| 摘要 |
<p>Lignocellulose materials for paper production are impregnated with Na2CO3, Na2S solution before treatment with NaOH, Na2S. The high pH (10 reducing to 8-9.5) encourages the formation of NaSH which attacks aldehyde groups. The impregnation is carried out at 100-140 degrees C, Na2S/Na2S + Na2CO3 = 0.2 to 0.4, Na2S/wood = 0.5 to 1.5%. 20-25% less NaOH, Na2S is required in the second stage. 1-2% increased yield of crude paste is obtained and the yield of subsequent bleaching steps is also improved.</p> |
