Technology of deep removal of impurities from scandium oxide with the acquisition of high-purity scandium oxide

A new production process for processing off-grade scandium oxide (98%) and scandium oxides 99.0 and 99.9 and the removal of impurities from them with the acquisition of high-purity scandium oxide 99.99% is developed and tested. This process is based on various solubilities of scandium formates and elements of impurities; it involves the dissolution of starting (98-99.8%) Sc(2)O(3) in HCl, the processing of the solution with NH(4)OH to pH = 5-7, filtering and washing the Sc(OH)(3) precipitate with water, repulpation in formic acid, separating the precipitate of scandium formate from the mother liquor, washing scandium formate with formic acid, and drying and calcinating it with the acquisition of Sc(2)O(3) of the OS-99.99 grade.