| Summary: | The reactivity of calcium dialuminate CaAl4O7 refractory cement containing little amount of gehlenite Ca2Al2SiO7, belite Ca2SiO4, calcium aluminum iron oxide Ca3(Al,Fe)2O6 and calcium iron aluminum oxide Ca3.18Fe15.48Al1.34O28 was studied with and without Li2CO3. The granularity of the cement is d97 = 112.58 µm, d50 = 9.72 µm and d10 = 1.41 µm with water cement ratio W/C = 0.375. Little amount of Li2CO3 from 0.1wt.% to 0.6wt.% was added to the cement paste, and the result from calorimetry showed hydration mean peak time reduced from 17 h to 32 min and showed that the hydration heat of CA2 cement paste with Li2CO3 was 123 J/g lower than the one without Li2CO3 of 168 J/g. XRD of stabilized hydrates show that CaAl4O7 and Ca3(Al,Fe)2O6 participate in the hydration reaction to form C3AH6, AH3 and Ca3Al1.54Fe0.46(OH)12. The results from SEM images show nucleation site with plate-like crystal of CAH10 and small particles of AH3 forming a membrane on the cement surface.
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