【作者】 张志强；

【导师】 李小斌；

【作者基本信息】 中南大学 ， 材料冶金， 2009， 硕士

【摘要】 我国有大量高铁含铝资源,包括高铁低铝硅比的铝土矿,高铁赤泥、含铝铁的粉煤灰和冶金炉渣。采用经济合理的方法从中提取铝和铁是资源综合利用和环境保护的大势所趋。在查阅了大量的国内外综合提取铝铁资料的基础上,选取“还原烧结-溶出-磁选”工艺作为综合提取铁铝的方案,并对此进行了细致地研究。首先,本工作以Al₂O₃、Fe₂O₃和Na₂CO₃为原料研究了Na₂O-Al₂O₃-Fe₂O₃系各组元在烧结过程中的反应行为。结果表明:Al₂O₃、Fe₂O₃与Na₂CO₃生成相应化合物的反应均属扩散控制的固相反应,符合相同的反应机理Zhuralev Lesokin&Tempelman方程,表观活化能分别为186.59 kJ/mol和80.92 kJ/mol,表明Na₂O·Fe₂O₃比Na₂O·Al₂O₃动力学上更容易形成;氧化铁对铝酸钠的形成有双重作用,一方面,在低温下,氧化铁能加速铝酸钠的生成,但是,另一方面,当温度超过1050℃后,氧化铁可加速铝酸钠的分解,且随温度升高或时间延长分解加剧;以高铁铝土矿为原料研究了还原烧结-溶出-磁选回收Na₂O、Al₂O₃和Fe的工艺技术条件。确定了最佳的炉料配方、烧结制度、溶出和磁选条件,取得了氧化铝溶出率大于90%、铁回收率达90%,铁精矿中TFe含量大于60%的良好结果,研究结果对采取“还原烧结-溶出-磁选”工艺处理高铁含铝物料提取率和铁具有重要意义。更多还原

【Abstract】 There are a lot of high iron Al-containing resources with low alumina-silica ratio in China,such as high iron bauxite,high iron red mud, coal ash and metalurgical slag containing Al and Fe.It is developing trend of resources comprehensive utilization and environmental protection to adopt an economic and reasonable method for extracting Al an Fe from those resources.On the basis of domestic and international literatures on comprehensive extraction of Al and Fe,"reductive sintering-leaching-magnetic separation" process was developed for comprehensively extracting Al and Fe,and studied in detail.Firstly,the reaction behavior of components in Na₂O-Al₂O₃-Fe₂O₃ system was studied with Al₂O₃,Fe₂O₃ and Na₂CO₃ as starting samples. The results of kinetic study show that both reactions of Al₂O₃ and Fe₂O₃ with Na₂CO₃ are in accordance with the Zhuralev Lesokin&Tempelman’s diffusion-controlled model in kinetics,and the apparent activation energy is 186.59 kJ/mol and 80.92 kJ/mol,respectively.The formation of Na₂O·Fe₂O₃ is prior to that of Na₂O·Al₂O₃.Fe₂O₃ has double effects on the formation of Na₂O·Al₂O₃,e.g.,it can accelerate the formation of Na₂O·Al₂O₃ at low temperature while accelerate the decomposition of Na₂O·Al₂O₃ as the temperature is higher than 1050℃,moreover the temperature increase or time prolongation favors the reaction between Fe₂O₃ and Na_O·Al₂O₃.Based on the theoretical study above,the technology condition of recovering Na₂O,Al₂O₃ and Fe by reductive sintering-leaching-magnetic separation process was studied with high iron bauxite.The optimal formula of sinter,conditions of sintering, leaching and magnetic separation were determined experimentally.The about 90%of alumina extraction and Fe recovery can be achieved,while TFe content in iron concentrate is more than 60%.We believe that it has important significance to recove Al and Fe by Process of Reductive Sintering-Leaching-Magnetic Separeation in order to utilize comprehensively such high iron Al-containing resources.更多还原