Interactions between bubble and particles of key minerals of diasporic bauxite through the extended DLVO theory

The flotation of diasporic bauxite is to separate diaspore (valuable mineral) from aluminosilicate minerals (gangue minerals, mainly including kaolinite, illite and pyrophyllite), and the microscopic interaction force between the two types of minerals and air bubbles determines the separation efficiency. In this paper, based on the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the van der Waals, electrostatic and hydrophobic interaction between particles of the four minerals mentioned above and air bubbles in collectorless solution were calculated first, and then diaspore and kaolinite were taken as examples to analyze the influence of various factors such as electrolyte concentration, mineral particle size, air bubble size, collector type (dodecylamine hydrochloride (DAH) and sodium oleate (NaOL)) and concentration, and pulp pH on the interactions between the particles of valuable mineral and gangue minerals and air bubbles. The results showed that the total extended DLVO interactions between the four minerals and air bubbles were repulsive in most cases in collectorless solution. The increase in electrolyte concentration reduced the interaction force or even changed the direction of the force under certain circumstances. The addition of DAH and NaOL can reduce the adhesion energy barrier of kaolinitebubble and diaspore-bubble respectively. Each type of minerals exhibited a specific interface interaction response with air bubbles in each collector with different pH values. The research results have theoretical guiding significance for the optimization and directional control of diasporic bauxite flotation conditions. (C) 2021 Published by Elsevier B.V. on behalf of China University of Mining & Technology.

Automated summary

In this paper, the interaction forces between diasporic bauxite minerals (diaspore and aluminosilicate minerals) and air bubbles were investigated using the extended DLVO theory. The results showed that the interactions were mainly repulsive in collectorless solution, and the electrolyte concentration had a significant influence on the interaction forces. The addition of collector reduced the adhesion energy barriers between the minerals and bubbles. Each mineral exhibited a specific interface interaction response with the bubbles under different collector types and pH values.