| 摘要 |
Bleaching of fibrous cellulosic materials (esp. Kraft pulp) is carried out in the absence of dissolved organic materials in 2 stages without intermediate washing, by (1) treating with an aq. soln. contg. ClO2 and Cl2, and (2) treating with an aq. soln. contg. Cl2. The amt. of ClO2 used corresponds to 20-90% (pref. 30-75%) of the total available chlorine (TAC) used in steps (1) and (2), and the amt. of Cl2 used in step (1) corresponds to 6-10% (pref. 7-8%) of the TAC used in step (1). Process gives a bleached pulp with better delignification characteristics than similar processes in which all of the ClO2 and Cl2 is used in a single stage or all of the ClO2 is used in the 1st stage and all of the Cl2 is used in the 2nd stage. |
