| 摘要 |
The invention relates to a method of pulping, wherein wood matter is cooked by using white liquor, chemical pulp is separated from resulting black liquor f or further processing, and black liquor is concentrated. The concentrated black liquor from pulping is pyrolyzed in a reducing atmosphere to produce coal dust, and the resulting soda (Na2CO3), hydrogen sulphide (H2S) are recovered for recycling, and the resulting carbon oxisulphide (COS) decomposes to hydrogen sulphide in the recovery of gases, the separated soda is causticize d to NaOH without the presence of Na2S, which is used in the preceding operati on for the absorption of hydrogen sulphide for producing alkaline cooking liquo r (white liquor).
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