Process for removal of sulfur oxides from waste gases
Sulfur oxides are removed from a waste gas containing SO/sub 2/ by: scrubbing the gas with an aqueous slurry containing Mg(OH)/sub 2/ as well as gypsum thereby to transform the SO/sub 2/ into MgSO/sub 3/ and to fix the same in this slurry; oxidizing the MgSO/sub 3/ in this slurry to convert the same into MgSO/sub 4/; filtering the slurry containing an aqueous solution of the MgSO4 thus formed and gypsum thereby to recover the gypsum; and adding Ca(OH)/sub 2/ to the aqueous solution of the MgSO/sub 4/ of the filtrate thereby to convert, by double decomposition reaction, at least the greater part of the MgSO/sub 4/ into Mg(OH)/sub 2/ and, at the same time, the Ca(OH)/sub 2/ into gypsum, the resulting aqueous slurry containing the Mg(OH/sub 2/ thus formed as well as the gypsum being used for the above mentioned scrubbing of the waste gas. The double decomposition reaction in this process is carried out in the presence of seed crystals of gypsum to obtain gypsum of good quality.
- Assignee:
- Kawasaki Jukogyo K K (Japan)
- Patent Number(s):
- US 4193971
- OSTI ID:
- 5724082
- Country of Publication:
- United States
- Language:
- English
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02 PETROLEUM
020800 -- Petroleum-- Waste Management
03 NATURAL GAS
030800 -- Natural Gas-- Environmental Aspects
ALKALINE EARTH METAL COMPOUNDS
AQUEOUS SOLUTIONS
CALCIUM COMPOUNDS
CALCIUM SULFATES
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
DESULFURIZATION
DISPERSIONS
GASEOUS WASTES
GYPSUM
HYDROGEN COMPOUNDS
HYDROXIDES
MAGNESIUM COMPOUNDS
MAGNESIUM HYDROXIDES
MINERALS
MIXTURES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PRODUCTION
REMOVAL
SEPARATION PROCESSES
SLURRIES
SOLUTIONS
SULFATE MINTERALS
SULFATES
SULFUR COMPOUNDS
SULFUR OXIDES
SUSPENSIONS
WASTES