Abstract: Efficacy for neutral deinking of waste recycled newspaper with laboratory prepared new anionic-nonionic Gemini surfactant was examined.Via orthogonal designed tests,the optimal operating conditions for the neutral deinking process were identified as follows:deinking agent dosage,0.8% (refer to mass of dry waste newspaper):pulping time,3 h;flotation time,30 min;curing time,50 min;curing temperature,50 ℃.The deinking efficacy of the new anionic-nonionic Gemini surfactants was compared separately with that of conventional anionic and nonionic surfactants,and the experimental results showed that the former is better.Meanwhile,the deinking efficacy of the blend of the new anionic-nonionic Gemini surfactant with other surfactants was also examined and the results showed that there is good synergistic effect between the new Gemini surfactant and other surfactants.

Key words: anionic-nonionic Gemini surfactant, neutral deinking, synergistic effect