Abstract:The MgO-CaO was prepared by the two-step calcination method through adding Al(NO3)3 in natural dolomite. The effects of Al(NO3)3 addition on the sintering properties and hydration resistance of dolomite were studied. Results show that, the MgO-CaO sample has the sintered density of 3.17 g/cm3, apparent porosity of 4.9%, hydration resistance weight gain rate of 3.1%, pulverization rate of 20.1%, and the MgO grain size of 2.92 μm when sintered at 1 600 ℃ for 3 h. The Al(NO3)3 decomposes into Al2O3, and Al2O3 reacts with CaO to form 3CaO2·Al2O3 at high temperature, thus the liquid phase forms during sintering, and promoting the sintering process of the samples. When adding 0.30% Al(NO3)3 (mass percent), the MgO-CaO sample has the sintered density of 3.24 g/cm3, apparent porosity of 3.8%, hydration resistance weight gain rate of 2.0%, pulverization rate of 15.6%, and the MgO grain size of 3.48 μm when sintered at 1 600 ℃ for 3 h.
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