Extraction of Metals (Cambridge (CIE) O Level Chemistry): Revision Note

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