Analysis of Phase Composition of Magnesite Clinker from Calcinated Brucite by X-ray Diffraction

The X-ray diffraction (XRD) has been used to analyze phase composition of magnesite clinker from calcinated brucite with different process conditions. The major phase of raw brucite powder is Mg(OH)₂ with content up to 85.9% and major impurities are Mg₃Si₂(OH)₄O₅, CaCO₃ and CaMg(CO₃)₂. Most of Mg(OH)₂ are decomposed into MgO under light calcined condition (700~1000℃) during the calcination at low temperature and about 12.3% of un-decomposed Mg(OH)₂ forms new phase of Mg₂SiO₄. Mg(OH)₂ in brucite is completely decomposed into MgO under dead-burned condition (1400~1800℃) and the impurities are Mg₂SiO₄ and CaCO₃ with total content of 18.5%. The results provide the guidance for reforming purification process and improving the quality of magnesite clinker.