( 1. 中國鋁業(yè)公司鄭州輕金屬研究院，鄭州450041；
2. 中南大學 化學化工學院，長沙 410083)
摘 要: 鋁酸鈉溶液聲致自由基的測定對超聲強化鋁酸鈉溶液種分過程反應機理的探討起著十分重要的作用。以DMPO(5, 5-dimethyl-1-pyrroline-N-oxide) 作為自旋捕獲劑，應用自旋捕獲技術與電子自旋共振（ESR）波譜連用的方法檢測到鋁酸鈉溶液在超聲空化作用下產(chǎn)生·OH自由基，討論了聲致自由基的產(chǎn)生與超聲作用時間及鋁酸鈉溶液濃度的關系。結果發(fā)現(xiàn)，只有在超聲波處理濃度較低的鋁酸鈉溶液時，才可能產(chǎn)生·OH自由基，且隨著超聲作用時間的延長，自由基的產(chǎn)量也隨之增加，但當超聲作用時間超過10 min時，自由基含量基本不隨作用時間的延長而改變。
關鍵字: 鋁酸鈉溶液； ·OH自由基； 超聲； 電子自旋共振
in sodium aluminate liquor
YIN Zhou-lan, ZHANG Ping-min
（ 1. Zhengzhou Light Metal Research Institute China Aluminium Corporation,
Zhengzhou 450041, China;
2. College of Chemistry and Chemical Engineering, Central South University,
Changsha 410083, China）
Abstract: In order to probe the mechanism of ultrasonic intensification on gibbsite precipitation process from sodium aluminate liquor, the ultrasonic induced hydroxyl free radicals was detected by electron spin resonance(ESR) spectroscopy using DMPO (5, 5-dimethyl-1-pyrroline-N-oxide) as a spin trap. The relationship of ultrasonic induced ·OH free radical with ultrasonic processing time and the concentration of sodium aluminate liquor were discussed. The results show that ·OH free radicals can be only produced in relative diluted sodium aluminate liquor. With the processing time prolonging, the yield of ultrasonic induced ·OH free radical increases, but the yield does not change when the processing time is longer than 10 min.
Key words: sodium aluminate liquor; ·OH free radicals; ultrasound; electron spin resonance
