PRELIMINARY-STUDY OF TREATMENT OF SULFURIC PICKLING WATER WASTE FROM STEELMAKING BY BIOOXIDATION WITH THIOBACILLUS-FERROOXIDANS

This report looks at the laboratory-scale recovery of iron oxides (alpha Fe2O3 type) through bio-oxidation with Thiobacillus ferrooxidans of the ferrous sulphate contained in steel industry sulphuric pickling liquors. This is done by calcining iron sulphates and iron and ammonium sulphates obtained from the crystallization of the oxidized solution. The products of the bacterial reaction and the iron oxides are then studied according to calcination temperature. The process carried out produced 50 kg of alpha Fe2O3 per m(3) of waste pickling liquor at 700 degrees C with 99.8% weight iron recovery.