Mining of Minerals and Methods of Extracting of Metals 

4. The extraction of copper from copper ores and its purification by electrolysis

Scroll down for revision notes on extraction procedures and theory

Useful for school/college assignments/projects on ways of extracting metals from their ores

1. Introduction to Metal Extraction * 2. Extraction of Iron and Steel Making

3. Extraction of Aluminium and Sodium * 4. Extraction of copper and purification by electrolysis

5. Extraction of Zinc, Titanium and Chromium * 6. Economic & environmental Issues - metal extraction

GCSE Multiple choice Quizzes on metal extraction: Foundation (easier) or Higher (harder) and word-fill

Revision Notes KS4 Science IGCSE/O level/GCSE Chemistry Information Study Notes for revising for AQA GCSE Science, Edexcel 360Science/IGCSE Chemistry & OCR 21stC Science, OCR Gateway Science  (revise courses equal to US grades 9-10)

Other associated KS4 Science GCSE/IGCSE chemistry web pages on this site

• Reactivity of metals : all the reactions of metals with oxygen (air), water and acids, displacement reactions.

• Oxidation-reduction explained (redox theory)

.

• Group 1 Alkali Metals: chemical and physical properties

• Extra Industrial chemistry : properties and uses of metals including titanium and aluminium

• Transition metals : properties and uses

• Extra Electrochemistry-electrolysis : electrolysis theory, experiment designs and links to all electrolysis section on this site.

• The impure copper from a smelter is cast into a block to form the positive anode. The cathode is made of previously purified copper. These are dipped into an electrolyte of copper(II) sulphate solution. 
• When the d.c electrical current is passed through the solution electrolysis takes place.  The copper anode dissolves forming blue copper(II) ions Cu²⁺.
• These positive ions are attracted to the negative cathode and become copper atoms. The mass of copper dissolving at the anode exactly equals the mass of copper deposited on the cathode. The concentration of the copper(II) sulphate remains constant.
• Any impurities present in the impure copper anode fall to the bottom of the electrolysis cell tank. This 'anode sludge' is not completely mineral waste, it can contain valuable metals such as silver!
• See section above for extraction of impure copper from an ore.

Raw materials for the electrolysis process:

• Impure copper from a copper smelter.

• Electrolyte of aqueous copper(II) sulphate.

• A pure copper cathode.

Electrolysis is using d.c. electrical energy to bring about chemical changes at the electrolyte connections called the anode and cathode  electrodes.

An electrolyte is a conducting melt or solution of ions which carry the electric charge as part of the circuit.

Scrap copper can be recycled and purified this way too ,and is cheaper than starting from copper ore AND saves valuable mineral resources.

• At the positive (+) anode, the process is an oxidation, electron loss, as the copper atoms dissolve to form copper(II) ions.

Cu_(s) ==> Cu²⁺_(aq) + 2e^-

• at the negative (-) cathode, the process is a reduction, electron gain by the attracted copper(II) ions to form neutral copper atoms.

Cu²⁺_(aq) + 2e^- ==> Cu_(s)

• Note: Reduction and Oxidation always go together, hence the use of the term redox change or reaction.
• Electroplating is mentioned on the ...
  • Industrial Chemistry
  • and Electrochemistry pages.

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