The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 1976
Filed:
Sep. 18, 1973
Tomijiro Morita, Iwaki, JA;
Isao Funahashi, Iwaki, JA;
Koichi Igarashi, Iwaki, JA;
Masakazu Takaiwa, Iwaki, JA;
Kureha Kagaku Kogyo Kabushiki Kaisha, Tokyo, JA;
Abstract
There is disclosed a method wherein sulfur dioxide contained in combustion exhaust gas is absorbed in an aqueous alkali sulfite solution to produce a corresponding alkali bisulfite and the resultant aqueous alkali bisulfite solution is added with calcium carbonate to form calcium sulfite, the method comprising wet-powdering the calcium carbonate into a particle size within a range of 0.1 - 30 .mu. in a slurry form by the use of a part of a filtrate which is obtained by separating calcium sulfite from the reaction solution, and re-using the remainder of the filtrate as an aqueous alkali sulfite solution for absorbing sulfur dioxide, whereby substantially no waste water is discharged out of the reaction system and sulfur dioxide can be recovered in the form of highly pure calcium sulfite.