goethite process; ferrite slurries

This paper deals with the problem of waste sludge from the production of zinc chloride in the company Bochemie (Czech republic). This sludge contains a high degree of zinc and a significant amount of dangerous waste is created. Waste sludge was treated under laboratory conditions, using the goethite precipitation process. Precipitation was carried out in a discontinuous as well as in a continuous flow reactor. Both processes proved that the ideal pH was 2.5 and the ideal time of precipitation (?) was 4 hours. The content of zinc in this sediment was 1.4 wt %. Attention was as well paid to using the air as an oxidizing agent and thus substituting potassium permanganate or hydrogen peroxide which are not acceptable from the economic point of view. When oxidizing iron by the air, total oxidation was not achieved in the given time under the existing experimental conditions.