Recovery of Sb and Fe from Sb-bearing Slags through a Reduction Roasting Process with Low Density Polyethylene

Abstract

A novel method for treating the Sb-bearing slag using LDPE as a reductant under N 2 atmosphere is proposed. The H 2 , CH 4 and C 2 (C 2 H 6 , C 2 H 4 , C 2 H 2) are released quickly during the LDPE pyrolysis process, and some of them have escaped off the roasting system before the reaction with the Sb-bearing slag. The Sb, Pb and Fe phases in the original Sb-bearing slag could be selectively reduced to Sb 4 O 6 , Pb and Fe 3 O 4 respectively by the pyrolysis gas at roasting temperature of 1 000°C and LDPE amount of 25 wt%. The Sb 4 O 6 could be separated and recovered effectively with the volatilization rate of 93.51% accompanying the Pb volatilization rate was only around 0.68% and the Fe phase was almost transformed into Fe 3 O 4 retaining in the residue. Then the Fe 3 O 4 can be separated and collected from the roasted residues using magnetic separation process.