Magnesium oxide was selected to replace ammonia water in ammonium sulfite pulping. When magnesium oxide is used as basic buffer, the indexes of slurry can reach the same level as that of ammonia-water method. Using magnesium oxide as buffer, pulp can be bleached easily, which can promote delignification during steaming, reduce pollutant emission, help to protect environment and reduce cost.
Magnesium oxide can be used in pulp bleaching. Compared with the traditional bleaching process, magnesium oxide can replace caustic soda. At the same time, MGO can improve the viscosity of pulp, maintain the brightness of pulp, and reduce the COD content and production costs. In the process of bleaching pulp with hydrogen peroxide, magnesium oxide can replace caustic soda, reduce the content of iron and manganese ions in pulp, avoid yellowing due to excess iron, and improve the quality of pulp. At the same time, magnesium oxide has a buffer effect, and easy to control the pH value. If with phosphate, silicate and other inorganic complexing agent with the use of better results.
Magnesium oxide can act as wetting agent to improve pulp deinking. The traditional sulfite pulping process improves on the sulfite mixing process, which uses lower-quality wood as raw material to produce pulp that can be used to make newsprint, and The Used Medicament and waste heat can be recycled. This solves many of the ecological and economic problems of traditional sulfite pulping for paper mills.