制革污泥及其固化块的微观结构研究

Study on the microstructure of the tannery sludge and solidified block

采用扫描电镜-能谱分析(SEM-EDS)对制革污泥及其固化块的微观结构进行研究。结果表明每千克污泥掺加石灰、粉煤灰和煤渣分别为0.12、0.02和0.08kg,经过6、8、10、15、20d自然条件养护后,污泥固化块污泥致密性及抗压强度均随养护时间的增加而增强。污泥固化块经过20d养护后通过5000倍扫描电镜观察,发现污泥固化块内部出现明显的针状结构。污泥固化块的抗压强度主要来源于石灰和活性硅酸盐料(粉煤灰、煤渣)与水反应生成的钙矾石,养护时间的延长也是制革污泥固化块抗压强度增大的主要原因。

The microstructure of the tannery sludge and solidified block was investigated by scanning electron microscope and energy dispersive X-ray spectroscopy（SEM-EDS）.The results showed when mixed lime,fly ash,cinder and the tannery sludge was 0.12,0.02,0.08 and 1.00kg respectively,the compressive strength and compactness of the solidified block was greatly improved when the curing time changed from 6,8,10,15 to 20d.The solidifying agents played a significant role at the later stage.The SEM test also showed that the solidified sludge block exhibited the acicular structure when the curing time was 20d and the magnification was 5000 times.The compactness of the solidified sludge mainly came from the ettringite,which was generated from the chemical reaction of lime,active silicate materials（fly ash and cinder） with water,and the longer curing time also played an important role in improving the compressive strength.