Performace of a Kind of Organic Emulsion Coated Phosphogypsum Particles

Abstract

The phosphogypsum particles coated with organic emulsion were prepared by coating three kinds of organic emulsion of silicone-acrylic, styrene-acrylic and acrylic. The structure and mineralogical characteristics, acid and alkali resistance, water resistance and dissociation degree of coated phosphogypsum were studied by means of SEM-EDAX, optical microscope, gravimetric analysis and chemical detection. The results showed that the initial emulsion can be used directly for coating and granulation of phosphogypsum. The spray re-coating was carried out by using diluted emulsion with the water-to-emulsion mass ratio of 1:1. The organic emulsion coated phosphogypsum crystal can be clearly observed, and the mixing zone at internal boundary between the organic emulsion and phosphogypsum crystal was distinguishable under the optical microscope. SEM photos showed that the surface of coated phosphogypsum particles was smooth. And the basic elements of C, O, S and Ca can be detected by EDAX. Organic emulsion can be solidified into filmnetwork between the phosphogypsum crystals inside of the coated particles, and it can play a protective role in improving the acid resistance, alkali resistance and water resistance of phosphogypsum, and reduce the degree of dissociation of phosphogypsum in water.

Keywords

organic emulsion / phosphogypsum / coating / particle / resistance to acid and alkali