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Cooperation between Aurubis and Grillo-Werke yields a perfect closed loop for copper and zinc

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As an expert in multi-metal recycling, Aurubis helps to close the loop for copper and other metals.

At the Aurubis plant in Lünen (Germany) the company uses the “Kayser-Recycling-System (KRS)” to produce copper. During this process a zinc-containing filter dust occurs that also consists of other valuable metals like copper, tin and lead. This so-called “KRS oxide” is used as raw material at Grillo-Werke AG for the production of zinc sulfate.

Zinc sulfate is used as a trace element carrier in the feeding stuff and fertilizer industry. When producing zinc sulfate from KRS oxide, a residue remains that contains copper, tin and lead in an enriched form. This residue is returned into Aurubis’ production process. Beforehand, the by-product lead sulfate from the residue is converted into lead carbonate via a further partner of Aurubis, Jean Goldschmidt International SA from Belgium. Valuable metal resources are returned to the cycle. The environmentally friendly recycling ensures that none of these valuable metals becomes wasted.

Without this cooperation between Grillo as a specialist in zinc-chemistry and Aurubis as an expert in multi-metal recycling, the value chain of KRS Oxide would be less efficient.

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Valuable metal resources are not dumped but returned to the cycle. Recycling takes place under benchmark environmental and technical standards. The metals remain in Europe and are not transported to Asia for treatment (CO2 avoidance and strengthening of European raw material supply “urban mine”). Long-term planning and business security of the Grillo zinc sulfate plant – the last remaining substantial plant of its kind in Europe.

Last but not least this project contributes to secure jobs at the two German plants.