Inhibiting heterocoagulation between microcrystalline graphite and quartz by pH modification and sodium hexametaphosphate

Abstract

This paper investigates the heterocoagulation between microcrystalline graphite and quartz particles using the in-situ particle size distribution and zeta potential distribution measurements. It was found that the heterocoagulation was significant at acidic pH but negligible at alkaline pH. Additionally, the heterocoagulation was eliminated by the addition of sodium hexametaphosphate (SHMP). The heterocoagulation mechanism was accounted for by the interparticle force analysis based on the Deyaguin-Landau-Verwey-Overbeek theory. The separation efficiency of the mixture of graphite and quartz was improved when pH was modified to alkaline or sodium hexametaphosphate was added due to the inhibition of heterocoagulation.