The mineral component of kaolin clay in Tung Ba commune analyzed by X-ray diffraction is composed mainly of kaolinite (24–27%), illite (26–30%) and quartz (40–44%). Chemical composition (wt%) of Tung Ba kaolin determined by X-ray fluorescence (XRF) shows SiO2 at –, Al2O3: –, Fe2O3: –, SO3: –, CaO: –, MgO: – and TiO2 at –1,08. To fabricate geopolymer ceramic, kaolin clay was transformed into metakaolin with the optimal parameters of calcination: the temperature at 750°C and heating time of 120 min. Obtained metakaolin is mixed with mixtures of NaOH/Na2SiO3 (40%wt) with ratios of , , , and NaOH molarities are 10M, 12M, 14M. Testing geopolymer ceramics after 28 days had a compressive strength of 40–196 KG/cm2, water absorption of – and density of – g/cm3, totally satisfied the Vietnamese standard for construction bricks and ceramics. | Research on fabrication of non-calcined geopolymer ceramics from kaolin Tung Ba, Vi Xuyen, Ha Giang
