高铁赤泥熔融还原过程中钠铝硅的行为研究

Study on the behavior of sodium,aluminum and silicon in the melting reduction of high-iron red mud

随着氧化铝行业的发展,国内堆存了大量高铁赤泥。赤泥的堆存不仅增加氧化铝企业生产成本,还会造成环境污染,同时高铁赤泥中的金属资源未有效回收。本文采用熔融还原法处理高铁赤泥,通过对还原渣进行成分分析、物相分析以及微观形貌分析,研究了赤泥熔融还原过程中Na、Al、Si_(3)种元素的行为变化,为赤泥熔融还原渣水泥化提供理论依据。结果表明,赤泥中的Na元素由NaAlSiO_(4)转化为NaCaAlSi_(2)O_(7)留在了尾渣中,Al元素多以3CaO·Al_(2)O_(3)转化为尾渣中的NaCaAlSi_(2)O_(7)、Ca_(2)Al(AlSi)O_(7)等,Si元素则是从Ca_(2)SiO_(4)转化为NaCaAlSi_(2)O_(7)、Ca_(2)Al(AlSi)O_(7)、Ca2Al2SiO7等。

With the development of the alumina industry in China,a large amount of high-iron red mud has been stockpiled.The storage of red mud not only has increased the production cost of alumina enterprises but also has caused environmental pollution.At the same time,the metal resources in the high-iron red mud have not been effectively recovered.In this paper,the red mud with high iron content was treated by the melting reduction method.The changes in Na,Al and Si behavior in the process of red mud melting reduction were studied through the composition analysis,phase analysis and microscopic morphology analysis of the reduction slag,which provided a theoretical basis for producing cement using red mud melting reduction slag.The results showed that the Na element in the red mud is transformed from NaAlSiO_(4)to NaCaAlSi_(2)O_(7)and remains in the tailings.The Al element was mostly transformed into NaCaAlSi_(2)O_(7),Ca_(2)Al(AlSi)O_(7),etc.,in the tailings by 3CaO·Al_(2)O_(3),while the Si element was transformed from Ca_(2)SiO_(4)to NaCaAlSi_(2)O_(7),Ca_(2)Al(AlSi)O_(7),Ca2Al2SiO7,etc.