( 1. 東北大學(xué) 材料與冶金學(xué)院, 沈陽(yáng) 110004;
2. 中國(guó)鋁業(yè)公司 山東分公司研究院， 淄博 255052)
摘 要: 在拜耳法氧化鋁生產(chǎn)中粒度依然存在著周期性細(xì)化現(xiàn)象， 嚴(yán)重影響到拜耳法系統(tǒng)的正常運(yùn)行。 為了解決周期性爆發(fā)性細(xì)化問題，模擬工業(yè)條件對(duì)種分過程產(chǎn)品的周期性細(xì)化進(jìn)行研究。 結(jié)果表明： 產(chǎn)品氫氧化鋁粒度變化的周期隨溫度的升高而縮短， 隨晶種量的增加而延長(zhǎng)； 粒度波動(dòng)的振幅隨溫度的升高而減小，隨晶種加入量的增加而增大； 在其它條件基本不變的情況下， 用于分解的晶種粒度分布出現(xiàn)斷層造成其分布不平衡， 特別是細(xì)粒子減少， 粗粒子增多， 導(dǎo)致種子的比表面積變小，以至于分解后期種子的比表面積小于某一臨界值， 從而導(dǎo)致產(chǎn)品粒度的爆發(fā)性細(xì)化。 在此基礎(chǔ)上對(duì)產(chǎn)品粒度周期性細(xì)化的機(jī)理做了進(jìn)一步的探討。
關(guān)鍵字: 氫氧化鋁； 周期性細(xì)化； 粒度分布； 比表面積；晶種分解
（ 1. School of Materials and Metallurgy,
Northeastern University, Shenyang 110004, China;
2. Research Institute of Shandong Aluminum Co. Ltd.,
China Aluminum Co. Ltd., Zibo 255052, China）
Abstract: Periodical attenuation of particles, which interferes seriously with the normal alumina production of Bayer method, exists in the alumina production process of Bayer method. In order to solve this problem, the reasons of the periodical attenuation of particle size were analyzed by simulating the real production. The results show that the period of Al(OH)3 particle size variation shortens with rising of temperature and lengthens with increasing of solid content, and that the amplitude of the particle size fluctuation reduces with rising of temperature and enhances with increasing of solid content. Unbalance of particle size distribution, that the particles become gradually bigger, induces the specific surface area of seeds smaller, which is the major factor causing explosive attenuation of seed precipitation. The mechanism of particles periodically explosive attenuating was also studied.
Key words: aluminate hydroxide; periodically attenuating; particle distribution; specific surface area; seed precipitation
