A laboratory scale study was made to elucidate the action characteristics of some bleaching oxidants in the multistage bleaching of kraft pulp.
The multistage bleaching practice should not be the simple combination of each bleaching agent. For the better understanding of essential feature of the practice, an attempt was made to divide the bleaching process into two parts. In the first part, the main requisite is the delignification with minimum degrading action on the carbohydrate's frame work, and in the second part the protection of carbohydrate fraction is the most important requisite with effective removal of the residual lignin.
The present experiments were carried out through the above consideration and it was emphasized that chlorine dioxide and hydrogen peroxide have better bleaching properties than other chemicals. Some other suggestions for future works on kraft pulp bleaching were also made to clear the evaluation of each action characteristics.