3.5. Artificially mixed minerals flotation Based on the results of microflotation experiments, zeta-potential measurements, and FT-IR and XPS analyses, the artificially mixed minerals flotation experiments were investigated at pH levels of 5.4, 8.4, and 10.7. The results of the artificially mixed minerals flotation experiments are listed in Table 8. The results indicate that the concentrate of TiO2 grade increases from 16.92% to 30.19%, 31.66%, and 21.43% for pH levels of 5.4, 8.4, and 10.7, respectively. Meanwhile, the flotation recovery of the artificially mixed minerals is decreased. Therefore, sodium oleate possesses some selectivity under the artificially mixed minerals flotation condition, and a weakly acidic solution is the appropriate condition for the flotation separation of ilmenite from titanaugite and forsterite. This result is consistent with the results of microflotation experiments.