In this process, the waste acid is thermally split into sulfur dioxide and water in a sulfuric acid incinerator.
The process temperature required for this is up to 1,600 °C. Here, too, the critical boundary conditions result from the highly corrosive atmosphere (SO2), possible temperatures under dew point, continuous / discontinuous operation as well as temperature cycling. Furthermore, increased slag formation is to be expected due to impurities in the waste acid (metal salts).
The selection of suitable refractory materials with low open porosity, alkali-resistant raw materials and the use of chemical bonding components are essential here.