锌铝水滑石的制备及其在制革少铬鞣中的应用

Preparation of ZnAl-LDH and its application in tanning with less chromium

摘要:

本研究通过共沉淀法制备了锌铝水滑石（ZnAl-LDH），采用X-射线衍射仪、傅里叶红外光谱仪和扫描电子显微镜对其结构进行了表征，结果表明：ZnAl-LDH是尺寸在100nm~400nm之间的片状材料。将其配合2%铬粉应用于制革鞣制工艺中，考察了水滑石制备时的金属离子配比、陈化时间对鞣制坯革收缩温度、鞣后废液中的铬含量等的影响。应用结果表明：与单独使用2%铬鞣鞣制坯革相比，当Zn2 与Al3 的摩尔比为2:1，陈化时间为6h时，ZnAl-LDH配合2%铬粉鞣制坯革Ts可由74.2℃提高到94.1℃，废液中的铬含量可由93.64 mg/L降低至46.98mg/L，且加入ZnAl-LDH后鞣制后废液BOD5/COD-Cr显著降低。

Abstract:

This study prepared zinc-aluminum hydrotalcite (ZnAl-LDH) by co-precipitation method. The structure was characterized by x-ray diffractometer, fourier infrared spectrometer and scanning electron microscope. The results showed that: ZnAl-LDH is a flake material with size between 100 nm~400 nm. In this paper, ZnAl-LDH with 2% chrome tanning agent was used in leather tanning process. The effects of ZnAl-LDH metal ion ratio and aging time on shrinkage temperature and chromium content in waste liquor were investigated. The application results show that when the molar ratio of Zn2 to Al3 is 2:1 and the aging time is 6h, the Ts of leather could be increased from 74.2 ℃ to 94.1 ℃, and the chromium content in the waste liquor can be reduced from 93.64 mg / L to 46.98 mg / L, the BOD5/CODCr of the waste liquor could be significantly reduced when ZnAl LDH was added.