Formula CoCO3 | Density 4.13 g/cm³ | |
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Appearance red/ pink crystals (anhydrous); pink, violet, red crystalline powder (hexahydrate) | ||
Cobalt(II) carbonate is the inorganic compound with the formula CoCO3. This reddish paramagnetic solid is an intermediate in the hydrometallurgical purification of cobalt from its ores. It is an inorganic pigment, and a precursor to catalysts. Commercially available pale violet basic cobalt carbonate, with the formula CoCO3(Co(OH)x(H2O)y (CAS 12069-68-0).
Contents
Preparation and properties
It is prepared by heating cobaltous sulfate with a solution of sodium bicarbonate.
Heating the carbonate, i.e. calcining, proceeds in the usual way:
3 CoCO3 + 1/2 O2 → Co3O4 + 3 CO2The resulting Co3O4 converts reversibly to CoO at high temperatures. Like most transition metal carbonates, cobalt carbonate is insoluble in water, but is readily attacked by mineral acids:
CoCO3 + 2 HCl + 5 H2O → [Co(H2O)6]Cl2 + CO2Uses
Cobalt carbonate is a precursor to cobalt carbonyl and various cobalt salts. It is a component of dietary supplements since cobalt is an essential element. It is a precursor to blue pottery glazes, famously in the case of Delftware.
Safety
The compound is harmful if swallowed, and irritating to eyes and skin.