In this study, pumice partially or fully as a replacement for potassium feldspar to chosen hard porcelain compositions. Pumice was added into the porcelain body in proportions 0, 5, 10, 15, 25 wt.%. The chemical and physical properties, phase-microstructure analysis of samples was evaluated and compared with standard porcelain composition. The crystal phases were found as quartz, mullite and amorphous phase. It was found that the just pumice added porcelain bodies fired at 1380 ℃ had good technical features such as lineer shrinkage, water absorption, bulk density, and flexural strength 50.4 MPa. SEM (scanning electron microscopy) and XRD (X-ray diffraction) analysis results showed the high flexural strength was due to the formation of high mullite crystalline content in the porcelain body and the densification of microstructures. The technological and microstructural features of new hard porcelain bodies showed the suitability of using pumice instead of potassium feldspar as the fluxing agent in hard porcelain bodies

Keywords: Hard porcelain, Pumice, Fluxing agent, Characterization, Materials