Carbonyl metallurgy
Encyclopedia
Carbonyl metallurgy is used to manufacture products of iron
, nickel
, steel
, and other metal
s. Coatings are produced by vapor plating using metal carbonyl
vapors. (Carbonyls are metal - ligand
complexes where carbon monoxide
is bonded in a pendant ligand structure to individual atoms of metals such as iron and nickel.)
Iron carbonyl is stable as iron pentacarbonyl
, where five carbon monoxide molecules are pendantly bonded to the iron atom, while nickel carbonyl
is stable as nickel tetracarbonyl, which has four carbon monoxide molecules pendantly bonded to the nickel atom. Both can be formed by the exposure of the powdered metal to carbon monoxide gas at temperatures of around 75 degrees Celsius. Both the metal carbonyls decompose near 175 °C, resulting in a vapor plated metallic coating. The thickness of the vapor plated deposit can be increased to desired thicknesses by controlling the amount of metal carbonyl used and the duration of the plating process.
Vale Inco produces over 100 million pounds of nickel metal annually by the carbonyl process. The carbonyl process has been used to produce molds in custom shapes for industry. Such molds have been used in plastic molding and other manufacturing techniques.
William Jenkin developed many of the techniques and procedures used in carbonyl metallurgy.
Carbonyl metallurgy is useful as a low temperature metal coating technique that may well find many applications in the future.
Carbonyl iron
Carbonyl iron is a highly pure iron, prepared by chemical decomposition of purified iron pentacarbonyl. It usually has the appearance of grey powder, composed of spherical microparticles. Most of the impurities are carbon, oxygen, and nitrogen.BASF invented carbonyl iron powder in 1925, and claims...
, nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
, steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
, and other metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
s. Coatings are produced by vapor plating using metal carbonyl
Metal carbonyl
Metal carbonyls are coordination complexes of transition metals with carbon monoxide ligands. These complexes may be homoleptic, that is containing only CO ligands, such as nickel carbonyl , but more commonly metal carbonyls contain a mix of ligands, such as Re3Cl...
vapors. (Carbonyls are metal - ligand
Ligand
In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...
complexes where carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
is bonded in a pendant ligand structure to individual atoms of metals such as iron and nickel.)
Iron carbonyl is stable as iron pentacarbonyl
Iron pentacarbonyl
Iron pentacarbonyl, also known as iron carbonyl, is the compound with formula 5. Under standard conditions Fe5 is a free-flowing, straw-colored liquid with a pungent odour. This compound is a common precursor to diverse iron compounds, including many that are useful in organic synthesis. Fe5 is...
, where five carbon monoxide molecules are pendantly bonded to the iron atom, while nickel carbonyl
Nickel carbonyl
Nickel carbonyl is the organonickel compound with the formula Ni4. This pale-yellow liquid is the principal carbonyl of nickel. It is an intermediate in the Mond process for the purification of nickel and a reagent in organometallic chemistry...
is stable as nickel tetracarbonyl, which has four carbon monoxide molecules pendantly bonded to the nickel atom. Both can be formed by the exposure of the powdered metal to carbon monoxide gas at temperatures of around 75 degrees Celsius. Both the metal carbonyls decompose near 175 °C, resulting in a vapor plated metallic coating. The thickness of the vapor plated deposit can be increased to desired thicknesses by controlling the amount of metal carbonyl used and the duration of the plating process.
Vale Inco produces over 100 million pounds of nickel metal annually by the carbonyl process. The carbonyl process has been used to produce molds in custom shapes for industry. Such molds have been used in plastic molding and other manufacturing techniques.
William Jenkin developed many of the techniques and procedures used in carbonyl metallurgy.
Carbonyl metallurgy is useful as a low temperature metal coating technique that may well find many applications in the future.
Further reading
- Iron recovery and steel manufacture using carbonyl chemistry - http://www.space-mining.com/IRONRECOVERY.htm
- Beneficiation of asteroidal iron by carbonyl metallurgy - http://www.space-mining.com/beneficiation.html
- William Jenkin inventor of numerous carbonyl processes - http://www.sitereviewboard.com/reviews-wc/wcjenkin-com-cache.html
- Preparation of Iron Carbonyl - http://www.patentstorm.us/patents/7276220-description.html
- Preparation of metallic shaped bodies - http://www.patentstorm.us/patents/5802437-claims.html