Reactivity Series and Metals
Metals above Carbon must be extracted using Electrolysis
Metals below Carbon can be extracted from their ores by Reduction
Copper, Silver, Gold & Platinum can occur Native and don't need to be extracted. Sometimes Copper needs to be extrated from an Ore.
Metal Extraction Basics
Au, Ag and Cu are found as Native elements
Most metals are compounds (oxides or sulphides)
Ores - rocks containing metal componds
All metals are extracted using reduction to be separated from their compounds
Two Main Ways of Extracting
Reduction with Carbon
Electrolysis, using electricity
1 The purified Aluminate is dissolved in molten cryolite and electrolysed at 950 degrees. The reason for this is that the cryolite lowers aluminium’s high melting point, and therefore decreasing the cost.
T The crystolite does not dissolve as a low voltage is used in the Hall-Hevott cell (as shown below)
3 Reactions take place in the Anode and the Cathode. These can be shown as equations below:
· Al + 3e- Al
· 2O 2O +4e-
4 The pure aluminium is then removed from the cell and added to other metals to form alloys, or simply cooled to form inglots.
Copper is found in a green ore called Malachite.
Malachite contains Copper Carbonate.
If you heat it gently, you get Copper Oxide
Using Carbon, the Copper Oxide gets reduced to Copper