Metals Revision lesson

Extracting metals

Metals found in the ground are normally found as a METAL ORE – combined with other elements in compounds

Metals found on their own are not highly reactive. We say they are found in their NATIVE STATE.

Is it worth it?

Before extracting a particular metal ore from the ground you must assess…

How easy it is to extract the metal from the ore

How much metal the ore contains

How do we extract metalsThis depends on where it is in the reactivity series!

Displacement reactions

Redox reactions

Electrolysis

Displacement Reactions

You can displace a metal from its ore by reacting it with a more reactive metal.

The more reactive metal takes the place of the less reactive metal

Practice!Sodium Carbonate + Lead Silver Oxide + Zinc

Redox reactions

We can REDUCE the metal ore by removing the oxygen.

Lead Oxide + Carbon

Electrolysis

For highly reactive metals (higher than carbon) we have to use electrolysis to remove the metal from its ore.

Electrodes are placed into the solution. The metal ions move towards the negative electrode because they are positively charged.

Some metals couldn’t be extracted from their ores until electricity was discovered!!!

Iron and Steel

Iron can be removed from its ore in the BLAST FURNACE.

Carbon is used to remove the oxygen from iron oxide to leave PURE IRON.

PURE IRON is too soft to be useful so it is alloyed with carbon to make STEEL.

Alloys

Steel

Aluminium and Titanium

When we need metals that are STRONG but LOW DENSITY (light) we pick aluminium or titanium.

They also resist CORROSION

BUT… they are EXPENSIVE to EXTRACT from THEIR ORES

Copper Copper – rich ores are running out.

We still mainly use SMELTING to extract copper

But we must begin to extract from lower grade ores.

Methods include…

Bioleaching (bacteria) and Phytomining (plants)!!!

Useful metals

Why are metals useful?