The effect of magnesite calcination conditions on magnesia hydration

The aim of this work was to analyze the effect of magnesite calcination conditions, i.e. kiln temperature and residence time, on magnesia response to activity tests and, further, the relationship of this response with MgO hydration behavior under different reaction conditions. The calcination of magnesite was carried out at various temperatures and residence times, in lab-scale Herreshoff and electrical kilns. The solids were characterized with respect to their chemical and physical properties, and then hydrated under different temperature and time. Magnesia activity was compared to the sample surface areas and the corresponding hydration levels. It is demonstrated that the activity test should be used with caution once its suitability to predict hydration behavior of magnesia depends on the sampleʹs characteristics and the conditions in which hydration will take place.