AN EFFECTIVE RESOURCE-SAVING OPTION IN THE SPHERE OF WOOD PROCESSING AND ITS PROCESSING IN THE PULP AND PAPER INDUSTRY

The possibility and expediency of obtaining and bleaching sulfite pulp from young small-sized spruce wood from thinning (thinning) fellings was studied in comparison with ripe wood. In the process of thinning, a significant amount of young small-sized wood is formed, which can serve as a significant reserve of wood raw materials for the production of pulp and paper. Sulfite pulping from young and ripe spruce wood obtained two samples of pulp of different degrees of penetration. Comparative pulp bleachings were carried out according to the traditional economical but effective D/C-EG-G-D-A scheme; For comparison, pulp samples from ripe and young spruce wood were bleached according to the modern ecological scheme Pa-E-Ch1-E-Ch2-A (ECF technology). It is shown that young small-sized spruce wood is delignified by sulfite cooking solution without difficulty, but somewhat more slowly than ripe wood. Sulfite spruce pulp obtained from thinnings is easier to grind and bleach, has higher mechanical strength than from ripe wood. Bleached pulp was obtained from young thin spruce wood by bleaching according to the scheme D/C–EG –G–D–A of pulp from young thin spruce wood, which in all quality indicators meets the standards for grade AK-II (GOST 3914), which is used mainly in the production of "cultural" grades of paper (written and printed). Comparative bleaching of pulp of approximately the same degree of penetration from ripe and young wood using ECF technology using only two oxidative bleaching agents (hydrogen peroxide and chlorine dioxide) significantly increases the efficiency of pulp bleaching in all quality indicators, but the cost of bleaching, in modern conditions, may be will be slightly higher than in the traditional scheme.