Phytomining and bioleaching for low-grade copper ores, reading a life cycle assessment, and how reducing, reusing and recycling save resources and energy.
What you will learn
- Describe phytomining and bioleaching (Higher)
- Calculate reacting masses for displacement by scrap iron (Higher)
- Compare products using life cycle assessment data
- Calculate the energy saved by recycling
New ways to get copper (Higher)
High-grade copper ores are running out, so copper is extracted from low-grade ores and mine waste.
These methods avoid digging, moving and dumping large amounts of rock.
- Phytomining: plants absorb metal compounds from the soil. They are harvested and burned; the ash contains metal compounds. Slow.
- Bioleaching: bacteria produce a leachate solution containing metal compounds.
- Copper is then obtained from the solution by displacement with scrap iron (cheap, and more reactive than copper) or by electrolysis.
- Fe + CuSO₄ → FeSO₄ + Cu (Ar: Fe = 56, Cu = 63.5)
- 1 mole of iron gives 1 mole of copper: 56 kg of iron gives 63.5 kg of copper
- iron for 10.0 kg of copper = 10.0 × 56 ÷ 63.5 = 8.82 kg (3 s.f.)
The rest of this lesson and its 9 practice questions are locked.
In this lesson
- New ways to get copper (Higher)
- Life cycle assessment
- Reduce, reuse, recycle
- Try it: Read an LCA table
9 practice questions, marked as you go; about 20 minutes in all.
Key terms
Low-grade ores, Leachate, Displacement, Electrolysis
In this unit: The Earth's atmosphere
The air now and how it formed, greenhouse gases and climate change, carbon footprints and the pollutants from burning fuels. Its later lessons on water, life cycles, materials and the Haber process stay here too; Using resources teaches them in full.