Chemical Properties
black powder(s); trig, yellow metallic luster; enthalpy of fusion 30.10 kJ/mol; can be formed by fusing Ni powder(s) and molten sulfur; other sulfides include Ni2S, 12137-08-5, Ni3S2, 12035-72-2 (heazlewoodite), NiS2, 12035-51-7, and Ni3S, 12137-12-1 (polydymite) [KIR81] [STR93] [CRC10] [JAN85]
Preparation
The black nickel sulphide precipitated from nickel(II) salt solutions
by ammonium sulphide in neutral but not strongly acid solution is the so-called α-NiS ; it
consists largely of amorphous Ni(SH,OH)2 when first precipitated. At low pH this crystallizes
to give mainly the rhombohedral γ-NiS, while at higher pH the hexagonal β-NiS(Ni
1-XS) crystallizes.
Flammability and Explosibility
Non flammable
Safety Profile
Confirmed carcinogen
with experimental carcinogenic and
neoplastigenic data. Mutation data reported.
When heated to decomposition it emits
toxic fumes of SOx. See also NICKEL
COMPOUNDS and SULFIDES.
