Evaluation of the Role of Nano Chromia on Densification of Magnesia-Chrome Refractories

摘要

In this study the effect of nano chromia on sintering behavior of magnesia grains was investigated. Citrate nitrate sol-gel method was utilized to coat the magnesia grains with nanochromia to have homogenous distribution of nanoparticles. Coated grains were pressed and calcined at various temperatures. XRD and FTIR were utilized to investigate the formation of nano particles and the phase evolution during calcination. Sintering behavior of prepared bars was studied by measuring the permanent linear change, apparent porosity and density of pellets. To interpret the difference in performance of the specimens with nanochromia, microstructure analysis was also carried out by SEM. The results show that the addition of nanochromia improves the densification in the magnesia-chrome system compared to the regular magnesia-chrome system at relatively low firing temperatures (T < 1450℃).