Determining the interaction energy of a quartz–kaolinite system at different pH levels by atomic force microscopy and extended DLVO theory

• Published in: Powder technology 2022-09, Vol.409, p.117842, Article 117842
• Main Authors: Shi, Zhiping, Ran, Bin, Liu, Liyan
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; Extended DLVO theory; Kaolinite; Quartz; Tailings dewatering
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2022.117842

The process of tailing dewatering poses significant challenges because of the presence of fine quartz and clay minerals with complex surface properties and multifaceted interactions. This work aims to determine the interaction energy of fine particles at different pH levels by using atomic force microscopy and the extended DLVO theory to develop separation processes. The results indicated that the interaction force between the quartz and alumina face of kaolinite was attractive at pH 6. According to the extended DLVO calculation, the repulsive energy between quartz and the two surfaces of kaolinite is expected to be low at pH 6, thereby increasing the probability of aggregation. Furthermore, heterocoagulation of quartz and kaolinite in the clay-rich tailings occurred at pH 6, resulting in better dewatering capacity. This fundamental study furthers our understanding of the interactions between fine gangue, and provides a framework to achieve better solid-liquid separation performance for clay-rich tailings. [Display omitted] •Interaction forces between quartz and kaolinite particles were measured using AFM.•The interaction forces between quartz and alumina face of kaolinite were basically attractive at pH 6.•Quartz and kaolinite are more likely to aggregate at acidic conditions.•Electrostatic interaction energy dominated the quartz-kaolinite particle interaction.