Preparation and interface state of phosphate tailing-based geopolymers  

磷尾矿基地质聚合物的制备与界面状态研究

作　　者：ZHANG Shou-xun XIE Xian XIE Rui-qi TONG Xiong WU Yu-yao LI Jia-wen LI Yue 张守逊;谢贤;谢瑞琦;童雄;吴雨瑶;李加文;李悦(Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming 650093,China;National&Regional Engineering Research Center for Green Comprehensive Utilization of Gangue Resources from Metal Mine,Kunming 650093,China)

机构地区：[1]Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming 650093,China [2]National&Regional Engineering Research Center for Green Comprehensive Utilization of Gangue Resources from Metal Mine,Kunming 650093,China

出　　处：《Journal of Central South University》2024年第6期1900-1914,共15页中南大学学报（英文版）

基　　金：Project(202202AG050010)supported by the Yunnan Major Scientific and Technological Projects,China;Project(202103AA080007)supported by the Key R&D Project of Science and Technology Department of Yunnan Province,China;Project(NECP2023-06)supported by the Open Project Fund of National Engineering and Technology Research Center for Development&Utilization of Phosphorous Resources,China。

摘　　要：The long-term storage of phosphate tailings will occupy a large amount of land,pollute soil and groundwater,thus,it is crucial to achieve the harmless disposal of phosphate tailings.In this study,high-performance geopolymers with compressive strength of 38.8 MPa were prepared by using phosphate tailings as the main raw material,fly ash as the active silicon-aluminum material,and water glass as the alkaline activator.The solid content of phosphate tailings and fly ash was 60% and 40%,respectively,and the water-cement ratio was 0.22.The results of XRD,FTIR,SEM-EDS and XPS show that the reactivity of phosphate tailings with alkaline activator is weak,and the silicon-aluminum material can react with alkaline activator to form zeolite and gel,and encapsulate/cover the phosphate tailings to form a dense phosphate tailings-based geopolymer.During the formation of geopolymers,part of the aluminum-oxygen tetrahedron replaced the silicon-oxygen tetrahedron,causing the polycondensation reaction between geopolymers and increasing the strength of geopolymers.The leaching toxicity test results show that the geopolymer has a good solid sealing effect on heavy metal ions.The preparation of geopolymer from phosphate tailings is an important way to alleviate the storage pressure and realize the resource utilization of phosphate tailings.磷尾矿的长期堆存会占用大量土地,污染土壤及地下水,它的无害化处置十分必要。本研究以磷尾矿为主要原料,粉煤灰为活性硅铝材料,水玻璃为碱性激发剂,在磷尾矿和粉煤灰固体掺量分别为60%和40%,水灰比为0.22的条件下,制备得到抗压强度为38.8 MPa的高性能地质聚合物。XRD、FTIR、SEM-EDS、XPS等分析结果表明,磷尾矿与碱性激发剂的反应活性较弱,硅铝材料则能够与碱性激发剂反应生成沸石和凝胶,并包裹/覆盖磷尾矿形成结构致密的磷尾矿基地质聚合物。在地质聚合物的形成过程中,部分铝氧四面体取代了硅氧四面体,引起地质聚合物之间的缩聚反应,增加了地质聚合物的强度。浸出毒性试验结果表明地质聚合物对重金属离子具有良好的固封效果。因此,磷尾矿基地质聚合物具有抗压强度高、固封性能好的优点,以磷尾矿制备地质聚合物是缓解堆存压力、实现磷尾矿资源化利用的重要途径。

关 键 词：phosphate tailing GEOPOLYMER interface state toxicity leaching 

分 类 号：TD926.4[矿业工程—选矿] TQ177[化学工程—硅酸盐工业]