Przemysl Chemiczny, Vol.94, No.7, 1086-1094, 2015
Response surface modeling and optimization of process parameters for leaching of zinc oxide ore with ammonia and ammonium bicarbonate solutions followed by flotation
A highly alk. refractory ZnO ore (Zn content 12.22%) was leached with aq. NH3 and NH4HCO3 solns. (concns. up to 3 and up to 4.50 mol/L, resp.) for 2 h using the response surface method. The optimum leaching conditions were detd. (NH3 concn. 2.23 mol/L, NH4HCO3 concn. 2.90 mol/L, leaching time 1.65 h). Under the optimum conditions, the Zn recovery degree was 59.04% (model-predicted value 59.75%). The leaching residues were processed by a closed-circuit flotation to recover ZnS contained. Total Zn recovery degree was 94.29%.