中和渣基地质聚合物的制备与性能表征

Preparation and Properties Characterization of Neutralization Slag Based Geopolymers

中和渣(NS)是矿物开采和冶金处理过程中生成的以硫酸钙为主要成分的工业废渣,中和渣大量堆积储存会给环境带来巨大威胁,因此,迫切需要探索一种回收利用中和渣的新技术。研究了不同粒化高炉矿渣掺量的中和渣基地质聚合物的力学性能,并通过X射线衍射测试、反应热测试、压汞测试、傅里叶变换红外光谱测试和扫描电子显微镜测试等手段,对中和渣基地质聚合物的物相组成、水化速率、孔结构及微观形貌进行了表征。结果表明:在激发剂作用下,中和渣与粒化高炉矿渣间地质聚合反应的主要产物为C(N)-A-S-H凝胶。粒化高炉矿渣的掺入可提高聚合反应速率,生成更多的地质聚合物凝胶,使得中和渣基地质聚合物微观结构更致密,力学性能也更高。粒化高炉矿渣掺量为30%(质量分数)的中和渣基地质聚合物28 d抗压强度可达17.8 MPa。

Neutralization slag(NS)is an industrial waste residue with calcium sulfate as the main component produced by mineral mining and metallurgical treatment processes.The large accumulation and storage of NS will pose a great threat to the environment.Therefore,it is urgent to explore a new technology for recycling NS.The mechanical properties of NS based geopolymers with different granulated blast furnace slag(GBFS)blending levels were investigated,and the phase composition,hydration rate,pore structure and micromorphology of the NS geopolymer were characterized by X-ray diffraction,reaction heat testing,mercury intrusion porosimetry,Fourier-transform infrared spectroscopy testing and scanning electron microscopy.The results show that the main product of the geopolymerisation between NS and GBFS under the action of activator is C(N)-A-S-H gel.The incorporation of GBFS can increase the rate of polymerization reaction,generate more geopolymer gels,make the microstructure of NS based geopolymer denser and the mechanical properties higher.The 28 d compressive strength of the NS based geopolymer with 30%(mass fraction)granulated blast furnace slag can reach 17.8 MPa.