THE INFLUENCE OF HYDROCHLORIC ACID ON THE ZINC EXTRACTION FROM FLUX SKIMMING

Abstract

This paper presents experimental results obtained by agitation leaching of hazardous waste sample – flux skimming. Such flux is formed by Zn(OH)Cl and NH4Cl phases. Distilled water and water solutions of hydrochloric acid were selected as a leaching media.
The aim of this study was to determine optimal conditions of zinc extraction into the solution. The apparent order of reaction with regard to the initial HCl concentration in the leaching solution is n=0.18 in the concentration range from 0.01 mol.dm-3 to 0.25 mol.dm-3. The obtained results also indicate that the temperature does not significantly affect zinc extraction. The value of apparent activation energy was estimated to Ea=3.985 kJ.mol-1. Optimal liquid to solid ratio L:S=80 for both used leaching media was also determined experimentally as well as the stirring rate at 200 rpm.