的工藝條件
(1. 武漢理工大學(xué) 化學(xué)工程學(xué)院，武漢 430070;
2. 漢江集團(tuán)鄖縣豐源電化制造有限公司，鄖縣 442500)
摘 要: 以硫酸鋁和尿素水熱均相沉淀合成的低密度一水軟鋁石為晶種，研究分解條件對(duì)溶液分解率和分解產(chǎn)物性質(zhì)的影響，還對(duì)從鋁酸鈉溶液析出低密度一水軟鋁石的過(guò)程進(jìn)行了初步分析。結(jié)果表明：適當(dāng)延長(zhǎng)分解時(shí)間，降低分解溫度，或采用Al2O3濃度和分子比較低的鋁酸鈉原液都可以得到較高的分解率；該晶種具有較好的水熱穩(wěn)定性，連續(xù)使用3次對(duì)溶液分解率、分解產(chǎn)物的堆密度和比表面積影響不大。推薦工藝條件為：分子比1.30~1.45、Al2O3濃度為140 g/L左右的鋁酸鈉溶液在種子比1.0和180 ℃左右下分解3 h。
關(guān)鍵字: 水熱均相沉淀；鋁酸鈉溶液；水熱種分；低密度一水軟鋁石
precipitation from sodium aluminate solution
（1. School of Chemical Engineering, Wuhan University of Technology,Wuhan 430070, China;
2. Fengyuan Electrochemical Manufacture Co. Ltd, Hanjiang Group,Yunxian 442500, China）
Abstract:Effect of decomposition conditions on the ratio of seeded decomposition and properties of precipitation products from sodium aluminate (SA) solutions with the very light boehmite seed prepared from the hydrothermal homogeneous precipitation between aluminum sulfate and urea, was studied. Mechanism of the very light boehmite precipitation process was also analyzed. The results show that with the appropriate increase of precipitation time and decrease of temperature, the initial alumina concentration and molar ratio of Na2O/Al2O3 (MR) can obtain higher ratio of seeded decomposition. The seed has better hydrothermal stability. Ratio of seeded decomposition, tape density and specific surface area of the product almost keep constant after three precipitation cycles. Process conditions are recommended as follows: the SA solutions with MR of 1.30−1.45 and alumina concentration about 140 g/L are decomposed for 3 h at approximate 180 ℃ with a low seed ratio of 1.0.
Key words: hydrothermal homogeneous precipitation; sodium aluminate solution; hydrothermal seed precipitation; very light boehmite
