METHOD OF RECYCLING ZINC-CONTAINING CONVERTER DUST

摘要

A method comprising: a first step in which coarse particles are separated from a converter dust recovered with a wet type dust collector to obtain a zinc-containing fine-particle dust having a zinc content of 0.5-10 mass% and an iron content of 50-90 mass%; a second step in which the dust is separated by a water cyclone (15) into a low-zinc-content medium-fine-particle dust having an average particle diameter of 8-25 µm and a zinc content of 1 mass% or lower and a high-zinc-content microfine-particle dust having an average particle diameter of 1-5 µm and a zinc content higher than 1 mass% and containing more iron oxide than the medium-fine-particle dust; a third step in which the medium-fine-particle dust, without undergoing a zinc elimination treatment, is mixed with a binder and pressed to form a mass for use as a converter feed material or electric-furnace feed material; and a fourth step in which the microfine-particle dust is dried and subsequently subjected to a zinc elimination treatment and the resultant dust is used as it is as a blast-furnace feed material or is converted to a mass for use as a converter feed material.