水热预处理富铝精炼渣CO2捕获性能研究

Study on the CO2 Capture Performance of Aluminum-rich Refining Slag with Hydrothermal Pretreatment

精炼渣是钢渣的一种,由于其CaO和MgO等碱性成分含量较高,可以用于捕获CO2.本文研究了水热预处理对提高富铝精炼渣CO2捕获容量的积极效果,分析了水热预处理时间、固液比、CO2流量、反应时间和温度等工艺条件对CO2捕获容量的影响,并结合XRD和FESEM分析阐明了水热预处理提高富铝精炼渣碳酸化程度的机理.研究结果表明:水热预处理精炼渣在常温常压条件下,最大的CO2捕获容量为0.126 g CO2/g渣,远远高于未经预处理渣的最大捕获容量0.042gCO2/g渣;水热预处理使渣中的C12A7快速水化,生成薄片状产物,增大了渣与CO2反应的面积,抑制了渣颗粒表面碳酸钙膜的形成,增大了反应速度,从而提高了反应程度.

The refining slag is a kind of steel slag,and it can be used for CO2 capture due to its high content of alkaline components such as CaO and MgO.The positive effect of hydrothermal pretreatment on the CO2 capture capacity of Al-rich refining slag was studied.The effect of process conditions such as hydrothermal pretreatment time,solid-liquid ratio,CO2 flow rate,carbonation time and temperature on CO2 capture capacity of Al-rich refining slag was discussed.Combined with XRD and FESEM analysis,the mechanism of hydrothermal pretreatment improving the carbonation extent of Al-rich refining slag was elucidated.The results show that the maximum CO2 capture capacity of pretreated refining slag is 0.126 g CO2/g slag at ambient temperature and pressure,which is much higher than the maximum capture capacity(0.042 g CO2/g slag)of unpretreated slag.The hydrothermal pretreatment makes C12 A7 in the slag rapidly hydrate to form a thin plate-like product,which increases the reaction surface between slag and CO2 and prevents the CaCO3 film formation on the surface of slag.This results in the increase of the reaction rate and therefore improve the reaction extent.