Traditional mining damages the environment and low-grade ores (ores with only small amounts of metal) are uneconomical to smelt. Two sustainable alternatives exist:
- Bioleaching: Bacteria are used to leach (dissolve) copper compounds from low-grade copper ore. The bacteria convert insoluble copper compounds into copper sulfate solution. Copper is then displaced from the solution using scrap iron.
- Phytomining: Plants that absorb copper from the soil are grown on low-grade copper deposits. The plants are harvested and burned. The ash contains copper compounds which can be processed to obtain copper.
Both methods have lower environmental impact than traditional mining and smelting, but are slower.
This deep dive covers Alternative Methods: Bioleaching and Phytomining within Extracting Metals for GCSE Chemistry. Revise Extracting Metals in Chemical Changes for GCSE Chemistry with 6 exam-style questions and 6 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 6 of 14 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Extracting Metals
Which method is used to extract a metal that is MORE reactive than carbon?
Iron is extracted from haematite in a blast furnace. Describe how iron is obtained from iron oxide using carbon, and explain the term 'reduction' in this context.