(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 通過測定溶液中有機(jī)碳含量的變化，結(jié)合X射線衍射光譜以及紅外光譜分析及表面性質(zhì)測定，研究氧化鋁粉塵吸附脫除鋁酸鈉溶液中的腐植酸鈉的影響因素及其作用機(jī)理。結(jié)果表明：500~800 ℃焙燒的氧化鋁粉塵結(jié)晶差，在600 ℃下焙燒的氧化鋁粉塵吸附脫除腐植酸效果最好；溶液堿濃度、吸附溫度也顯著影響吸附效果，45 ℃時(shí)的吸附量最大。同時(shí)，相對于500、700和800 ℃焙燒的產(chǎn)品，600 ℃焙燒的氧化鋁粉塵表面疏水性較強(qiáng)、溶劑化能力較差；吸附過程中主要以物理吸附為主，也有化學(xué)吸附；吸附動(dòng)力學(xué)與準(zhǔn)二級(jí)模型吻合，化學(xué)吸附為控制步驟，表面吸附為主要的吸附形式。
關(guān)鍵字: 氧化鋁粉塵；焙燒；鋁酸鈉溶液；腐植酸鈉；吸附
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The removal of organics from sodium aluminate solution will significantly improve alumina quality and production efficiency. The removal of sodium humate with alumina dust was investigated by detecting total organic carbon, contact angle and analysis of X-ray diffraction and infrared spectra. The results show that roasted alumina dust is in poor crystallization in the range of 500~800 ℃ for 0.5 h. The alumina dust roasted at 600 ℃ performs the greatest adsorption capacity and adsorption rate. Moreover, the concentration of alkali soda and duration have remarkable effect on removal in sodium humate. A maximum adsorption capacity can be found at 45 ℃ within temperature range of 30~65 ℃. The results also indicate that alumina dust roasted at 600 ℃ is more hydrophobic and more difficult to be solvation relative to alumina dust roasted at 500, 700 and 800 ℃. The physisorption is predominant in addition to some occurrence of chemisorption. The adsorption kinetics mechanism satisfies second order equation, the adsorption is controlled by chemisorption and mainly occurs in the form of surface adsorption. All results provide an economical method for separation and richness of sodium humate from sodium aluminate solution.
Key words: alumina dust; roasting; sodium aluminate solution; sodium humate; adsorption
