소나무로 제조된 화학열기계펄프의 표백 시가성소다와 수산화마그네슘의 효과 연구

Abstract

The use of a new, technical Mg(OH)2-based bleaching additive was evaluated compared to a NaOH-based additve for peroxide bleaching of CTMP (chemithermomechanical pulp) made from domestic pine, Pinus densiflora . It is well known that NaOH-based bleaching system can cause the dissolution of low-molecular carbohydrates into the bleaching effluents and is responsible for the increased COD load and the formation of a significant amount of anionic trash. It was confirmed that, under the normal condition, the Mg(OH)2- based process generated a brightening effect closed to that of the conventional NaOHbased process at the same peroxide dosage. At a similar brightness level, the Mg(OH)2- based bleaching also produced less anionic trash, lower COD and less residual peroxide in the bleaching effluent. In conclusion, the change of caustic soda to Mg(OH)2 might well prove to be an efficient solution to bleach CTMP from softwood without sacrificing brightness and increasing effluent troubles.