Process for treating oxygen delignified pulp using an organic peracid or
salt, complexing agent and peroxide bleach sequence
    2.
    发明授权
    Process for treating oxygen delignified pulp using an organic peracid or salt, complexing agent and peroxide bleach sequence 失效
    使用有机过酸或盐,络合剂和过氧化物漂白剂序列处理氧脱木素的方法

    公开(公告)号:US5785812A

    公开(公告)日:1998-07-28

    申请号:US436243

    申请日:1995-05-17

    摘要: A process for delignifying and bleaching lignocellulose-containing pulp, in which the pulp is delignified with a peracid or a salt thereof, treated with a complexing agent, and subsequently bleached with a chlorine-free bleaching agent. Suitably delignification is carried out with the strongly oxidizing peracetic acid, giving a considerable increase in brightness and a considerable reduction of the kappa number after bleaching with a chlorine-free bleaching agent comprising at least one of a peroxide-containing compound, ozone or sodium dithionite, or optional sequences or mixtures thereof. The brightness increasing effect is highly selective, i.e. the viscosity of the pulp is maintained to a comparatively great extent. Both the delignification and the treatment with a complexing agent are advantageously carried out at a close to neutral pH, thus minimizing the need of pH adjustment and making it possible to use spent bleach liquor internally, e.g. for washing the pulp. By final bleaching with ozone and hydrogen peroxide it is possible to produce softwood pulps having a brightness exceeding 90% ISO, and to remove practically all lignin in the pulp while maintaining sufficient pulp strength.

    摘要翻译: PCT No.PCT / SE93 / 01019 Sec。 371日期1995年5月17日 102(e)日期1995年5月17日PCT 1993年11月25日PCT公布。 第WO94 / 12721号公报 日期1994年6月9日一种用于脱木素纤维素的纸浆脱木素和脱色的方法,其中用络合剂处理纸浆与过酸或其盐脱木质,随后用无氯漂白剂漂白。 用强氧化性过乙酸进行合适的脱木质素,可以显着提高亮度,并且用含有过氧化物的化合物,臭氧或连二亚硫酸钠中的至少一种的无氯漂白剂漂白后显着降低卡伯值 ,或任选的序列或其混合物。 亮度增加效果是高选择性的,即纸浆的粘度保持在较大程度上。 螯合剂的脱木质素和处理都有利地在接近中性pH下进行,从而最小化pH调节的需要,并且可以在内部使用废漂白液,例如, 用于清洗纸浆。 通过用臭氧和过氧化氢进行最终漂白,可以生产亮度超过90%ISO的软木纸浆,并且几乎除去纸浆中的所有木质素,同时保持足够的纸浆强度。