Influence of supersaturation on structure of sodium aluminate solutions with medium concentration: a solution X-ray diffraction study
来源期刊:中国有色金属学报(英文版)2002年第5期
论文作者:李洁 陈启元 尹周澜 张平民 李元高
文章页码:992 - 996
Key words:solution X-ray diffraction; sodium aluminate solution; structural property
Abstract: Influence of supersaturation on the structure of a series of freshly prepared supersaturated sodium aluminate solutions with medium concentration was investigated by solution X-ray diffraction. Experimental results show that the basic Al-containing species in all kinds of supersaturated solution is four-coordinated ions. Opposite to Al—O distance contracted in highly concentrated solution, a little expand of the Al—O distance from 1.75℃ to 1.85℃ occurs with increasing supersaturation, which is consistent with the occurrence of oligomeric aluminate species. Meanwhile, O—O distance in the first shell of H2O—H2O(OH) in supersaturated sodium aluminate solution is obviously longer than in hydroxide sodium solution and becomes longer and longer with increasing supersaturation. Na—O bond length is about 2.4℃ and changes little with supersaturation. The reason for Al—O bond expanding with supersaturation and its influence on the stability of solution was discussed.