4.10.1.4

Alternative methods of extracting metals (HT only)

Contents

  1. The Earth’s resources of metal ores are limited.
  2. Copper ores are becoming scarce and new ways of extracting copper from low-grade ores include phytomining, and bioleaching. These methods avoid traditional mining methods of digging, moving and disposing of large amounts of rock.
  3. Phytomining uses plants to absorb metal compounds. The plants are harvested and then burned to produce ash that contains metal compounds.
  4. Bioleaching uses bacteria to produce leachate solutions that contain metal compounds.
  5. The metal compounds can be processed to obtain the metal. For example, copper can be obtained from solutions of copper compounds by displacement using scrap iron or by electrolysis.
  6. Students should be able to evaluate alternative biological methods of metal extraction, given appropriate information.