| 摘要 |
<p num="1"><br/><br/><br/>Impregnating or spraying softwood chips in a solution containing an <br/>appropriate concentration of alkaline earth <br/>metal ions selected from the group consisting of calcium ions, barium ions and <br/>strontium, preferably calcium ions, at room temperature <br/>before a reductive alkaline pulping process, for example kraft pulping, <br/>significantly increases pulp yield. Using an agent <br/>that complexes with the metal ions, such as hydroxyethylidene diphosphonic <br/>acid (HEDP) allows this benefit of metal ions to be <br/>achieved during the pulping process rather than in a separate impregnation <br/>step.<br/>
|
