Extraction of Metals
- The Earth’s crust contains metals and metal compounds such as gold, copper, iron oxide and aluminium oxide
- Useful metals are often chemically combined with other substances forming ores
- A metal ore is a rock that contains enough of the metal to make it worthwhile extracting
- They have to be extracted from their ores through processes such as electrolysis, using a blast furnace or by reacting with more reactive material
- In many cases the ore is an oxide of the metal, therefore the extraction of these metals is a reduction process since oxygen is being removed
- Common examples of oxide ores are iron and aluminium ores which are called hematite and bauxite respectively
- Unreactive metals do not have to be extracted chemically as they are often found as the uncombined element
- This occurs as they do not easily react with other substances due to their chemical stability
- They are known as native metals and examples include gold and platinum which can both be mined directly from the Earth’s crust
- The position of the metal on the reactivity series influences the method of extraction
- Those metals placed higher up on the series (above carbon) have to be extracted using electrolysis
- Metals lower down on the series can be extracted by heating with carbon
The Extraction Method Depends on the Position of a Metal in the Reactivity Series
