Hydrogen Peroxide and Related Chemical Additives in Deinking Processes, 1992 Pulping Conference Proceedings

The increasing requirement for high quality printing paper consisting partially or entirely of secondary fibers, along with environmental pressure to use as low levels of chemicals as possible, have motivated a search for the optimum use of chemicals in a deinking line. An examination was made of the role of each chemical in the different stages of the deinking processes. A clear distinction was drawn between pulping chemistry and bleaching chemistry; i.e., although some chemicals are used in both pulping and post-bleaching, their effects on the operation in question can be totally different. In particular, the optimum point of introduction of hydrogen peroxide was investigated. Special attention was given to the interaction between the chemicals and to the different actions of the chemicals in the presence and in the absence of ink.

In addition to studies of deinking chemistry, work was done on the refinement of measurement techniques used for the evaluation of different aspects of recycling.