NaOH溶液浓度及反应时间对偏高岭土地质聚合反应的影响

摘要

The products of metakaolin (MK) activated by NaOH solutions with different concentration and reaction time were analyzed by means of isothermal conductive calorimetry (ICC),X-ray diffraction (XRD) and Fourier transform infrared (FT-IR).The results showed that when metakaolin was activated by 10 and 12 mol/L NaOH solutions at 40 ℃,the resulted products were Na-A zeolite and geopolymer,respectively.In the early reaction stage,the processes of dissolution,polymerization and reorganization decided the structure order of products and properties.To make sure that the amorphous geopolymeric gels would be formed in the alkali activation sytem,reaction conditions and activator concentration should be controlled to avoid the formation of zeolite.%采用等温量热法(ICC)、X线衍射仪(XRD)及傅里叶变换红外光谱仪(FT-IR),分析偏高岭土经不同浓度NaOH溶液激发后反应不同时间生成的产物.结果表明:40℃下偏高岭土与10和12 mol/L NaOH溶液反应,分别生成Na-A型沸石和硅铝酸钠材料(地质聚合物).地质聚合反应初期涉及溶解、聚合及重排的过程,决定了产物的有序程度及性能.为保证地质聚合物的制备,应控制反应条件及激发剂浓度,避免产物向沸石转变.