Hydrometalurgická separace zinku ze železité sraženiny

Abstract

This thesis deals with comparing two different methods of counter-current leaching of zinc from iron sludge (decantation and filtration). This sludge has been precipitated by chloride-goethite method from the waste de-zinc baths. Sludge containing residues of ZnO has been leached in HCl and straight after ZnCl2 has been separated by this method. In order to accurately follow separation method processes we used mathematical models, which allowed us to detect a concentration of Zn2+ in the final (output) solution in each cycle. For this experiment 10g of sludge, 24ml of 0,75M HCl and 50ml/25ml of wash water were used during filtration/decantation. This experiment showed that the decantation efficiency was lower (66%) than the math. model one (77%) and that the Zn2+ concentration in the final (output) solution was 49.9 g.dm-3. Contrariwise the filtration efficiency turned up to be almost the same as the math. model one. In number it was 99% and the Zn2+ concentration in the final (output) solution was 44,7 g.dm-3. The final Zn2+ concentration depends on used amount of wash water and so while using decantation the concentration is higher than when using filtration.