The assessment of zinc precipitation from sulfate solutions using magnesium-rich ores

This study systematically investigates the mechanisms and optimization of zinc precipitation from sulfate solutions using magnesium-containing ores. The dominant reaction pathway leads to the formation of zinc hydroxysulfate (Zn۵(OH)۶(SO۴)۲) at moderate pH (۴–۶.۵), as confirmed by a consistent final pH of ۶.۵ in all experiments. Temperature critically influences reaction kinetics, with ۸۰ °C identified as optimal for maximizing zinc recovery (۷۳.۴ %) and ensuring effective magnesium participation in precipitation reactions. Process efficiency is governed by ore dosage, where ۱۰۰ g/L of magnesium-rich ore yields peak zinc recovery, beyond which marginal improvements occur. Time-dependent studies reveal that ۱۵۰ minutes represents the practical equilibrium for zinc precipitation at ۸۰ °C, achieving ۷۳.۴% recovery with diminishing returns thereafter. Key findings demonstrate that controlled parameters—pH ۶.۵, ۸۰°C, ۱۵۰-min reaction time, and optimized ore dosage—collectively enhance zinc recovery while minimizing reagent consumption and energy costs. Under the optimized conditions (T = ۸۰°C, ore dosage = ۱۰۰ g/l, time = ۱۵۰ minutes), the magnesium content demonstrated a significant reduction from ۷.۰ g to ۵.۱ g, corresponding to an absolute decrease of ۱.۹ g (۲۷.۱% decrement), which clearly indicates effective magnesium participation in the precipitation process, where the combination of elevated temperature and controlled ore dosage synergistically enhanced magnesium removal efficiency while minimizing residual content, ultimately contributing to improved process performance.

کلیدواژه ها:

Zinc precipitation ، Basic zinc sulfate ، Magnesium-rich ore ، Magnesium removal