Impact of acid surface pretreatment on the aggregation and flotation behavior of micro-fine ilmenite and its functional mechanism

Abstract

Acid surface pretreatment was demonstrated as an effective method to enhance the floatability of ilmenite and promote selective collector adsorption on ilmenite versus gangue mineral surfaces. This study systematically investigated its role in improving the in-phase aggregation of micro-fine ilmenite particles. Microflotation experiment showed that the acid surface pretreatment enhanced the flotation recovery of micro-fine ilmenite and its combination with −45 +19 μm particle sizes from below 50 % to over 80 %. Turbidity, optical microscope, and laser particle size analyses confirmed that the acid surface pretreatment strengthened the original aggregation of micro-fine ilmenite within a pH range of 5.0 to 8.0. Atomic Force Microscope and E-DLVO theory analyses proved that the acid surface pretreatment primarily focused on reducing the surface hydrophilicity of micro-fine ilmenite. This reduction weakened the hydration interaction repulsion force between particles, leading to an increase in the total interaction attractive force, reinforcing the aggregation of micro-fine ilmenite. Micro-fine ilmenite treated with acid surface pretreatment easily absorbed on the in-phase ilmenite surfaces, facilitating the collection of micro-fine ilmenite with collectors. Taken together, the acid surface pretreatment is a potential method to strengthen the flotation recycling of micro-fine ilmenite.