Preparation and properties of porous tourmaline filter balls

Taking tourmaline flour as the main material，the light and porous tourmaline filtration balls with average grain size about 30 mm was obtained by using high-temperature sintering. The porosity and density of filter balls were measured by Archimedes weighting method. Compression strength was done by Micro control electronic universal testing machine. The chemical structure and thermal stability of tourmaline material, as well as its apparent morphology were characterized by thermogravimetric analysis (TGA)，X-ray diffraction and SEM. The results indicate that the porous tourmaline balls have stable structure and performance with doping amounts less than 50 %, and sintering temperature between 500~750 ℃. Porosity and compression strength of filter balls increase when the temperature of sintering rises with the density between 1.0~1.5 g/cm³.