Process Improvement Change Over to Caustic Lye from Lime for Sulphur Neutralisation

摘要

All sulphur based sulphuric acid plants use elemental sulphur to produce SO2 gas which in subsequent steps is converted to SO3 and then absorbed in cone. H2SO4. Elemental sulphur has about 1000 ppm acidity, which needs to be minimized by neutralization to acceptable levels. As common industrial practice this is achieved by adding Lime Powder to the molten sulphur and filtering out clean sulphur. For a plant capacity of 700MTPD Sulphuric Acid (SA) plant the sulphur sludge generated from melter section will be around 2000kg/day Considering environmental safety, safe disposal of sludge is a challenge in sulphuric acid production plants. There is a cost effective alternative which has not only reduced sludge generation but also improved safety by eliminating problems associated with lime handling. The article describes the newly adopted and stabilised method to neutralize sulphur.