Abstract:Extraction performance of polyphosphate (PEMP) on rare earth was studied to find a green metallurgy process of rare earth. Effects of diluent type, initial acidity of aqueous solution, system temperature, and concentration of extractant on extraction of lanthanum were investigated. The results show that extraction process is an exothermic process and has the best extraction of La(Ⅲ) under weakly acidic conditions, thereby avoiding environmental pollution caused by application of neutral extractant with strong acid media. It is beneficial to extract lanthanum with addition of salting-out agent and separate La(Ⅲ) from other rare earth ions at low acidity. Within a certain concentration of La(Ⅲ), it is beneficial to extract La(Ⅲ) when increase of extractant concentration of PEMP, and extraction of La(Ⅲ) is neutral complex mechanism.