Preparation of basic zinc carbonate from low-grade zinc oxide ore and zinc-bearing waste rock by acid leaching

Sulfuric acid leaching process for Xin-jiang Zijin low grade zinc oxidized ore and waste rock contained zinc was studied to prepare basic zinc carbonate . About 63% of zinc was extracted under the following conditions: grinding size at 30% passing 74 μm, liquid to solid ratio at 2, sulfuric acid dosage with 52 kg per ton ore, final pH of 1.5~2.0 and leaching time for 2h. As high as 99% of zinc in leaching solution was recovered by the process of pre-neutralization using limestone and precipitation reaction using sodium carbonate with the conditions of pre-neutralization at pH 4.5~5.0 and precipitation reaction at pH around 8.0. The zinc grade of basic zinc carbonate could reach 50%, which could be used as raw material for electrolytic zinc production.