Novel technology of resource recovery from reed black liquor

作者：Yang Wei Chun^*; You Xiang Yu; Wang Yun Yan; Zhao Jing; Chai Li Yuan; Shu Yu De

来源：Chinese Journal of Nonferrous Metals, 2012, 22(7): 2109-2115.

• Acidulation
• Black liquor
• Causticization
• Desilication
• FTIR
• Hydroxyl groups
• Paper mill
• Precipitation methods
• Pulp making
• Reed pulp
• Removal rate
• Residual concentrations
• Resource recovery
• Three-dimensional electrode

A novel process was proposed to treat reed black liquor: desilication-acidification-three-dimensional electrolysis-causticization-reuse in pulp making. The precipitation method was used to remove silicon by adding Ca(OH)2. The residual concentration of silicon decreases from 6.68 g/L to 0.12 g/L and the removal rate of silicon is maintained at 98.2%. Lignin was recovered by acidulation-precipitation after the addition of sulfuric acid. The residual concentration of CODCr can be reduced from 220.648 g/L to 54.179 g/L and its removal rate is maintained at 75.45%. 8.5 g lignin was recovered from 100 mL black liquor. Based on the analysis of FTIR, EDX and SEM, it is found that the structure of lignin consists mainly of syringyl monomers and hydroxyl groups, and the lignin particles are not fibrous but granular. The reed pulp black liquor pretreated by acidification method was treated by electrolysis with a three-dimensional electrode reactor. The removal rate of TOC is maintained at 35.57% and the residual concentration of CODCr can be reduced to 36.761 g/L. Then, causticization was adopted to recovery residual alkali from the black liquor, which can be reused in the paper mill. After causticization, the concentration of effective alkali is 8.30 g/L and the causticization rate of the solution is about 78.60%, the residual concentration of CODCr in the black liquor is further reduced to 33.085 g/L and the removal rate of TOC is 9.99%.

• 出版日期2012
• 单位中南大学