RICE STRAW SCMP PRODUCTION WITH RECYCLED SPENT LIQUOR AND ITS USE IN CORRUGATING MEDIUM MANUFACTURE

摘要

Rice straw SCMP was produced with recycled cooking spent liquor and used for corrugating medium manufacture in laboratory. Sulfonation was optimized as follows: liquor ratio 1: 6, Na_2SO_3 charge 14%,Na_2CO_3 charge 2 %, sulfonation 70 min from 40°C to max. temp. 130°C ,retention time 40 min at 130°C. The cooking spent liquor was recycled for the next cook with the recycling of spent liquor for digestion. Tt was found that pulp yield increased about 3% and Kappa No. went up 2 points. The recycled spent liquor was found to contain 70% total dissolved solids. SCMP was processed in a GNM-300 refiner with a gap 0. 5mm for the first throughput and then 0. 2mm gap for a secondary throughput and also in a PFI mill at 10% stock consistency. The breaking length of the SCMP handsheet dropped from 3600m to 3400m but ring crush compression index remained about 10N·m/g at 40～46°SR after five recyclings. The Na_2SO_3 charge was reduced from 14% to 11% and the cooking wash liquor was discharged at 5. 9°Be.