Radiation shielding integrity of mullite-barite ceramic (MBC) due to fire events

Abstract

Mullite-barite ceramic (MBC) prototype which contains a major phase of barium aluminosilicate (BAS) mineral is an anti-radiation ceramics which is derived from Malaysian kaolin Akima-35 and local barites using conventional ceramics processing route. MBC is a low cost and high performance ceramics which resistance to fire events are fabricated and characterised according to their microstructure properties and radiation test to ensure the shielding capability of the ceramics. The MBC will be used as shielding materials for walls, floor and ceiling of medical x-ray radiation facilities in clinics, medical centers and hospitals. The prepared MBC was undergoing microstructure analysis using X-ray diffraction (XRD) and Scanning Field Electron Microscope (FESEM) to see the phase and morphological of the ceramics. Lead equivalent (LE) and homogeneity test was carried out to evaluate the shielding performance of the MBC before the ceramics are fired with different building fire temperature. The temperature used to simulate the fire events are 400, 900, and 1100°C which is burnt in the high temperature electrical furnace. The fired MBC once again underwent XRD and FESEM to see any changes in the phase and morphology. The lead equivalent and homogeneity test also repeated to see the changes in the shielding performance. From the study, the microstructure analysis from XRD and FESEM obtained shows no significant changes of Monoclinic Barium Aluminosilicate (BAS), which are the major shielding phase in the ceramics before and after fire events. The lead equivalent test and homogeneity also remains the same before and after fire events with the maximum LE calculated are 0.38 mm Pb and 3.6% of homogeneity. From the study, it can be concluded that if the fire event occurred in the radiation facilities, the shielding performance and integrity of the shielding will be remained and the temperature will not degraded the shielding capabilities of the ceramics as do happen for a conventional shielding material.