Cobalt(II) carbonate is the

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the formula CoCO₃. This pink paramagnetic solid is an intermediate in the hydrometallurgical purification of cobalt from its ores. It is an inorganic pigment, and a precursor to

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

s. Cobalt(II) carbonate also occurs as the rare red/pink mineral spherocobaltite.

Preparation and structure

: left, Structure of solid cobalt(II) carbonate shown with space-filling ions. Color code: red = O, green = Co, blck = C, 220px It is prepared by combining solutions of cobalt(II) sulfate and

sodium bicarbonate Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda (or simply “bicarb” especially in the UK) is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cat ...

: :CoSO₄ + 2 NaHCO₃ → CoCO₃ + Na₂SO₄ + H₂O + CO₂ This reaction is used in the precipitation of cobalt from an extract of its roasted ores. CoCO₃ adopts a structure like

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

, consisting of cobalt in an octahedral coordination geometry.

Reactions

Like most transition metal carbonates, cobalt carbonate is insoluble in water, but is readily attacked by mineral acids: :CoCO₃ + 2 HCl + 5 H₂O → o(H₂O)₆l₂ + CO₂ It is used to prepare many coordination complexes. The reaction of cobalt(II) carbonate and acetylacetone in the presence of

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...

gives tris(acetylacetonato)cobalt(III). Heating the carbonate proceeds in a typical way for

calcining Calcination is thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), generally fo ...

, except that the product becomes partially oxidized: : 6CoCO₃ + O₂ → 2Co₃O₄ + 6CO₂ The resulting Co₃O₄ converts reversibly to CoO at high temperatures.

Uses

Cobalt carbonate is a precursor to cobalt carbonyl and various cobalt salts. It is a component of

dietary supplement A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients eithe ...

s since cobalt is an essential element. It is a precursor to blue pottery glazes, famously in the case of

Delftware Delftware or Delft pottery, also known as Delft Blue () or as delf, is a general term now used for Dutch tin-glazed earthenware, a form of faience. Most of it is blue and white pottery, and the city of Delft in the Netherlands was the major cen ...

Related compounds

At least two cobalt(II) carbonate-hydroxides are known: Co₂(CO₃)(OH)₂ and Co₆(CO₃)₂(OH)₈·H₂O. The moderately rare spherocobaltite is a natural form of cobalt carbonate, with good specimens coming especially from the

Republic of Congo The Republic of the Congo, also known as Congo-Brazzaville, the Congo Republic or simply the Congo (the last ambiguously also referring to the neighbouring Democratic Republic of the Congo), is a country located on the western coast of Central ...

. "Cobaltocalcite" is a cobaltiferous

variety that is quite similar in

habit A habit (or wont, as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously. A 1903 paper in the '' American Journal of Psychology'' defined a "habit, from the standpoint of psychology, ...

to spherocobaltite. Sodium tris(carbonato)cobalt(III) is a cobalt(III) complex containing three carbonate ligands.

Safety

Toxicity has rarely been observed. Animals, including humans, require trace amounts of cobalt, a component of

vitamin B12 Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. One of eight B vitamins, it serves as a vital cofactor (biochemistry), cofactor in DNA synthesis and both fatty acid metabolism, fatty acid and amino a ...

References

External links

* {{Cobalt compounds Cobalt(II) compounds Carbonates