Comparing production methods

  • Created by: Saarah17
  • Created on: 31-10-22 20:58

Electrolysis or reduction of a metal oxide

{Electrolysis - want in molten state -> from solid to molten state

  • high temperature = more energy}

—> the extraction method used depends upon the metal’s position in the reactivity series.

—> in principle, any metal could be extracted from its compounds using electrolysis.
—> however, large amounts of electrical energy are needed to do this, so electrolysis is expensive.

—> if a metal is less reactive than carbon, it can be extracted from its compounds by heating with carbon.

1 of 6

Reactivity series

{MOST reactive}

K Potassium
Na Sodium
Ca Calcium
Mg Magnesium
Al Aluminium
C Carbon
Zn Zinc
Fe Iron
Sn Tin
Pb Lead
Cu Copper
Ag Silver
Au Gold
Pt Platinum

{LEAST reactive}

2 of 6

Comparing electrolysis and reduction


—> Key features of the method :

  • elements are formed at cathode & anodes
  • electricity is used for decomposition

—> It is more expensive than reduction because :

  • anodes need to be replaced
  • large amount of energy needed to go from solid to molten
  • high temperatures
  • electrodes need replacing

—> The metals that are extracted this way and why :

  • aluminium -> electrolysed
  • more reactive than carbon
3 of 6



—> Key features of the method :

  • high temperatures
  • batch process
  • additional substances, e.g. metals are involved in the reduction process
  • inert substance required

—> The metals that are extracted this way and why :

  • titanium can’t be electrolysed
  • titanium carbode forms which is brittle
4 of 6

Batch process

—> a series of operations are carried out over a period of time in a separate, identifiable item or part of material

—> extraction of Ti

—> time consuming - is constantly stopped and restarted to clean etc.

—> flexibility - can change products

—> trial and error opportunities

—> more labour required - transfer of products to the next stage

5 of 6

Continuous process

—> all operations occur at the same time and the material being processed is not divided into identifiable positions

—> extract ion of brine and Al

—> time efficient - does not need to be stopped

—> less flexible

—> self sufficient - not much labour is required

—> large investment required

6 of 6


No comments have yet been made

Similar Applied Science resources:

See all Applied Science resources »See all Comparing production methods resources »