Microwave Roasting Characteristics of Cuprous Chloride Residue from Zinc Hydrometallurgy

High-efficiency dechlorination processes are crucial for the clean utilization of CuCl waste residue from zinc hydrometallurgical processes. A new method of oxygen-enriched microwave roasting has been proposed to improve the dechlorination process. The cavity perturbation method was used in this paper to measure the permittivity of a CuCl residue at various temperatures and apparent densities. The results show that temperature had a more significant effect on the loss tangent when it exceeded 400 degrees C more than that of apparent densities. The degree of dechlorination of CuCl residue exceeded 93% after 90 min of microwave roasting at 450 degrees C and 150 mL/min oxygen flow, which was 12% higher than that of conventional calcination. The elemental distribution in samples was studied using single-point, linear, and lateral scans at the microscale, and the microstructure and phase changes of the CuCl residue under a microwave field were characterized by XRD and SEM-EDS. This study shows that microwaves can promote the dechlorination reaction by decreasing the activation energy from 52.69 kJ/mol to 42.36 kJ/mol.

Automated summary

A new method of oxygen-enriched microwave roasting has been proposed to improve the dechlorination process of CuCl waste residue. The results show that microwaves can promote the dechlorination reaction by significantly improving the dechlorination efficiency and reducing the activation energy.