Abstract: High-purity zircon (ZrSiO₄) powders were synthesized by high-temperature solid-phase reaction method, using 99.9% (mass fraction) high purity ZrO₂ and SiO₂ powders as raw materials and small amount of TiO₂ as additive. The effects of temperature and reaction time on the synthesis efficiency of high-purity zircon powders were studied. It is found that the fraction of the ZrSiO₄ phase reaches 95.77% (mass fraction) after the solid-phase reaction is carried out at 1 500 ℃ for 48 h using raw material powders with particle size less than 50 μm. The prepared high-purity zircon powders were used as a raw material, and sintered at a high temperature above 1 550 ℃ after ball milling cold isostatic pressing to form a high-purity dense zircon brick. The concentrations of Fe and Cu impurities in high-purity dense zircon are 29 μg/g and less than 1 μg/g, respectively, which are only 1/10 of those in the commercial high dense zircon samples. The static optical loss of phosphate glass caused by the high-purity dense zircon samples is only 1/3 of that of the commercial high dense zircon samples. Using this high-purity dense zircon material for laser glass furnaces can reduce the optical loss at 1 053 nm and improve the laser performance of laser glasses.

Key words: high-purity dense zircon, high-temperature solid-phase synthesis, corrosion resistance, laser glass furnace, optical loss