| 摘要 |
<p>1507396 Sulphur dioxide from waste sulphuric acid ALLIED CHEMICAL CORP 16 Sept 1976 [20 Nov 1975] 38453/76 Heading C1A Sulphur dioxide is obtained from waste sulphuric acid containing impurities by introducing the waste acid into a pool of molten sulphur maintained at at least 250‹C. to generate a gaseous stream comprising SO 2 , S and H 2 O; cooling to below 160‹C. but above the melting point of S to condense out S, which is returned to the pool; and further cooling to condense out H 2 O. Solid residues from impurities in the acid may be removed from the pool by withdrawing a stream of molten S, removing solids by filtration or sedimentation, and returning the stream to the pool; or a purge stream may be burnt, and the heat evolved may be used for heating the pool; the resulting SO 2 , and that from the main process, may be used for H 2 SO 4 production. The pool may be heated by direct passage of an oxygen-containing gas into the pool to burn some of the S.</p> |
