Transactions of the American Electrochemical Society Volume 24 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1914 Excerpt: ... as an arc furnace throughout the experiments. Two experiments, Nos. 6 and 7, were made in which the furnace was left full and several tappings made during the run. In this way the usual practice of ferrochrome manufacture was followed. Commercial ferrochrome is in grades of from 0.5 to 10 percent carbon, containing 60 to 65 percent chromium. In these experiments the percentage of chromium in the alloy closely approached the theoretical. The percentage of carbon was also lower in these alloys because of the decarburizing effect of the unreduced oxide in the charge above the molten metal. The slag loss of iron and chromium was higher in these runs than in the intermittent experiments because of unreduced oxide getting into it on tapping. A total of 50 pounds of ferrochrome was tapped during the experiments, or an average extraction of 69.5 percent. The average iron content of the slag for all experiments was 13.4 percent FeO (10.4 percent Fe); the average chromium in the slag was 10.3 percent Cr203 (6.6 percent Cr). In the intermittent experiments the average percentages in the slag were 12.1 percent FeO (9.4 percent Fe) and 8.07 percent Cr203 (5.32 percent Cr). Thus, of the loss of 30.5 percent which was not tapped, 11.9 percent was chromium and 18.6 percent was iron, figuring that of the total average loss 39 percent was chromium and 61 percent iron. A large part of the ferrochrome not tapped stuck in the furnace. While the average electrode consumption was 158 pounds per ton of 2,000 pounds, the figure obtained in experiment No. 6 would probably be obtained in practical operation (48.1 pounds). The average power consumption was 3.7 kilowatt hours per pound, or 0.85 kilowatt year per ton. The conclusions drawn are: First, that ferrochrome can be easily man...