| 摘要 |
The present invention provides for improvements in the preparation of chemical cellulosic wood pulp for use in papermaking, and specifically to enhancement of the quality of a kraft pulp which has been subjected to a chlorine dioxide/chlorine bleaching stage and thereafter subjected to ozonation prior to an extraction stage in the bleaching sequence. The improved pulp of the present invention exhibits reduced total organically bound chlorine residues in the wood pulp and adsorbed organic halides (AOX) in the effluent, and has good brightness and viscosity. The advantages of the present invention may be accomplished by means of a bleaching sequence that employs a minimum of stages, namely (D->C)ZED or DcZED with attendant relatively lower capital investment than heretofore possible. |
