CaF_2含量对熔融态高炉渣微晶玻璃析晶及性能的影响

Effect of CaF_2 on Crystallization and Properties of Glass-ceramics from Molten Blast Furnace Slag

利用液态高炉渣为主要原料,采用熔融法制备了微晶玻璃。借助DSC、XRD、SEM等分析测试方法研究了CaF_2含量对高炉渣微晶玻璃析晶及性能的影响。试验结果表明,CaF_2能够有效降低微晶玻璃的形核析晶温度,促进微晶玻璃析晶。微晶玻璃中晶体含量随着CaF_2含量的增加而增加。当CaF_2含量小于4%时,微晶玻璃的晶相为透辉石、普通辉石和钙镁黄长石;当CaF_2含量大于4%时,析出了新晶相枪晶石。最终确定CaF_2的最佳添加量为6%,此时微晶玻璃结晶度高,平均晶粒粒度100 nm,体积密度2.81 g/cm3,吸水率0.04%,耐酸腐蚀性98.92%,耐碱腐蚀性99.98%,抗弯强度173.41 MPa。

The glass-ceramics were obtained successfully with molten blast furnace stag as the main raw materials by the melting method. Effect of CaF2 on the crystallization temperature, crystal phase, microstrueture and properties of glass-ceramics samples were analyzed by means of DSC, XRD, SEM and other methods as well. The results showed that the CaF2 is not only helpful to decrease the nucleation and crystallization temperature for preparing glass-ceramics, but also promote to crystallize. The contents of crystals increased with the increase of CaF2. The crystalline phases of the glass-ceramics were diopside, augite and akermanite-gehlenite with the content of CaF2 less than 4%. Increasing the content of CaF2 to 4%, a new phase-cuspidine generated in the glass-ceramics, and the content of cuspidine increased with the CaF2 increasing. The glass-ceramics samples with good crystallinity, small grain size （average 100nm）, bulk density （2.81 g/cm3 ）, water absorption （0.04%）, acid corrosion （98.92%）, alkali corrosion（99.98% ） and bending strength （ 173.41 MPa） were prepared with 6% CaF2.