Metal Extraction

Reduction and Oxidation: 1 - ‘Reduction’ refers to the loss of oxygen in a reaction from a substance (e.g - iron oxide + carbon → iron + carbon dioxide [iron oxide has been reduced]) 2 - Oxidisation refers to the gain of oxygen in a reaction from a substance (e.g - iron + oxygen → iron oxide [iron has been oxidised])

Oxidation: The tendency to become oxidised is thus linked to how reactive a metal is and therefore its position on the reactivity series Metals with a high reactivity are therefore less resistant to oxidation than the metals with a lower reactivity down which are more resistant to oxidation

1 - Potassium, Sodium, Lithium, Calcium, Magnesium and Aluminium are extracted by electrolysis of the molten chloride or oxide 2 - Large amounts of electricity are required, which makes this an expensive process

1 - Zinc, Iron and Copper are extracted by heating with a reducing agent such as carbon or carbon monoxide in a blast furnace 2 - A cheap process as carbon is cheap and can also be a source of heat

Gold and silver are found as pure elements by mining within the Earth’s crust

A metal ore is a rock that contains enough of a specific compound metal to be worth extracting Useful metals are often chemically combined with other substances forming ores

Metal Extraction: Unreactive Metals Unreactive metals, such as gold and silver, can be found as pure metals in the Earth’s curst and can be mined as a method of extraction.

Metal Extraction: Less Reactive Metals Metals that are less reactive than carbon can be extracted by reduction with carbon through heating (metal oxide + carbon → metal + carbon dioxide)

Metal Extraction: Highly Reactive Metals Metals of a high reactivity have to be extracted from their ores through processes such as electrolysis, using a blast furnace or by reacting with more reactive material.