(中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083)
摘 要: 利用離子膜電解鋁酸鈉溶液的方法制備氫氧化鋁，研究制備過程中分解條件和非離子型表面活性劑聚乙二醇對產(chǎn)品氫氧化鋁的影響，并通過掃描電鏡以及紅外光譜分析等檢測手段對產(chǎn)品氫氧化鋁進(jìn)行表征。結(jié)果表明：當(dāng)攪拌速度為400 r/min、苛堿濃度為150 g/L、溫度為35 ℃時，氫氧化鋁粒度分布情況最好；聚乙二醇的加入有利于制備粒度較細(xì)且分散性好的氫氧化鋁，且隨其添加量的增加，氫氧化鋁平均粒徑減小；聚乙二醇的最佳添加濃度為0.175 g/L，對應(yīng)產(chǎn)品氫氧化鋁的平均粒徑為3.9 μm。紅外光譜表明：聚乙二醇通過在氫氧化鋁表面的吸附作用抑制顆粒間的附聚，離子膜電解鋁酸鈉溶液的產(chǎn)品為拜耳型氫氧化鋁。
關(guān)鍵字: 超細(xì)氫氧化鋁；鋁酸鈉溶液；離子膜電解；聚乙二醇
（School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:Preparation of superfine aluminum hydroxide powders from sodium aluminate solution by ion-exchange membrane electrolysis was investigated. The effect of experimental conditions in precipitation process and the effect of polyethylene glycol dosages on aluminum hydroxide products were studied to achieve the required fineness. The results show that the grain size distribution is best under the process conditions of 35 ℃, alkaline concentration of pregnant liquor 150 g/L, stirring speed 400 r/min. The addition of glycol dosages is beneficial to produce the finer and well-dispersive aluminum hydroxide. The average sizes of aluminum hydroxide were reduced gradually with the increase of the polyethylene glycol dosages. When concentration of the additive in sodium aluminate solution reach 0.175 g/L, the average size of ATH is 3.9 μm. The infrared spectra analysis show that, agglomerative particles were dispersed by the adsorption of polyethylene glycol on the surfaces of the aluminum hydroxide particles. The products of ion-exchange membrane electrolysis from sodium aluminate solution are Bayerite.
Key words: superfine aluminum hydroxide; sodium aluminate solution; ion-exchange membrane electrolysis; polyethylene glycol
