Definition and Uses :
Nickel (II) chloride (or simply nickel chloride), NiCl2 is the chemical compound. The anhydrous salt is yellow, but the more familiar hydrogen NiCl2.6H20, is green. Nickel (II) chloride, in its various forms, is the most important source of nickel for chemical synthesis. Nickel chlorides are assimilated by absorbing moisture from the air to form solutions. In the case of long-term inhalation exposure, nickel salts have been shown to be carcinogenic to the lungs and nasal passages.
The largest-scale production of nickel chloride involves the extraction of nickel matte with hydrochloric acid and residues from the refining process of nickel-bearing ores.