煤基固废制备胶凝材料研究进展及应用

Research progress and application of cementing materialsprepared from coal based solid waste

煤矸石、粉煤灰、气化渣作为煤炭开采—化工转化—燃煤发电等过程产生的固体废弃物,年排放量超过15亿t,综合利用率约60%,主要以低端建工建材消纳为主,市场趋于饱和。随着环保政策趋近,煤基固废的资源化利用新途径开发迫在眉睫。基于煤基固废具有铝硅酸盐成分、潜在的火山灰活性和特殊的微观结构等胶凝特性,低成本高性能的低碳胶凝材料成为其规模化高值利用的新途径。综述煤基固废胶凝材料的活性激发技术及应用领域。活性激发方面,阐述了物理激发、碱激发和酸激发等活化方式对胶凝材料矿相变化的影响规律和产品性能调控,总结了现有技术的优势和需要解决的问题。应用领域方面,分析了煤基固废胶凝材料在建筑材料、道路修复、环境修复等领域的应用效果。基于上述现状,对煤基固废胶凝材料激发机理研究、组分配比优化、材料环保性能、工程应用推广等未来发展方向进行展望。研究对煤基固废制备胶凝材料具有重要的借鉴意义,为煤基固废规模化利用提供新途径。

Coal gangue,fly ash,and gasification slag are solid wastes generated from coal mining,chemical conversion,and coal-fired power generation processes.These wastes have an annual emission of over 1.5 billion tons with a comprehensive utilization rate of about 60%.However,their current utilization mainly focuses on low-end construction materials consumption,leading to market saturation.In light of impending environmental protection policies,there is an urgent need to develop new methods for resource utilization of coal-based solid waste.Due to the cementing properties of coal-based solid waste such as aluminosilicate composition,potential pozzolanic activity,and unique microstructure characteristics,low-cost and high-performance low-carbon cementitious materials have emerged as a promising avenue for large-scale and high-value utilization.The activation technology and application fields of coal-based solid waste cementitious materials were reviewed and prospected.The impact of physical excitation,alkali excitation,and acid excitation on the mineral phase transformation of gelled materials and their influence on product properties were elucidated.Furthermore,an overview was provided regarding the merits of existing technologies as well as the challenges that need to be addressed.In terms of application fields analysis includes building materials production road repair environmental remediation among others where coal-based solid waste cementitious materials can be utilized effectively.Based on the above situation,the future development direction of coal-based solid waste cementitious materials such as excitation mechanism research,component ratio optimization,material environmental protection performance,engineering application and promotion were prospected.It has important reference significance for the preparation of cementitious materials from coal-based solid waste,and provides a new way for large-scale utilization of coal-based solid waste.