Elucidating the enhancement of kaolinite flotation by iron content through density functional theory: A study on sodium oleate adsorption efficiency

This study delves into the intricate relationship between iron (Fe) content in kaolinite and its impact on the adsorption behavior of sodium oleate. The effects of different iron concentrations on adsorption energy, hydrogen bond kinetics and adsorption efficiency were studied through simulation and experimental verification. The results show that the presence of iron in the kaolinite structure significantly improves the adsorption capacity of sodium oleate. Kaolinite samples with high iron content have better adsorption properties, lower adsorption energy levels and shorter and stronger hydrogen bonds than pure kaolinite. The optimal concentration of oleic acid ions for achieving maximum adsorption efficiency was identified as 1.2 mmol/L across different kaolinite samples. At this concentration, the adsorption rates and capacities reach their peak, with Fe-enriched kaolinite samples exhibiting notably higher flotation recovery rates. This optimal concentration represents a balance between sufficient oleic acid ion availability for surface interactions and the prevention of self-aggregation phenomena that could hinder adsorption. This study offers promising avenues for optimizing the flotation process in mineral processing applications.