This chapter highlights the different methods used to turn old scrap and waste back into new copper metal. Copper scrap is smelted in primary (concentrate) and secondary (scrap) smelters. Primary smelters mainly smelt concentrate. Some, however, are well adapted to smelting all grades of scrap. Smelters with Ausmelt/Isasmelt, Mitsubishi, Noranda, reverberatory, and top-blown rotary converter smelting furnaces are particularly effective. Scrap is also extensively recycled to the converters in primary smelters. The heat from the converter's exothermic Fe and S oxidation reactions is particularly useful for melting scrap, especially if considerable oxygen is used for the oxidation reactions. Secondary scrap smelters primarily use top submerged lance technology furnaces and top-blown rotary converters for smelting low Cu-grade scrap. The main smelting product is molten black copper (80% Cu), which is converted to rough copper (96% Cu), then fire refined and cast into anodes (98.5% Cu). These processes do not completely remove Ni and Sn from Cu, so the refining furnace product must be electrorefined. Electrorefining also recovers Ag, Au, and platinum-group metals. Secondary copper electro refining is similar to primary copper electro refining. However, scrap may contain more impurities than concentrates, so larger electrolyte purification and slimes treatment facilities may be required.