The Earth's crust is about 0.008% by weight of nickel in the water of the oceans - 0.002 mg / l.World reserves of nickel are around 70 mln. Tons.Nickel is an essential trace element for plants and mammals, in the human body contains from 5 to 13.5 mg of nickel.
There are about 50 minerals of nickel, the most important ones: pentlandite, Miller garnierite, Revdinsky, nickeline and annabergite.Nickel is extracted from silicate-oxide and sulphide copper-nickel ores.
Pure Nickel is easy to work both hot and cold.Chemically it maloaktiven not react with water and atmospheric moisture, at ambient temperatures of nickel coated with a thin oxide film.Surface oxidation begins at about 800 ° C.
Nickel is very slow to react with sulfuric, hydrochloric, phosphoric and h
ydrofluoric acids, it almost does not apply organic acid in the presence of air.While in the particulate state, the metal exhibits higher catalytic activity in the oxidation reactions, condensation, isomerization, hydrogenation and dehydrogenation.
Molten nickel dissolve the carbon to form a carbide, which is in the crystallization of the melt decomposes and releases carbon.In reactions with carbon monoxide particulate metal gives the volatile nickel tetracarbonyl, and when alloyed with silicon - silicide.Working with pairs of phosphorus, nickel phosphide forms.
For processing silicate and oxide ores using a reduction to produce ferronickel smelting, after which it is subjected to a purge in the converter refining and enrichment.Nickel concentrates obtained in the beneficiation of sulfide ore, followed by melt blowing in the converter.
Nickel can be found on the blue-violet color after reaction with acid rubeanic or pinkish-red connection with dimethylglyoxime in an ammonia environment.Quantitatively, it is determined by precipitation with dimethylglyoxime or elektrogravimetricheskim way, photometric titration, and chelators.It also used fluorescence, X-ray, atomic absorption and emission methods.
Most nickel is used as a component for corrosion-resistant, magnetic, and heat-resistant super-hard alloys.Metal nickel is structural material for nuclear reactors and chemical apparatus, as well as for battery electrodes.
- HiMiK.ru, Nickel