Application of Monoalkyl Methanephosphonates to Extraction of Selected Metals

Abstract

The distribution of scandium and hafnium between 0.1 or 1.0 mol l-1 HNO3 and solutions of monoalkyl methanephosphonates (HA; alkyl = methyl, propyl, butyl, isobutyl, pentyl, 2-methylbutyl, cyclohexyl, 1,2,2-trimethylpropyl) in chloroform and 1,1,2,2-tetrachloroethane has been studied. The organic solvents mentioned allow to obtain the optimum values of partition coefficients of the two metals. The corresponding extraction constants of the ScA3(HA)x and Hf(NO3)4(HA)4 complexes have been calculated.