Zeta potential of inorganic fine particle—Na‐bentonite binder mixture systems

Abstract The zeta potential of single and multi‐inorganic fine particle mixtures (hematite and gangues, i.e., SiO 2 + Al 2 O 3 ) with Na‐bentonite was investigated to understand and properly control the mineral surface properties relevant to pelletization of low‐grade fine iron ores. The zeta potential of hematite‐bentonite mixture showed more negative charge up to 1 wt.% bentonite dosage and became constant. In the multiparticle mixture systems with bentonite, the SiO 2 amount in the system controlled the changes in zeta potential due to its high negative charge (−54.9 mV at natural pH) and the bentonite attachment on its surface based on the electrostatic interaction while Al 2 O 3 had no effect due to its negligible surface charge (−1.6 mV at natural pH). This article reports the new insight into the characterization of surface chemistry of inorganic/mineral mixture systems to understand their surface charge properties in relation to fine mineral particle processing, and to show a direction toward the elucidation of particle dispersion/aggregation mechanism in complex ore systems aiming for their beneficiations.