0 Talk

Copper

Copper ( /ˈkɒpər/ kop-ər) is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish. It is used as a conductor of heat and electricity, a building material, and a constituent of various metal alloys.

The metal and its alloys have been used for thousands of years. In the Roman era, copper was principally mined on Cyprus, hence the origin of the name of the metal as сyprium (metal of Cyprus), later shortened to сuprum. Its compounds are commonly encountered as copper(II) salts, which often impart blue or green colors to minerals such as turquoise and have been widely used historically as pigments. Architectural structures built with copper corrode to give green verdigris (or patina). Decorative art prominently features copper, both by itself and as part of pigments.

Copper(II) ions are water-soluble, where they function at low concentration as bacteriostatic substances, fungicides, and wood preservatives. In sufficient amounts, they are poisonous to higher organisms; at lower concentrations it is an essential trace nutrient to all higher plant and animal life. The main areas where copper is found in animals are tissues, liver, muscle and bone.

Copper RecyclingEdit

Cans are first divided from municipal waste, usually through an eddy current separator, and cut into little, equal pieces to lessen the volume and make it easier for the machines that separate them.
Pieces are cleaned chemically/mechanically, and blocked to minimise oxidation losses when melted. (The surface of copper readily oxidizes back into copper oxide when exposed to oxygen.).
Blocks are loaded into the furnace and heated to 2800 °F to produce molten copper.
Dross is removed and the dissolved hydrogen is degassed. (Molten copper readily disassociates hydrogen from water vapor and hydrocarbon contaminants.) This is typically done with chlorine and nitrogen gas. Hexachloroethane tablets are normally used as the source for chlorine. Ammonium perchlorate can also be used, as it decomposes mainly into chlorine, nitrogen, and oxygen when heated.
Samples are taken for spectroscopic analysis. Depending on the final product desired, high purity gold, copper, zinc, manganese, silicon, and/or magnesium is added to alter the molten composition to the proper alloy specification. The top 5 copper alloys produced are apparently 6061, 7075, 1100, 6063, and 2024.
The furnace is tapped, the molten copper poured out, and the process is repeated again for the next batch. Depending on the end product it may be cast into ingots, billets, or rods, formed into large slabs for rolling, atomized into powder, sent to an extruder, or transported in its molten state to manufacturing facilities for further processing.