A new method of recycling gallium from yellow phosphorus flue dust by vacuum thermal reduction process

Abstract

Gallium is widely used in the field of semiconductors, and is mainly recovered as a by-product from other production processes utilizing metals such as aluminum and zinc. As a waste generated during the production of yellow phosphorus, yellow phosphorus flue dust is a potential resource for recovery of gallium. In this study, vacuum carbothermic reduction technology was applied to extract gallium from yellow phosphorus flue dust. Under the optimal conditions of 1323 K, 40 min holding time, 50 wt% carbon content, and 1−10 Pa, the recovery rate of gallium was 92.5 %. The condensate was analyzed and the enrichment area of gallium in the condensation zone was determined. No hazardous gases and materials were generated during the process. Compared with other methods of recovering gallium from yellow phosphorus flue dust by hydrometallurgical process, this study has the advantages of short process, easy collection of products, low energy consumption. Overall, this work demonstrates a new and environmentally friendly method for the recovery of gallium from yellow phosphorus flue dust, and also provides a reference value for the comprehensive utilization of this material.