Clinker Sintering Process Thermodynamic Analysis

The dominant process of alumina production is Bayer process in the world, and the researches are mostly concerning this process. But for the uniqueness of the ore, mixed process and sintering process act special roles in our country. So it has great meanings to work over the sintering process.This dissertation classified the known reactions of sintering process and discussed the reactions which have never been reported, thought over the possibilities of other compounds' creation. Then the process was compartmentalized to different systems according to the existent reactions and their own peculiarities, which were listed as six binary systems (Na₂O-Al₂O₃ system, CaO-Al₂O₃ system, CaO-SiO₂ system, Na₂O-Fe₂O₃ system, Fe₂O₃-CaO system and Na₂O-SiO₂ system), two trinal systems (Na₂O-CaO-Al₂O₃ system and Al₂O₃-CaO-SiO₂ system), three multisystems (Na₂O-Al₂O₃-CaO-SiO₂ system, Na₂O ·Al₂O₃-Na₂O · Fe₂O₃-2CaO · SiO₂ system, Na₂O · Al₂O₃-Na₂O · Fe₂O₃-mCaO ·Fe₂O₃-2CaO ·SiO₂ system). Based on the mentions above, a large quantity of thermodynamic problems regard to the reactions were studied. The course and stability were analysed to discuss the component and construction of multi-equilibrium solid phase, which can offer reasonable technologic parameters to restrain unwanted reactions and intensify wanted reactions.The reactions of CaO-SiO₂ system and kaolin were investigated. CaO and kaolin were mixed with SiO₂ and then sintered according to [CaO]/[SiO₂] mole ratio 1 or 2,respectively.The components and reaction rates of the sinters were detected and then leached in NaOH Na₂CO₃ NaAlO₂ solutions to know the reaction properties.