YU Hui, HAN Bingqiang, ZHANG Tao, WEI Yaowu, LI Nan
(The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology，Wuhan 430081,Hubei, China)
Abstract: CaO clinker was prepared using Ca(OH)2 as raw material, which was obtained by active lime, and Al2O3 as additive. The effects of Al2O3 content on sintering properties of CaO clinker was carried out in this paper. XRD was used to determine the mineral phases,and thermo-chemical simulation of phase change during heat process was carried out through FactSage® 6.2 software. SEM and EDS characterization method were performed to analyses microstructure of CaO clinker . The results showed that: (1) The sample with 2-4wt.% Al2O3 has lower apparent porosity, and higher bulk density; (2) The main phase of blank sample is CaO. New phase of 3CaO•Al2O3 is formed and it’s diffraction peaks are gradually enhanced with the increase of Al2O3amount;( 3) The average grain size of the samples with 2-4 wt.% Al2O3fired at 1500 ℃ is 37.3 μm, 34.9 μm, respectively. The average grain size of CaO samples with 4 wt.% Al2O3 fired at 1450 ℃, 1500 ℃, 1550 ℃, is 33.3 μm, 34.9 μm, 36.3 μm, respectively. When the firing temperature increased to 1500 ℃, the sample has larger grain size, and its bulk density reaches the largest. However, further increasing temperature has slightly effect on the grain size, and has negative effect on bulk density.
Key words: lime; hydration resistance; grain growth