Electrolysis of the molten ore (form three - four)

Take the electrolysis of the molten ore of aluminium(Bauxite) as an example.

Electrolysis carries out in a very large steel tank lined with graphite, which acts as negative electrode. Huge blocks of graphite hang in the middle of the tank, act as positive electrode. During the process, molten aluminium forms at the negative electrode while oxygen gas bubbles off from poxitive electrode.

2007-12-02 23:52:27 補充：
Advantage:(1)Since aluminium (or more reactive metals) cannot be extracted by simple physical methods.The invention of electrolysis allows us to obtain aluminium (and more reactive metal such as potassium) from the metal ores.

2007-12-02 23:52:53 補充：
Advantage:(2)Some of extratcion which make use of electrolysis can also give out some useful substances apart from the metal. For example, extracting aluminium can also produce oxygen gas.

2007-12-02 23:53:12 補充：
Disadvantage:(1)Very expensive(2)Waste energy(electricity)