Novel process for recycling metallic elements from mixtures of metal oxide wastes and waste polyvinyl chloride

Abstract

A new pyrometallurgical process that involves recycling steel-making dusts and waste PVC simultaneously is proposed. In this work, firstly, a thermodynamic analysis of the proposed reaction process for steel-making dusts + PVC system is performed using the Facility for the Analysis of Chemical Thermodynamics (F*A*C*T) computational system. It is found that the simultaneous chlorination and reduction of ZnO and Fe2O3 in the dusts by PVC and the separation of Zn from Fe under controlled chlorine and oxygen potentials are thermodynamically possible. To testify the results of the thermochemical consideration, thermogravimetry-mass spectrometry (TG-MS) analysis of the reactions in the ZnO/Fe2O3/PVC system is carried out at temperatures up to 950°C. A batch-type reactor experiment is also made to investigate the possibility of the separation of Zn from Fe in ZnO/Fe2O3 mixture by the reactions between the oxides and PVC. The results of the TG-MS and batch type reactor experiments show that recovering zinc and metallic iron from mixtures of ZnO, Fe2O3 and PVC and effective Zn/Fe separation can be achieved.