Effects of aqueous metal cations on the flotation of fine microcrystalline graphite

This study systematically investigates the effects of aqueous metal cations on the stability, interfacial behavior, and flotation performance of ultrasonically emulsified kerosene in fine microcrystalline graphite flotation. Emulsified kerosene was prepared via ultrasonic emulsification, and the influence of Na+, Mg2+, Ca2+, and Al3+ was evaluated under controlled ionic conditions. The results indicate that aqueous metal cations are associated with changes in emulsion dispersion and collector retention behavior, which may contribute to differences in flotation performance. Compared with the ion-free water system, the presence of metal cations increased the fixed carbon recovery from 17.08% to 37.07% for Na+, 33.92% for Mg2+, 25.74% for Ca2+, and 25.05% for Al3+. The flotation efficiency followed the order Na+ > Mg2+ > Ca2+ > Al3+ > ion-free water. In addition, under the optimum Na+ condition, the total kerosene dosage was reduced from 22,000 g/t to 10,000 g/t while maintaining comparable flotation performance, corresponding to a 54.5% reduction. This work demonstrates that rational regulation of aqueous ionic species is an effective strategy for improving flotation efficiency and reducing reagent consumption in fine graphite processing systems.