摘要 |
<p>A method of peroxide bleaching lignocellulose-containing material for providing a pulp of both high strength and brightness. Increas in strength is provided in a first stage by hyper-alkaline peroxide bleaching known per se, i.e. bleaching carried out at an initial pH of over 12, measured in the bleaching liquid at 24oC before mixing into the pulp. The desired brightness increase is provided in a subsequent stage with or without intermediate washing of the pulp and at a lower initial pH. </p> |