Pulp bleaching solution.

摘要

An aqueous sodium borohydride/sodium hydroxide solution for dithionite generation contains sufficient levels of diethylene triamine pentacetic acid pentasodium salt (DTPA Na5) to chelate metals in the dithionite generation process and also in a pulp bleaching process. A preferred solution contains at least 2.5 weight percent DTPA Na5, 8 to 12 weight percent sodium borohydride and at least 30 weight percent sodium hydroxide.