Effect of Different Fluxing Agents on Basic Performance of Quartz Porous Ceramics for Molten Salt Infiltrating Spontaneously

Abstract

Using quartz, feldspar as raw material, charcoal as pore-forming agent, adding CaSO4, Na2CO3, kaolin, KCl, LiF and NaF as fluxing agent respectively, quartz micro-porous ceramic matrices were prepared for inorganic salt/ceramic composite phase change energy storage materials. The effect of different fluxing agents on basic performance of porous ceramics and infiltration process were researched. The research shows that NaF can improve the strength of porous ceramics as fluxing agent, and have little impact on high temperature mechanical strength of Na2SO4/SiO2phase change energy storage materials. When the mass ratio of quartz, feldspar and charcoal is 7:2:1 and NaF is 1 wt% of them, the quartz porous ceramics have good performance as follows: the apparent porosity is 53.74%, the bulk density is 1.19 g/cm3, the compressive strength is 10.1 MPa, the average pore size is 12.53 μm, molten salt infiltration rate is 50.02 %, and the molten salt leakage rate is only 0.42 ‰ after 20 times of thermal loops.