Effect of Raw Materials Ratio on Properties of Pore Gradient Quartz Ceramics

The low grade quartz sand was used as the main raw material, and then the pore gradient quartz ceramics with different ratios of raw materials were prepared by the process of pulping, forming, drying and sintering. The effects of quartz sand content, mass ratio of water to material and blowing agent content on the porosity, compressive strength and microstructure of the ceramics were studied, and the optimal raw materials ratio was obtained. The results show that with the increase of the quartz sand content, the porosity of the sample increased and the sample showed a macroscopic pore gradient structure. With the water to material mass ratio increasing, the porosity of the sample increased and then decreased, the pores became homogenous and the cracks decreased. With the incerase of the blowing agent content, the porosity increased. The compressive strength had opposite changes comparing with the poeposity. The relatively optimal raw materials ratio was listed as follows:quartz sand mass fraction of 70%, water to material mass ratio of 1.0 and blowing agent mass fraction of 0.8%. The pore gradient quartz ceramics with compressive strength of 6.18 MPa, porosity of 63.5% and better hole shape were obtained.