Никель

Химические свойства

RANEY NICKEL is a hard, ductile, magnetic metal with a silver-white color.

Физические свойства

Nickel metal does not exist freely in nature. Rather, it is located as compounds in ores ofvarying colors, ranging from reddish-brown rocks to greenish and yellowish deposits, andin copper ores. Once refined from its ore, the metallic nickel is a silver-white and hard butmalleable and ductile metal that can be worked hot or cold to fabricate many items. Nickel,located in group 10, and its close neighbor, copper, just to its right in group 11 of the periodictable, have two major differences. Nickel is a poor conductor of electricity, and copper is anexcellent conductor, and although copper is not magnetic, nickel is. Nickel’s melting point is1,455°C, its boiling point is 2,913°C, and its density is 8.912 g/cm³.

Изотопы

There are 31 isotopes of nickel, ranging from Ni-48 to Ni-78. Five of these arestable, and the percentage of their contribution to the element’s natural existence onEarth are as follows: Ni-58 = 68.077%, Ni-60 = 26.223%, Ni-61 = 1.140%, Ni-62 =3.634%, and Ni 64 = 0.926%. All of the other 26 isotopes of nickel are artificially madeand radioactive with half-lives ranging from a few nanoseconds to 7.6×10⁴ years.

Происхождение имени

The name is derived from the ore niccolite, meaning “Old Nick,” referred to as the devil by German miners. The niccolite mineral ore was also called “kupfernickel,” which in German stands for two things; first, it is the name of a gnome (similar to Cobalt), and second, it refers to “Old Nick’s false copper.”

Вхождение

Nickel is the 23rd most abundant element found in the Earth’s crust. It is somewhat plentiful but scattered and makes up one-hundredth of 1% of igneous rocks. Nickel metal is foundin meteorites (as are some other elements). It is believed that molten nickel, along with iron,makes up the central sphere that forms the core of the Earth.There are several types of nickel ores. One is the major ore for nickel called pentlandite(NiS ? 2FeS), which is iron/nickel sulfide. Another is a mineral called niccolite (NiAs), discovered in 1751 and first found in a mining area of Sweden. By far, the largest mining area fornickel is located in Ontario, Canada, where it is recovered from what is thought to be a verylarge meteorite that crashed into the Earth eons ago. This large nickel deposit is one reasonfor the theory of the Earth’s core being molten nickel and iron, given that both the Earth andmeteorites were formed during the early stages of the solar system. Some nickel ores are alsofound in Cuba, the Dominican Republic, and Scandinavia. Traces of nickel exist in soils, coal,plants, and animals.

Характеристики

As mentioned, nickel is located in group 10 (VIII) and is the third element in the specialtriad (Fe, Co, Ni) of the first series of the transition elements. Nickel’s chemical and physicalproperties, particularly its magnetic peculiarity, are similar to iron and cobalt.Some acids will attack nickel, but it offers excellent protection from corrosion from air andseawater. This quality makes it excellent for electroplating other metals to form a protectivecoating. Nickel is also an excellent alloy metal, particularly with iron, for making stainless steelas well as a protective armor for military vehicles. It is malleable and can be drawn throughdies to form wires. About one pound of nickel metal can be drawn to about 200 miles of thinwire.

Использование

Nickel-plating; for various alloys such as new silver, Chinese silver, German silver; for coins, electrotypes, storage batteries; magnets, lightning-rod tips, electrical contacts and electrodes, spark plugs, machinery parts; catalyst for hydrogenation of oils and other organic substances. See also Raney nickel. manufacture of Monel metal, stainless steels, heat resistant steels, heat and corrosion resistant alloys, nickel-chrome resistance wire; in alloys for electronic and space applications.

Подготовка

The carbonyl process is most commonly employed when very pure nickel is required. The impure metal is reacted with pure carbon monoxide at 50° and the carbonyl produced fractionated several times prior to pyrolysis at around 200°. The nickel thus obtained has a purity of 99.90-99.99% depending upon the materials used.
Electrolytic methods for producing high purity nickel depend upon the production of high purity nickel salts. The nickel obtained by the electrolysis of pure nickel chloride solution with inert platinum-iridium anodes is 99.99% pure.

Методы производства

Nickel is obtained by processing sulfide and laterite ore concentrates using pyrometallurgic and hydrometallurgic processes. The resultant nickel matte obtained by roasting and smelting is subjected to further cleaning by electro-, vapo-, and hydrometallurgic refining methods. Some portion of the matte is roasted to obtain commercial nickel oxide agglomerate. Pure, 99.9% nickel can be obtained by electrolytic refining process.
The most pure, 99.97%, nickel is obtained by vapometallurgy. In this process, known also as the Mond method,nickel and copper sulfide blend is converted to oxides and then reduced by heating with water gas at 350–400°C. The resultant active form of nickel is treated with carbon monoxide to give volatile nickel carbonyl [Ni(CO)4]. The latter reaction is reversible; heating results in pure nickel and carbon monoxide.

Определение

ChEBI: Chemical element (nickel group element atom) with atomic number 28.

Общее описание

Nickel catalyst, is extremely fine powdered nickel. Nickel is grayish colored. Insoluble in water. Nickel catalyst is used to promote the chemical action in manufacturing synthetics and to process vegetable oil and petroleum. If exposed to air or moisture, Nickel may become hot enough to ignite. Nickel is insoluble in water and does not react with larger volumes of water.

Реакции воздуха и воды

Pyrophoric, Ignites spontaneously in the presence of air; during storage, H2 escapes with fire and explosion hazards; reacts violently with acids forming H2. [Handling Chemicals Safely 1980. p. 807].

Профиль реактивности

Metals, such as METAL CATALYST, are reducing agents and tend to react with oxidizing agents. Their reactivity is strongly influenced by their state of subdivision: in bulk they often resist chemical combination; in powdered form they may react very rapidly. Thus, as a bulk metal Nickel is somewhat unreactive, but finely divided material may be pyrophoric. The metal reacts exothermically with compounds having active hydrogen atoms (such as acids and water) to form flammable hydrogen gas and caustic products. The reactions are less vigorous than the similar reactions of alkali metals, but the released heat can still ignite the released hydrogen. Materials in this group may react with azo/diazo compounds to form explosive products. These metals and the products of their corrosion by air and water can catalyze polymerization reactions in several classes of organic compounds; these polymerizations sometimes proceed rapidly or even explosively. Some metals in this group form explosive products with halogenated hydrocarbons. Can react explosively with oxidizing materials.

Опасность

Nickel dust and powder are flammable. Most nickel compounds, particularly the salts, aretoxic. NiSO₄ is a known carcinogen.
Although nickel is not easily absorbed in the digestive system, it can cause toxic reactionsand is a confirmed carcinogen in high concentration in the body. Nickel workers can receivesevere skin rashes and lung cancer from exposure to nickel dust and vapors.
Nickel is stored in the brain, spinal cord, lungs, and heart. It can cause coughs, shortnessof breath, dizziness, nausea, vomiting, and general weakness.

Пожароопасность

Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated.

Профиль безопасности

Confirmed carcinogen with experimental carcinogenic, neoplastigenic, and tumorigenic data. Poison by ingestion, intratracheal, intraperitoneal, subcutaneous, and intravenous routes. An experimental teratogen. Ingestion of soluble salts causes nausea, vomiting, and diarrhea. Mutation data reported. Hypersensitivity to nickel is common and can cause allergic contact dermatitis, pulmonary asthma, conjunctivitis, and inflammatory reactions around nickel-containing medcal implants and prostheses. Powders may ignite spontaneously in air. Reacts violently with F2, NH4NO3, hydrazine, NH3, (H2 + dioxane), performic acid, P, Se, S, (Ti + KCLO3). Incompatible with oxidants (e.g., bromine pentafluoride, peroxyformic acid, potassium perchlorate, chlorine, nitryl fluoride, ammonium nitrate), Raney-nickel catalysts may initiate hazardous reactions with ethylene + aluminum chloride, pdioxane, hydrogen, hydrogen + oxygen, magnesium silicate, methanol, organic solvents + heat, sulfur compounds. Nickel catalysts have caused many industrial accidents.

Канцерогенность

Metallic nickel is reasonably anticipated to be a human carcinogenbased on sufficient evidence of carcinogenicity from studies in experimental animals.

Перевозки

UN3089 Metal powders, flammable, n.o.s., Hazard Class: 4.1; Labels: 4.1-Flammable solid. UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard Class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

Несовместимости

Nickel dust is a spontaneously flammable solid and a dangerous fire hazard.

Утилизация отходов

Nickel compoundsencapsulation followed by disposal in a chemical waste landfill. However, nickel from various industrial wastes may also be recovered and recycled as described in the literature.