融合石膏组分和微纳米结构“双基因”调控的铁尾矿粉无熟料固结体力学性能  

Mechanical Properties of Clinker-free Consolidated Body of Iron Tailing Powders Regulated Synergistically by Gypsum Component and Micro-Nano Structure

作　　者：刘娟红[1,2,3] 安树好 陈德平[1] 张月月 LIU Juanhong;AN Shuhao;CHEN Deping;ZHANG Yueyue(College of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;Research Institute of Urbanization and Urban Safety,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Urban Underground Space Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]北京科技大学城镇化与城市安全研究院,北京100083 [3]北京科技大学城市地下空间工程北京市重点实验室,北京100083

出　　处：《材料导报》2024年第21期159-168,共10页Materials Reports

基　　金：国家重点研发计划(2022YFB2602605)。

摘　　要：为了探究超细铁尾矿粉颗粒表面非晶态SiO_(2)和Al_(2)O_(3)在石灰-石膏体系中的水化固化机理及调控因素,本工作考察了石膏掺量和铁尾矿粉中微纳米级颗粒含量之间的匹配对固结体强度的影响,利用XRD、TG-DSC、SEM和化学滴定法测试分析了固结体试样中水化产物的种类、形貌及含量的变化,研究了这些变化对固结体强度的影响及作用机理。结果表明,超细铁尾矿粉中小于1.096μm的微纳米颗粒含量显著影响着铁尾矿粉在碱溶液中Si和Al元素的溶出行为,固结体强度随着这些微纳米颗粒含量的增加而提高。固结体中的主要水化产物是铝掺杂的水化硅酸钙(C-(A)-S-H)和钙矾石(AFt)。石膏掺量与铁尾矿粉中微纳米颗粒含量的最佳匹配值对固结体的强度具有显著影响,并且微纳米颗粒含量越高,对应的石膏最佳掺量越大。石膏组分保证了AFt的生成和稳定,同时也加速了铁尾矿粉颗粒表面非晶态成分的水化。本工作探明了固结材料中最佳石膏掺量与微纳米铁尾矿粉颗粒含量的关联关系及其机理,证实了微纳米级颗粒是无熟料固结体结构中的基本活性单元,石膏的掺入对微纳米颗粒的水化起到调控作用,水化后的微纳米颗粒演变为固结体的基本结构单元,这种组分和结构的“双基因”调控机制影响着固结体的力学性能。In order to explore the hydration and solidification mechanism and regulation factors of amorphous SiO 2 and Al 2O 3 on particle surfaces of ultrafine iron tailing powder in lime-gypsum system,this work investigated the influence of the matching between the gypsum s doping amount and the iron tailing powders micro-nano particle content on strength of the consolidated body.The evolution of chemical species,morphologies and contents of hydration products in several samples of consolidated body of were tested and analyzed by means of XRD,TG-DSC,SEM and chemical titration,and their impacts on strength of the consolidated body and the corresponding underlying mechanisms were studied.The results showed that the content of micro-nano particles smaller than 1.096μm in the ultra-fine iron tailing powder significantly affected the dissolution behavior of SiO_(2)and Al_(2)O_(3)components in the alkaline solution,and the increase of this content resulted in improved strength of the consolidated body.The main hydration products in the consolidated body were aluminum-doped calcium silicate hydrate(C-(A)-S-H)and ettringite(AFt).The best matching value between gypsum content and micro-nano iron tailings powder content had a significant impact on the strength of the consolidated body,and the required optimal amount of gypsum addition varied directly proportional with the content of micro-nano particles.Gypsum component not only ensured the formation and stability of AFt,but also accelerated the hydration of amorphous components on surfaces of tailing powder particles.This study clarified the relationship between the optimal gypsum doping amount and micro-nano tailing particle content in the consolidated material and its underlying origins.It could be confirmed that the micro-nano particles are the basic active units in the structure of the non-clinker consolidated body.The hydration process of these micro-nano particles of tailing powders is regulated by the addition of gypsum,and makes the micro-nano particles become the basic

关 键 词：超细铁尾矿粉 微纳米颗粒 石膏掺量 无熟料固结体 力学性能 调控机制 

分 类 号：TD926.4[矿业工程—选矿]