不同骨料掺量与级配下白钨尾矿-偏高岭土基地聚合物的制备及其早期强度

Preparation of Scheelite Tailing-Metakaolin Based Geopolymer with Different Aggregate Content & Gradation and Its Early Strength

将富含Si、Ca的白钨尾矿和富含Si、Al的偏高岭土复合作为硅铝原料(基质),在水玻璃激发作用下制备地聚合物砂浆,以调整骨料掺量与级配的方式去优化试样的早期抗压强度;并借助XRD和SEM-EDS对优选试样的微结构进行表征。结果表明:当骨料掺量为50%时,产生高强度砂浆试样的个数最多;当骨料掺量为40%,且细、中、粗骨料在总骨料中分别占10%、60%、30%时,试样的早期抗压强度获得最高值26.7 MPa;在对硅铝原料进行的活化预处理和水玻璃激发以及对砂浆试样进行的蒸压养护之后,硅铝原料中的Si、Al、Ca等元素得以部分溶出,参与形成地聚合物凝胶体,赋予砂浆试样良好的早期强度性能。

Activated by water glass,the mixture which contained scheelite tailing rich in Si Ca and metakaolin rich in Si Al was used as aluminosilicate source material（ i. e. base material） for geopolymer mortar preparation. Early-aged compressive strength of the mortar samples was optimized by adjusting content and gradation of aggregate. Microstructure of the optimum samples was characterized by XRD and SEM-EDS analyses. Results showed that,the greatest number of high-strength mortar samples can be produced when the content of aggregate was 50%. A highest early-aged compressive strength of26. 7 MPa can be obtained,when the content of aggregate was 40%,and the respective mass percentage of fine,intermediate and coarse aggregate in the total aggregate was 10%,60% and 30%. After pretreatment and water glass-alkaline activation on aluminosilicate source material,as well as autoclavedcuring on mortar samples,elements such as Si,Al and Ca were partly dissolved from the aluminosilicate source material and then participated in forming geopolymer gel,giving satisfactory early-aged strength performance of mortar samples.