlehem, Pa Aug., '71110 3, Troy, N. Y Nov., '71.. 113 4. Philadelphia, PaFeb,, '72.. 117 5, New York, N, Y.*May, '72,, 120 6. Pittsburgh, Pa Oct,, '72,, 125 7. Boston, Mass Feb,, '73.. 128 8. Philadelphia, Pa,*May, '73., 23 9. Easton, PaOct., '73., 27 10. New York, N, Y Feb., '74,, 211 11. St. Louis, Mo,*May, '74.. 33 12, Hazleton, PaOct., '74., 38 13, New Haven, ConnFeb., '75., 315 14. Dover, N. J,*May, '75.. 43 15, Cleveland, 0Oct,, '75,, 49]

Jan 1, 1928

PROF RICHARD ÅKERMAN Stockholm, Sweden PROF RICHARD BECK Friberg, Germany ANDREW CARNEGIR New York, N.Y. DR. JAMES DOUGLAS New York, N.Y. PROF HATON DE LA GOUPILLIERE Paris, France SIR ROBERT A. HADFEILD London, England PROF HANS HOFFER Leoben, Austria PROF HENRI LOUIS LE CHATELIER Paris France M FLORIS OSMOND Paris, France ALEXANDRE POURCEL Paris, France DR. ROSSITER W. RAYMOND New York, N.Y. PROF ROBERT W. RICHARDS Boston Mass. DR. ING H. C. EMIL SCHROEDTER Dusseldorf, Germany JOHN E. STEAD Middlesborugh, England JAMES M. SWANK (Associate) Philadelphia, Pa. PROF DIMITRY CONSTANTIN TSCHERNOFF St Petersburg, Russia PROF TSUNASHIRO WADA Tokyo, Japan CHARLES D WALCOT Washingtion D.C.

Jan 1, 1917

By N. A. Zeigler

GRaphitization phenomena occurring in solid cast iron have principally been studied from the angle of the reactions taking place during annealing of white castings in the manufacturing of malleable iron. The selected bibliography at the end of this paper presents the high spots of the published information in this field. Graph-itization of gray iron upon reheating has received much less attention, primarily because only on rare occasions is this material subjected to any kind of industrial heat-treating. Moreovcr, articles made from gray iron are seldom used commercially at temperatures when any graphitization can take place. When used in such conditions, it is assumed that the articles can be replaced at frequent intervals, which can be afforded because of the low cost of gray iron. However, there is at least one commercial process in which articles made from gray iron, during their manufacturing processing, are subjectcd to rather high temperatures; that is, manufacturing of cast-iron enamelware, which is glazed at about 1600° to 1700°F. (870' to 930°C.) From practical experience, it has been found that one of the convenient and economical compositions of gray iron suitable for enameling is, in round figures, as follows: Si, 2.50 per cent; Mn, 0.35; S, 0.07; P, 0.80; T.C., 3.35; C.C., 0.70. Since this iron usually is cast into thin-walled sections, the percentage of com- bined carbon in it is relatively high. Upon heating in the enameling furnaces, this combined carbon graphitizes, which causes permanent dimensional changes of the articles. Obviously, from practical considerations, it is desirable to maintain these dimensional changes as constant as possible. In the course of experimentation with this iron, two series of experimental heats were prepared in which the manganese to sulphur ratio of the standard cupola metal was offset by ladle additions of: (I) progressively larger amounts of sulphur, and (2) progressively larger amounts of manganese. Each one of these ladle charges was cast into experimental plates 8 by 4 in. and about 5/16 in. thick. All told, 13 ladle charges were thus treated. All of them are listed in Table I, together with their chemical analyses. It may be noted that the manganese to sulphur ratio in these samples ranges between 1.2 and 30.2. Every one of these compositions was subjected to thermal allalysis, using an automatic, self-recording differential dila-tometer. The specimens used in this instrument are 50 mm. long and 4 mm. in diameter. During the dilatometer cycle they are kept under a vacuum of about 3 microns. Each one of them was subjected to a thermal cycle by heating it to I830°F. (1000°C.) in 3 hr. and cooling to room temperaturc in 5 hr. Figs. I, 2 and 3 present three automatically recorded dilatometer curves for irons: Serial No. I (normal composition), Serial No. 6 (high sulphur), and Serial No. 13 (high manganese). All three of these figures are

Jan 1, 1945

By C. E. SWANN

NOT long ago an engineering study was made to determine if the time had arrived to lower the head of standing water in abandoned Rock Springs mines Nos. I and 3 of The Union Pacific Coal Co. so that this water would not become a menace to the future operations of adjacent mines or mines developed on seams lower in the coal measures. This survey resulted - in a decision to unwater the No. 1 mine workings and, incidentally, the old No. 3 mine workings by drilling a large-diameter hole from the surface to an opening in No. 1 mine at the sump below 21 entry, provided it was found practical to operate a large-capacity, vertical, deep-well pump under the existing conditions. This would relieve the static bead of 200 ft. of water at the fault that separates Rock Springs mines Nos. 1 and 4, which is the

Jan 1, 1935

By AIME AIME

SHORTLY after he started his professional career, the subject of this sketch acquired the sobriquet "Moose" Allen. At the time he was engaged in geological exploration it1 the Canadian wilds. The nickname was given .him because of the wide, straight trail that he broke with unusual speed when going through the bush. Like a moose he was strong, energetic, and determined. To a considerable degree, Rolland Craten Allen today displays the same characteristics in larger affairs-business, civic, and professional. It is his habit to study a problem thoroughly, to decide u11on the best course of action, and then to pursue that course with vigor and

Jan 1, 1936

Jan 1, 1913

Jan 1, 1907

[ ]

Jan 1, 1938

Jan 1, 1912

Jan 1, 1911

Jan 1, 1908

Jan 1, 1910