Yield of the kraft pulp which is due to the heat treatment of the polysulfide liquid which is formed and by oxidation is improved

摘要

The white liquid which is oxidized is heat-treated, 285 or PS _{ULTRAVIOLET RADIATION} density or are measured with 416nm PS _VIS density, and PS _{UV/PS GR} ratio or the PS _{VIS/PS GR} ratio which are measured with 286nm are raised, density of the active polysulfide in the entire polysulfide is increased with that. As for this active polysulfide, it is possible to utilize for yield increase of the pulp in kraft pulp converting.