Copper And Its Production
Copper is marked via a host of good engineering properties. The foremost is copper's good electrical conductivity and bulk of copper is utilized as electrical conductor. This also has a high thermal conductivity and coupled along with its resistance to corrosion this is largely employed as heat exchanger tubes particularly beneath circumstances while corrosive atmosphere exists. Its fabrication ease and medium tensile strength are added advantages in its industrial application.
Copper is removed from its sulfide ore. That ores also comprise sulfides of iron. Low grade ore is transformed in sulfide concentrate that is smelted in reverberatory furnace to generate a mixture of sulfides of copper and iron, called mate. The level is separated from matte. The copper sulfides are then chemically transformed in impure or blister copper of 98 percent purity, via blowing air via the matte. The iron sulfides is oxidized and converted in slag. The blister copper is after that transferred to refining furnace where main impurities are transformed in slag and removed. Such fire refined cooper is termed as tough pitch copper and is then refined electrolytically to produce 99.95 percent pure copper termed as electrolytic tough pitch or ETP copper.
Electrolytic tough pitch copper is utilized for production of strip, rod plate and wire. Such products offer several industrial reasons. But electrolytic tough pitch copper contains 0.04% oxygen that forms interdendritic Cu2O while copper is cast. If copper is heated to a temperature of 400oC in the atmosphere of hydrogen, then hydrogen reacts along with densritic Cu2O and generates steam. Such H2O molecules being large in size do not diffuse readily and cluster around grain boundaries hence causing internal holes. This phenomenon is known as hydrogen embrittlement. The methods of refusing hydrogen embrittlement are adding phosphorous in the alloy copper and hence allowing P2O5 to form. The alternative method is to cast electrolytic tough pitch copper under a controlled reducing atmosphere to produce copper that is oxygen free high conductivity or OFHC copper.