The recovery of iron is the key step for zinc recycling by electrolysis in zinc hydrometallurgy industry. Iron exists mainly as ferrites in the zinc neutral leaching residue and is difficult to decompose. In this paper, the reductive leaching process using sulfur dioxide was adopted to replace the traditional hot-acid leaching method, and the magnetic seed-assisted iron precipitation was developed. Under the optimum reductive leaching conditions, the initial concentration of sulfuric acid, the temperature and the partial pressure were determined as: 80 g/L H2SO4, 90 degrees C, 200 kPa at the f...
