Extracting Metals - AQA GCSE Core

Revision notes on Extracting Metals - AQA GCSE Core

HideShow resource information
  • Created by: Sophie
  • Created on: 03-01-12 12:32
Preview of Extracting Metals - AQA GCSE Core

First 504 words of the document:

Extracting metals:
Reactivity series ­ the more reactive metal will displace the less reactive metal. Carbon can
also displace less reactive metals.
Rocks that contain metals are called metal ores. Some metals such as gold and silver are so
unreactive they are found in their native states.
Many metals are found as metal oxides like zinc, copper, lead and iron.
Because carbon is more reactive than these metals, we can use it to extract them from their
ores.
Eg. Metal Oxide + Carbon Metal + Carbon Dioxide
Lead Oxide + Carbon Lead + Carbon Dioxide
The removal of oxygen in the way is called reduction reaction.
Extracting iron:
It is extracted using a blast furnace.
The materials used in the furnace are:
Haematite ­ the most common iron ore. It contains iron oxide (Fe2O3) and
sand.
Coke ­ made from coal and is almost pure carbon. Provides the reducing agent.
Limestone ­ removes impurities.
Hot air is blown into the furnace which makes the coke burn, which heat the furnace and forms
carbon dioxide.
C + O2 CO2
At high temps in the furnace, the carbon dioxide reacts again with the coke to form carbon
monoxide.
Co2 + C 2CO
The carbon monoxide reacts with the iron oxide, removing its oxygen and reducing it to molten
iron. This then flows out of the bottom of the furnace.
Fe2O3 + 3CO 2Fe + 3CO2
Some molten iron is left to solidify in moulds. This is called cast iron.
Most is kept molten to be turned into steel. Steel is made by taking out more impurities and
adding other elements to change its properties.
Alloys are a mixture of two or more metals (or carbon). They are stronger because they have
different sized elements in them. Therefore the regular arrangement of the atoms is distorted,
making it harder for the atoms slide over each other.
Eg: Steels ­the simplest steels are carbon steels. They are alloys of iron with carbon.
High carbon steel has a high carbon content. It is very strong but brittle
Low carbon steel has a low carbon content. It is soft and easily shaped. It isn't as strong but
less likely to shatter.
Low alloy steels ­ more expensive because they contain a higher % of other metals.
Nickelsteel is used for long span bridges, bike chains + armour plating
because it is resistant to stretching force
High alloy steels are the most expensive as they contain 12 15% of other metals
Stainless steels are chromiumnickel steels. They are used for cutlery because they have a
good resistance to corrosion.
Smart alloys have a very special property. If you deform them and then reheat them, they return to their
original shape. They are also known as Shape Memory Alloys and are used for holding bones in place
and braces.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Extracting Copper:
Copper is a transition metal. It is soft, easily bent and it is a good conductor of electricity. This
makes copper useful for electrical wiring. Copper does not react with water, which makes it
useful for plumbing.
Copper is purified by electrolysis. Electricity is passed through solutions containing copper
compounds, such as copper sulphate. Pure copper forms on the negative electrode.
It is expensive to extract because a lot of energy is needed.
Aluminium and titanium:
Many metals are strong but also dense.…read more

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »