Recovery of magnetite from waste ferrous sulfate using polyethylene glycol (PEG) as a dispersant
(1. School of Materials and Chemical Engineering, Hunan City University, Yiyang 413000, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China)
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract: The effect of PEG dispersant on the magnetic separation of magnetite (Fe3O4) synthesized from ferrous sulfate solution via co-precipitation method with calcium hydroxide as the precipitant was investigated. The results indicated that a PEG dispersant could significantly affect Fe3O4 recovery. Adding PEG during the preparation of Fe3O4 was unfavorable for Fe3O4 recovery. When the PEG-6000 concentration was increased from 0 to 8 g/L, the iron grade and median particle size of the Fe3O4 product decreased from 65.58% and 2.35 μm to 57.79% and 1.35 μm, respectively. However, adding PEG during the wet milling of the mixed product promoted the subsequent recovery of Fe3O4. When the amount of PEG-200 increased from 0% to 4% of the powder mass, the grade of iron in the Fe3O4 product increased from 65.58% to 68.32%. While the relative molecular mass of PEG at an amount of 4% of the powder mass increased from 200 to 20000, the grade of iron was reduced from 68.32% to 66.70%.
Key words: ferrous sulfate; Fe3O4; PEG; co-precipitation; magnetic separation; wet milling