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›› 2002, Vol. 2 ›› Issue (4): 0-0.

• 4 •    

纳米羟基磷灰石粉体的制备和低温烧结

李蔚，高濂   

  1. 中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室，上海 200050
  • 出版日期:2002-08-20 发布日期:2002-08-20

Concentration Polarization of Membrane Absorption Process of Acidic Gases

ZHANG Wei-dong, GAO Jian, SHI Ji-fen   

  1. Beijing University of Chemical Technology, Beijing 100029, China
  • Online:2002-08-20 Published:2002-08-20

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摘要： 对沉淀法制备纳米HAp粉体及低温烧结HAp材料进行了研究. 结果表明：陈化对于防止HAp在高温下分解有重要作用；在陈化前加入一定量的聚乙二醇，可以明显增大纳米HAp粉体的比表面积，降低烧结温度；在普通无压烧结条件下，可在950℃的低温下，获得相对密度达98%左右的HAp材料，致密化温度比商业用粉低数百度. 研究还表明：醇洗不能有效提高纳米HAp的烧结性能.

关键词: 纳米, HAp, 低温烧结

Abstract: A special reaction system was proposed to investigate the mechanism of the mass transfer process in membrane absorption process. The mass transfer resistance of this process was calculated by using hydrophobic PP hollow fiber, for either SO2/air–NaOH system or CO2/air–NaOH system. Different phenomena in these two systems were discussed. Since the reaction mechanism of SO2–NaOH system and CO2–NaOH system is different, SO2 and CO2 mass transfer in solution side is different. The diffusion of different ions and the concentration polarization in liquid phase boundary layer, instead of the ionization effect, was the reason of deviation in SO2 absorption process. The influences of liquid phase velocity and the concentration of absorbent were discussed in this study.

Key words: membrane absorption, mass transfer resistance, boundary layer

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