Study on the influence of particle size on the flotation separation of kaolinite and quartz

Abstract

The influences of particle size on the flotation separation of kaolinite and quartz was explored by flotation tests of full-size and various sizes, zeta potential analysis. The flotation separation effects of kaolinite and quartz mixed minerals under different conditions were analyzed by calculating the characteristic parameters such as K, R ∞ , Km, SI and SE. Results show that in the sodium oleate scenario, kaolinite has better floatability under neutral conditions, while quartz has better floatability at pH 12. Ca 2+ has little effect on the floatability of kaolinite but it does inhibit the floatability of quartz under acid and weak alkali conditions. As well it can improve the floatability of quartz at a pH 12. In the two mineral flotation separation tests, reverse flotation had better selectivity for coarse-grained minerals. The maximum separation efficiency of the mixed ore with a particle size of 0.125–0.075 mm was 71.88%, the recovery of kaolinite in the concentrate was 84.97%, and the recovery of quartz amounted to 13.10%. It is of great significance to the research on the flotation separation of kaolinite and the high resource utilization of kaolinite. • 0.250–0.030 mm can be separated through positive and reverse flotation. • −0.030 mm fine kaolinite and quartz can't be separated by sodium oleate flotation. • When pH is less than 8, Ca 2+ is conducive to positive flotation separation. • Conforms the first kinetic model, reverse flotation has high separation efficiency.