PURPOSE: To easily obtain zirconium dioxide advantageously in terms of a cost by melting zirconyl chloride in the presence of a specific diol and calcining the reaction product at an elevated temp. in an oxygen-containing gaseous atmosphere.
CONSTITUTION: The objective zirconium dioxide powder is obtd. by. melting the zirconyl chloride in the presence of the diol expressed by HO-X-OH (X is 2-5C satd. hydrocarbon residue) to evaporate water and hydrogen chloride, calcining the reaction product at the elevated temp. in the oxygen-containing gaseous atmosphere and pulverizing the calcined residue in some cases. The representative diols to be used include ethane-1,2-diol; propane-1,2-diol, etc. The resulted zirconium dioxide powder has the size of about 10 to 60 nm crystals depending on the conditions for production and generally has a gentle flocculation state having a bimodal pore distribution. The powder is well press formed, by which the highdensity greenware having the mechanical and thermal stability of the desired extent is obtd.