A technical note on the production of zirconia and zircon brick from locally available zircon in Bangladesh

In this study, the potentiality of Bangladesh zircon as a raw material for zirconia and zircon brick production was examined. Decomposition of zircon (ZrSiO4) into zirconia (ZrO2) was attempted by using caustic soda (NaOH) as the decomposition agent. 5–10 μm size zircon, 5–30 wt.% NaOH, and decomposition temperatures ranging from 1300 to 1500 °C were investigated. X-ray diffraction method using Mo Kα radiation was used in order to find out the extent of decomposition of zircon into zirconia. Zircon bricks of 0.06 mm× 0.06 mm× 0.025 mm shaped were made under a pressure of 15 MPa. Carboxi methyal cellulose (CMC) and Fe2O3 were used as a binder. With increasing temperature and percentage of NaOH, decomposition of zircon increases. Crushing strengths and density of these bricks could be found as high as 53.36 MPa and 3210 kg/m3, respectively. Bangladesh zircon can be used successfully for preparation of refractory bricks for high temperature use.