Chemical Properties
White, bulky, amorphous powder.Decomposes to ZrO2 at 550C. Soluble in dilute
mineral acids; insoluble in water and alkalies.
Description
Zirconium hydroxide, often called hydrous zirconia is a water-insoluble, slightly alkaline amphoteric oxide, which is widely used in the preparation of pigments, glass, dyes and other industries, and is also an important intermediate for the preparation of other zirconium compounds.
Physical properties
White, bulky amorphous powder; density 3.25 g/cm3; decomposes to oxide at about 500°C; very slightly soluble in water, about 200 mg/L at 20°C; soluble in mineral acids.
Uses
Zirconium hydroxide is used in the pigment, dye, and glass colorants. The compound also is used to prepare zirconium oxide, sulfate, phosphate, and other salts.
Preparation
Zirconium hydride precipitates on adding sodium hydroxide solution to an aqueous solution of zirconium salt:
ZrCl4 (aq)+ 4NaOH(aq) → Zr(OH)4 (s) + 4NaCl(aq)
Reactions
When heated at 550°C the hydroxide decomposes to oxide:
Zr(OH)4 → ZrO2 + 2H2O
Reacitons with mineral acids followed by crystallization forms corresponding zirconium salts. Thus hydrochloric, sulfuric, and phosphoric acids yield chloride, sulfate and phosphate of zirconium respectively.
Properties and Applications
Zirconium Hydroxide is a highly water insoluble crystalline Zirconium source for uses compatible with higher (basic) pH environments.
