THE EFFECT OF FLOCCULANTS AND SURFACTANTS ON THE FILTRATION DEWATERING OF IRON-ORE FINES

The filtration and separation characteristics of iron ore fines have b een investigated. The experimental work included: characterization, ev aluation of suitable flocculants to enhance settling and dewatering ra te, determination of optimum dosages of flocculants, and influence of surfactants on filtration dewatering of both flocculated and unfloccul ated iron ore fines by vacuum filtration. The results showed that 1) t he 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 surfacta nt 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 flocculan t filter aids and surfactant dewatering aids before thermal drying is described and discussed.