Study on the mechanism of froth flotation separation and enrichment of magnesite ore using a novel anionic Gemini surfactant

• Published in: Powder technology Vol. 461; p. 121112
• Main Authors: Ma, Jinpeng, Wu, Jingjie, Chen, Yong, Zhong, Hong, Chen, Xiangping, Huang, Zhiqiang, Burdonov, Aleksandr E., Vchislo, Nadezhda V., Bavuu, Chinzorig, Ouyang, Liaoyuan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31.07.2025
• Subjects: anionic surfactants; chemical reactions; contact angle; density functional theory; Flotation; foams; Fourier transform infrared spectroscopy; Hydrophobicity; Magnesite; Quartz; Separation; sodium; sodium dodecyl sulfate; technology; X-ray photoelectron spectroscopy; zeta potential; Flotation; Separation; SDS; SBDD; Hydrophobicity; XRD; Quartz; Magnesite; NMR; DFT; FTIR; MEP; XPS
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2025.121112

Magnesite is an important source of MgO, which is often used as a refractory. Magnesite is usually associated with quartz, so the foam flotation separation and purification of magnesite 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 magnesite and quartz, and compared with the traditional surfactant sodium dodecyl sulfate (SDS). Micro-flotation experiments show that SBDD can efficiently collect magnesite, where the recovery was increased by 20.5 % at pH = 8 and dosage is 1.5 × 10−4 mol/L than SDS. Contact angle test and Fourier transform infrared (FTIR) analysis show that SBDD selectively adsorbs on the surface of magnesite and significantly enhances the surface hydrophobicity of magnesite. Zeta potential test and X-ray Photoelectron Spectroscopy (XPS) shows that the mechanism of SBDD interaction with magnesite is that the -CHOSO3− group of SBDD forms a cyclochelate with the Mg action site on the surface of magnesite. Density functional theory (DFT) shows that the ∆ELUMO-HOMO value of SBDD (0.148409) is smaller than that of SDS (0.202056), and the CLogP value of SBDD (9.240) is larger than that of SDS (4.521), which indicate that SBDD has strong chemical reactivity and hydrophobicity. [Display omitted] •Gemini collector is expected to improve the recovery of magnesite.•Adsorption mechanism of SBDD on magnesite surface.•Gemini SBDD showed a stronger collecting ability than traditional collector SDS.•The ClogP value of SBDD is higher than that of SDS.