| 摘要 |
<p>2128225 9316226 PCTABS00025 Waste cellulosic paper products, for example, old corrugated containers are recycled employing oxygen delignification in the presence of an alkaline material to produce a recycled pulp of lower kappa number, while maintaining adequate strength in the pulp. The recycling process preferably employs an acid pretreatment in combination with the oxygen delignification, and exposure of the waste product to the alkaline material is preferably controlled so that at any point in the delignification the waste product is exposed to not more than 50 %, by dry weight, of the alkaline material based on the weight of residual lignin in the waste paper product.</p> |
