3: Recycling

Scrap material is generated at three distinct points in the life cycle of metals: during the production of metal (in-plant scrap), during the conversion of this metal into useful industrial and consumer products (new scrap, sometimes termed prompt scrap, industrial scrap, etc.), and when these products are discarded at the end of their useful lives (old scrap, sometimes termed obsolete scrap, post-consumer scrap, waste stream scrap, etc.). The basic flow sheet is demonstrated in Fig. 3.1.

In-plant scrap generally does not enter into any industry statistics. It is all recycled immediately within the plant in question. At a copper refinery, for example, spent anodes in the tank house that still contain copper are sent back to the anode plant, and re-melted and recast into new anodes with additional blister copper from the smelter. Companies try to minimise the generation of this kind of scrap, as furnace time and energy requirements to recast it are obviously a significant economic factor and also because of the cost of working capital that becomes tied up in constantly circulating scrap within the plant. However, it plays no role on either the supply or demand side of the market. All of the statistics of primary metal production are, for example, net of this effect.