分解產生Al(OH)3和Al2O3的影響
(1. 東北大學 理學院, 沈陽 110004;
2. 東北大學 材料與冶金學院, 沈陽 10004)
摘 要: 研究了疏水性添加劑脂肪酸類陰離子表面活性劑與21-碳烷不同配比對鋁酸鈉溶液分解產生氫氧化鋁和氧化鋁的粒度、強度及分解率的影響, 考察了產物Al(OH)3和Al2O3的強度和粒度之間的關系， 探討了添加劑影響鋁酸鈉溶液晶種分解的相關機理。結果表明： 脂肪酸質量分數在32％～49%， 添加劑加入量為150×10-6 g/L時， 有利于提高分解率， 但對提高Al(OH)3和Al2O3的強度和粒度不利； 脂肪酸質量分數在15％～22.5%時， Al(OH)3和Al2O3在強度和粒度方面呈相一致的對應關系, 添加劑可促進Al(OH)3的附聚， 提高Al(OH)3和Al2O3的粒度和強度， 但對提高分解率作用不大； Al(OH)3的粒度過大時， 會引起其強度降低， 導致Al2O3粒度下降；加入添加劑后， 可形成球狀的Al(OH)3晶體， 有利于形成粒度大、 強度高的氧化鋁。
關鍵字: 鋁酸鈉； 陰離子表面活性劑； 種子分解； 強度； 粒徑
Al2O3 made by seed precipitation from
sodium aluminate solution
YANG Yi-hong2, CHEN Yu-guo1
（ 1. School of Science, Northeastern University, Shenyang 110004, China;
2. School of Materials and Metallurgy,
Northeastern University, Shenyang 110004, China）
Abstract: The effect of hydrophobic additive on the seed precipitation from sodium aluminate solution was studied by adding fatty acid and heneicosane at different proportions. The results show that when the mass fraction of fatty acid is in the range of 32%-49% and the additive concentration in sodium aluminate solution is 150×10-6 g/L, the rate of precipitation increases, but the particle size of Al (OH)3 and Al2O3 reduces. When the mass fraction of fatty acid is in the range of 15%-22.5%, there is compatible corresponding relation in intensity and grain size for Al(OH)3 and Al2O3, and the particle size of them increases with the quantities of fine particles reduced and the particle strength improved, but the rate of precipitation reduces slightly. After adding additives, Al(OH)3 generates a large globe crystal, this is good for getting a large particle and high intensity Al2O3.
Key words: sodium aluminate；anionic surfactant；seed precipitation process； particle strength；particle size
