赤泥-粉煤灰免烧陶粒的制备及应用

Preparation and Characterization of Red Mud and Fly Ash Non-fired Ceramsite

以赤泥和粉煤灰为主要原料,通过添加硅酸钠和碳酸氢钠不需要高温煅烧便可制备出具有吸附性能的陶粒。以陶粒的解体率为评定指标,通过响应曲面研究了赤泥、粉煤灰、硅酸钠和碳酸氢钠的配比对陶粒解体率的影响,研究结果表明:赤泥、粉煤灰、碳酸氢钠和硅酸钠的最佳配比分别为72%、10%、3%和15%,可得到陶粒的最佳解体率为4%。采用X射线荧光光谱(XRF)仪、X射线衍射(XRD)仪和全自动比表面积及孔隙分析仪等对陶粒的组分、表面形貌特征、孔径分布进行研究,免烧工艺制备的陶粒生成了新的铝-硅化合物,陶粒表面具备多孔的特点。将陶粒应用于吸附磷石膏渗滤液中的磷和氟离子,总磷和F-的去除率最高分别可达79.80%和97.28%。

Using red mud and fly ash as the main raw materials,ceramic particles with adsorption properties can be prepared by adding sodium silicate and sodium bicarbonate without high-temperature calcination.Taking the disintegration rate of ceramsite as the evaluation index,the effect of the ratios of red mud,fly ash,sodium silicate and sodium bicarbonate on the disintegration rate of ceramsite was studied by response surface.The results showed that the optimal ratios of red mud,fly ash,sodium bicarbonate and sodium silicate were 72%,10%,3%and 15%respectively,and the optimal disintegration rate of ceramsite was 4%.The composition,surface morphology and pore size distribution of ceramsite were studied by means of XRF,XRD and full-automatic specific surface and voidage analyzer.The ceramsite prepared by non firing process formed a new aluminum silicon compound,and the surface of ceramsite was porous.Ceramsite was applied to adsorb phosphorus and fluorine ions in phosphogypsum leachate,the maximum removal rates of total phosphorus and F-in phosphogypsum leachate were 79.80%and 97.28%respectively.