Modified surfactants can regulate their adsorption at the target surface and are essential for various separation applications such as froth flotation. Thioether-containing hydroxamic acid (BTHA) is an excellent oxidized-ore collector with poor dispersibility. Herein, acylamino, which possesses the ability to improve the surfactants' self-assembly and dispersion, was introduced to synthesize N-[6-(hydroxyamino)-6-oxohexyl] benzylthioacetamide (BTAHA); thus, applying it to cassiterite flotation. Surface tension, adsorption capacity, in situ AFM, and surface energy results reveal BTAHA displays strong bubble stability and readily adsorbs onto the mineral's surface, promoting hydrophobic flotation. BTAHA is an effective cassiterite collector and has good separation effects on cassiterite against calcite. It can form Van der Waals forces and five-membered hydroxamate-(O,O)-Sn rings with Sn atoms on cassiterite surfaces via thioether and hydroxamate groups. Meanwhile, the presence of intermolecular hydrogen bond between the amide groups facilitates the self-assembly of the collectors on the cassiterite surface, and has broad industrial application prospects in various separation processes.
Yang Cao,Xian Xie,Xiong Tong,Dongxia Feng,Jinfang Lv,Yumeng Chen,Qiang Song
This paper systematically analyzed the effects of Fe(II) ions on the cassiterite surface to promote the adsorption of salicylhydroxamic acid (SHA). The interaction behavior and mechanisms re investigated using micro-flotation experiments, adsorption experiments, zeta potential measurements, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The micro-flotation tests revealed that the Fe(II) ions had a strong activation effect on the cassiterite, and the recovery reached the maximum at pH values of 7–8. The results of the adsorption experiment showed that the adsorption capacity of SHA on the mineral surface significantly improved after Fe (II) ion activation; this result was confirmed by the zeta potential test. In addition, the zeta potential results indicated that the positively charged Fe species absorbed on the cassiterite surface led to positive changes in the mineral surface potential and an increase in the number of active sites, thereby increasing the SHA adsorption. The XPS and FTIR results demonstrated that the Fe(II) ions activated the cassiterite through the interaction of terminal oxygen atoms with Fe species on the cassiterite surfaces, and redox reactions and displacement reactions occurred between Fe 2+ and Sn 4+ . SHA was chemisorbed on the cassiterite surface, allowing the anions to react readily with the Fe species to form Fe-SHA complexes. Therefore, the Fe(II) ion-activated cassiterite surfaces enhanced the strength and stability of the SHA chemisorption. Based on the results, an adsorption model of the Fe(II) ion-activated cassiterite surface in the SHA system was established.
危险品化学品经营许可证（带存储）