Flotation separation mechanism of malachite from calcite using the pentyl xanthate as the collector

Calcite is a commonly associated gangue mineral in oxidized copper ore, while the flotation separation of oxidized copper ore from calcite is a bottleneck technology in the utilization of carbonate-type oxidized copper ore. The present study applied the pentyl xanthate (PX) as a collector to efficiently separate malachite and calcite without any other reagents. The flotation results indicate that the PX dosage is a key factor determining the flotation separation results of malachite and calcite. When its dosage reaches 1000 mg/L, the flotation recovery rate of malachite can reach 88.7 %, while calcite is less than 5 %. The flotation test of real ore contained these two minerals further confirmed that the malachite could be separated from calcite using PX as the collector. The mechanism and characterization analysis show that the selective substitution reaction between xanthate ions and OH ions on the malachite surface could generate hydrophobic substances of copper xanthate, which largely improves the hydrophobicity of the malachite surface. This study is expected to provide theoretical and practical assistance for the efficient flotation beneficiation of low-grade marble-type copper oxide ore.