Herein, the development and application of a high performance polymeric flocculant based on hydroxypropyl methyl cellulose grafted with polyacrylamide (HPMC-g-PAM) is reported. The flocculation characteristics were evaluated in two different synthetic effluents, namely kaolin and iron-ore suspensions using floc size measurement as well as traditional turbidity and settling velocity measurement. The flocculation kinetics demonstrate that it is in good agreement with both aggregation of particle and particle collision models. Moreover, raw mine wastewater was used for further investigation of the flocculation properties of HPMC-g-PAM. Above all, the flocculation experiments suggest that the HPMC-g-PAM based flocculants show better flocculation efficacy in compared to the base polysaccharide. (C) 2013 Elsevier B.V. All rights reserved.