Copper than less-developed countries (30–40 kg per capita). The process of recycling copper is roughly the same as is used to extract copper but requires fewer steps. High-purity scrap copper is melted in a furnace and then reduced and cast into billets and ingots; lower-purity scrap is refined by electroplating in a bath of sulfuric acid. Numerous copper alloys have been formulated, many with important uses. Brass is an alloy of copper and zinc. Bronze usually refers to copper-tin alloys, but can refer to any alloy of copper such as aluminium bronze. Copper is one of the most important constituents of
Tin-silver-copper been increasing. Large companies such as Sony and Intel switched from using lead-containing solder to a tin-silver-copper alloy. The process requirements for SAC solders (Pb-free) and Sn-Pb solders are different both materially and logistically for electronic assembly. In addition, the reliability of Sn-Pb solders is well established, while SAC solders are still undergoing study, (though much work has been done to justify the use of SAC solders, such as the iNEMI Lead Free Solder Project). One important difference is that Pb-free soldering requires higher temperatures and increased process control to achieve the same results as that of the tin-lead method.