氟磷石灰石对熟料硅酸盐相形成过程的影响

Effect of Phosphorus-containing Limestone on the Formation of Silicate Phases of Clinker

利用XRD和化学分析方法研究了Ca_5(PO_4)_3F的稳定性和石灰石中的Ca_5(PO_4)_3F对C_3S和C_2S形成过程的影响。结果表明,Ca_5(PO_4)_3F在1450℃下能稳定存在,1450℃时Si O_2和C_2S能使Ca_5(PO_4)_3F分解;用含磷石灰石制备C_2S和C_3S时,1100℃和1200℃煅烧时生成β-C_2S,1300℃煅烧时Ca_5(PO_4)_3F分解形成的PO_4^(3-)与β-C_2S生成α'-C_2S-x C_3P,β-C_2S与Ca O生成C_3S。在1450℃保温4 h,用含磷石灰石制备的C_2S全部转换为α'-C_2S-xC_3P的固溶体。当煅烧温度由1100℃逐渐升至1450℃时,含磷石灰石中的氟随着煅烧温度的升高逐渐减少,Ca_5(PO_4)_3F随着煅烧温度的升高逐渐分解,含磷石灰石-Si O_2体系(C/S=2∶1)和含磷石灰石-Si O_2体系(C/S=3∶1)在1450℃煅烧0.5 h后Ca_5(PO_4)_3F分别分解了94.00%和81.25%。

The stability of Ca5 （PO4 ）3F and the effect of Ca5 （PO4）aF in limestone on the formation of silicate phases of clinker were analyzed by using X-ray diffraction and chemical analysis. The results show that Ca5 （PO4 ）3 F is stable at 1450 ℃. Ca5 （PO4 ）3F decomposes with the presence of SiO2 and C2S at 1450 ℃; When phosphorus-containing limestone uses to produce C2S and C3S, β-C2S is generated at 1100 ℃ and 1200 ℃, PO43 decomposed by Ca5 （PO4 ）3F enters gradually into β-C2S to form the solid solution of α-C2S-xC3P and C3S are generated at 1300 ℃. β-C2S from limestone containing phosphorus-SiO2 （C/S =2 ：1） fully transformes to the solid solution of α-C2S-xC3P when calcined at 1450 ℃ for 4 h. When the calcining temperature increases gradually from 1100 ℃ to 1450 ℃, the F ion content decreases and the Ca5 （ PO4 ） 3 F decomposes gradually with the rise of calcining temperature, the Ca5 （ PO4 ） 3 F content in the systems of limestone containing phosphorus-SiO2 （ C/S = 2 ： 1 ） and limestone containing phosphorus-SiO2 （ C/S = 3：1 ） calcined at 1450 ℃ for 0.5 h decomposes respectively by 81.25% and 94.00%.