Removal of zinc(II) and iron(II) from spent hydrochloric acid by means of anionic resins
[ 1 ] Instytut Technologii i Inżynierii Chemicznej, Wydział Technologii Chemicznej, Politechnika Poznańska | [ P ] employee
2005
scientific article
english
- animal feed
- anions
- organic polymers
- regeneration
- solution chemistry
EN Anion exchange removed Zn(II) effectively from a spent hydrochloric acid with the practical exchange capacity of 0.62−0.76 mol/L Zn(II). The main species retained was monovalent ZnCl3- (80−90%) in the case of strongly basic anion exchangers, whereas in the case of weakly basic anion exchanger, its contribution was only 40%. Regeneration with water gave only dilute (15−20 g/L) Zn(II) solution contaminated with Fe(II). Improved regeneration with 6 M HCl and 25% ammonia solution eluted a Zn(II) solution of 42−100 g/L with iron(II) content below 0.1 g/L. Acid retardation provided effective separation of HCl and Fe(II) using the strongly basic Lewatit VP OC 1071. The productivity of the separation column amounted to 50−60 kg/(m3 h) of iron(II) with a reasonable separation factor of Fe(II)/HCl equal to about 10. A new idea of acid retardation mechanism is proposed, in which two Donnan equilibria are considered: normal FeCl2 exclusion and HCl partition due to the membrane potential and salting-out effect.
1004 - 1011
1,504