Journal of Applied Polymer Science, Vol.70, No.13, 2619-2625, 1998
Investigation on flocculation characteristics of polysaccharide-based graft copolymers in coal fines suspension
The article deals with the synthesis of two polysaccharide-based graft copolymers of acrylamide, namely, starch-g-polyacrylamide (St-g-PAM) and amylopecting-polyacrylamide (Ap-g-PAM). Intrinsic viscosity of the graft copolymers was determined. A flocculation jar test was carried out with -200 # ASTM particles for two coking and two noncoking coal samples from Indian coalfields. It is observed that both the grafted products are very effective flocculants in bringing down the turbidity of supernatant liquid of coking coal fines suspension. Though they are effective flocculants in the case of noncoking coal suspension as well, the supernatant turbidity remains somewhat high. Ap-g-PAM performed better than St-g-PAM, which is distinctly apparent in the case of noncoking coal suspension. This may be ascribed to the presence of longer grafted polyacrylamide chains in case of Ap-g-PAM.