Sustainable Mining and Metallurgy

This paper analyzed the causes for the high iron content in lean cadmium solutions and the fact that such solutions cannot be directly reused in the purification system in zinc hydrometallurgy. Experiment shows the iron in the lean cadmium solution mainly comes from the skim of the supernate.By comparing the iron removal effect of potassium permanganate, manganese ore powder, hydrogen peroxide and other oxidants, potassium permanganate has the best iron removing abilities under the following process parameters: using 1.6 times the theoretical amount of potassium permanganate, with a pH value of around 5 and a reaction time of 1h. The paper also proposed that the integrated utilization process of “lean cadmium solution supernate filtration-oxidation and iron removal-return to purification system”. This process can relieve the pressure caused by the high turnover of leaching liquid, and can achieve the purposes of reducing the zinc content in the slag, improving the zinc recovery rate, and reducing the consumption of zinc powder.