BIOSORPTION OF SCANDIUM AND YTTRIUM FROM SOLUTIONS

The usage of biosorbents allows separation of scandium and yttrium fro m each other and from Fe, Al, Ti, Si, and Ca in hydrometallurgical pro cessing of ores and wastes. It was shown that sorption of scandium and yttrium increased with the increase in pH of solution. Initial rate o f scandium sorption depended on the biomass type; however 85-98% of sc andium was sorbed within 10-30 min with most biomass types tested. The presence of aluminum, iron (III), and titanium in the solution inhibi ted sorption of scandium and particularly yttrium. After four cycles o f sorption, 98.8% of scandium and 87% of yttrium was extracted from re d mud leach solution by the biomass of Saccharomyces cerevisiae and As pergillus terreus, respectively. Selectivity of the process of scandiu m and yttrium recovery could be achieved during sorption and also deso rption, when solubilization of sorbed associated elements was inhibite d by high pH values.