The effect of flocculants and surfactants on the filtration dewatering of iron ore fines

Abstract

The filtration and separation characteristics of iron ore fines have been investigated. The experimental work included: characterization, evaluation of suitable flocculants to enhance settling and dewatering rate, determination of optimum dosages of flocculants, and influence of surfactants on filtration dewatering of both flocculated and unflocculated iron ore fines by vacuum filtration. The results showed that 1) the settling rate can be enhanced many-fold (from 2.52 to 90 m/h) by a suitable flocculant, 2) the residual filter cake moisture content can be reduced from 18.2% without reagents to 12.6% with suitable surfactant dewatering aids while the filtration rate can be enhanced from 4.8 to 97.2 L/h with suitable dewatering filter aids, and 3) the specific cake resistance to filtration can be brought down from 8.6 x 10(9) to 1.0 x 10(9) m/kg by using a surfactant sodium petroleum sulfonate at a concentration of 1.47 x 10(-3) kg/t. The economics of using flocculant filter aids and surfactant dewatering aids before thermal drying is described and discussed.