Study on adsorption mechanism of a novel anionic Gemini surfactant for selective separation of celestite and gypsum by foam flotation

• Published in: Separation and purification technology Vol. 370; p. 133221
• Main Authors: Ma, Jinpeng, Wu, Jingjie, Huang, Zhiqiang, E. Burdonov, Aleksandr, V. Vchislo, Nadezhda, Bavuu, Chinzorig, Wang, Hongling, He, Guichun, Yu, Xinyang, Ouyang, Liaoyuan, Jiao, Qinghao, Ding, Kaiwei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 18.10.2025
• Subjects: Celestite; Flotation; Gypsum; Reaction; Separation; Flotation; Separation; SDS; Gypsum; SBDD; XRD; Reaction; NMR; DFT; FTIR; MEP; XPS; Celestite
• ISSN: 1383-5866
• DOI: 10.1016/j.seppur.2025.133221

[Display omitted] •Gemini collector is expected to improve the recovery of celestite.•Adsorption mechanism of SBDD on celestite surface.•Gemini SBDD showed a stronger collecting ability than traditional collector SDS.•The ClogP value of SBDD is higher than that of SDS. Celestite is mainly used in the manufacture of SrCO3, which is widely used in the production of cathode ray tubes. Celestite is usually associated with gypsum, so the foam flotation separation and purification of celestite is still a difficult subject. Herein a novel Gemini anionic surfactant sodium bis(dodecylethoxy) disulfate (SBDD) was synthesized for the first time for the separation of celestite and gypsum, and compared with the traditional surfactant sodium dodecyl sulfate (SDS). Micro-flotation experiments show that SBDD can efficiently collect celestite, where the recovery was increased by 20.5 % at pH = 8 and dosage is 2 × 10−4 mol/L than SDS. Contact angle test and Fourier transform infrared (FTIR) analysis show that SBDD selectively adsorbs on the surface of celestite and significantly enhances the surface hydrophobicity of celestite. Zeta potential test and X-ray photoelectron spectroscopy (XPS) analysis show that the mechanism of SBDD reaction with celestite is that the −CHOSO3− group of SBDD forms a ring chelate with the Sr site on the surface of the celestite. Density functional theory (DFT) shows that the ΔELUMO-HOMO value of SBDD (0.148409) is smaller than SDS (0.202056), and the CLogP value of SBDD (9.240) is larger than SDS (4.521), which indicate that SBDD has strong chemical reactivity and hydrophobicity.