粉煤灰研磨过程中铝氧多面体结构变化的核磁共振研究

NMR RESEARCH ON ALUMINIUM-OXIDE POLYHEDRON STRUCTURE OF FLY ASH IN GRINDING PROCESSING

采用核磁共振 (NMR)技术和SEM方法 ,对机械研磨的粉煤灰中铝氧多面体结构的变化进行了研究。研究发现 :在粉煤灰研磨过程中 ,粉煤灰中的铝氧多面体结构发生明显的变化 ,原先的 6配位网络不对称大分子结构在机械力的作用下发生键断裂 ,向 6配位铝氧多面体对称小分子结构转变 ;4配位的铝氧多面体网络不对称大分子结构变化不明显。当经过长时间研磨后 ,所谓粉煤灰颗粒发生的变化 ,从NMR谱图得出的解释是 :裂解的 6配位铝氧多面体对称小分子结构重新向 6配位铝氧多面体不对称网络结构再转变的过程 ,机械研磨导致这种可逆变化。粉煤灰研磨过程中 ,水介质的氢键作用强于机械力作用 。

The aluminium-oxide stereo polyhedron structures changes were studied by NMR and SEM in fly ash treated by mechanical grinding. The results show that the original aluminium-oxide stereo structures of fly ash are changed evidently in grinding processes. The original octahedral AlO 6 polymeric dissymmetry structure in fly ash is broken down to small symmetry molecular by the mechanical force. At the same time, tetrahedral AlO 4 dissymmetry polymeric structure in fly ash is stable. According to the NMR spectra, the fly ash powder particles gather due to octahedral AlO 6 symmetry molecule re_changed to polymeric dissymmetry form. This is a reversible process caused by mechanical grinding. In mechanical grinding process, the interaction of hydrogen bond of water is the most effective to mechanical force and mechanical heat.