Research on fractal and microscopic quantitative characterization of unclassified tailings flocs

In this paper, a series of laboratory investigations are carried out to explore the effect of flocculant type on the spatial morphology and microstructural characteristics of flocs in the flocculation and settling of tailings. Four types of flocculants (ZYZ, JYC-2, ZYD and JYC-1) are considered in this study. The fractal characteristics and internal structure of tailings flocs with different flocculant types and settlement heights are analyzed through scanning electron microscopy (SEM) and X-ray microtomography (μCT) scanning experiments based on fractal theory. Results show that unclassified tailings flocs are irregular clusters with fractal characteristics, and the flocculation effect of flocculants has the following trend: ZYZ > JYC-2 > ZYD > JYC-1. The size and the average gray value of tailings flocs decrease as the settlement height decreases. The average gray values at the top and bottom are 144 and 103, respectively. The settlement height remarkably affects the pore distribution pattern, as revealed in the constructed three-dimensional pore model of tailings flocs. The upper part of the flocs has good penetration, while the bottom part is mostly dispersed pores. The number of pores increases exponentially as the settlement height increases, whereas their size initially increases and then decreases as settlement height increases.