| 摘要 |
The raw material is chipped, prepd. for the digester and then digested in alkaline sulphite-sulphide digesting liq. Theis contains 70-400 g sodium sulphite per kg dry wood, 35-110 g sodium sulphide per kg drywood, 20-150 g sodium carbonate per kg dry wood and sufficient sodium hydroxide to raise the pH to 9-13. The delignified fibrous material is then ground 0.05-0.3% Anthraquinone based on the quantity of wood, is added to the digestion liquid to accelerate digestion, reduce the concn. of the digestion chemicals and prevent the formation of thiosulphate. The sodium sulphide is introduced into the liquid as white lye. (Provisional Basic previously advised in Week 8427) |
