Equilibrium Ultrafiltration of Hydrolyzed Thorium (￥3) Solutions

摘要

The polymeric species formed on the hydrolysis of Th(コ) from solubility experiments of ThO2 in 0.1M NaClO4 and Th(OH)4 in 0.5M NaClO4 were removed by ultrafiltration using 1 nm ultrafilters. The resultant equilibrium concentrations of mono-hydroxy Th(コ) species in solutions between pH 1.5 to 13 were measured by the NAA method. From these data solubility product of thorium dioxide and the stability constants of mono-hydroxy Th(コ) were determined. The values obtained were log Ksp - 50.76 【 0.08, log モ1,1 12.42 【 0.02, log モ1,2 22.46 【 0.15, log モ1,3 34.36 【 0.07, log モ1,4 42.58 【 0.08, which are in good agreement with the values given in the literature. In addition, several dimeric species, Th2(OH)26+, Th2(OH)35+ and Th2(OH)44+ have been identified.