Facile synthesis of MgAl₂O₄ with high crystallinity from KCl–MgCl₂ composite molten salts

Synthesis and Characterization of Magnesium Aluminate Spinel Porous Ceramics by Novel Molten Salt Method

“…For the samples obtained with different contents of MgCl 2 as molten salt, the salt was believed to have dual roles for the preparation of MgAl 2 O 4 porous ceramics: on one hand, the salt which was removed by water washing acted as template for pore formation, so the apparent porosity of the prepared sample was enhanced with the content of MgCl 2 increase. On the other hand, when the firing temperature was higher than about 750 o C (the melting point of MgCl 2 : 714 o C), the molten MgCl 2 salt provided a liquid environment for the formation of MgAl 2 O 4 since both MgO and Al 2 O 3 can be dissolved in the MgCl 2 molten salt [15,16], and the presence of liquid was also helpful to accelerate the growth of MgAl 2 O 4 grains.…”