| 摘要 |
<p>PURPOSE: To immobilize sulfur oxides or soot in an absorbent and thereby obtain high-quality gypsum containing a low percentage of impurities by bringing a discharged gas from combustion, without being previously treated for soot and dust removal, into contact with an absorption liquid containing a calcium compound and oxidizing the discharged gas. CONSTITUTION: A discharged gas from combustion containing soot and dust is guided to the inlet part of a storage tower 1, and is brought into contact with an absorption liquid containing a calcium compound which is circulated by a pump 11. Through this vapor liquid contact, sulfur oxides, soot and dust are removed to immobilize them in the absorption liquid by oxidation. In addition, part of the absorption liquid containing a calcium ion is extracted and the extract is supplied to a solid liquid separation device 4 to separate a solid composed mainly of gypsum. On the other hand, a mother liquor is sent to a mother liquor tank 5 and part of the mother liquor is recycled as a supplementary water for the cooling of and removing dust from the discharged gas from combustion at the inlet of the absorption tower 1. Further, the other part of the mother liquor is sent to a slurry tank 3 for slurry production. A cleaning liquid for gypsum cake is also sent to the mother liquor tank 5 and is used likewise.</p> |
