What Is Nickel Sulfide?
Nickel sulfide is an inorganic compound with the chemical formula NiS.
Nickel sulfide (NiS) is formed when nickel salts are treated with hydrogen sulfide. Nickel sulfide is known in several forms, with nickel monosulfide (NiS) being found in needle nickel ore. It is insoluble in water, soluble in nitric acid, and is amorphous and black in color.
Nickel sulfide (NiS2) is obtained by heating nickel (II) carbonate with potassium carbonate and sulfur. It is dark iron-gray crystalline and insoluble in water. Nickel Sulfide (Ni3S2) is almost insoluble in water and soluble in nitric acid.
Uses of Nickel Sulfide
Nickel sulfides are widely used as catalysts for nickel sulfide. Examples include high-pressure hydrogenation cracking of heavy oil, dehydrogenation of organic compounds, and desulfurization catalysts.
Nickel sulfide hazard information includes the risk of inhalation causing allergies, asthma, breathing difficulties and allergic skin reactions, carcinogenicity, and respiratory damage from prolonged or repeated exposure. When using the product, appropriate protective gloves and respiratory protective equipment should be worn, and hands should be washed thoroughly after handling.
Properties of Nickel Sulfide
NiS is a black solid that is formed by treating nickel (II) salts with hydrogen sulfide. A number of nickel sulfides are known, including needle nickel ore, a mineral with the same chemical formula NiS. In addition to useful ores, nickel sulfide is also obtained as a product of desulfurization reactions and is often used as a catalyst.
Structure of Nickel Sulfides
Nickel sulfide includes nickel monosulfide (NiS), nickel disulfide (NiS2), and trinickel disulfide (Ni3S2). Other indeterminate ratio compounds, such as Ni9S8 and Ni3S2 are also known. As in base ore (NiS2), one nickel atom can combine with several sulfur atoms.
Nickel sulfide (II), like many related substances, takes the nickel arsenide motif. In this structure, nickel sulfide is octahedral and the sulfide center is triclinic.
Nickel sulfide (II) has both alpha and beta polymorphs: alpha is a hexagonal unit cell and beta is a rhombohedral unit cell. Alpha is stable above 379°C, but converts to beta at lower temperatures. This phase transition increases the volume by 2-4%.
Other Information on Nickel Sulfide
1. Synthesis of Nickel Sulfide (II)
The black precipitation of nickel sulfide (II) is well known in traditional qualitative inorganic analysis. This means that metals containing nickel (II) can be separated based on differences in the solubility of the sulfide.
A full range of controlled synthesis methods has been developed, including solid-phase metathesis synthesis and high-temperature reactions of elements.
2. Natural Nickel (II) Sulfide
Needle nickel ore is nickel sulfide (II), which has the same chemical formula as NiS. Besides occurring naturally, such as in low-temperature hydrothermal systems or in cavities in carbonate rocks, it can also occur as a byproduct of other nickel minerals. However, depending on the conditions under which nickel sulfide(II) is formed, its structure differs from that of synthetic stoichiometric NiS.
3. Nickel Sulfide (II) In Glass
Float glass contains small amounts of nickel sulfide (II) formed by nickel in the clarifier sodium sulfate and impurity metal alloys. These nickel sulfide inclusions are a problem in the manufacture of tempered glass.
This is because nickel sulfide inclusions become a metastable α-phase after the tempering process and are eventually converted to a stable β-phase at low temperatures, which increases in volume and causes glass cracks. Tension is applied to the material inside the tempered glass and propagation of cracks leads to spontaneous glass fracture. This spontaneous glass fracture usually occurs several years to decades after the glass is manufactured.
4. Other Nickel Sulfide Structures
Nickel sulfide is known to include NiS, NiS2, and Ni3S2, as well as compounds such as Ni9S8 and Ni3S2. For example, NiS2, also known as base ore, is a sulfide mineral composed mainly of nickel sulfide with small amounts of cobalt and iron.