Sulphite Pulping Technology

Aeid sulphite pulping was one of the earliest proeesses used for the produetion of ehemieal pulp. Sulphur dioxide is obtained by burning sulphur and absorbing the gas in the desired base, for example sodium earbonate, to give a solution of sulphur dioxide and sodium bisulphite. This is further fortified with vented sulphur dioxide from previous cooks to give a liquor which contains about 5 to 6% sulphur dioxide (H2SO3) and from 1.0 to 1.5% combined sulphur dioxide (Na2S03). 

The aeid sulphite proeess is suited to non-resinous softwoods sueh as spruee, hemloek and fir and to some hardwoods. 

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Lignin, Industrial production. Sulphite pulping, Kraft pulping. Soda pulping, Lignosulphonates, Properties, Applications, Steam explosion, Organosolv technology... 

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