掺杂对高C_3S水泥熟料烧成及C_3S形成动力学的影响

Effect of Foreign Ions on the Sintering of High C_3S Cement Clinker and Formation Kinetics of C_3S

利用铁尾矿作为作硅铝质原料进行生料配料（熟料率值KH=0．97，SM=2．5，IM=1．5），其中c，S含量超过70％。在此空白生料的基础上分别掺入氟、硫和氟硫复合阴离子，各试样分别在1300℃，1350℃，1400℃和1450℃下煅烧30min，然后测定熟料中f-CaO的含量，并计算C3S的形成活化能。通过差热分析和XRD分析，研究高C3S熟料的烧成过程。结果表明：氟、硫的掺入能够显著改善生料的易烧性，大幅降低C3S的活化能，促进熟料的烧成。单掺时硫比氟的效果要好，氟硫复掺比单掺效果好。生料的差热分析表明，氟、硫能够使石灰石的分解温度降低10-20℃，同时能促进熟料的液相烧结。在1450℃时复掺氟硫熟料的主要矿相是C3S，还有少量的C2S，C3A和C4AF，表明高C3S水泥熟料已经烧成。

A high C3S content composition of Portland cement clinker was prepared by iron tailings, in which KH, SM, IM was 0.97, 2.5, 1.5 respectively. The iron tailings was used as silicate-alumina raw material, and the C3S content of clinker is over 70%. The fluoride ion, sulfide ion and fluoride-sulfide compound ions were added to the blank sample respectively, and the raw meals were fired at 1300 ℃, 1350 ℃, 1400 ℃ and 1450 ℃ for 30 rain. The f-CaO content of clinkers were analyzed, then the apparent activation energy of C3S of clinkers were calculated. The sintering process of high C3S clinker were studied by XRD analysis and differential thermal analysis. The results shows that fluoride ion and sulfide ion can significantly lower the f-CaO content of clinkers and the apparent activation energy of C3S, in which fluoride ion was better than fluoride ion and the fluoride-sulfide compound ions gives the best result. The differential thermal analysis reveals that the addition of fluoride ion and sulfide ion can lower the decomposition temperature of limestone up to 10-20 ℃, and promote the liquid phase sintering of clinker. The results of XRD analysis shows that the mineral composition of clinker with fluoride-sulfide compound ions at 1450 ℃ is dominantly C3S , following by minor C2S, C3A and C4AF,which indicatesthat high C3S cement clinker has been prepared.