Behavior of calcium silicate in leaching process
(School of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China)
Central South University, Changsha 410083, China)
Abstract: Based on the thermodynamic calculation, the mole ratio of CaO to SiO2, temperature and A/S of bauxite have a profound influence on the mole ratio of 2CaO·SiO2 to CaO·SiO2 in sinter. CaO·SiO2 and β-2CaO·SiO2 appear stable in caustic solution but unstable in soda solution, and CaO·SiO2 is more stable than β-2CaO·SiO2 under the same leaching condition. Compared with the conventional sinter, the rate of alumina extraction of the new sinter is large and the secondary reaction is restricted in the leaching, which might be mainly due to the more content of CaO·SiO2 in sinter and better stability of CaO·SiO2 in leaching.
Key words: sinter; leaching; β-2CaO·SiO2; CaO·SiO2