Ion-adsorption type rare earth tailings (RET), a type of solid waste that contains clay minerals, were used as a starting material to prepare alkali-based geopolymer. The effects on the compressive strength of RET-based geopolymer, including the modulus and concentration of the alkaline activator, curing temperature, and liquid/solid ratio, were investigated. Pb²⁺ and Cd²⁺ were added during the preparation of the RET-based geopolymer for evaluating the immobilization capacity of heavy metals in the as-obtained geopolymer. The results showed that geopolymer with a compact and dense microstructure was obtained through the optimization of the above factors, with the highest compressive strength being 28.5 MPa. The leaching test indicated that the RET-based geopolymer possessed a desirable capacity for immobilizing heavy metals, where the immobilization efficiency of Pb²⁺ was above 99% and that of Cd²⁺ ranged from 92% to 96%. Heavy metals were immobilized in the RET-based geopolymer matrix through the formation of chemical bonds (T (Si, Al)–O–M (Pb, Cd)) or through an electrostatic attraction between the metal cations and negatively charged [AlO₄]⁻.

离子吸附型稀土尾矿（RET）是一种含有粘土矿物的固体废物，被用作制备碱基地质聚合物的起始原料。研究了对RET基地质聚合物抗压强度的影响，包括碱性活化剂的模量和浓度、固化温度和液固比。Pb²⁺和 Cd²⁺在 RET 基地质聚合物的制备过程中添加，用于评估固定化获得的地质聚合物中重金属的容量。结果表明，通过对上述因素的优化，得到了微观结构致密、致密的地质聚合物，最高抗压强度为28.5 MPa。浸出试验表明，RET基地质聚合物具有较好的重金属固定化能力，Pb ²⁺固定化率在99%以上，Cd ^2+固定化率在92%~96%之间。重金属通过化学键 (T (Si, Al)–O–M (Pb, Cd)) 的形成或金属阳离子与带负电荷的 [AlO ₄ ]^{之间的静电吸引力固定在基于 RET 的地质聚合物基质中-}。