A PILOT-PLANT SCALE COMPARISON OF PP AND PRP BRIGHTENING OF LOW-FREENESS CTMP - STEPS ON THE WAY TO MAKING THE PROCESS EASIER

A pilot-plant scale comparison of the PP and PRP sequences was perform ed using a low-freeness CTMP. PRP pulp was brighter and consumed less hydrogen peroxide than pulp treated dth PP for this CTMP, which was pa rticularly difficult to brighten. In contrast, laboratory comparisons indicated that PRP resulted in only small brightness improvements at a slightly higher hydrogen peroxide consumption. The differences betwee n laboratory and pilot plant work were attributed to improved contacti ng between pulp and process chemicals.