Ion exchange method for the purification of scandium

摘要

A process is disclosed for purifying scandium from an acid solution containing scandium and various impurities. The process involves mixing the acid solution with a chelating resin in the hydrogen form to from a slurry and packing the slurry in a short ion exchange column. The ion exchange column is rinsed with a mineral acid and the scandium is removed by passing diglycolic acid through the column. The diglycolic acid containing scandium is then passed through a chelating resin in the H form. When the scandium concentration in the effluent from the chelating resin reaches a preselected level the effluent of digylcolic acid and scandium is collected. Collection is stopped when the scandium concentration in the eluent falls below a preselected level. This collected eluent is passed through a strong cation exchange column where the scandium is collected. After rinsing the strong cation exchange column with deionized water, the scandium is removed from the column by passing a solution of ammonium nitrate through the strong cation exchange resin. The scandium is precipated from the ammonium nitrate by adding oxalic acid. The precipate of scandium oxalate is collected by filtration and rinsed. The precipate is calcined at approximately 975 DEG C. to form scandium oxide. This process is applicable to the recovery and purification of scandium from any acid soluble matrix.