中國有色金屬學(xué)報
ZHONGGUO YOUSEJINSHU XUEBAO
| 第18卷 第11期 總第116期 2008年11月 |
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文章編號：1004-0609(2008)11-2118-09
油酸對鋁酸鈉溶液分解過程的影響及在產(chǎn)物表面的相互作用行為
吳爭平，尹周瀾，陳啟元，曾紀(jì)術(shù)，李 潔
(中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083)
摘 要: 研究添加油酸雜質(zhì)時，鋁酸鈉溶液分解過程中分解率、氫氧化鋁產(chǎn)品的形貌和粒度的分布變化規(guī)律；計算以各種不同方式位于氫氧化鋁(gibbsite)的(001)和(100)面時油酸分子的總能量和電子結(jié)構(gòu)，并分析各體系的平衡形態(tài)及生長習(xí)性。結(jié)果表明：油酸對鋁酸鈉溶液的種分過程產(chǎn)生比較明顯的抑制作用，油酸的添加量越大，抑制作用越明顯；添加1×10−5 mol/L油酸時可促進(jìn)附聚，添加1×10−4 mol/L油酸時抑制附聚。計算結(jié)果表明：油酸接近氫氧化鋁(gibbsite)(001)和(100)表面時，體系總能量升高，說明油酸的存在可降低體系的穩(wěn)定性；油酸在氫氧化鋁(gibbsite)(001)和(100)表面上時，油酸分子呈“臥”式時，長大后晶粒體積大于無雜質(zhì)存在的情況，而油酸分子呈“立”式時，長大后體積小于無雜質(zhì)時晶粒的體積。理論計算說明油酸的存在會促進(jìn)或抑制晶體長大的實驗結(jié)果，從微觀層次揭示油酸對氫氧化鋁結(jié)晶行為影響的實驗規(guī)律。
關(guān)鍵字: 鋁酸鈉溶液；油酸；產(chǎn)物表面
Effect of oleic acid on process of precipitation of sodium aluminate solution and interaction mechanism of oleic acid on surface of production Al(OH)3
WU Zheng-ping, YIN Zhou-lan, CHEN Qi-yuan, ZENG Ji-shu, LI Jie
（School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:The change rules of precipitation ratio, microstructure and particle size and the effect of oleic acid on the seed precipitation of sodium aluminate solution were investigated. According to these experimental results, the total energy and electronic structure of oleic acid locating on gibbsite (001) and face (100) with different modes were calculated, and the equilibrium and growth morphology of the systems were analyzed. The experimental results indicate that oleic acid has inhibitory effect on the precipitation, and the inhibitory effect is more obvious with increasing addition of oleic acid. Specially, oleic acid of 1×10−5 mol/L would facilitate the agglomeration of gibbsite, oleic acid of 1×10−4 mol/L would inhibit the agglomeration of gibbsite. Calculation results indicate that the total energy increases when oleic acid is on the surfaces of (001) and (100) of gibbsite respectively. This can explain that the stability of systems decrease when there is some oleic acid on the surface of gibbsite. The calculation results of equilibrium morphology and growth habit show that the volume of growth crystal is larger when some oleic acids with “horizontal” mode exist on the surfaces (001) and (100) of gibbsite. On the contrary, the volume is smaller when there is some oleic acid with “vertical” mode. Theoretical calculations show the correlative experimental facts and unveil the effect of oleic acid on the crystalline of gibbsite at microcosmic level.
Key words: sodium aluminate; oleic acid; production surface
