Sodium lignosulfonate as a sustainable depressant for selective lepidolite flotation

作者：Xiaohua Yu, Yanbo Zhong, Youwei Liu, Shuo Guo, Guichun He, Ziyi Liu · 发表于：Results in Engineering · 年份：2025 · DOI：10.1016/j.rineng.2025.108040 · 被引用次数：4 · 研究领域：Minerals Flotation and Separation Techniques、Membrane Separation Technologies、Adsorption and biosorption for pollutant removal

• Sodium lignosulfonate (SLS) acts as a highly selective depressant for gangue minerals (quartz, K-feldspar, muscovite) in lepidolite flotation. • Optimal conditions (pH=6, SLS=120 mg/L, OK-84=80 mg/L) yielded a lepidolite concentrate with 2.89% Li 2 O grade and 80.12% recovery from artificial mixed ore. • DFT calculations revealed stronger adsorption of SLS on gangue minerals (e.g., -290.21 kJ/mol on K-feldspar) than on lepidolite (-150.33 kJ/mol). • Multi-scale analyses (FTIR, zeta potential, contact angle) confirmed chemical adsorption on gangue vs. physical adsorption on lepidolite. • Closed-circuit tests on real ore demonstrated industrial potential, achieving a final concentrate of 3.68% Li 2 O with 81.07% recovery. The flotation separation of lepidolite from its common gangue minerals (muscovite, quartz, and K-feldspar) remains challenging due to their similar surface properties. This study introduces sodium lignosulfonate (SLS) as a novel selective depressant to enhance the separation efficiency in the presence of the anionic-cationic hybrid collector (OK-84), where dodecylamine serves as the cationic component and vegetable oleic acid as the anionic component. Micro-flotation tests showed that sodium lignosulfonate strongly depressed quartz, K-feldspar, and muscovite while minimally affecting lepidolite floatability. Under optimal conditions (pH = 6, sodium lignosulfonate dosage = 120 mg/L, OK-84 = 80 mg/L), artificial mixed ore flotation achieved a lepidolite concen...