Preparation of arsenic-antimony from arsenic alkali residue by calcification transformation-carbonthermal reduction

• Published in: Journal of Central South University 2023-07, Vol.30 (7), p.2193-2204
• Main Authors: Yi, Qin, Gong, Ao, Xu, Jia-cong, Wen, Sheng-hui, Xu, Zhi-feng, Tian, Lei
• Format: Article
• Language: English
• Subjects: Antimony; Arsenic; Calcification; Engineering; Hazardous wastes; Metallic Materials; Metallurgy; Reduction; Residues; Separation; Slag; Smelting; Solid wastes; Vacuum distillation
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-023-5379-4

Arsenic alkali residue is a hazardous solid waste typically produced during antimony smelting and its comprehensive utilization is relatively difficult, with problems such as low As and Sb recovery rates, incomplete separation, and risks of secondary pollution. To address these problems, this study develops a novel method to treat arsenic alkali residue obtained from antimony smelting using a calcification transformation-carbothermal reduction process. The thermodynamic results reveal that the calcification transition increases the temperature difference between arsenic and antimony reduction, thus facilitating the separation of arsenic and antimony during the reduction process. Arsenic and antimony in the arsenic alkali residue get calcification rates of 99.67% and 98.74%, respectively, under the optimal conditions. The reduction of calcified slag under vacuum effectively separates arsenic and antimony, and the reduction rate in the calcified slag during the carbothermal reduction process is more than 99%. After the reaction and purification by vacuum distillation, As and Sb purities greater than 99.8% are achieved. Compared with traditional arsenic alkali residue treatment methods, this method can better separate and recover arsenic and antimony with higher purity.