Broadly speaking, the end-of-life treatment of metal scrap consists of three very different steps: collection, pre-processing and sorting, and physical metal recovery, with challenges arising in each.
End-of-life products, which account for around three quarters of the copper recycled each year, are collected through multiple channels, depending on their application. As examples, through stores and take-back schemes in the case of electric and electronic waste, at construction sites, when copper is extracted from demolition waste, and at dealerships and garages, in the case of end-of-life vehicles. The other quarter comes from the industrial value chain which produces articles from copper and a broad range of copper alloys. By-products from production processes, such as offcuts and shavings, are returned for recycling and, hence, reintroduced back into the material cycle.
Following collection, copper-containing scrap is delivered to sorting centres where a variety of automated and manual processes are used to separate it into various qualities. As examples, higher quality, higher value scrap is generated after the insulation is removed from old wires and cables. Lower quality, lower value scrap comes from electronic equipment such as mobile phones and personal computers. The Institute for Scrap Recycling Industry (ISRI) has named nearly fifty different copper and copper alloy scrap classifications.
At this stage, the day to day, supply/demand driven economics of the market influence the share delivered to companies, which will recover and reuse the metal within the EU, from that exported to countries with lower yield technologies and far poorer environmental and human health practices. Due to lower cost structures, tax incentives and overall demand requirements, customers based in emerging economies are generally able to pay a higher price.
Within the physical metal recovery sector, companies need to be able to handle increasingly complex mixtures of organic (plastics and greases) and inorganic (metals) materials. Their diversity and lack of information on their composition can impact yields and quality. Pure copper is infinitely recyclable. Other metals present in scrap, such as iron, aluminum, silicon and zinc, can be separated relatively easily from copper. Others, such as bismuth, antimony and arsenic, present greater challenges. The recovery of these alloy components requires many steps, which are often not performed by the mainstream copper producers (smelters) themselves.
Taking the whole recycling sector as a single block, the increasing complexity of today’s products is making recycling more difficult and therefore more costly. There is need for more information on scrap types and flows in order to improve collection systems and treatment processes. Improved communication and information exchange between product designers, waste professionals and recyclers is also required so that the development of new products takes more account of end-of-life realities.