公开(公告)号：US06290812B1

公开(公告)日：2001-09-18

申请号：US09652781

申请日：2000-08-31

申请人： Christos Rampotas ,  Viveka Svensson ,  Jonny Hansson ,  Margareta Nilsson

发明人： Christos Rampotas ,  Viveka Svensson ,  Jonny Hansson ,  Margareta Nilsson

IPC分类号： D21C1100

CPC分类号： D21C11/0078 ,  D21C11/0028 ,  Y10S162/08 ,  Y10S210/912 ,  Y10S210/928

摘要： A method treats process water containing metal ions, in connection with bleaching of lignocellulosic pulp. The method is characterized by the steps of a) adjusting the Mg2+ content of the process water to form a flocculating base for metals and an organic substance; b) supplying a carbonate source to the process water to precipiate calcium as calcium carbonate; c) increasing the pH of the process water by adding white liquor to precipipate metals such as metal hydroxides; d) adding a flocculating agent to the process water; and e) separating the precipitated, flocculated metal compounds from the process water by flotation.

摘要翻译： 一种处理含有金属离子的工艺水，与木质纤维素纸浆的漂白有关。 该方法的特征在于以下步骤：a）调节工艺水的Mg2 +含量，形成金属和有机物质的絮凝碱; b）向工艺水中提供碳酸盐源以使碳酸钙沉淀; c）通过向析出的金属如金属氢氧化物中加入白液来提高工艺水的pH值; d）向工艺水中加入絮凝剂; 和e）通过浮选将沉淀的，絮凝的金属化合物与工艺用水分离。

公开(公告)号：US06746568B1

公开(公告)日：2004-06-08

申请号：US09662801

申请日：2000-09-15

申请人： Hans Terelius ,  Anette Olsson ,  Margareta Nilsson ,  Jessica Svensson ,  Christos Rampotas

发明人： Hans Terelius ,  Anette Olsson ,  Margareta Nilsson ,  Jessica Svensson ,  Christos Rampotas

IPC分类号： D21C902

CPC分类号： D21C9/1036 ,  D21C9/163 ,  D21C11/0028 ,  D21C11/0085

摘要： A method in bleaching of pulp is described, in which the pulp is subjected to a peroxide bleaching step, whereupon the pulp is washed and the washing liquid from the washing is separated from the pulp in the form of a filtrate. The method is characterised in that the filtrate is treated with an aluminium compound, such as aluminium sulphate or polyaluminium sulphate, for precipitation of interfering substances, such as oxygen-demanding organic material and metals, that the precipitated material is removed from the filtrate, that the aluminium content of the filtrate after precipitation of interfering substances is adjusted to at most 20 ppm, and that the filtrate is then recirculated to the peroxide bleaching step. By the method, a reduced consumption of hydrogen peroxide in the peroxide bleaching step is achieved.

摘要翻译： 描述了纸浆漂白方法，其中对纸浆进行过氧化物漂白步骤，然后清洗纸浆，将洗涤液中的洗涤液与纸浆以滤液的形式分离。 该方法的特征在于用铝化合物如硫酸铝或聚硫酸铝处理滤液，用于沉淀出需要有机物质和金属的干扰物质，使沉淀物从滤液中除去， 将干燥物质沉淀后的滤液的铝含量调节至至多20ppm，然后将滤液再循环至过氧化物漂白步骤。 通过该方法，可以实现过氧化氢漂白工序中的过氧化氢消耗量的降低。