Structure-activity relationships of oxime compounds as flotation collectors by DFT calculations
(Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
Abstract: The relationships between the structure of oxime compounds (R1R2C=NOH, R1/R2=alkyl groups) with different substituents and their corresponding flotation performances were studied. The analyses of density functional theory (DFT) calculations illustrated that the introduced phenyl group at the R1 position could enhance the acidity, while the heptyl group could effectively increase the hydrophobicity and benefit van der Waals interactions. Meanwhile, the introduced amino group at the R2 position could provide cationic sites to interact with negatively charged surfaces of minerals, while the introduced hydroxyl group could provide additional action sites to form stable chelates with metal ions. Based on the structure-activity relationships, structural optimization was carried out to obtain three efficient collectors, which possessed superior flotation separation performances, proving the effectiveness of the structural modification to oxime compounds in this work.
Key words: oxime compounds; flotation collector; DFT calculations; structure–reactivity relationship; structural modification