Studies on the spent liquor recirculation during soda-amine pulping of jute

Spent liquor of soda-monoethanolamine and soda-ethylenediamine processes were recirculated with white liquor in different proportions and its effect was studied on pulp properties and solid content in spent liquor. Pulp yield, kappa number, and solid contents in spent liquor were increased with increasing spent liquor recirculation. These increases were higher in soda-ethylenediamine process than that in soda-monoethanolamine process. There was not much significant change in strength properties up to 35 per cent of the spent liquor recirculation. The bleachability of the spent liquor recirculated pulp did not change much.