Probing the selective interaction mechanisms of propyl gallate with diaspore and kaolinite from a microscopic force view

Abstract

The microscopic force between collector and mineral is the fundamental mechanism for selective adsorption of collector on mineral surface. Propyl gallate (PG) is a highly selective collector for the separation of diaspore and kaolinite, and its selective collection performance is better than that of traditional collector sodium oleate (NaOL). The selective interaction mechanisms of PG with diaspore were analyzed using EDLVO theory and AFM analysis in this study. EDLVO calculation results indicate that the electrostatic interaction energy and hydrophobic interaction energy of diaspore particles treated by PG were higher than that of NaOL. AFM results also show that the interaction force between PG and diaspore is greater than that between NaOL and diaspore, confirming the fact that PG had better collection and selectivity than NaOL for diaspore. This work revealed the selective interaction mechanism of PG collector with diaspore other than kaolinite at a molecular level, which would deepen the understanding of the selective flotation of PG for diaspore from kaolinite.