CaF_2对CAMS系矿渣微晶玻璃析晶特性及抗腐蚀性能的影响

Influence of CaF_2 on the Crystallization and Corrosion Resistance of CaO-Al_2O_3-MgO-SiO_2 Slag Glass Ceramics

以白云鄂博二次选后尾矿、高炉渣和粉煤灰为主要原料,采用熔融法制得不同CaF_2含量的CaOAl_2O_3-MgO-SiO_2(CAMS)系微晶玻璃,利用DSC、XRD、SEM、EDS等测试手段,研究了CaF_2对微晶玻璃析晶行为、显微结构及抗盐酸腐蚀性能的影响。结果表明:氟化钙添加量由2%增加至8%(质量分数),基础玻璃的析晶温度降低,析晶活化能由416.28kJ/mol降为309.02kJ/mol,但微晶玻璃的主晶相仍为透辉石相。氟化钙的添加在一定程度上降低了微晶玻璃的抗盐酸腐蚀性能,当氟化钙添加量为2%时,微晶玻璃经盐酸溶液浸泡21d,腐蚀层厚度为240μm;随着CaF_2添加量继续增大,微晶玻璃抗盐酸腐蚀性能急剧下降,当氟化钙添加量为8%时,盐酸腐蚀21d后,腐蚀层厚度为743μm。

CaO-Al2O3-MgO-SiOe （CAMS） glass ceramics with different CaFz contents were prepared by melting method using Bayan Obo mine secondary tailings, blast furnace slag and fly ash as raw materials. The effect of CaF2 on the crystallization behavior, microstructure and corrosion resistance of the glass ceramics was investigated by means of DSC, XRD, SEM and EDS. Results indicated that the crystallization temperature of the basic glass declined and the crystallization activation energies （E） decreased from 416. 28 kJ/mol to 309. 02 kJ/mol as the mass fraction of CaF2 increased from 2% to 8%. The addition of CaF2 did not change the primary crystal phase （Diopside） of glass ceramics, but it made the corrosion resistance reduced to a certain extent. For the glass-ceramics with 2% of CaF2, the thickness of corrosion layer of glass ceramics was 240 μm after immersed in hydrochloric acid solution for 21 days. The hydrochloric acid corrosion resistance of glass-ceramics declined sharply with the increase of CaF2. The thickness of corrosion layer of glass ceramics was found to be 743μm with 8 % of CaF2 after immersed in hydrochloric acid solution for 21 days.