| 摘要 |
<p>1521893 Sulphur dioxide from waste acid and sulphur HOECHST AG 13 Oct 1975 [12 Oct 1974] 41883/75 Heading CIA Waste sulphuric acid mixtures are decomposed to a product comprising sulphur dioxide by introduction of the waste acid into the hot gases formed by the combustion of sulphur in oxygen or oxygen containing gas containing at least 70 vol. per cent oxygen. The sulphur is preferably combusted in a flame produced by a burner which is fed with liquid sulphur and which ejects liquid sulphur in droplet form and the sulphuric acid mixtures are preferably introduced in droplet form into the generated hot gases. The sulphur is burned in at least the equimolar quantity of oxygen and preferably in the presence of 1 to 1À55 moles of oxygen per mole of sulphur. Any organic impurities which may be present are obtained in the final product as carbon dioxide. Inorganic impurities may be recovered by collection either as a liquid on a coded surface, or as a solid with subsequent remelting. Alternatively the inorganic impurities, metal salts, may be recovered by collection in a salt melt, particularly in molten sodium bisulphate.</p> |
