(1、中南工业大学粉末冶金国家重点实验室、矿物工程系， 长沙 410083
2、中国有色金属工业总公司，北京 100814)
摘 要: 通过对高岭石和铝土矿焙烧过程物相变化的X射线衍射研究，阐明了铝土矿化学选矿预脱硅的机理。实验表明，矿石中固有的α-SiO2(石英)是不能被脱除的， 只有在焙烧温度高达900 ℃以上、 由偏高岭石分解形成的那部分非晶SiO2才 能被NaOH溶出而脱除。此外，溶出精矿的相分析结果澄清了过去认为在低压溶出脱硅条件下高岭土是稳定存在的误解。给出了提高铝土矿铝硅比值的最佳焙烧工艺制度。
关键字: 铝土矿 高岭石 脱硅 焙烧 X射线衍射
（1.P/M National Key Laboratory, Central South University of Technology, Changsha 410083 ;
2.China National Nonferrous Metals Industry Corporation, Beijing 100814）
Abstract:The phase transitions of kaolinite and diasporic bauxite during roasting were studied by means of XRD analysis. The desilication mechanism of diasporic bauxite by chemical processing was explained. It was shown that the α-SiO2(quartz) in green ores can not be separated, but the amorphous SiO2 formed by roasting kaolinite at temperature above 900 ℃ can be desilicated. The XRD analysis results of digested products cleared the misunderstanding that the kaolinite was the stable phase under the low pressure digestion condition. The suitable roast rule to increase the Aluminum/Silicon ratio(A/S) of diasporic bauxite was also presented.
Key words: diasporic bauxite kaolinite desilication roast XRD
