Study of magnesium aluminate spinel formation from carbonate precursors

• Published in: Journal of the European Ceramic Society Vol. 28; no. 13; pp. 2495 - 2500
• Main Authors: Wajler, Anna, Tomaszewski, Henryk, Drożdż-Cieśla, Ewa, Węglarz, Helena, Kaszkur, Zbigniew
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.2008; Elsevier
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Calcination; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; MgAl 2O 4; Miscellaneous; Powders-chemical preparation; Spinels; Technical ceramics; Calcination; Powders-chemical preparation; Spinels; MgAl 2O 4; MgA12O4; Scanning electron microscopy; Aluminium Magnesium Oxides Mixed; Differential thermal analysis; Experimental study; X ray diffraction; Precursor; Oxide ceramics; Powder; Calcining; Aluminium Oxides; Spinel; Chemical preparation; Technical ceramics; Carbonates; Manufacturing; Magnesium Oxides; Coprecipitation
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2008.03.013

The aim of the presented work was to study formation of magnesium aluminate spinel precursor powder during the co-precipitation of magnesium and aluminium nitrate with ammonium carbonate and its thermal transformation to spinel powder. After precipitation, the only crystalline phase is NH 4Al(OH) 2CO 3·H 2O (ammonium dawsonite). The second one, Mg 6Al 2(CO 3)(OH) 16·4H 2O (hydrotalcite) appears during ageing. As found by DTA-MS and HT-XRD measurements, co-existence of both phases in very close contact results in their easier decomposition. On the base of the results obtained the scheme of phase transformations of co-precipitated precursor leading to formation of MgAl 2O 4 is proposed.