The Enhanced Formation of Magnesium-Silica-Hydrates (M-S-H) Phase in Magnesia Castables
The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081/China
Revision 21.04.2017, 09.05.2017
Volume 9, Issue 3, Pages 89 - 92
Magnesium-silica-hydrates (M-S-H) is regarded as an ideal bonding phase in magnesia castables due to its bonding strength and progressive dehydration behaviour over a wide temperature range during the heating-up stage. In this work, the effect of addition of sodium silicate solution and caustic magnesia powder on the formation of magnesium-silica-hydrates (M-S-H) in magnesia castables was investigated by means of XRD, FTIR and SEM. The results showed that M- S-H product was promoted to form in MgO–SiO2–H2O system with the increase of curing time as well as in the presence of sodium silicate and caustic magnesia. Finally, the cold crushing strength and cold modulus of rupture of magnesia castables were improved by combination addition. The improvement was attributed to the enhanced formation of M-S-H bonding phase. In addition, it also improved the explosion resistance of magnesia castables.
magnesium-silica-hydrates (M-S-H), magnesia castables, sodium silicate, caustic magnesia
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