热活化温度对氧化铝赤泥反应活性的影响及机理研究

通过热重-差热分析(TG-DTA)赤泥的相变温度,通过X射线衍射(XRD)、红外光谱(FT-IR)分析赤泥热活化前后矿物的组成变化和键能变化,并以活性指数来评定活化赤泥的反应活性,分析了热活化温度对赤泥反应活性的影响规律和作用机理。实验结果表明:热活化后赤泥中硅酸二钙的衍射峰明显,硅酸二钙增多,方解石分解转化成不稳定的高活性物质,Si-O键和Al-O键的结构稳定性降低;热活化温度低于700℃时,赤泥的活性指数随着活化温度的升高而增加,700℃时活化赤泥的活性指数比原生赤泥提高19.1%,而热活化温度升高至800℃时,活化赤泥的活性指数急剧下降。

Effect of thermal activated temperature on activation and mechanism of red mud from alumina production

The effect and activation mechanism of thermal activated temperature on activity of red mud were analyzed.Phase transition temperature of red mud was analyzed by TG-DTA,and the changes of mineral composition and bond energy were also analyzed by XRD and FT-IR.Activity index was to assess the reactive activity of red mud.The test results showed that the diffraction peaks of dicalcium silicate was intensified after thermal activation.Calcite was decomposed into unstable and highly active substances. The stability of Si—O and Al—O bond were reduced.The activity index of activated red mud increased with the rising of activation temperature when it was no more than 700 ℃.Comparing with original red mud,the activity index of red mud activated at 700 ℃ increased 19.1%.While,the activity index of activated red mud decreased sharply when the thermal activation temperature was over 800 ℃.