. Journal . mber is surmountedby a shaft of brickwork containing tin- ores, fuel, andfluxing materials, which are charged in from the top. Thereduction of the metal at first takes place on the hearthonly, but after a time it extends throughout the whole is kept constantly full. Electric Fining Furnace. — The method of electricdistribution is similar to that described above. The finingfurnace, however, contains only molten metal, togetherwith the substances necessary for completing the elimina-tion of the non-metals, and the surface of the bath is keptat a sufficiently low level to
. Journal . mber is surmountedby a shaft of brickwork containing tin- ores, fuel, andfluxing materials, which are charged in from the top. Thereduction of the metal at first takes place on the hearthonly, but after a time it extends throughout the whole is kept constantly full. Electric Fining Furnace. — The method of electricdistribution is similar to that described above. The finingfurnace, however, contains only molten metal, togetherwith the substances necessary for completing the elimina-tion of the non-metals, and the surface of the bath is keptat a sufficiently low level to allow of samples being takenduring working. A pressure of 50—75 volts for each focusis employed, and it is important to prevent the electrodesfrom coming into contact with the slag. The author concludes by giving a description of thearrangement of an electrical steel works, with finingfurnaces worked in conjunction with reducing furnace- ( seiLigure), It is stated that in a works with an available fori i. of 10,000 on the shaft of the turbines, fiO tons of steelcould he produced per day. viz., 50 tons from the reducingfurnaces working on 55 per cent, ore, and 10 tons from thesmelting of scrap in the fining furnaces. The total cost(exclusive of royalties) of producing 1 ton of ingot steel isestimated at 72s.—80s., taking the cost of 1 kilowatt-year of8,400 hours to be 2/., including amortisation.—A. S. Zinc Extraction; Electrolytic ■. in/ tlie Hoepfner Process. E. Guenther. Eng. and Mining J., 1903, 75, [20], 750—752. The author gives a description of the Hoepfner processfor the extraction of zinc, as successful I \ worked atFuhrfort-a d-Lahn, Germany, from 1895 to 1897. Theraw material used was the cinder from zinciferous pyritesused in the manufacture of sulphuric acid. It containedfrom 10 to 16 per cent, of zinc. It was ground to 1 -5 , mixed with 18—20 per cent, of common salt, androasted in a muffle furnace for 20—22 hours at a tempera-ture not e
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
