Method for removing sulfur dioxide in the form of calcium sulfite from combustion exhaust gas

Patent · Tue Nov 02 04:00:00 EST 1976

OSTI ID:7321526

Morita, T; Funahashi, I; Igarashi, K; Takaiwa, M

A method is described in which 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 consists of wet-powdering the calcium carbonate into a particle size within a range of 0.1 to 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 reusing 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.

• Assignee: Kureha Kagaku Kogyo Kabushiki Kaisha
• Patent Number(s): US 3989796
• OSTI ID: 7321526
• Country of Publication: United States
• Language: English

Related Subjects

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500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ABSORPTION
AIR POLLUTION CONTROL
CHALCOGENIDES
CHEMICAL REACTIONS
DESIGN
DESULFURIZATION
DISPERSIONS
EQUIPMENT
EXHAUST GASES
FILTERS
FLUE GAS
GASEOUS WASTES
MIXTURES
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
POLLUTION CONTROL EQUIPMENT
REMOVAL
SLURRIES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SUSPENSIONS
WASTES