How can smelted copper be made pure
By using electrolysis
Why so recycling copper cheaper than extracting it from its ore
- it saves resources; we don’t need so many huge copper mines
- it saves the energy needed to crush rocks and to operate smelters and electrolysis cells
How does electrolysis work
In an electrolysis cell, the ANODE is impure copper. The ANODE dissolves into the ELECTROLYTE (solution) and pure copper coats the CATHODE. The CATHODE is ‘plated’ with new copper
What are the benefits of recycling copper
- fairly low melting point
- easy to melt down and recycle
- cheaper than extracting it from the ore
What are the problems with recycling copper
- getting people to recycle it in the first place
- sorting the copper from other metals
- even the copper samples must be sorted; valuable ‘pure’ copper scrap mustn’t be mixed with less pure scrap. Copper with solder on it will contaminate the metal when the copper is melted
What does electrolysis actually mean
The break up of a chemical compound (the electrolyte) by using an electric current.
What is the equation for when the sulphate electrolyte gains electrons and deposits them onto the copper cathode
Cu^(2+) + 2e^(-) -> Cu
What is the equation for when copper atoms in the anode turn into ions, and put copper ions back into the electrolyte
Cu - 2e^(-) -> Cu^(2+)
What is reduction and oxidation
Reduction is a gain in electrons
Oxidation is a loss of electrons
OILRIG
What is bronze and how was it made
Bronze is an ALLOY
During The Bronze Age, tin was added to copper to create bronze; a much harder version of copper
What is an alloy
An alloy is a mixture of a metal element with another element. Alloys have different properties from the metals they are made from, which is why we use them
What is the removal of oxygen called
Reduction
What is a smart alloy
Smart alloys are more bendy than steel and so are harder to damage; eg nitinol is a smart alloy made from nickel and titanium
What is a solder
Alloys can have lower melting points than pure metal, and this can be useful. An alloy of lead and tin melts so readily that it can be used to join (solder) metals together. The ALLOY is called a solder
