Effect of Temperature and Additives on the Hydration Behaviour of MgO Powders
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High performance MgO-based castables have many advantages for refining clean steel. However, hydration of MgO powder limits the application of MgO-based castables. The effects of temperature, hydration time and additives (calcium aluminate cement and microsilica) on the hydration behaviour of MgO powders are investigated in this paper. The results show that the hydration content of MgO powders increases noticeably with an increase of hydration time and temperature, indicating that the intensity of brucite (Mg(OH)2) diffraction peaks and the brucite amount increase. With 5 mass-% microsilica or cement addition, the amount of hydrated product Mg(OH)2 decreases noticeably from 26 to 11 mass-% and 19 mass-%. Microsilica has a retarding influence on the hydration of magnesia.
Keywordshydration behaviour MgO powders brucite microsilica calcium aluminate cement
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