Separation of thorium from rare earths with high-performance diphenyl phosphate extractant

In this article, some novel extractants were synthesized for the separation of Th and rare earth (RE). Among the synthesized neutral organophosphorus extractants, n-octyl phosphate diphenyl (ODP) revealed excellent extraction efficiencies and selectivities for Th(IV). Moreover, loading capacity of ODP for Th(IV) (0.015 mol/L) reached 130 mg/L, the loading capacities and speed were higher and faster than those of P507, TBP and C272, respectively. Furthermore, the loaded Th(IV) could be fully stripped by sulfuric acid and hydrochloric acid. The novel extractant ODP has been indicated to be an efficient extractant for the separation of Th, REs and Fe from ion-adsorption type RE minerals, which reveals significances in the fields of resource, environment and energy.