In Lunen the treatment process begins – insofar as necessary – with sampling, followed by a preparation stage. Depending on consistency and composition, the raw materials can be crushed with shears, treated in a special material preparation plant or directly conditioned into feed mixtures. This ensures that both very coarse and moist or dusty material can be treated. Aluminium and plastics are separated in some cases and collected into saleable lots for other recycling companies.

Pyrometallurgical processing, i.e. melting and refining in furnace facilities, starts in the Kayser Recycling System (KRS). The central operation is a submerged lance furnace which is almost 13 m high. A special feature is the use of a submerged combustion lance, which is immersed into the furnace from above and supplies the process with heating oil, oxygen and air. The reduction process is very fast in the KRS. Charging times are short. The in that step of the process extracted iron silicate sand has only very low residual copper contents. Copper, nickel, tin, lead and the precious metals contained in the raw materials are enriched in an alloy with a copper content of about 80 %. In a Top Blown Rotary Converter (TBRC) the copper content is further enriched to 95 % and tin and lead are separated into a slag. The lead/tin slag is subsequently processed into a lead/tin alloy in the directly connected lead/tin furnace. During the KRS process, zinc is enriched in the KRS oxide, a flue dust.

The Kayser Recycling System is suitable not only for the treatment of recycling materials with low copper and precious metal contents, but also very complex materials such as electrical and electronic scrap. Crude copper is produced with an average copper content of 95 % which is further processed in the anode furnace in a molten form. It is refined with additional amounts of copper scrap. The melt is initially oxidised with air and oxygen and then deoxidised with natural gas after the slag that has formed has been removed. At the end of the pyrometallurgical process, the meanwhile 99 % pure copper is cast into copper anodes. These are the starting product for the final refining stage of secondary copper production, the copper tankhouse process, where high grade copper cathodes are produced in identical quality as copper cathodes from primary copper production. Important by-products, in particular, gold and silver, are enriched in the anode slimes. Nickel is extracted as crude nickel sulphate from electrolyte treatment oder regeneration.

The basic material for Hamburg’s secondary copper production consists of a variety of recycling materials rich in precious metals as well as intermediary smelter products, originating both from the Aurubis’ production plants and from external metal smelters and precious metal separating plants. In accordance with the requirements of the specific raw materials, processing is performed in a modern electric furnace in various melting campaigns. The most important target is the pyrometallurgical separation of lead and copper and the enrichment of precious metals.

By-elements still existing during the copper production, such as lead, bismuth, antimony and tellurium, are separated in the connected lead refinery and sold as lead bullion, lead/bismuth alloy, antimony concentrates and tellurium concentrates. The precious metals are fortified in a so-called rich lead, which has an about 70 % precious metal content.

The anode slimes from the Aurubis copper tankhouses are processed together with the rich lead from the lead refinery in the precious metal production plant. With Aurubis’s modern, environmentally-friendly precious metal production facilities, we also cover a wide range of feed materials rich in precious metals. Thus, Aurubis also processes anode slimes from other copper smelters, bullion, precious metal and coin scrap as well as precious metal-bearing sweeps and slag. Sales products include, apart from fine silver, fine gold and concentrates of the platinum group metals, wet selenium, which is processed at RETORTE.

The secondary copper production in Hamburg thus focuses on the enrichment and production of precious metals and the separation of various by-metals from copper production.

Copper scrap is also processed at our primary smelter site in Pirdop, Bulgaria.

Copper scrap and Blister copper is treated to extract the copper in Olen, Belgium.