Although high-performance basic refractory materials play an essential role in state-of-the-art steel-making,magnesia castables have not been widely used until now. A major challenge is that brucite formation（ Mg（ O...Although high-performance basic refractory materials play an essential role in state-of-the-art steel-making,magnesia castables have not been widely used until now. A major challenge is that brucite formation（ Mg（ OH）2） during Mg O hydration causes volume expansion and subsequent cracking—a phenomenon commonly called ＂slaking＂. To overcome problems related to slaking,a new specialty product,Siox X- Mag,has recently been developed for cement-free Mg O castables based on Mg O- SiO 2- H2 O bond. Specimens from industrial-scale-sized blocks after dry-out were characterised by SEM and XRD techniques. Using Siox X- Mag in combination with microsilica,cracking caused by brucite formation is suppressed. The results demonstrate that the dosage of microsilica plays essential roles in the crack formation in large samples. Furthermore,the compatibility of Siox X- Mag with different types of basic aggregates, medium to high-grade dead-burned magnesia and olivine, has also been evaluated. High-performance,self-flowing cement-free Mg O castables have been developed.展开更多
文摘Although high-performance basic refractory materials play an essential role in state-of-the-art steel-making,magnesia castables have not been widely used until now. A major challenge is that brucite formation（ Mg（ OH）2） during Mg O hydration causes volume expansion and subsequent cracking—a phenomenon commonly called ＂slaking＂. To overcome problems related to slaking,a new specialty product,Siox X- Mag,has recently been developed for cement-free Mg O castables based on Mg O- SiO 2- H2 O bond. Specimens from industrial-scale-sized blocks after dry-out were characterised by SEM and XRD techniques. Using Siox X- Mag in combination with microsilica,cracking caused by brucite formation is suppressed. The results demonstrate that the dosage of microsilica plays essential roles in the crack formation in large samples. Furthermore,the compatibility of Siox X- Mag with different types of basic aggregates, medium to high-grade dead-burned magnesia and olivine, has also been evaluated. High-performance,self-flowing cement-free Mg O castables have been developed.
