煤基固废复合改性剂高温重构钢渣的性能及机理研究  

Properties and Mechanism of Steel Slag after High-temperature Modification Containing Coal-based Solid Waste Composite Modifier

作　　者：王长龙[1] 李鑫 陈敬亮 张岳文[1] 张苏花 荊牮霖 马锦涛 平浩岩 齐洋 郑永超[3] 翟玉新 刘枫 WANG Chang-long;LI Xin;CHEN Jing-liang;ZHANG Yue-wen;ZHANG Su-hua;JING Jian-lin;MA Jin-tao;PING Hao-yan;QI Yang;ZHENG Yong-chao;ZHAI Yu-xin;LIU Feng(School of Civil Engineering,Hebei University of Engineering,Handan 056038,China;Handan Jianye Construction Engineering Quality Inspection Co.,Ltd.,Handan 056000,China;State Key Laboratory of Solid Waste Reuse for Building Materials,Beijing Building Materials Academy of Science Research,Beijing 100041,China;China Railway Construction Group Co.,Ltd.,Beijing 100040,China;Construction Development Co.,Ltd.,China Railway Construction Group,Baoding 074207,China)

机构地区：[1]河北工程大学土木工程学院,邯郸056038 [2]邯郸市建业建设工程质量检测有限公司,邯郸056000 [3]北京建筑材料科学研究总院有限公司/固废资源化利用与节能建材国家重点实验室,北京100041 [4]中铁建设集团有限公司,北京100040 [5]中铁建设集团建筑发展有限公司,保定074207

出　　处：《科学技术与工程》2023年第28期12215-12224,共10页Science Technology and Engineering

基　　金：国家重点研发计划(2021YFC1910605);河北省自然科学基金(E2020402079);河北省科技重大专项项目(21283804Z);固废资源化利用与节能国家重点实验室开放基金(SWR-2023-007);中铁建设集团有限公司科技研发计划(22-14b,22-11b);邯郸市科学技术研究与发展计划项目(21422111260)。

摘　　要：为了促进钢渣(steel slag,SS)和煤基固废的综合利用,研究了煤基固废复合改性剂(CMCSR)(煤气化渣-硅钙渣-煤田区域水库底泥)对高温重构钢渣(SHTM)的胶凝性能和体积稳定性的影响,采用X射线衍射(X-ray diffraction,XRD)、扫描电镜(scanning electron microscope,SEM)、能谱仪(energy dispersive spectrometer,EDS)等测试方法,对重构钢渣的物相组成、微观结构及高温重构机理进行分析。结果表明:CMCSR可以提高钢渣的胶凝性能,显著降低了钢渣中游离氧化钙(f-CaO)含量。当重构温度为1250℃,CMCSR掺量为25%时,重构钢渣28 d活性指数比原钢渣可提高16.1%,重构钢渣中f-CaO的含量由4.04%降至1.90%,满足《用于水泥和混凝土中的钢渣粉》(GB/T 20491—2017)中f-CaO含量≤3%的要求。CMCSR掺量由15%增加至35%,重构钢渣中形成透辉石(CMS2)、钙铝黄长石(C_(2)AS)、C_(3)A等硅铝基矿物。高温重构过程促使RO相(CaO-FeO-MnO-MgO固溶体)中的FeO转变为镁铁尖晶石(MgFe_(2)O_(4))和磁铁矿(Fe_(3)O_(4))。重构温度为1250℃,掺25%CMCSR的重构钢渣形成结晶良好、粒径可达10μm以上椭圆形的C_(2)S颗粒。掺入煤基固废复合改性剂的高温改性钢渣,其体积稳定性、胶凝活性和易磨性得到了有效改善,从而为钢渣的低能耗细磨加工进行制品开发,或在水泥和混凝土中的直接应用提供了可能,实现了煤基固废与冶金固废的协同利用。In order to promote the comprehensive utilization of steel slag(SS)and coal-based solid waste,the effects of coal-based solid waste composite modifier containing coal gasification slag,silica calcium slag and coalfield reservoir sediment(CMCSR)on the cementitious properties and volume soundness of SS after high-temperature modification(SHTM)were investigated.The phase composition,microstructure and mechanism of SHTM were analyzed via the test methods of X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS).The results show that CMCSR improves the cementitious property and significantly reduces the content of free calcium oxide(f-CaO)in raw SS.When the high-temperature modification(HTM)is 1250℃and the CMCSR content is 25%,the 28-day activity index of SHTM can be increased by 16.1%compared with the raw SS,and the content of f-CaO in SHTM can be reduced from 4.04%to 1.90%,meeting the requirements of f-CaO content≤3%in Steel Slag Powder for Cement and Concrete(GB/T 20491—2017).CMCSR increases from 15%to 35%,and silicon-aluminum based minerals such as diopside(CMS2),gehlenite(C_(2)AS)and tricalcium aluminate(C_(3)A)are formed in the SHTM.The HTM process promotes the transformation of FeO in RO phase(CaO-FeO-MnO-MgO solid solution)into spinels(MgFe_(2)O_(4))and magnetite(Fe_(3)O_(4)).When the HTM is 1250℃and the CMCSR content is 25%,the C_(2)S particles with oval size of more than 10μm can be formed with good crystallization.The volume soundness,cementitious properties of SHTM mixed with CMCSR are improved effectively,which provides a possibility for the development of low energy consumption fine grinding products of SS,or the direct application in cement and concrete,and realizes the collaborative utilization of coal-based solid waste and metallurgical solid waste.

关 键 词：钢渣(SS) 复合改性剂 高温重构(HTM) 胶凝性能 体积稳定性 

分 类 号：TU522.3[建筑科学—建筑技术科学]