Recovery of tantalum from waste of hard alloys production

The main goal of the present work is the development of a technological process for the hydrometallurgical processing of iron-titanium cake with the production of tantalum oxide as an end-product and the development of the individual stages. Various methods of leaching tantalum-containing raw materials have been studied: sulfuric acid and hydrochloric acid processing, alkaline processing followed by sulfuric acid leaching, fluoride-sulfuric acid leaching. The use of a mixture of hydrofluoric and sulfuric acids is the most promising (recovery rate of Ta2O5 is 97.4%) and creates the preconditions for further solvent extraction of tantalum with the selected extractant – octanol-1. A scheme for the selective solvent extraction of tantalum after the leaching of the iron-titanium cake has been developed, the operating conditions of the extraction multistage countercurrent continuous cascade were selected. Samples of tantalum oxide containing Ta2O5 99.8 wt% have been produced by the sedimentation method from the tantalum re-extraction solution formed at the extraction cascade.