The Effect of Polymeric Flocculants on Settling and Filtration of Iron Ore Slimes

Abstract

During the wet processing of iron ores, a substantial amount of fine particles known as slimes are generated in downstream which need to be recovered effectively for their usage and beneficiation. Besides water from slime ponds overflow remains contaminated with very fine particles which are difficult to settle and cause environmental pollution when contaminated water is discharged to the downstream river. The settling behaviour in the slime pond gets affected in particular when ore contains hydrated oxides. The above problems necessiatate to study the settling and filtration behaviour of the slimes by means of effective flocculants. The flocculants namely, amylopectin-g-polyacrylamide (Ap-g-PAM), sodium alginate-g-polyacrylamide (SAG) were synthesized by graft copolymerization using redox initiated catalyst. The high molecular weight flocculants, namely, magnafloc (1011) superfloc (N 300) were used for comparative studies. The present paper reports the settling and filtration behaviour of iron ore slimes. The experiments show that sedimentation rate increases with increasing flocculant dose upto a certain limiting value. The settling rate decreases with increasing the pulp density. The volume of filtrate increases with increasing flocculant dose. The filtration efficiency of synthesized polymer is comparable with the commercial one, i.e., magnafloc (1011) at natural pH.