【摘要】 以NaOH—AQ麦草浆为原料,进行了Mg(OH)2替代NaOH用作氧脱木素碱源的研究。对Mg(OH)2不同程度取代NaOH后氧脱木素浆的性能、废液污染负荷以及后续过氧化氢漂白性能进行了探讨。结果表明:Mg(OH)2用作部分或全部氧脱木素碱源,能够完全取代MgSO4及部分NaOH。氧脱木素中使用Mg(OH)2能够提高纸浆得率、黏度和脱木素选择性,降低废液的化学需氧量(COD)。而且,Mg(OH)2作为部分碱源的氧脱木素浆具有较好的后续H2O2可漂性。氧脱木素中使用Mg(OH)2对最终OQP漂白浆的强度没有影响,纸浆的得率和黏度提高,白度随着氧脱木素中Mg(OH)2取代量的增加略有下降。当最终白度为80%ISO时,氧脱木素中Mg(OH)2最大可取代50%的NaOH。更多还原

【Abstract】 Partial substitution of Mg(OH)2 for NaOH as alkali source in oxygen delignification was studied in OQP bleaching of wheat straw NaOH-AQ pulp.The effects on pulp properties and deligni-fication characteristics including delignification ratio,delignification selectivity and chemical oxygen demand(COD) were discussed as well as the subsequent bleachability of delignified pulps.The results show that the application of Mg(OH)2 in oxygen delignification can replace the usage of MgSO4 and part of NaOH.With the increase of Mg(OH)2 substitution ratio,the pulp viscosity,pulp yield and del-ignification selectivity increase,while the delignification ratio,brightness and COD decrease.Oxygen delignification has better subsequent H2O2 bleachability when Mg(OH)2 is used as part of alkali source.The use of Mg(OH)2 in oxygen delignification has no influence on the final strength of OQP bleaching pulp,with the yield and the viscosity of pulp improved.The resulting pulps gave a decreased brightness with the increase of substitution ratio in oxygen delignification.When the final brightness is specified at 10% ISO,the substitution ratio of Mg(OH)2 for NaOH in oxygen delignification can reach 50%.更多还原