EAF dust treatment

Abstract

A process in which a calcining step is used to provide a stable clinker containing the EAF dust. The clinker meets all of the applicable leaching standards. It also appears to be possible to use largely oxidic wastes from other processes, such as zinc electroplating residues, and the largely oxidic residues from refuse fuelled power generators. In this low temperature vitrification process a powder composition containing from 20% to 63% by weight waste material, from 30% to 73% by weight silica, and from 7% to 30% by weight alumina, is wetted to form a homogenous mass. The mass is fired in a furnace for a sufficient time and to a temperature of less than about 1,300.degree. C. to cause vitrification; and the vitrified product is recovered as a fired clinker. The clinker, after crushing, can be used as a road aggregate, in tarmac mixes, or after crushing to a suitably small powder, in the making of bricks and tiles having good abrasion and heat resistance.

Dependencies are inferred from the claim text.