Journal of Northeastern University Natural Science ›› 2015, Vol. 36 ›› Issue (5): 685-689.DOI: 10.12068/j.issn.1005-3026.2015.05.017

• Materials & Metallurgy • Previous Articles     Next Articles

Reaction Behaviors of CaO-TiO2-SiO2-NaAlO2 System

WANG Yan-xiu, ZHANG Ting-an, LYU Guo-zhi, ZHU Xiao-feng   

  1. School of Materials & Metallurgy, Northeastern University, Shenyang 110819, China.
  • Received:2014-03-10 Revised:2014-03-10 Online:2015-05-15 Published:2014-11-07
  • Contact: ZHANG Ting-an
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Abstract: Reaction behaviors of CaO-TiO2-SiO2-NaAlO2 system (anatase mainly) was investigated. The equilibrium phase and relatively stable level were determined by means of thermodynamic calculation. The reaction order, activation energy and reaction control mechanism were determined through kinetics analysis. The reaction behaviors were analyzed by calcification experiments. The results showed that the reaction behaviors of CaO-TiO2-SiO2-NaAlO2 system are as follows: under given conditions (the mass ratios of m(TiO2)/m(CaO) and m(TiO2)/m(SiO2) are 1.42 and 0.49, respectively, the time is 1h, the stirring speed is 300r/min, the mass concentration of Na2O (mk) is 220g/L and the molar ratio of Na2O and Al2O (αk) is 3.1), TiO2 reacts with alkali liquor to produce Na2TiO3, then reacts with NaAl(OH)4 and Na2SiO3 to produce Al4Ti2SiO12. With the increase of temperature, Al4Ti2SiO12 decomposes and sodium aluminosilicate hydrate and hydrogarnet form,the peak intensity of CaTiO3 increases and CaTiO3 becomes the main part of calcified slags. Finally, anatase converts to stable CaTiO3. The initial transition temperature is 260℃.

Key words: reaction behavior, alumina, anatase, CaO-TiO2-SiO2-NaAlO2 system, temperature

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