Molecular design of flotation collectors: A recent progress

• Published in: Advances in colloid and interface science 2017-08, Vol.246, p.181-195
• Main Authors: Liu, Guangyi, Yang, Xianglin, Zhong, Hong
• Format: Article
• Language: English
• Subjects: Azole-thiones; Density functional theory; Flotation collector; Molecular design; Structure-activity relationship
• ISSN: 0001-8686; 1873-3727
• DOI: 10.1016/j.cis.2017.05.008

The nature of froth flotation is to selectively hydrophobize valuable minerals by collector adsorption so that the hydrophobized mineral particles can attach air bubbles. In recent years, the increasing commercial production of refractory complex ores has been urgent to develop special collectors for enhancing flotation separation efficiency of valuable minerals from these ores. Molecular design methods offer an effective way for understanding the structure-property relationship of flotation collectors and developing new ones. The conditional stability constant (CSC), molecular mechanics (MM), quantitative structure-activity relationship (QSAR), and first-principle theory, especially density functional theory (DFT), have been adopted to build the criteria for designing flotation collectors. Azole-thiones, guanidines, acyl thioureas and thionocarbamates, amide-hydroxamates, and double minerophilic-group surfactants such as Gemini, dithiourea and dithionocarbamate molecules have been recently developed as high-performance collectors. To design hydrophobic groups, the hydrophilic-hydrophobic balance parameters have been extensively used as criteria. The replacement of aryl group with aliphatic group or CC single bond(s) with CC double bond(s), reduction of carbon numbers, introduction of oxygen atom(s) and addition of trisiloxane to the tail terminal have been proved to be useful approaches for adjusting the surface activity of collectors. The role of molecular design of collectors in practical flotation applications was also summarized. Based on the critical review, some comments and prospects for further research on molecular design of flotation collectors were also presented in the paper. [Display omitted] •The CSC of surfactants with metal ions used for design of collectors.•MM selects collectors based on Van der Waals and electrostatic force.•QSAR correlates collector's structures with its flotation performances.•DFT reveals collector's reactivity to design its minerophilic groups.•Log P as criteria to adjust collector's hydrophilic-hydrophobic balance.