Alternative Methods of Metal Extraction

Metal ores are FINITE RESOURCES, meaning they will eventually RUN OUT.

As METAL ORES become harder to find and extract, alternative methods of extraction are becoming more important.

Traditional mining involves digging, moving and disposing of large amounts of rock which can DAMAGE the ENVIRONMENT.

There are TWO methods that can extract LOW GRADE ORES (rocks with a small amount of metal) while minimising damage to the environment:

1. Phytomining

PHYTOMINING uses plants to absorb METAL COMPOUNDS from the soil. The steps involved are:

• GROWING PLANTS: Plants that can absorb metal compounds are grown on soil that contains these compounds.
• HARVESTING: Once the plants have absorbed the metals, they are harvested and dried.
• PROCESSING: The harvested plants are then BURNED to produce ASH that contains the metal compounds.

2. Bioleaching

BIOLEACHING involves using bacteria to extract metals. The process is as follows:

• BACTERIA APPLICATION: Bacteria are introduced to the ore where they produce LEACHATE solutions that contain metal compounds.
• COLLECTING LEACHATE: The leachate is collected as it contains the desired metals.

Extracting the Metals

Once you have the metal compounds from phytomining or bioleaching, you can DISSOLVE THEM IN ACID and they can be processed to extract the pure metal. This can be done by:

• DISPLACEMENT: Using a more reactive metal, like scrap iron, to displace the metal from its compound.
• ELECTROLYSIS: An electrical process that separates the metal from its compound.