Recovery of iron from waste ferrous sulphate by co-precipitation and magnetic separation
(1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. School of Chemistry and Environmental Engineering, Hunan City University, Yiyang 413000, China)
2. School of Chemistry and Environmental Engineering, Hunan City University, Yiyang 413000, China)
Abstract: Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal reaction parameters are proposed as follows: n(CaO)/n(Fe2+) 1.4:1, reaction temperature 80 °C, ferrous ion concentration 0.4 mol/L, and the final mole ratio of Fe3+ to Fe2+ in the reaction solution 1.9-2.1. In magnetic separation process, the effects of milling time and magnetic induction intensity on iron recovery were investigated. Wet milling played an important part in breaking the encapsulated magnetic phases. The results showed that the mixed product was wet-milled for 20 min before magnetic separation, the grade and recovery rate of iron in magnetite concentrate were increased from 51.41% and 84.15% to 62.05% and 85.35%, respectively.
Key words: ferrous sulphate; titanium dioxide; magnetite concentrate; co-precipitation; wet milling; magnetic separation