摘要
采用河湖淤泥为主要原料制备淤泥基免烧陶粒,是一种固废资源化利用的有效技术T艺.在此工艺基础上进一步探究了原料中Al2O3、SiO2和Fe2O3含量变化对陶粒颗粒强度、1 h吸水率和颗粒密度的影响,并利用X射线衍射(XRD)和扫描电镜(SEM)表征技术分析其影响机制,旨在得出相应氧化物含量的控制参数,以优化制备工艺.结果表明:在基础物料配合比条件下,过量Al2O3的存在,会导致脆性晶相二水钙长石的结晶生长,使陶粒颗粒强度下降;SiO2所具有的火山灰效应与晶核效应协同水化反应生成更多的水化硅酸钙,当SiO2含量为26％时,陶粒内部结构致密,最优强度达到3.11 MPa;适量Fe2O3体现的异质成核作用,利于晶相生成,可提升陶粒性能,当Fe2O3含量为6％时,陶粒强度达2.84 MPa,吸水率为5.66％.
Abstract
The use of solid waste river and lake sludge as the main raw material to prepare sludge-based non-sintered lightweight aggregates(LWAs)is an effective technological process for the resource utilization of solid waste.The effects of the content of Al2O3,SiO2 and Fe2O3 in the raw materials on the strength,1 h water absorption rate and particle density of LWAs were further systematically explored,and effects mechanism were analyzed by X-ray diffractometer(XRD)and scanning electron microscopy(SEM)characterization techniques,aiming to derive corresponding oxide content parameters to optimize the process.The results show that under the conditions of base material ratio,excessive Al2O3 leads to the crystalline growth of the brittle crystalline phase lawsonite,resulting in a decrease in the strength of the LWAs.The pozzolanic effect and crystalline nucleation effect possessed by SiO2 synergize the hydration reaction to generate more hydrated calcium silicate,and when the SiO2 content is 26％,the internal structure of LWAs is dense and the optimum strength reaches 3.11 MPa.The appropriate amount of the nucleation effect embodied by Fe2O3,which facilitates the generation of crystalline phase can improve the performance of LWAs.
基金项目
"十三五"国家重点研发计划资助(2018YFD1101001)
万方数据