Cobalt (II) Chloride

Brief Overview

Cobalt(II) chloride is an inorganic compound of cobalt and chlorine, with the formula CoCl₂ and sky blue in colour. It is most commonly supplied as the hexahydrate CoCl₂·6H₂O, which is pink in colour. Concentrated aqueous solutions are red at room temperature but become blue at higher temperatures. CoCl₂·6H₂O is deliquescent while the anhydrous salt CoCl₂ is hygroscopic.

Manufacturing Process

Hydrated cobalt chloride is manufactured from reaction of cobalt(II) hydroxide or cobalt(II) carbonate with hydrochloric acid according to the reactions below:

CoCO₃ + 2 HCl + 5 H₂O → Co(H₂O)6Cl₂ + CO₂

Upon heating, the hexahydrate dehydrates. Dehydration can also be effected with trimethylsilyl chloride:

CoCl₂•6H₂O + 12 Me₃SiCl → CoCl₂ + 6 (Me3Si)₂O + 12 HCl

Painting and printing Industry: Used as a catalyst, printing and dyeing mordant.

Chemical Industry: Used as an analytical reagent.

Other Applications:

• Used as a necessary catalyst in synthetic fiber industry

• ceramic pigment, glaze ingredients, cobalt glass curing agent

• Also used in surface treatment in aluminium as hiding color ink.