METHODS FOR CARBONATE PRETREATMENT AND PULPING OF CELLULOSIC MATERIAL

摘要

A method of pretreating comminuted fibrous material with sodium carbonate and then cooking the pretreated material in the presence of anthraquinone (AQ) is provided. The resulting pulp produced has a higher yield, enhanced strength, and better bleachability compared to pulp produced by prior art methods. AQ may also be introduced to the carbonate pretreatment stage. The method may further include an acid pretreatment providing further enhanced properties to the pulp produced.