Cobalt(II) carbonate is the

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

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

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

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

spherocobaltite Spherocobaltite or sphaerocobaltite is a cobalt carbonate mineral with chemical composition CoCO3. In its (rare) pure form, it is typically a rose- red color, but impure specimens can be shades of pink to pale brown. It crystallizes in the ...

Preparation and structure

It is prepared by combining solutions cobaltous sulfate and sodium bicarbonate: :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 mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scra ...

, 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 Acetylacetone is an organic compound with the chemical formula . It is a colorless liquid, classified as a 1,3- diketone. It exists in equilibrium with a tautomer . These tautomers interconvert so rapidly under most conditions that they are tr ...

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 viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3% ...

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

calcining Calcination refers to 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), gene ...

, 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 one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in orde ...

s since cobalt is an

essential element In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life. However, the four major structural elements in the human body by weight (oxygen, hydrogen, carbon, ...

. It is a precursor to blue pottery glazes, famously in the case of

Delftware Delftware or Delft pottery, also known as Delft Blue ( nl, Delfts blauw) 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 ...

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

is a natural form of cobalt carbonate, with good specimens coming especially from the

Republic of Congo The Republic of the Congo (french: République du Congo, ln, Republíki ya Kongó), also known as Congo-Brazzaville, the Congo Republic or simply either Congo or the Congo, is a country located in the western coast of Central Africa to the w ...

. "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.

to spherocobaltite.

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. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. It ...

References

External links

* {{Cobalt compounds Cobalt(II) compounds Carbonates