High performance flocculating agent based on partially hydrolysed sodium alginate–g–polyacrylamide

The partial hydrolysis of the sodium alginate–g–polyacrylamide was carried out in alkaline medium. Four grades of partially hydrolysed products were synthesized by varying the reaction parameters. The neutralization equivalent of these products was determined by titrating with standard sodium hydroxide solution. Flocculation characteristics of all the hydrolysed graft copolymers and the unhydrolysed sodium alginate–g–polyacrylamide were determined in 10 wt% iron ore suspensions. The partially hydrolysed product with neutralization equivalent of 2865 gm shows better performance than other partially hydrolysed as well as unhydrolysed products in flocculation. The flocculation performance of the above best performing product was also compared with two commercially available flocculants Rishfloc-440 and Magnafloc-1011, as well as with one flocculant developed in our laboratory (amylopectin–g–polyacrylamide) in 10 wt% iron ore suspension. Here also it was found that the polymer with neutralization equivalent 2865 gm shows better performance than others.