Method for preparing dissolving pulp by TCF bleaching of poplar KP

A method for preparing dissolving pulp by TCF bleaching of poplar kraft pulp (KP), said method comprising:

• preparing poplar KP from raw poplar using a pre-hydrolysis kraft process;
• and
• performing OZQP bleaching on the poplar KP to obtain dissolving pulp, wherein O denotes oxygen delignification, Z denotes ozone bleaching, Q denotes chelating treatment, and P denotes hydrogen peroxide bleaching, wherein ozone bleaching step Z comprises:
• placing pulp bleached and concentrated from the O-stage in a reactor, adjusting pH of the pulp to 1.5-3.0 with acetic acid, adding 1.5-3.0% of ozone and 0.3-0.6% of tetrasodium iminodisuccinate (IDS) to obtain a mixture, and subjecting the mixture to a reaction at a temperature of 25-35° C. for 10-30 min while stirring at a speed of 60 revolutions/min;
• removing excess ozone generated during the reaction through a gas outlet into an absorption device filled with KI solution;
• and
• washing the pulp with water to neutral, and adjusting the pulp to a concentration of 8-15%.