| ‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘ KAWASAKI STEEL TECHNICAL REPORT No.18 ( May 1988 ) ‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘‘ |
| High-Purity Zirconia Powder Produced from Zircon by Carbothermic Reduction under Reduced Pressure Toshihiko Funahashi, Kenichi Ueda, Ryoji Uchimura, Yukio Oguchi |
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Synopsis : A new production method for high-purity ZrO2 powder has been developed. Non-stabilized ZrO2 powder high purity can be produced by heating a mixture of zircon (ZrO2₯SiO2) and carbon powders under reduced pressure. Stabilized ZrO2 powders with high purity can also be obtained by adding a stabilizer such as CaO or Y2O3 to the zircon/carbon mixture. The generation of SiO(g) from a zircon/carbon mixture is greatly accelerated by heating under reduced pressure compared with under atmospheric pressure. The purity of ZrO2 powder produced by this method is about 99.8%, and the average grain size is smaller than 5Κm. Fine Y2O3-partially-stabilized ZrO2 powder(<1Κm) can also be obtained by wet grinding for use as the raw material for a ZrO2 sintered body with high strength and high toughness. In addition, ultra-fine SiO powder (<50nm) as a by-product of this process can be obtained by vapor-phase condensation of SiO(g). |
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