用离子型稀土尾矿制备多孔免烧陶粒

为实现离子型稀土尾矿的综合利用，减少离子型稀土尾矿对生态环境的影响，以赣南足洞离子型稀土尾矿为主要原料制备多孔免烧陶粒，考察了胶凝材料、激发剂、发泡剂的用量对陶粒性能的影响，并运用扫描电镜（SEM）对所制陶粒的微观形貌进行了表征。试验结果表明：用该离子型稀土尾矿制备多孔免烧陶粒的适宜固体原料配方为稀土尾矿占76%、水泥占10%、生石灰占8%、石膏占4%、铝粉占2%。按此配方制备的陶粒吸水率为30.28%、显气孔率为49.96%、真密度为1.65 g/cm³、抗压强度为3.17 MPa，且含泥量、盐酸可溶率和孔隙率均符合有关标准要求，可用作水处理滤料。SEM分析结果显示，所制陶粒内部孔隙发达，颗粒表面有水化硅酸钙生成。以上研究成果证明，以离子型稀土尾矿为主要原料制备多孔免烧陶粒是可行的。

Preparation of Porous Non-sintered Ceramsite with Ion-absorbing Type Rare Earth Tailings

In order to reduce the impact of rare earth tailings（RET）on the ecological environment and achieve the RET recycling，the ion-absorbing type RET was used as the main raw material for preparing the porous non-sintered ceramsite.The effects of binding material，activating agent and foaming agent amount on ceramsite performance were studied.Scanning electron microscope（SEM）was used to characterize the microstructure of the representative ceramsite.Results showed that the best formula for preparing the ceramsite with the ion type rare earth tailings was 76% RET，10% cement，8% quicklime，2% aluminum powder；Performance indicators of the ceramsite prepared were as follows:water absorption（W）was 30.28%，apparent porosity（P）rate was 49.96%，density（D）was 1.65 g/cm³，and compressive strength was 3.17 MPa；SEM analysis showed that the hole in the ceramsite was well-developed and calcium silicate hydrate（CSH）was generated on the surface of the particle.The study indicates that it is feasible for preparing the porous non-sintered ceramsite with the ion-absorbing type RET as main source material.