Method of producing high purity zirconia powder from zircon powder

Patent · Tue Jul 05 04:00:00 EDT 1988

OSTI ID:6810630

Funahashi, T; Uchimura, R; Oguchi, Y; Ueda, K

A method is described of producing a zirconia powder from zirconia containing SiO/sub 2/, comprising the steps of: preparing a raw material mixture comprising the zircon powder containing the SiO/sub 2/ and a powdery carbon-containing material such that the mole ratio of C, which is contained in the carbon-containing material and does not gasify at temperatures below 100/sup 0/C. in a nonoxidizing atmosphere, to SiO/sub 2/ contained in the zircon powder is in the range from 0.4 to 2.0; and subjecting the raw material mixture to a desiliconizing heat treatment in a nonoxidizing atmosphere of which the presence is not higher than 0.6 atm, the desiliconizing heat treatment being a combination of a first-stage heat treatment which is performed at a temperature in the range from 1200/sup 0/ to 1550/sup 0/C. for separating silica from the zircon powder and a second-stage heat treatment which is performed at a higher temperature in the range from above 1550/sup 0/C. to 2000/sup 0/C. for completely converting silica in the mixture under heat treatment into gaseous SiO and dissipating the gaseous SiO, wherein the raw material mixture is subjected to the desiliconizing heat treatment in the form of at least one lump whose bulk density is in the range from 0.7 to 2.0.

• Assignee: Kawasaki Steel Corp., Hyogo
• Patent Number(s): US 4755365
• OSTI ID: 6810630
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CARBON COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DENSITY
DISPERSIONS
ELEMENTS
HEAT TREATMENTS
METALS
MIXTURES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWDERS
PRODUCTION
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VERY HIGH TEMPERATURE
ZIRCONIUM
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES