CHLORINE DIOXIDE PULP BLEACHING PROCESS USING SEQUENTIAL CHLORINE ADDITION

摘要

CHLORINE DIOXIDE PULP BLEACHING PROCESS USING SEQUENTIAL CHLORINE ADDITION A high-efficiency wood pulp bleaching process to produce wood pulps with high brightness and with high levels of chlorine substitution. The process comprises reacting chlorine and chlorine dioxide with wood pulp at a pH of about 7-10 for about 5-40 minutes. Next, the remaining chlorine is added and the mixture brought to a pH of 4 or less, where it is allowed to react for 30 or more minutes to complete the two-step high/low pH sequential chlorine addition bleaching process.