Study on Pre-Concentration and Calcium Removal of Low Grade Zinc Oxide Ore

The zinc oxide sample from the Lanping mine located in the west of Yunnan province，China, is characterized with low grade, high calcium content, high oxidation rate and heavy slime. According to the properties of the ore, a new dressing-metallurgy combined method is proposed to process the ore and the beneficiation part is discussed by this paper. Based on the regulation of reagent scheme, flotation flowsheet of pre-desliming and two rougher is conducted to obtain a zinc concentrate that Zn grade is 18.72% at Zn recovery of 90.88%. The calcium removal rate of zinc concentrate reaches to as high as 78.15% for the flotation operation, which could lay the foundation for the next acid leaching process.