METHOD FOR RECLAIMING IRON AND PHOSPHORUS FROM STEELMAKING SLAG

摘要

The invention provides a method for recovering (collecting) iron and phosphorus from steelmaking slag, which includes a first step in which phosphorus-containing steelmaking slag such as dephosphorization slag is reduced using a reducing agent containing for example carbon, Si or Al to reduce iron oxide and phosphorus oxide in the slag and to recover them as phosphorus-containing molten iron, a second step in which the steelmaking slag from which the iron oxide and the phosphorus oxide have been removed is used as a CaO source in a sintering step and the resultant sintered ore is recycled to a blast furnace, a third step in which the phosphorus-containing molten iron recovered by the reduction is dephosphorized to a phosphorus concentration in the phosphorus-containing molten iron of not more than 0.1% by mass, thereby phosphorus being concentrated in a CaO-containing flux, and a fourth step in which the phosphorus-containing molten iron dephosphorized to a phosphorus concentration of not more than 0.1% by mass is mixed as an iron source with a blast furnace hot metal. The method thus enables inexpensive recovery of phosphorus and iron from the steelmaking slag, and the phosphorus and the iron recovered are effectively used as resources.