Regulation role of calcium lignosulfonate on the entrainment behavior of serpentine during brucite recycling: A new perspective

The entrainment behavior of fine serpentine seriously deteriorates the recycling efficiency of brucite. In this paper, the effect of calcium lignosulfonate (CLS) on the flotation separation of brucite and serpentine was creatively investigated using a self-made Hallimond apparatus. The experiments revealed that the entrainment rate of fine-grained serpentine decreased from 1.15 to 0.41 with increasing CLS dosage. The pulp viscosity as well as the surface tension analysis, combined with the froth properties investigated using a Foamscan analyzer, confirmed that after CLS addition, the foam generation time increased, while the average bubble diameter gradually decreased, resulting in a decrease in the fluid content of the foam layer as well as the serpentine entrainment rate. Besides, the results were analyzed mechanistically based on Plateau foam structure equilibrium theory. This paper innovatively provides a feasible approach to minimize the content of fine-grained serpentine in brucite concentrate from the perspective of foam entrainment behavior.