Alkaline Earth Metals
Group of metals in the periodic table. Includes beryllium, calcium, strontium, barium and radium.
A combination of two or more metals with their own distinct properties.
An alloy containing aluminum nickel and cobalt. The original high-strength permanent-magnet alloy.
Oxide of aluminum. Usually produced from bauxite as a first stage in the manufacture of aluminum. About two tons of alumina make one ton of metal. Also a refractory and an abrasive.
Coating steel with aluminum. Has similar results to galvanizing with the added advantage of heat resistance, e.g. on exhaust systems.
Aluminum was already 12 years into its second century as a viable commercial metal when the Third Millennium got under way. Its historysave for a few pieces of flatware worked up for one of the Napoleonsdates back to 1889 and the launching of Pittsburgh Reduction Co.later Aluminum Co. of America and, finally, Alcoa Inc. The metals discovery goes back to 1827, but it took its discoverer, Frederich Wholer, another 18 years before he could isolate a few small beads of it. And it wasnt until 1886 that Charles Martin Hall in the United States and Paul Heroult in France independently discovered the first practical method for producing aluminum through electrolytic reduction. Alcoa and other producers have systematically improved and modernized the Hall-Heroult Process and the equipment ever since, but the process remains basically the same.
RECYCLING: Aluminum recovered in the U.S. from purchased scrap totaled roughly 3 million tonnes. Of that total, 60 percent was derived from new scrap through manufacturing and the balance from old scrap through discarded products, according to the USGS.
SUBSTITUTES: Some substitutes for aluminum include copper in electrical applications; steel, magnesium and titanium in structural and ground-transportation uses; composites, wood and steel in construction; and glass, paper, plastics and steel in packaging applications.
An alloy of 89-95% copper and 5-11% aluminum with good bearing properties. Used for bushes and moving parts.
Standard long product in steel, aluminium and other metals. The arms of the angle may be equal or unequal.
A process of heat treatment for restoring the ductility of metals work-hardened by
A process of improving the corrosion resistance of aluminum by thickening the natural oxide film on the surface. The coating may be coloured with dyes or integrally in a few colours by tailoring the composition of the alloy treated.
Antimony is a lustrous, extremely brittle and hard crystalline semi-metal that, in its most common allotropic form, is silvery white. Antimony is a poor conductor of heat and electricity. More than 80 percent of the worlds mined antimony is produced in China, where mine production was about 100,000 tonnes in 2000. In nature, antimony has a strong affinity for sulfur and such metals as lead, silver and copper. The elements most significant compound is antimony trioxide, which is used as a flame retardant in textiles, plastics, adhesives and building materials. In the United States, 55 percent of its consumption by end-use is for flame retardants. Antimony trioxide also is used in battery components, ceramics, bearings, chemicals, glass and ammunition.
RECYCLING: Secondary antimony traditionally has been recovered as antimonial lead from batteries. The battery industry traditionally also consumed the recovered antimonial lead. But lesser amounts of secondary antimony have been produced in recent years due to changing industry trends, the USGS reported.
SUBSTITUTES: Some substitutes for antimony include compounds of chromium, tin, titanium, zinc and zirconium in paint pigments and enamels; combinations of cadmium, calcium, copper, selenium,strontium,sulfur and tin for hardening lead; and selected organic compounds and hydrated aluminum oxide as flame retardants.
The knowledge of arsenic dates back to ancient Greece, but it wasnt until the Middle Ages that its poisonous characteristics were described. Metallic arsenic was first produced in the 17th century by heating arsenic with potash and soap. The silver-gray semi-metal is rarely found in nature in its elemental form and is basically recovered as a byproduct of ore processing. Traditionally used as a toxin and a nonferrous alloy for enhancing properties such as resistance to corrosion, arsenic is now blended with gallium to produce semiconductors.
SUBSTITUTES: Pentachlorophenol and creosote in wood preservatives where permitted; ammoniacal copper quarternary, copper azole copper citrate and copper dimethyldithiocarbamate in other wood preservatives; and concrete, steel or plastic lumber in some applications for treated wood.
A major class of alloy steel, especially stainless. Classically 18%Cr 8%Ni, the latter is ductile, easily welded and work hardens. May contain molybdenum.
A long product in a non-ferrous or ferrous metal of rectangular, or sometimes circular, cross-section, normally over 10mm thick and up to 300mm wide. Not to be confused with Rebar.
Major industrial non-ferrous metals other than precious metals and minor metals. See also Noble metals.
BauxiteAluminum trihydrate, the most common raw material for the production of alumina. Roughly two tons of bauxite make one ton of alumina.
BeamA steel or sometimes aluminum structure.
Extracted from the mineral beryl, bertrandite and phenakite ores, Beryllium exhibits both metallic and non-metallic properties. The element was discovered by Nicolas Louis Vauquelin in 1798 while examining an emerald in beryl form but was not isolated until 1828. This silver-colored, brittle metal is one of the lightest structural materials. Stiffer than 1010 steel, beryllium is also highly conductive. In fact, beryllium and its alloys are often chosen materials for it-has-to-work electronic and aerospace equipment. Automobile air bags, for example, use pricey beryllium-copper alloys to ensure deployment. Although solid beryllium poses no health hazard, inhaling beryllium particles or fumes can produce acute or chronic lung disease.
Beryllium is typically used in applications in which its properties are crucial. While substitutes are available for some applications, beryllium substitutes can result in a dramatic loss in performance.
RECYCLING: Unspecified quantities of new scrap generated in the processing of beryllium-copper alloys and quantities of obsolete military equipment containing metallic beryllium were recycled, according to the USGS.
SUBSTITUTES: Some substitutes for beryllium include graphite, steel and titanium in some applications that use beryllium metal; phosphor bronze in some applications using beryllium-copper alloys; and aluminum nitride in some applications using beryllium oxide.
Copper with a small addition of beryllium used for springs and non-sparking tools.
(i) In steel, a long product of square cross-section used for rolling into finished shape as a rebar or light long product; the form in which steel is traded on the LME. (ii) In non-ferrous (mostly aluminum and brass) a cylindrical shape for use in an extrusion press; or in a piercing machine as the start of solid-drawn tube production.
An alloy composed of two metals
Heavy, soft, brittle and silver white in color, bismuth might be one of the most environmentally safe metals around. Bismuth is non-toxic and non-carcinogenic. Classified as one of the low-melting-point metals, bismuth is one of the few elements that doesnt shrink upon solidification. Demand for the material as a replacement for lead has grown in recent years. It is also used as a remedy for stomach ailments. In fact, it is the bismol in Pepto Bismol. Bismuth is generally mined as a by-product of lead, tin, copper, tungsten, silver and gold ores.
RECYCLING: Some bismuth was recovered from fusible alloy scrap, according to the USGS, but that contributes less than 5 percent of the U.S. supply.
SUBSTITUTES: Some substitutes for bismuth include antibiotics, magnesia and alumina in pharmaceutical applications; titanium dioxide-coated mica flakes and fish scale extracts in pigment uses; indium in low-temperature solders; resins in machining uses; glycerin-filled glass bulbs in fire sprinkler triggering devices; and selenium, tellurium and lead in free-machining alloys.
A very impure (85-90%) first smelting of copper prior to fire refining.
A furnace in which a mixture of ore and coke is raised to a high temperature by blowing air in at the bottom. Metal and slag are continuously tapped from the bottom and fresh charge is added at the top. Mainly used for iron, mostly then used to make steel, and lead.
Steel semi for rolling into other semi-finished and finished products. Generally considered an antiquated method of casting crude steel.
Basic oxygen furnace. Oxygen-blown steelmaking furnace with basic refractory lining.
A family of copper-zinc alloys, classically 60/40. Variations in composition give different colours and physical characteristics.
An alloy of 50% copper, 50% zinc used for joining iron and steel at a lower temperature than welding.
Bright Drawn- Steel
Long products such as bar are sometimes drawn after rolling to achieve greater dimensional accuracy and a bright finish.
(i) In ferro-alloys a briquette is a granular form of the alloy held together with a binder and contains an exact amount of the alloying metal. (ii) In scrap processing, particulate material (e.g. chopped cable, swarf) is briquetted under pressure to reduce surface area and increase density for charging to the furnace.
An alloy of 90% copper 10% tin. Variants are aluminium bronze and manganese bronze; the latter is better known as High Tensile Brass.
Ores shipped in very large volume without packing mainly iron and managanese.
Cadmium is a bluish-white soft metal that can be cut with a knife. It is recovered primarily through the smelting of zinc. Discovered in Germany in 1817, its principal use has been in nickel-cadmium batteries for portable communications, electronic and electrical equipment. Other applications include pigments, coatings and plating, stabilizers for plastics and similar synthetics, alloys, lasers and solar cells.
RECYCLING: At present, cadmium recycling has been practical only for nickel-cadmium batteries, some alloys, and dust from electric furnaces. The exact amount of recycled cadmium is not known, according to the USGS.
SUBSTITUTES: Some substitutes for cadmium include lithium-ion and nick-el-metal hydride batteries in some applications; zinc or vapor-deposited aluminum coatings in plating applications; and cerium sulfide in plastics, replacing cadmium pigments.
Copper with a small addition of cadmium for greater strength. Standard metal for overhead conductor on electric railways.
Usually refers to copper. Rectangular shapes suitable for rolling into plate, sheet etc.
A calot (in zinc) or slug (in aluminium) is a thick disc of soft metal which is the raw material for an impact extrusion (e.g. collapsible (aluminium) tube for toothpaste).
Ordinary unalloyed steel.
(i) The product of a foundry. Molten metal is poured into a mould to produce the desired finished shape, often complex. Castings are mostly made of iron, steel, aluminium, copper alloys and zinc, but most metals can be cast. They may be sand-cast, gravity die cast, pressure die cast or, more rarely, cast by the lost wax process. The structure of cast metal is different from that of wrought metal. (ii) The process of casting steel in a continuous process.
A flat rectangular piece of metal which has been refined by electrolysis or electrowinning. Copper and nickel are commonly traded and delivered in this form. Copper is always traded as whole plates. Nickel may be whole plates or cut into squares of various sizes down to 1in.x1in. Cobalt cathode is traded as chips.
Most often found with tantalum, beryllium or lithium, cesium takes the form of a soft and malleable silver-white alkali metal. Discovered by Robert Bunsen (of burner fame) and Gustaff Kirchhoff in 1860 in mineral water from Durkheim, Germany, it was the first element to be detected spectroscopically. Cesium is the heaviest of the natural alkali metals, in the same group as lithium, sodium, potassium and rubidium, and is similarly reactive, cesium metal.
But to a much higher degree due to its extreme electropositivity. It reacts explosively with water, and with ice down to -116 C. In air, it catches fire spontaneously and burns with a brilliant sky-blue flame. The metal had no significant use until the 1920s, when it was used as a coating for tungsten filaments in lighting. In the form of chemical compounds, cesium is used in research and development and commercially in electronic, photoelectric and medical applications.
SUBSTITUTES: As the properties of rubidium and its compounds are very similar to those of cesium and its compounds, the two are used interchangeably in many applications.
Chromium is a critical alloying ingredient for the production of stainless and hardened steels. It was discovered in 1797 and, like aluminum, it is very resistant to corrosion. It is a silver-gray, lustrous, hard and brittle metal that takes its name from the Greek word for color, khroma. Chromium is extracted primarily from chromite, which is composed of iron, chromium and oxygen. It is not found in nature in its free state. In addition to steel alloying, chromium is used as a corrosion chromium resistant decorative plating agent and as a pigment in glass.
RECYCLING: In 2001, chromium contained in purchased stainless steel scrap accounted for 22 percent of apparent consumption, the USGS reported.
SUBSTITUTES: Chromium has no substitute in stainless steel, the largest end use, or for chromium in superalloys, the major strategic end use, according to the USGS. Chromite ore has no substitute in the production of ferrochromium, chromium chemicals or chromite refractories.
Cobalt has been in use since at least 2250 BC, when the Persians used it to color glass. It was not until 1735, however, that Swedish scientist Georg Brandt first isolated metallic cobalt and 1780 that it was recognized as an element. Today, cobalt is used mainly in high-temperature steel alloys, magnetic alloys and hard-facing alloys resistant to abrasion. Alloys containing 25-percent cobalt have been developed for use as fasteners in gas turbine engines. In fact, 747 jet engines are estimated to contain about 400 pounds of cobalt apiece.
RECYCLING: The USGS estimated that 2,520 tonnes of cobalt was recycled from purchased scrap in 2001, representing about 33 percent of estimated reported consumption for the year.
SUBSTITUTES: Potential substitutes include barium and strontium ferrites, neodymium-iron-boron or nickel-iron alloys in magnets; nickel, cermets or ceramics in cutting and wear-resistant materials; nickel-base alloys or ceramics in jet engines; nickel in petroleum catalysts; rhodium in catalysts; iron, manganese or nickel in batteries; and manganese, iron, cerium or zirconium in paints.
Sheet metal is coiled up as it emerges from the rolling mill and is then normally strapped and sold in this form. In steel, hot rolled coil (HRC) is sold to independent cold rollers who sell CRC, or cold rolled in-house by vertically integrated mills. Vertical integration of hot and cold rolling is more normal in non-ferrous metals, as is continuous casting at the start of the process.
A plant for converting metallurgical grade coal to coke for use in blast furnaces.
A process used to fine-tune the surface finish and dimensional tolerance of hot rolled steel. Also to change cross-sectional shape.
A process of casting a product, such as a rolling slab or extrusion billet, through an open-ended die in which it is rapidly frozen. Strictly speaking this is semi-continuous casting. See also Hazelett and Properzi.
Copper was first discovered around 8000 BC in what is now northern Iraq, in the valley of the Tigris and Euphrates rivers, the cradle of civilization. Deposits were worked in Egypt as early as 5000 BC. The word copper is derived from Cyprus, because the Mediterranean island was a primary source of the metal. Its symbol, the ankh, is Egyptian in origin and also represents the planet Venus. It has an atomic weight of 63.54 and a melting point of 1,083.4 degrees Celsius. Copper is a reddish metal that is widely used in industry because it is both an excellent conductor of electricity and has strong corrosion-resistance properties. Used in a broad range of alloys, it is the basis for brass and bronze. With the advent of the telegraph, telephone and electric lights at the turn of the last century, large-scale copper mining became economically viable for the first time. The first large mines were located in Montana, Arizona, Utah and Michigan. South American deposits were developed by U.S. companies, which controlled them until the 1960s, when nationalization swept the continent.
RECYCLING: Domestically, old scrap, converted to refined metal and alloys, provided 310,000 tons of copper, equivalent to 11 percent of apparent consumption, according to the USGS. Purchased new scrap, from fabricating operations, yielded 910,000 tonnes of contained copper. Roughly 90 percent of the copper contained in new scrap was consumed at brass or wire-rod mills. Of the total copper recovered from scrap, including aluminum- and nickel-base scrap, brass mills recovered 65 percent; copper smelters and refiners, 13 percent; ingot makers, 11 percent, and miscellaneous manufacturers, foundries and chemical plants, 11 percent. Copper in all old and new, refined or remelted scrap contributed 33 percent to the U.S. copper supply, the USGS reported.
SUBSTITUTES: Aluminum is a substitute for copper in various products, including electric power cables, electric equipment, auto radiators and cooling/refrigeration tubing. Other substitutes include titanium and steel in heat exchangers; steel for artillery shell casings; optical fiber in some telecommunications applications; and plastics in water pipe, plumbing fixtures and many structural applications.
The first solid steel product upon solidification of liquid steel. It includes ingots and semis. Crude steel also includes liquid steel which goes into production of steel castings.
Copper with about 30% nickel. Used for coinage.
Casting a non-ferrous metal (usually zinc or aluminium) into a closed steel die either by gravity pouring (gravity die casting) or injection under pressure (pressure die casting). More accurate and faster than sand casting.
Direct Stip Casting
Casting steel strip very close to final dimensions to minimise the need for subsequent hot rolling to size (from conventional slab).
Short for drawn over mandrel. Steel industry term for solid drawn tube.
The process of drawing metal thorugh a die to accurately produce long lengths of wire, tube or strip sections.
Direct Reduced Iron. An alternative to the blast furnace in which iron ore or pellets are heated by a reducing gas. The product contains up to 90% Fe. Subsequently charged to an EAF to make steel.
Duplex Stainless Steel
A fast-growing class of stainless steels. So-called because it is a combination of austenitic and ferritic types, with intermediate nickel content. Good for high strength applications.
Electric arc furnace. Mostly used for melting steel scrap or iron.
Electric Resistance Furnace
Electric furnace for smelting ferro-alloys where heating is achieved through resistance to the passage of the current from carbon electrodes through the charge, as well as from arcing. May be slowly rotated. See also EAF.
Steel for use in laminations in electric motors, transformers etc. See also Grain oriented. Electrode See electrolysis and electric resistance furnace.
Abbreviation for Electro Plated Nickel Silver. Nickel silver plated with silver. Used for cutlery and decorative items.
Steel tube formed from skelp and longitudinally electric resistance welded. See also welded tube.
An alloy of two (occasionally more) metals that melts at the lowest temperature of any combination of those metals.
An imprecise term generally covering very small volume minor metals with very special characteristics, some degree of rarity and often a discontinuous market.
A process of heating a billet of metal to a plastic state and forcing it through a die. This enables the quick and economical production of long lengths of complicated sections. Lead was the first metal to be extruded, but today aluminium, brass, magnesium and even stainless steel are extruded.
Electro zinc. Refers to galvanized sheet or coil where the zinc has been deposited electrolytically, not hot-dipped.
A class of stainless steels with no nickel content, so lower-cost. Good for high-temperature applications (e.g. motor car exhausts), but less good for aggressively corrosive conditions. See also austenitic and duplex.
An alloy with iron of a metal used to make steel alloys. The ferro-alloy is more easily produced from the ore than the pure metal and may also be easier to add to the melt. Most ferro-alloys are used to add alloying elements and to treat or modify iron or steel. See also Master alloy.
Materials mainly containing the element iron, i.e. iron and steel.
Expression mostly used in steel, covering plate, coil and sheet.
The thinnest form of rolled metal, less than 0.15 mm thick, most commonly aluminium, but also other metals and steel. Thicker aluminium, e.g. for pie dishes, is also known as foil. See also shim.
Shaping steel and some non-ferrous metals while hot by repeated hammer blows. Forces of up to several tons may be used. Often results in the strongest form of the metal in the alloy used.
Very low melting point alloy, e.g. for sprinkler systems.
Gallium is a bluish metal that is frequently derived from bauxite ore. At extremely high levels of purity, the metal takes on a glassy white appearance. Gallium arsenide and gallium nitride are important compounds used in advanced semi conductors and other electronic applications. Gallium is magnetic, an excellent conductor of heat and electricity and remains in liquid state in a wide range of temperaturesfrom 29.78 to more than 2,237 degrees Celsiusmaking it a good high-temperature lubricant. French chemist Paul Lecoq de Boisbaudran discovered the material in 1875, but it was not widely used until the 1940s, when commercial recovery began in the United States.
A proprietary corrosion-resistant rolled steel coated with an alloy of 55% aluminium 45% zinc for advantages of both galvanizing and aluminising.
The process of protecting steel against corrosion by coating it with zinc. Sheet is usually continuously galvanized in coil, either by immersing in molten zinc (hot dipping) or electrodeposition. After galvanizing it may be corrugated and cut to length. Other products such as tube, angle and post-fabrication structures such as roof trusses and gates are hot-dipped. See also metal spraying.
Discovered in 1885 by Himmelsfurst Fundgrube near Freiburg, Germany, and first isolated by chemist Clemens Alexander Winkler the following year, germanium is largely produced as a byproduct of zinc ores. Germanium can be found in germanite, argyrodite, renieride and coal. It is often derived from zinc smelter flue systems. It has a melting point of 937.4 degrees Celsius and an atomic weight of 72.59. Germanium was the first metal used in the transistor, the electronic device that requires far less current than the vacuum tube. Germanium oxide is used in the manufacture of optical glass and as a drug in the treatment of pernicious anemia.
RECYCLING: More than half of the germanium metal used for the manufacture of most electronic and optical devices is routinely recycled as new scrap, according to the USGS. As a result of the low unit use of germanium in various devices, little germanium returns as old scrap. Worldwide, the USGS reported, about 25 percent of the total germanium consumed is produced from recycled materials.
SUBSTITUTES: Silicon is a substitute for germanium in certain electronic applications, as are various bimetallic compounds of gallium, indium, selenium and tellurium, as well as zinc selenide for infrared guidance systems.
Gold was first used in parts of Central and Eastern Europe in 4000 BC. Also known as the heraldic metal, its symbol Au is derived from the Latin word aurum, meaning shining dawn. In 3000 BC, Egyp-World Production 82.47 million troy oz. Egyptians mastered the art of beating gold into U.S. Production 11.9 million troy oz.gold leaf and alloying it with other metals. In 1500 BC, the Shekel, composed of two-U.S. Demand 200 tonnes thirds gold, was used as a standard unit of Price Range $257-$294/troy oz. value throughout the Middle East. In 1091
BC, squares of gold were legalized in China as a form of money. In 58 BC, Julius Caesar seized enough gold in Gaul to repay Romes debts. Gold is the most malleable and ductile of all metals. It does not tarnish or corrode, enhancing its utilization in electronic and computer applications, as well as in aeronautics for such uses as protective shields for the space shuttle.
SUBSTITUTES: Some substitutes for gold include base metals clad with gold alloys in jewelry and electrical/electronic products to economize on gold, as well as palladium, platinum and silver.
A strong alloy of 85% copper, 5% tin, 5% lead and 5% zinc, or near variant of this mix.
Process for increasing the mechanical properties (strength, hardness) of steel and some non-ferrous metals. See also annealing.
High Speed Steel
High-alloy, high melting point, high hardness alloy steels for machine tools (drill bits, lathe tools, milling cutters etc.). Contain cobalt, molybdenum, tungsten etc.
High strength low alloy. Refers to steels used in pipelines, engineering and construction of higher strength and corrosion resistance than carbon steel. Their properties are obtained by small additions of alloying elements such as manganese, molybdenum and vanadium.
Indium is a silvery-white, malleable semi-precious metal with a brilliant luster. Its name was suggested by the indigo-blue color of its spectrum. Softer than lead, indium is used in thin-film coatings for liquid-crystal displays, electro-luminescent lamps and high-definition televisions, in solders and alloys and batteries, as well as certain other applications. In recent years, thin-film coatings such as indium oxide and indium-tin oxide for glass have accounted for around half of the applications in the United States. Found mainly in sphalerite, indium also is present in ores of tin, copper and lead. Sphalerite is a sulfide ore of zinc. Reich and Richter in Germany discovered indium in 1863, but the semi-precious metal was not used commercially until 1934. Its first major application was in dental alloys. Indium, which is not used in very high quantities in any single application, can be refined to purities of up to 99.99999 percent.
Indium occurs predominantly in solid solution in sphalerite, a sulfide ore of zinc. Indium also is contained in ores of copper, lead and tin, but the USGS said there is not enough information to formulate reliable estimates of those resources. The average indium content in zinc deposits ranges from less than 1 part per million to 100 parts per million.
RECYCLING: In the United States, indium was recycled to some degree from scrap, old and new, the USGS said. The scrap from the fabrication of indium products is becoming more significant in the recycling picture, particularly overseas but also domestically, according to USGS. SUBSTITUTES: In semiconductor and solar cell applications, gallium arsenide can take the place of indium phosphide; and in transparent conductive coatings for glass, silver-zinc oxide or tin oxide can substitute for indium-tin oxide.
Form of cast refined metal used for convenience of shipment and handling. The form approved for delivery in LME aluminium, aluminium alloy, lead, tin and zinc contracts. Also see ingot maker.
(i) In steel, a company which may or may not be an iron ore mine owner, but is a producer of both iron and steel, usually down to a finished product like rails or sheet. (ii) In non-ferrous, a producer of metal who owns mines, smelters and refineries, and sometimes also fabricating plants.
Much of the lead used today is obtained through recycling. Mined lead is primarily extracted from galena and cerussite. Leads principal application, accounting for approximately 67 percent of its total consumption during the past six years, is vehicular batteries. The soft bluish-white metal is also used extensively in the formation of remote-access power systems, load-leveling systems, glass and plastic additives, and for radiation shielding. Another useful attribute of lead is its extreme corrosion resistance. Because of that it can be used for containers that hold radioactive materials and corrosive chemicals.
SUBSTITUTES: Some substitutes for lead include plastics in building construction, electrical cable covering, cans and containers, as well as aluminum, tin, iron and plastics in other packaging and protective coatings. Also, domestically tin has replaced lead in solder for new or replacement potable water systems.
Self-explanatory term mostly used in steel to refer to products such as rod, rebars, rails and structurals.
The old avoirdupois ton of 2240 lb. Still used in some iron ore trade. See also metric ton and short ton.
Magnesium's detection as a chemical element dates back to 1755, but it took Sir Humphrey Davys efforts in 1808 to first isolate it and another 22 years and the efforts of French scientist A. Bussy to produce it via magnesium-chloride reduction. Its name reportedly comes from Magnesia, a district in the region of Thessaly, Greece. There is enough magnesium in seawater to meet global requirements into the next millennium and much of it still is produced from saltwater, namely the Great Salt Lake and the Dead Sea. Nearly half the magnesium produced in the Western World and shipped in by Russia and China finds its way into aluminum sheet alloys used mainly to produce aluminum beverage can stock. The can sheet sectors share of total primary magnesium use has been shrinking slowly for reasons that include recycling efforts, gains in the die-casting sector and slow growth in the aluminum beverage can sector.
Manganese is a critical ingredient for high-strength steel production. It was first produced by reduction of the dioxide with carbon. It is a gray-white, hard and brittle metal, first recognized as an element in 1774 by Carl Wilhelm Scheele, the Swedish chemist and apothecary, whose fellow countryman, Johan Gottileb Gahn, isolated the metal in the same year. Its use in steelmaking dates to 1839, with the first commercial application coming in 1856. The leading end-uses of manganese are construction, machinery and transportation. Manganese dioxide is used in the production of dry-cell batteries, while manganese sulfate is used in manufacturing paints and varnish driers and is also a key ingredient in some fertilizers.
Manganese is an essential nutritional element for people, animals and plants, but it can be harmful in excessive amounts. Thus, manganese can be an industrial poison, but it is not a hazard, the USGS said.
RECYCLING: Scrap recovery specifically for manganese was negligible, but a significant amount was recycled through processing operations as a minor component of ferrous and nonferrous scrap and steel slag.
Nickel-containing steels which attain their highest strength by heat treatment followed by ageing for several hours at lower temperature.
A heat treatable type of stainless steel with some of the characteristics of austenitic.
An alloy usually non-ferrous,with a high content of an alloying metal. The master alloy is more easily added to a specification alloy mix than the metal itself.
Merchant means the normal commercial quality. Mostly used in steel, e.g. merchant bar, merchant pig iron.
Mercury, named after the fleet-footed ancient Roman god of commerce as well as the messenger of the gods, has been used for more than 3,000 years. The ancient Chinese and Hindus knew of it, and it was found in an Egyptian tomb dating from about 1500 BC. The first recorded mention of it was by Aristotle in the fourth century BC, when the heavy, silvery-white metal which later was also known as quicksilverwas utilized in religious ceremonies. The only metal that is liquid at room temperature, mercury seldom occurs freely in nature. It is recovered mostly from cinnabar ores, and also can be found in coderite and in tiny amounts with other minerals. It is also produced in small quantities as a byproduct of gold refining. It is a rather poor conductor of heat for a metal but a fair conductor of electricity. It easily forms alloys with many metals, such as gold, silver and tin, which are called amalgams.
Mercury is usually sold in 76-pound flasks for commercial use in electrical apparatus, the electrolytic preparation of chlorine and caustic soda, pesticides, dental fillings and the manufacture of mildew-proof paint.
SUBSTITUTES: Lithium, nickel-cadmium and zinc air batteries are substitutes for mercury-zinc batteries. Indium compounds substitute for mercury in alkaline batteries. Diaphragm and membrane cells replace mercury cells in the electrolytic production of chlorine and caustic soda. Ceramic composites can replace dental amalgams. Organic compounds have replaced mercury fungicides in latex paint. Digital instruments have replaced mercury thermometers in many applications.
Also called tonne. 1,000 kg or 2204.6 lb. See also long ton and short ton.
A steel production plant using ferrous scrap as its primary raw material. Usually this type of plant produces crude steel from an electric arc furnace (EAF) which is normally used to roll long products, although some EAF-based flat products mills also exist. Mini-mills can also use pig iron and DRI for their raw material feed.
Non-ferrous metals of smaller volume of international trade and frequently higher value than base metals. Often by-products. See also exotic metals and MMTA.
Molybdenum was discovered by Swedish chemist Carl Wilhelm Scheele in 1778 and first isolated in 1782 by fellow countryman Peter Jacob Hjelm. The silvery-gray metal, commonly referred to as moly, occurs in nature as molybdenite and other minerals. Today, it is primarily used as an alloy to strengthen steel and inhibit corrosion. About 70 percent of the worlds molybdenum is produced as a product of copper, with only 30 percent being produced as a primary product, according to Roskill Information Services Ltd. Analysts estimate that the iron and steel industries consume about 80 percent of the worlds molybdenum to increase product durability and hardness. It is also used for high-tech metal alloys and industrial chemicals.
RECYCLING: Some secondary molybdenum in the form of molybdenum metal or superalloys was recovered, but the amount was small, according to the USGS. About 1,000 tonnes of molybdenum was reclaimed from spent catalysts. Although molybdenum is not recovered from scrap steel, recycling of steel alloys is significant, and the molybdenum content is reutilized. Data on the quantities of molybdenum recycled in this manner were not available, the USGS said.
SUBSTITUTES: There is little substitution for molybdenum in its major application as an alloying element in steels and cast irons, the USGS reported. Because of the availability and versatility of the metal, industry has sought to develop new materials that benefit from the alloying properties of molybdenum. Potential substitutes for molybdenum include chromium, vanadium, columbium (niobium) and boron in alloy steels; tungsten in tool steels; graphite, tungsten and tantalum for refractory materials in high-temperature electric furnaces; and chrome-orange, cadmium-red and organic-orange pigments for molybdenum orange pigment.
First identified by Baron Axel Fredrik Cronstedt in 1751, nickel is a white-gray metal similar in some respects to iron but with good resistance to oxidation. Nickel is used primarily in stainless and specialty World Mine Output 1.19 million tonnes steel production, plating and high-temperature alloys. The stainless steel sector consumes about two-thirds of the worlds primary nickel. Since 1975, world demand for U.S. Recovery 75,000 tons stainless steel has grown at an average of This growth rate is expected to continue, or even accelerate, for the next 20 years.
SUBSTITUTES: With few exceptions, nickel substitutes would result in increased cost or some tradeoff in the economy or performance of the product, according to the USGS. Aluminum, coated steels and plastics can replace stainless steel to some degree in several construction and transportation applications. Nickel-free specialty steels are sometimes used in place of stainless steel in the power generating, petrochemical and petroleum industries. Titanium alloys or specialty plastics could substitute for nickel metal or nickel-based super alloys in some highly corrosive chemical environments.
Old-fashioned designation of precious metals. Opposite of Base Metals.
All metals except ferrous metals.
Most non-ferrous metals are non-magnetic, except nickel and cobalt, which are strongly magnetic. Most ferrous metals are magnetic except some grades of stainless steel.
An ingot which has several deep notches along its length to enable it to be broken and allow precise amounts of metal or alloy to be added to the melt.
Oil Country Tubular Goods. Refers to a category of larger diameter steel pipe.
Platinum group metals platinum, palladium, rhodium, iridium and osmium.
Immersing hot rolled steel, for example, in acid to remove millscale.
(i) A rough cast shape from the blast furnace, e.g. pig iron. (ii) Also the standard form in which lead is traded internationally and delivered on the LME.
Thick rolled metal. May be sold as such, especially in steel and aluminium, or rolled further to sheet.
Platinum group metals -- platinum group metalsplatinum, palladium, rhodium, ruthenium, iridium and osmiumhave been dubbed the noble metals because of their high resistance to oxidation and corrosion. Rare and costly, they are mainly used in catalysts, electronics and jewelry. It was first believed that these metals were one metal instead of six, but British chemist William H. Wollaston separated platinum and, later, palladium and rhodium from their ores in the early 1800s. His partner, Smithson Tennant, discovered iridium in 1802 and osmium in 1804; and a Russian chemist, Karl Klaus, extracted ruthenium in 1844.
SUBSTITUTES: Some motor vehicle manufacturers have substituted platinum for the more expensive palladium in catalytic converters. In addition, according to the USGS, electronic parts manufacturers are reducing the average palladium content of the conductive pastes used to form the electrodes of multi-layer ceramic capacitors by substituting base metals or silver-palladium pastes.
Gold, silver and PGMs. See also Noble metals.
Metal which has been produced from ore as distinct from that produced from scrap.
Rare earth metals are the elements that include scandium (Sc), yttrium (Y) and the periodic row of lanthanides ranging from atomic numbers 57-71. While relatively abundant in the Earths crust, discovered, minable concentrations of these metals are less common than for most other ores. Generally soft, malleable and usually reactive, especially at high temperatures, the rare earth metals range in color from iron-gray to silvery-white, and concentrate on a rare earth oxide (REO) basis. Principal uses include catalyst crackers and converters, metallurgy, glass polishing compounds, permanent magnets, nickel-hydride batteries and X-ray intensifying phosphors.
SUBSTITUTES: Substitutes are available for many applications, but generally are less effective, according to the USGS.
Short for reinforcing bar. Steel rod intended for incorporation in concrete to reinforce it.
A processing plant which produces high purity metal either by electrolysis, electrowinning or fire-refining. In copper and lead production, refining is preceded by smelting, but for tin, zinc and nickel, smelting and refining blend into one process of recovering marketable quality metal from concentrates. Refiners (and smelters) may also treat scrap materials. For aluminium, a refinery produces alumina, which is then fed into a smelter to produce the metal.
Tantalum is a refractory metal that is ductile, easily fabricated, has a high melting point, is highly resistant to corrosion by acids and is a good conductor of heat and electricity. It was discovered in 1802, but it did not find a commercial application until a century later when tantalum filaments were used in incandescent light bulbs. Tantalums usage increased when tantalum capacitors were perfected in 1940. Also pushing its use was the introduction of radar and military radio communication in World War II. Since the 1960s, tantalum has been added to nickel-based superalloys at levels up to 4 percent. Columbium, commonly referred to as niobium, is found in columbite, pyrochlore, euxenite and columbite-tantalite. Uses range from electronic components, transportation and metalworking machinery, to chemical equipment and superalloys. Columbium (niobium) was discovered in 1801, a year earlier than tantalum, but did not find commercial success until the 1930s, when metallurgists alloyed ferrocolumbium for steelmaking and columbium carbide for high-speed steel cutting tools. Columbium-containing superalloys were used in planes at the end of World War II. It is also used in high-strength, low-alloy steels.
RECYCLING: Combined prompt industrial and obsolete scrap consumed represented about 20 percent of apparent consumption of tantalum, according to the USGS. While columbium is not recovered from scrap steel and superalloys containing it, recycling of these alloys is significant, and columbium content is reused.
SUBSTITUTES: Tantalum substitutes, although usually less effective, include columbium in carbides; aluminum and ceramic in electronic capacitors; columbium, glass, platinum, titanium and zirconium in corrosion-resistant equipment; and columbium, hafnium, iridium, molybdenum, rhenium and tungsten in high-temperature applications. Columbium substitutes, possibly subject to performance or cost penalty, include molybdenum and vanadium as alloying elements in high-strength low-alloy steels; tantalum and titanium as alloying elements in stainless and high-strength steels; and ceramic, molybdenum, tantalum and tungsten in high-temperature applications.
(i) Non-ferrous; a round, square or polygonal solid section supplied in straight lengths. Usually produced by extrusion. See also Wire rod. (ii) Ferrous. As for non-ferrous, except usually produced by rolling. Used to make mesh for concrete reinforcement or as a semi-finished product for wire drawing.
Special Bar Quality. Steel bar products beyond the commodity grades of merchant bar (such as rebar or construction bar), but below the specialist products such as stainless steels and nickel alloys. SBQ is generally used in the USA, while in Europe the term engineering steels is more common. Both terms refer to steel types as well as to bar products, so also refer to qualities of billet and slab as well as bar.
Secondary Ferrous Materials
Ferrous scrap metals includes carbon steel and iron, as well as stainless steel and steel alloys left from manu-facturing processes or obtained from the disposal of products that have reached the end of their lifecycles. When this scrap is collected, it is sorted and either sheared, baled or shredded by processors. It then becomes a raw material for steel mills and foundries.
Secondary Nonferrous Materials
Nonferrous scrap is the metal left from manufacturing processes or obtained from the disposal of products that have reached the end of their lifecycles that has no iron content. Copper and aluminum are the two most widely traded forms of nonferrous scrap, although there is also substantial demand for recovered lead, nickel, zinc and precious metal scrap. Processing of nonferrous scrap metal ranges from simple sorting operations to baling and shredding. Buyers of these metals include secondary refiners and smelters who melt the scrap and recast it into alloys that serve as intermediate products for other fabricators and manufacturers. Some brass and aluminum mills use scrap directly to produce their finished products.
PRODUCTION AND USE: Nonferrous scrap falls within one of three categories defined by how it is generated. "Home" or revert scrap is produced within a mill, smelter or foundry, and can include materials such as the trimmings from the end of aluminum sheet products. "Prompt" industrial scrap is the clean metallic byproduct like brass rod ends and copper-nickel turnings generated by manufacturers as they produce finished durable goods. "Obsolete" scrap is the metal drawn from products that have reached the end of their lifecycles. This is often the broadest category, ranging from aluminum beverage cans to defunct lead-acid auto batteries to the tiny gold connectors on printed circuit boards.
Extruded or rolled long products of relatively complex cross-section. Sometimes also drawn.
Selenium, a lustrous-gray metal, is named after Selene, the Greek goddess of the moon. It was first discovered in 1817 by J.S. Berzelius in Fahlun, Sweden, as part of the red residue found in sulfuric acid prepared at a pyrite mining operation. Selenium is primarily recovered from anode slimes in the electrolytic refining of copper and is used in glass and ceramic manufacturing. It is also used for conductive cells, voltage rectifiers and to improve the machinability of stainless steel and copper-based alloys. Selenium can also be found in human dietary supplements and dandruff shampoos, as well as dietary supplements for livestock.
SUBSTITUTES: High-purity silicon has replaced selenium in high-voltage rectifiers and is the major substitute for selenium in low- and medium-voltage rectifiers, the USGS reported. Other inorganic semiconductor materials, such as silicon, cadmium, tellurium, gallium and arsenic, as well as organic photo-conductors, substitute for selenium in photoelectric applications. Other substitutes include cerium oxide in glass manufacturing; tellurium in pigment and rubber compounding; bismuth, lead and tellurium in free-machining alloys; and bismuth and tellurium in lead-free brasses.
(i) Non-ferrous; usual trade term for semi-fabricated products (sheet, wire, tube etc.).
(ii) Ferrous; refers to shapes from which sheet, tube etc. are produced billet, slab etc.
Non-ferrous; a loose term for unwrought metal forms designed for semi-fabrication such as billet and rolling slab. Comparable to steel semis.
A thin flat rectangular piece of rolled metal. May be hot rolled or cold rolled. Nowadays almost always cut from coil.
Steel or brass strip rolled to a precise thickness, usually below 0.5 mm.
A ton of 2,000 lb, mostly used in the USA . See also long ton and metric ton.
A powerful machine used in the scrap industry to batter large items of scrap such as cars and domestic equipment into fragments which are then sorted as between steel, non-ferrous and waste (also called fluff). See also chopping.
Silver's history dates back 6,000 years. The Romans based their monetary system on it. The Incas of Peru called silver the tears of the moon. The ancient Greeks minted the drachma, which contained 1/8th ounce of silver, and in Rome the basic coin was the denarius, weighing 1/7th ounce. Also, the British pound sterling originally denoted a specific weight of silver. Silver is considered the most industrial of the precious metals, with a history of usage in photography and electronics. It is malleable, ductile and has a low level of electrical resistance. But its glamorous persona makes it a major source for jewelry, decorative accessories and flatware. Pre-Columbian civilizations used silver extensively in religious applications, and in India silver is held in special esteem as an integral part of dowries. The metal had a history on the Indian black market, and at one time those transactions held considerable influence in assessing market fundamentals.
PRODUCTION AND USE: More than two-thirds of the world's silver resources are associated with copper, lead and zinc deposits, often at great depths, according to the U.S. Geological Survey (USGS). The remainder is in vein deposits in which gold is the most valuable metallic component. Significant future reserves and resources are expected from major base metal discoveries that contain byproduct silver, although most recent discoveries have been primarily gold and silver deposits.
While the price of silver and improved technology would appear to increase the reserves and reserve base, the extraction of silver from these resources will be driven by demand for the primary base metals, the USGS said.
SUBSTITUTES: Aluminum and rhodium can be substituted for silver in mirrors and other reflecting surfaces. Tantalum can be used in place of silver for surgical plates, pins and sutures. Stainless steel is an alternate material used widely in the manufacture of table flatware. Non-silver batteries under development may replace silver batteries in some applications. Silver-less black and white film, xerography and film with reduced silver content are alternatives to some uses of silver in photography.
The semi (in steel) or non-ferrous equivalent intended for rolling into coil or sheet.
A process of converting sheet in coils into strip by passing the metal through a machine with multiple rotary knives.
A processing plant which produces crude non-ferrous metal by treating mine feed (concentrate) or residues. In the case of aluminium a smelter produces refined metal from alumina.
Tube drawn down from a tube shell into straight lengths or in coils without a welded joint.
Expression used to refer to higher-specification alloy steels.
The form in which certain primary metals are recovered, namely platinum, palladium and titanium. Also iron obtained by direct reduction from ore.
Rust-resistant steels containing chromium; also, according to alloy, nickel, molybdenum and other metals. A fast-growing segment of the steel market. See also Austenitic, Ferritic and Duplex.
Steel is primarily an alloy of iron and carbon, with hundreds of variations made possible by alloying it with silicon, vanadium, molybdenum, nickel, chromium, cobalt and other elements. The carbon content in common steel ranges from 0.25 to 2 percent, while harder grades have a higher carbon content. Manufacturing methods such as annealing, quenching and cold working are used to further tailor the steel to specific needs. Stainless steel is the most popular of the alloy steels. The most common stainless steels contain 18-percent chromium and 5-percent nickel.
Long lengths of narrow rolled material, usually sold coiled. Often produced by slitting coil. See also Hunter Douglas.
Steel girders and heavy angles used in construction.
Primarily recovered from the anode slimes that accumulate during the electrolytic refining of copper, tellurium was discovered by Franz Joseph Muller Von Reichenstein in 1782. Silvery-white in appearance, crystalline tellurium exhibits a metallic luster when pure. It is a semimetal that can be doped with silver, gold, copper and other elements. Tellurium became widely used after World War II as an alloy in the production of free-machining steels, cast iron and copper, but it also found use as an additive in chemical, ceramic and nonferrous products. In 1958, interest developed in the thermoelectric properties of bismuth-telluride and lead-telluride materials and solid-state cooling devices subsequently found their way into satellites, but consumer products were not developed until later. In the 1970s, tellurium was added to selenium photoreceptor materials to broaden the spectral range of copiers.
PRODUCTION AND USE:Domestically, tellurium and tellurium dioxide of commercial grades were recovered at one copper refinery, principally from anode slimes, and also from lead refinery skimmings, according to the USGS. High-purity tellurium, tellurium master alloys and tellurium compounds were produced by primary and intermediate processors from commercial-grade metal and tellurium dioxide.
Tellurium is used mainly in the production of free-machining steels, the USGS said. It is used as a minor additive in copper and lead alloys and malleable cast iron, as an accelerator in rubber compounding, in thermoelectric applications and as a semiconductor in thermal-imaging and photoelectric applications. According to the USGS, tellurium is added to selenium-base photoreceptor alloys to increase the photo speed.
RECYCLING: There was no domestic secondary production of tellurium. However, the USGS reported that some tellurium may have been recovered abroad from selenium-base photoreceptor scrap exported by the United States for recycling.
SUBSTITUTES: Selenium, bismuth and lead are the chief substitutes for tellurium in metallurgical applications; selenium and sulfur in rubber compound applications; and selenium, germanium and organic compounds in electronic applications.
Tin is a non-toxic metal with a history that can be traced to 3500 BC through objects found at the mouth of the Euphrates River. Since then, tin has found its major application as a coating for other metals, such as steel, to prevent corrosion. Tin is also used in lead solder, bronze, U, die-cast alloys, biocides and as an alloy with titanium.
SUBSTITUTES: Aluminum, glass, paper, plastic or tin-free steel might be used to substitute for tin in cans and containers. Other materials that substitute for tin are epoxy resins for solder; aluminum alloys, copper-base alloys and plastics for bronze; plastics for bearing metals that contain tin; and compounds of lead and sodium for some tin chemicals.
Thin steel sheet coated with a minute amount of tin. Used to make tin cans.
Titanium, which was named after the Greek god Titanes, has a lustrous white color when purified. The metal has a low density, good strength, excellent corrosion resistance and it is easily fabricated. It is present in meteorites and the sun and is the only element that burns in nitrogen. The Rev. W. Gregor discovered it in 1789 while examining the mineral ilmenite. It was not until 1895 that it was partially purified by Henri Moissan. Due to its excellent strength-to-weight ratio, most end-product applications of titanium metal are in the aerospace industry. Titanium dioxide is used in paints, varnishes and lacquers.
SUBSTITUTES: There are few substitutes for titanium in aerospace applications without negative performance implications. For industrial applications, highnickel steel, zirconium and, to some extent, superalloy metals might be substituted for titanium, according to the USGS. In certain applications, ground calcium carbonate, precipitated calcium carbonate, kaolin and talc compete with titanium dioxide as a white pigment.
Tungsten, a silver-gray metal, is mined from scheelite and wolframite and appears in nature in four major forms combined with calcium, iron or manganese. Most current mine production of tungsten is from vein/stockwork, skarn, porphyry and strata-bound deposits. Minor amounts are produced from pegmatite, breccia and placer deposits. It has a high melting point and density, good thermal and electrical conductivity, a low coefficient of expansion and exceptional strength at elevated temperatures. It is consumed predominantly as tungsten carbide in cutting and wear-resistant components as well as an alloying agent in steelmaking. Also, often as an alloy, it is used for lamp and lighting filaments and electrodes, electrical and electronic contact surfaces, heat and radiation shielding in high-temperature furnaces and X-ray equipment, and electrodes in certain welding methods. Some non-metallurgical applications of tungsten are as phosphorescent chemicals in pigments, X-ray screens, television picture tubes and fluorescent lighting. Tungsten is also used in armor-piercing ordnance and tank shielding. The name tungsten comes from the Norse word thungr-steinn, which means heavy stone.
SUBSTITUTES: Cemented tungsten carbide is a primary cutting-tool insert material because it generally meets the technical requirements of many turning and milling operations, but ceramics, ceramic-metallic composites and other materials continue to be developed and used as substitutes to meet the changing needs of the world market, the USGS reported. Increased quantities of carbide cutting-tool inserts were coated with alumina, diamond, titanium carbide or titanium nitride to extend the life of the inserts. There remained no viable substitutes for tungsten in filaments, electrodes and contacts in lamp and lighting applications, but lamps containing no electrodes and no tungsten are available for commercial and industrial use, the USGS reported.
In 1789, German chemist Martin Klaproth discovered an unknown element in pitchblende ore, naming it after the recently discovered planet Uranus. Uranium was first isolated in 1841 by French chemist Eugene-Melchoir Peligot, but its radioactive nature was not discovered until 55 years later by Henri Becquerel. Traces of the element have been found in archeological artifacts dating back to 79 AD. Metallic-gray in color and the heaviest of natural elements, natural uranium is constructed of 99.3-percent isotope 238 and 0.7-percent isotope 235. U-235 is used widely in nuclear fission applications, such as in reactors for electricity production. U-238 is highly prized by the military for its ability to be converted to fissionable plutonium. The metal is fluorescent in many of its compounds and in its powder forms might spark and self ignite when struck.
A soft, ductile metallic element, vanadium has good structural strength and is used as an alloying agent in steel and iron, and in the production of titanium alloys for the aerospace and other industries. Discovered in 1801, vanadium was not isolated from its compounds, principally vanadite and carnotite, until 1869 by H.E. Rosco. Bearing the atomic number 23,vanadium has a melting point of 1,890 degrees Celsius, an atomic weight of 50.9415 and a boiling point of 3,380 degrees Celsius. The major non-metallurgical use of vanadium is in catalysts for the production of sulfuric acid and maleic anhydride. Named for the Scandinavian love goddess Vanadis, vanadium is found in deposits of titaniferous magnetite, phosphate rock, uraniferous sandstone and siltstone, bauxite, crude oil, coal, utility ash and certain other materials.
SUBSTITUTES: To a certain degree, metals such as columbium, manganese, molybdenum, titanium and tungsten are interchangeable with vanadium as alloying elements in steel. In some chemical processes, platinum and nickel can be used in place of vanadium compounds as catalysts.
(i) Small-diameter steel or aluminium tube roll-formed from strip and longitudinally HF welded. (ii) Large-diameter steel tube formed from plate and welded. See also ERW and Spiral welded tube.
(i) Steel; Product of first rolling of billet intended for further rolling and drawing to wire. (ii) Non-ferrous; Raw material, commonly 8 mm in diameter, for subsequent drawing to wire. Usually produced continuously by casting and rolling. See also Properzi.
Zinc, a bluish-gray metal, is best known for its ability to control corrosion in iron and steel. It is the worlds fourth most used metal. Zinc also plays a vital role inside the human body as a trace element essential for digestion, reproduction and renal function, and during recent years has gained acclaim as a remedy for cold and flu symp-toms. More than 200 enzymes in the human body are known to require zinc. Zinc is also completely recyclable without any loss of its physical or chemical properties.
SUBSTITUTES: Aluminum, steel and plastics substitute for galvanized sheet, according to the USGS. In die casting, aluminum, plastics and magnesium are zinc's major competitors. In corrosion protection applications, plastic coatings, paint and cadmium and aluminum alloy coatings replace zinc. Aluminum alloys are used in place of brass. In chemical, electronic and pigment uses, many elements serve as zinc substitutes.
Zirconium, a lustrous, hard, strong, ductile metal, is similar in appearance to stainless steel. It is obtained mainly from the zirconium-silicate mineral zircon. Discovered by Martin Heinrich Klaproth in Germany in 1789, zirconium has the atomic number 40 and an atomic weight of 91.22. Zirconium is grayish-white, has a specific gravity of 6.53, a boiling point of 3,578 degrees Celsius and a melting point of 1,852 C. A byproduct of the mining and processing of heavy mineral sands for the titanium minerals ilmenite and rutile, zircon was first made into high-purity metal in 1925. The metal is used chiefly in refractory blocks, bricks, foundry sands and glazes and colors for ceramic products. Stabilized zirconium oxide serves as an opacifier and pigment in pottery glass. Molds for castings in foundries use zircon in their facings because it resists metal penetration and helps provide a uniform finish on the castings themselves. Significant additional applications include cladding for fuel rods in nuclear reactors, welding rod coatings and abrasives. Some combustion control sensors in automotive engines, industrial furnaces and other equipment employ yttria-stabilized zirconia.
SUBSTITUTES: Chromite and olivine are sometimes used instead of zircon in foundry applications, and hafnium can be used interchangeably with zirconium in certain superalloys. Dolomite and spinel refractories can substitute for zircon in some high-temperature applications, and limited substitution of columbium (niobium), stainless steel and tantalum for zircon has been reported in nuclear applications.