In chemical industry:
in the production of hydrosulphites, sulfoxilates, sulphites, bisulphites, thiosulphates, sulphonates, chlorine dioxide and sulphuryl-chloride, sulphitated aethanolamines, chromium basic sulphate, manganese sulphate, phtalic anhydride, caprolactame, acrylonitrile, dye intermediates.
In sugar and wine industries:
as antifermentative, bacteriostatic, antioxidant and preservative.
In food industry:
In the preserving and bleaching treatment of dried and candied fruit, fruit in syrup, citrus fruit, cherries, apples, fruit juices, potatoes, cereals, mushrooms, animal fats and oils.
In the starch production:
In the bee-keeping:
as larvae killer of some parasite species.
In the waste water treatment:
as reductant of metallic ions and as oxidant of sulphides and cyanides.
In drinking water treatment:
in order to remove the excess of chlorine.
In pulp mills:
in wood cooking phase or as bleaching agent.
In metallurgical industry:
- In order to produce a reducing ambient during magnesium casting.
- In the extraction and refining of some metals from their ores.
In pharmaceutical industry:
as antiseptic and disinfectant.
In the petroleum refinery:
as solvent of sulphur-, oxygen- and nitrogen-containing compounds from kerosene and light oils.
In the glass manufacture:
as acidifying agent.
In electric power plants:
for conditioning stack gas to facilitate removal of fly ash.
As a refrigerant:
being easily condensed and possessing a high heat of evaporation, sulphur dioxide is a candidate material for refrigerants.