Influence of Two-Stage Dosing on Flocculation and Settlement of Kaolinite and Associated Mechanisms

Abstract

In mineral processing operations, it is essential to effectively remove the fine particles in slime and tailings slurry with appropriate methods. In this study, a unique two-stage flocculation scheme was developed for achieving effective separation of fine kaolinite particles from water by polyacrylamide. The slurry turbidity and flocculation kinetic parameters were used to characterize the effect of the dosing ratio between the first and second stage on the kaolinite flocculation behavior and settling rate. The results showed that the maximum kaolinite settling rate and the minimum turbidity of slurry supernatant was achieved when 60% and 40% polyacrylamide was added in the first and second stage, respectively. Focused beam reflectometer (FBRM) and particle video microscope (PVM) results showed that the flocs formed in the first stage of dosing were large in size but small in fractal dimension and no significant sedimentation was observed. The second stage of dosing produced large size of flocs with large fractal dimension, which settled fast in slurry. Fourier transform infrared spectroscopy (FTIR) results showed that polyacrylamide was mainly adsorbed on the surface of kaolinite by hydrogen bonding and kaolinite particle flocculation was achieved by trapping and coiling of the polymer chain structure. The two-stage dosing process accomplished effective flocculation and rapid settlement of fine kaolinite particles. The findings from this study provide a feasible approach for mining companies to optimize the flocculation and sedimentation of fine particles.

Department(s)

Mining Engineering

Keywords and Phrases

dosing method; flocculation kinetics; kaolinite; Polyacrylamide; turbidity

International Standard Serial Number (ISSN)

1547-7401; 0882-7508

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Taylor and Francis Group; Taylor and Francis, All rights reserved.

Publication Date

01 Jan 2024

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