ADJUSTMENT OF MN IN MOLTEN IRON

摘要

PURPOSE:To obtain a product of which the Mn value in molten iron is adjusted to a target value by blowing pulverous Mn oxide powder having a specific grain size into the molten iron at such a rate at which the Mn value therein attains nearly the target value then decreasing the residual slag to a specific amt. and executing blowing. CONSTITUTION:The Mn value in the molten iron is so adjusted as to attain a -0.50-+0.25% value with respect to the value of the Mn content of the target product by blowing the pulverous Mn oxide having <=2mm grain size into the molten iron by an injection method. The slag amt. is then decreased to <=30kg/T molten iron and thereafter the blowing is executed and, if neces sary, the Mn oxide or Mn alloy iron is added to the molten steel to adjust the Mn value to the target value. The product Mn value is thus obtd. Calcium chloride is preferably compounded with the molten iron in a >=25% range with respect to the content of the Mn oxide if the Mn oxide to be blown to the molten iron is >=5kg/T molten iron.