Copper is seldom mined alone and comes with a range of by-products. Some of these metals are economically very important (e.g. gold and silver). They contribute to the profitability of a mining operation and are usually accounted for as negative costs. Others are important because of their toxicity which needs to be adequately managed while these metals might find limited uses in specialised applications (e.g. arsenic, cadmium or thallium). A third group of elements serves significant and often growing market niches.
For some of these elements, copper mining complements the production infrastructure of the by-product (e.g. gold, silver, lead, zinc or molybdenum). Other minor metals have limited or no own production infrastructure (e.g. selenium or tellurium).
Hereby a list of commonly found by-metals in copper mining with a few of their applications:
- Bismuth: low melting alloys for soldering or as an additive to improve machinability
- Cobalt: superalloys, batteries
- Gold: jewelry, electronics, monetary uses. Freeport's Grasberg mine is one of the world's largest deposits for both copper and gold.
- Molybdenum: alloying element, catalyst, wires for high-temperature heating. Codelco is one of the world's largest molybdenum producers.
- Nickel: stainless steel, superalloys, batteries.
- Rare Earth Elements, e.g. cerium, dysprosium, lanthanum, neodynium, praseodynium: alloys, magnets
- Rhenium: superalloys, catalyst.
- Selenium: glass industry, silicon cells, food additive. The world's largest producer is RETORTE, a subsidiary of Aurubis.
- Tellurium: steel or copper additive to improve machinability, element for thin-film photovoltaics. Rio Tinto will build a plant to recover tellurium at its Kennecott mine.
- Silver: reflective coatings, jewelry, imaging, medical devices, high performance batteries, catalyst. KGHM is one of the world's largest silver producer.
- Aurubis, Metals Lexicon. August 2012.
- Study of By-Products of Copper, Lead, Zinc and Nickel, https://www.oakdenehollins.com/reports/2014/1/15/study-of-by-products-of-copper-lead-zinc-nickel-executive-summary (accessed August 2012, 2021)
- USGS Critical Minerals List. https://www.usgs.gov/centers/nmic (accessed August 2021)
- Brief overview of by-products in secondary copper production, internal report by Fraunhofer for International Copper Association, November 2015
Last update: October 19, 2021