Verfahren zur thermischen Spaltung von Abfallschwefelsäuren

SO2 is formed by the thermal decomposition of waste sulphuric acid with the stoichiometric amount of carbonaceous fuel and at least the stoichiometric amount of a free oxygen-containing gas under high turbulence at 650-1000 DEG C., such that the residence time for reactants and products in the combustion zone is less than 1 second. The carbonaceous fuel, e.g. oil, illuminating gas, water gas, lignite dust or organic impurities in the acid, may be mixed with H2SO4 prior to the reaction zone. Liquid sulphur may be used with the carbonaceous fuel, and may be injected in the opposite direction to the acid which may have previously been mixed with the carbonaceous fuel. The waste acid may contain 20-96% H2SO4. An apparatus is described in which the heated acid and carbonaceous fuel are passed through a mixing valve and injected into the combustion chamber with heated air, in opposition to a charge of liquid sulphur if used, and then through heat-exchangers into an electrostatic dust separator to remove inorganic impurities.