Influence of acidity of solutions on sorption of rhenium and molybdenum on some weakly basic anion exchangers

Abstract

The equilibrium of sorption of rhenium and molybdenum on weak base macroporous and gel anion exchange
resins Purolite A170 and Purolite A172 accordingly in a wide range of concentrations of sulfuric and nitric acids has been
investigated. It has been shown that increasing of the concentration of sulfuric acid from 0,2 to 2 mol/l does not significantly
influence the sorption of rhenium both on the macroporous and the gel anion exchangers and the sorption of molybdenum on
the gel anion exchanger, but also reduces the sorption of molybdenum on the macroporous anion exchanger. The separation
coefficients of rhenium and molybdenum at the sorption on the macroporous anion exchanger at increasing of the
concentration of sulfuric acid increase and at the sorption on the gel anion exchanger reduce. The presence in solutions of
nitric acid leads to a reduction in the ability of macroporous and gel anion exchangers to the sorption of rhenium and
molybdenum, but the distribution coefficients of molybdenum at increasing of the concentration of nitric acid decrease more
significantly than the distribution coefficients of rhenium, and thus the separation coefficients of rhenium and molybdenum
increase. It has been shown that in presence of nitric acid at a concentration of 0,5 mol/l rhenium capacity of anion
exchangers A170 and A172 is by around 2,5 times lower than at the sorption from sulfuric acid solutions in the absence of
nitric acid at the same equilibrium concentrations of rhenium.