Mechanism of agglomeration and dispersion during flotation process of serpentine and ascharite
(School of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China)
Abstract: During the flotation process with serpentine in the pulp, serpentine is prone to form slime and absorb to the surface of other minerals, leading to decrease of floatability of target minerals. In the process of ascharite flotation, serpentine has significant influence on ascharite recovery. The aggregation and dispersion phenomenon in the pulp, and the mechanism of particles interaction between serpentine and ascharite were investigated based on DLVO theory. The results show that both particle size and pH value of pulp can influence the particles interaction behavior, and the latter is the main influence factor. The basic reason is that the surface charges can be changed by pH values. In different pH value, particles assume different flotation behaviors. At pH of 9.0, aggregation occurs in the same particles of serpentine and ascharite particles, and it also happens between serpentine and ascharite particles; at pH of 11.0, particles interaction is extremely complicated, particles interaction behaviors vary with particles distance. Dispersion occurs while the ascharite particle distance between 2.5 and 12.5 nm. However, while the particle distance of less than 2.5 nm or larger than 12.5 nm, agglomeration is dominated.
Key words: serpentine; ascharite; flotation; agglomeration; dispersion; DLVO theory