KRAFT PULPING WITH ANTHRAQUINONE - LABORATORY AND FULL-SCALE MILL TRIALS

The effects of anthraquinone on alkaline pulping processes in general and kraft pulping in particular are discussed. Results of laboratory trials and of a full-scale mill trial are presented. Anthraquinone may be viewed as a pulping catalyst in alkaline processes, leading to increased rates of delignification under constant conditions. Conditions may be altered to result in reduced alkali requirements, increased pulp production, lower residual lignin levels, or combinations of these effects. When compared with control pulps at constant residual lignin levels, pulps produced in the presence of anthraquinone show substantial yield gains which may also be accompanied by pulp-quality gains.