Review on Separation and Treatment of Thorium Resources

Thorium is frequently the main radioactive element in rare earth ores and is a resource that can potentially substitute for uranium. Thorium must be separated from rare earths in order to obtain products with low radioactivity. There are abundant resources of thorium in the rare earth ores in China, especially in Baiyunebo mixed ores. As an associated element coexisting in rare earth ores, thorium is, or can be, separated from rare earth concentrate, iron concentrate, as well as from waste water and slag to achieve recovery of thorium. The methods of separation include ion exchange resin, liquid-liquid extraction, and liquid-solid extraction. TBP extraction has been the main method applied to separate thorium by domestic and foreign scholars. This paper presents a comparison of different processes for the separation of thorium from rare earth ores, especially Baiyunebo mixed ores, single bastnaesite and monazite ore, and provides suggestions for the future recovery of thorium resources.