Ion exchange recovery of zinc from chloride and chloride–sulfate solutions

The present work is focused on sorption recovery of zinc (II) ions from chloride and chloride–sulfate solutions on some commercial anion exchangers with different physical and chemical structures. Initial zinc concentration was 1.0–5.0 mmol/L. HCl concentration in initial solutions was from 0.001 to 4.0 mol/L, whereas chloride–sulfate systems were investigated at molar ratios of HCl:H2SO4 = 1:1; 1:2 and 1:4. Acids concentrations were 0.001 and 2.0 mol/L. It was shown that the anion exchangers investigated possess good sorption and kinetic properties. After ion exchange recovery, zinc was effectively eluted by means of 2 M HCl. The elution results in complete zinc removal from the sorbents investigated and complete purification of solutions from zinc. Based on the data obtained, the anion exchangers Purolite S 985, Purolite A 500 and AM-2B can be recommended for zinc recovery from industrial solutions and waste water.

Research Highlights
► Sorption recovery of Zn from chloride and chloride-sulfate solutions was studied.
► Minor effect of medium acidity on sorption of Zn was observed.
► Sorption mechanism for Zn recovery was proposed.
► Apparent constants of sorption equilibrium and kinetic parameters were calculated.
► Complete desorption of Zn from the resins investigated was achieved.