Chlorine dioxide is an oxidizing agent for pulp bleaching. The chemical formula of this chlorine dioxide bleach is ClO2. It is a yellowish-green gas, bad odor and liquefied in 11⁰C which is red in color. It is an ECF (elemental chlorine-free) bleaching process which is currently most important bleaching technology in worldwide, especially for sulfate … Read more
Alkaline extraction stage is essential after chlorination bleaching stage is to remove chlorinated and oxidizing lignin products from the pulp. It is also help to reactivate the remaining lignin for the next oxidation stage. All the chlorinated lignins are not soluble in the water. About 40-42% of them are soluble in water and wash out. … Read more
Globally, there are several bleaching sequences are shown in different pulp mills to achieve the bleaching action. Different chemicals are used in each stage usually with washing between two stages to removes products. The preference of bleaching sequences depends on many things such as pulp categories, environment issue, operating cost, product quality of final bleached … Read more