Sustainable recovery of titanium from secondary resources: A review

The exploitation and utilization of secondary resources have the social benefits of saving resources, reducing pollution, and reducing production costs. Currently, less than 20% of titanium secondary resources can be recycled, and there are few reviews on titanium secondary resources recovery, which cannot fully reveal the technical information and progress of titanium secondary resources recovery. This work presents the current global distribution of titanium resources and market supply and demand, then focuses on an overview of technical studies on titanium extraction from different titanium-bearing secondary slags. The following types of titanium secondary resources are mainly available: sponge titanium production, the production of titanium ingot, titanium dioxide production, red mud, titanium-bearing blast furnace slag, spent SCR catalyst, and lithium titanate waste. The various methods of secondary resource recovery are compared, including the advantages and disadvantages, and the future development direction of the titanium recycling process is pointed out. On the one hand, recycling companies can classify and recover each type of residual waste according to its characteristics. On the other hand, solvent extraction technology can be the direction of attention due to the increased requirement for the purity of recovered materials. Meanwhile, the attention to lithium titanate waste recycling should also be enhanced.