Despite being widely used in tailings treatment, polyacrylamide continues to face performance challenges. In this study, two commercial polyacrylamides with different molecular weights were used to flocculate iron ore tailings and their performance was compared with two polymers designed to treat oil sand tailings: poly(vinylbenzyl)trimethylammonium chloride and partially hydrolyzed poly(methyl acrylate) grafted onto ethylene-propylene-diene copolymer backbones. The polyacrylamide with the highest molecular weight performed better than the one with the lowest molecular weight, but its efficiency was still considerably lower than what would be desired for good solid-liquid separation. The new polymer flocculants performed better than the commercially available polyacrylamides but retained high amounts of water in the sediments. This comparison shows that polymers other than polyacrylamide may be used to treat iron ore tailings.
Keywords: dewatering; flocculation; iron ore tailings; polyacrylamide.