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

摘要

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 1000°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.