A sustainable green technology for separation and simultaneous recovery of rare earth elements and fluorine in bastnaesite concentrates

The current metallurgical process for the treatment of bastnaesite concentrates was developed when comprehensive utilization of resources and environmental impacts were not important issues. Today, these issues need to be addressed through designing more efficient processes that enable cleaner production and achieve sustainable development. A novel beneficiation-metallurgy combination process mainly comprised of calcification roasting, gravity separation and hydrochloric acid leaching was proposed in this work. Compared with current production process, the new process can reduce the dosage of chemical reagents and energy consumption, and significantly inhibit the generation and emission of fluorine containing wastes. In addition to rare earths, fluorine in the concentrates and the auxiliary calcium can also be effectively recovered, resulting in higher economic benefits. The experimental results show that, under the optimum conditions, the recoveries of rare earths, fluorine and calcium can reach 98.07 wt%, 64.76 wt% and 85.48 wt%, respectively. The new method can make the process and products more sustainable, and is supposed to be suitable for the treatment of bastnaesite concentrates around the world.

Automated summary

The current metallurgical process for bastnaesite concentrates needs to be updated for cleaner and more efficient production. A novel beneficiation-metallurgy combination process is proposed, which can significantly reduce chemical reagent usage and energy consumption, while also inhibiting fluorine waste generation. Recovery rates for rare earths, fluorine, and calcium are high under optimum conditions, indicating economic benefits and sustainability.