PROCESS FOR THE DECARBONIZATION OF HIGH CARBON FERRO MANGANESE

摘要

High carbon ferromanganese or ferrochrome is decarburised by refining using gas envelope nozzles, e.g. with double walls, the molten alloy being super heated before blowing in oxygen to a temp. >100 degrees C above that of the fusion zone. The temp. is further heated by the blowing to 1650-1900 degrees C for ferromanganese and 1750-2000 degrees C for ferrochrome so as to produce a phase of manganese oxide or chromic oxide having a high m.pt.; this oxide phase is subsequently reduced by introducing lime and addn. of solid producing agents such as Si, Al or their alloys. The operation can be effected with improved yield at above the temp. of the molten alloy using much larger charges than in prior art.