Influence of coarse tailings on flocculation settlement

The composition of tailings particles in mines plays a key role in the flocculation settlement of slurries. To study the influence of coarse particle tailings (CPTs) on the flocculation settlement of tailings slurries (TSs), static flocculent settling tests, scanning electron microscopy observations, and laser particle size analyses were conducted using the tailings obtained from a copper mine. The results demonstrate that (i) in the accelerated and free settling process, CPTs did not directly settle at the bottom of graduated cylinders; instead, they were netted by the flocculent structures (FSs) and settled together more quickly. The CPTs accelerate the rapid settlement of TSs; the acceleration effect is more obvious when the CPTs content is greater than 50wt%. (ii) The most appropriate flocculant unit consumption (FUC) is 20 g·t⁻¹, and no substantial increase is observed in the flocculant settling velocity with an increase in the flocculant because the effective FSs did not substantially change and thus did not lead to a notable increase in the settling velocity of the solid–liquid interface (SLI). (iii) In the effective settling space of the thickening facility, free water quickly flowed from the pores of FSs, which is reflected in the period from 0 to 1 min.