Synthesis of a copolymeric system and its flocculation performance for iron ore tailings

The medium grade iron ores contain high ultrafine fractions of soft slime which result in poor dewatering characteristics. Herein, a detailed study was conducted to assess the settling behaviour of iron slimes or tailings using a novel starch-based binary graft copolymeric flocculant (St-g-(pAAm-co-pSS)) and the performance was compared with four commercial reagents. The copolymer has been synthesized by grafting of acrylamide and sodium p-styrene sulfonate on starch using free radical polymerization. The polymer demonstrated outstanding settling behaviour with respect to settling speed and capacity to remove turbidity during iron-ore tailings flocculation as compared to other commercial reagents. An optimal dosage of synthesized reagent has been recommended based on the mud-level index and settling rate, for single-step and multi-step addition to the iron tailings slurry. The synthesized reagent has been assessed upon its capacity to produce clear overflow water and compaction of the solids.