Recent advances of rhenium separation and enrichment in China: Industrial processes and laboratory trials

China is a major producer of rhenium, which is widely used in aerospace technologies (as superalloy) and petrochemical industries (as catalyst). There is a gap between the demand and fact for the enrichment of rhenium, due to its rather small content (10–9) in the earth’s crust. Also, there is no available single occurrence of mineral rhenium. Instead, the rhenium is associated with either molybdenum or copper (of up to 0.2% in content) as a by-product in metallurgical industry. This makes the separation of rhenium from the major mineral metals a challenge. The recent progresses in the separation and enrichment of rhenium were reviewed in this paper, especially, the advances in China. The details of varied separation methods used either in laboratories or factories, such as ion-exchange, solvent extraction, separation utilizing extractive resins, liquid membrane, or novel materials, etc., were elaborated. Comparison of the different methods was disclosed and an outlook on the rhenium chemistry and industry in the future was brought forward.