Enrichment of schist mined in Morocco resulted in an extract essentially made of andalusite, quartz and muscovite, which was investigated with the aim to synthesize mullite refractory materials. X-ray diffraction anal...Enrichment of schist mined in Morocco resulted in an extract essentially made of andalusite, quartz and muscovite, which was investigated with the aim to synthesize mullite refractory materials. X-ray diffraction analysis was used to assess phase transformations upon heating at different temperatures. Mullite formation starts as early as 1200℃ and seems almost total at 1450℃. This process correlates with a weak shrinkage (3.5% at 1450℃) and the formation of an important glass phase. Green compacts obtained by unidirectional pressing the extract powder were heated under air in the temperature range 1200℃ - 1600℃. Chemical and mechanical properties of these materials were investigated and correlated with their microstructure.展开更多
In search of new mineral raw materials with industrial potential, we identified a deposit located in the southwest of Oujda (in the Northeastern Morocco). The physicochemical analyses indicate that the ore consists ma...In search of new mineral raw materials with industrial potential, we identified a deposit located in the southwest of Oujda (in the Northeastern Morocco). The physicochemical analyses indicate that the ore consists mainly of diaspore, topaz and quartz, and also secondary minerals. The presence of topaz in the ore is explained by hydrothermal action on the structure of diaspore. The investigation of structural transformations reveals complex reaction mechanisms that result in a mixture of corundum-mullite at 1200℃, which is of great industrial interest. Thus, the peculiarity of this ore is the presence of fluorine and secondary minerals.展开更多
基金the Centre d’Etude et de Re-cherche des Phosphates Mineraux(Cerphos,Morocco)for their collaboration and financial support.
文摘Enrichment of schist mined in Morocco resulted in an extract essentially made of andalusite, quartz and muscovite, which was investigated with the aim to synthesize mullite refractory materials. X-ray diffraction analysis was used to assess phase transformations upon heating at different temperatures. Mullite formation starts as early as 1200℃ and seems almost total at 1450℃. This process correlates with a weak shrinkage (3.5% at 1450℃) and the formation of an important glass phase. Green compacts obtained by unidirectional pressing the extract powder were heated under air in the temperature range 1200℃ - 1600℃. Chemical and mechanical properties of these materials were investigated and correlated with their microstructure.
文摘In search of new mineral raw materials with industrial potential, we identified a deposit located in the southwest of Oujda (in the Northeastern Morocco). The physicochemical analyses indicate that the ore consists mainly of diaspore, topaz and quartz, and also secondary minerals. The presence of topaz in the ore is explained by hydrothermal action on the structure of diaspore. The investigation of structural transformations reveals complex reaction mechanisms that result in a mixture of corundum-mullite at 1200℃, which is of great industrial interest. Thus, the peculiarity of this ore is the presence of fluorine and secondary minerals.
