Extracting metals Flashcards
What are ores?
Naturally occurring rocks that contain metal or metal compounds in sufficient amounts to make it worthwhile extracting them.
What are most everyday metals called?
They are mixtures called alloys.
Where is gold, iron oxide and aluminium oxide found?
The Earth’s crust
What needs to happen to a metal ore before metal can be extracted from it?
It needs to be mined and concentrated before the metal is extracted and then purified.
How are metals produced?
The metal oxides need to reduced (have their oxygen removed)
How are reactive metals such as aluminium extracted?
Electrolysis.
How are unreactive metals such as iron extracted?
By reaction with carbon or carbon monoxide
What does the method of extraction of a metal depend on?
It’s position in the reactivity series.
What happens because gold is so unreactive?
It is a native metal, it does not need to be extracted from it’s ore. Although, chemical reactions may be needed to remove other elements that might contaminate the metal.
Where can transition metals be found on the periodic table?
In a large block between groups 2 and 3.
What are the properties of transition metals?
They are good conductors of heat and electricity.
They can be hammered or bent into shape easily.
They are useful as building materials.
How is iron extracted from it’s ore?
In a huge container called a blast furnace.
Why must oxygen be removed from iron oxide?
To leave the iron behind.
What are reactions called where oxygen is removed?
Reduction Reactions
What are the properties of copper?
It is soft and easily bent and is therefore a good conductor of electricity. It is also a good conductor of heat and does not react with water.
What is smelting?
When copper is placed in a furnace and extracted from it’s ore.
How is copper purified?
A process called Electrolysis.
What happens during electrolysis?
Positively charged copper ions move towards the negative electrode and are deposited as copper metal.
What is phytomining?
When plants absorb copper compounds through their roots. They concentrate these compounds as a result of this. The plants can be burnt to produce an ash that contains the copper compounds.
What is bioleaching?
When bacteria absorbs copper compounds they produce solutions called leachates.
What are the properties of aluminium and titanium?
They are two metals with a low density, meaning they are lightweight for their size. They have a thin layer of their oxides on the surface which stops air and water getting to the metal meaning they resist corrosion.
What is aluminium used for?
Aircraft, trains, overhead power cables, sauce pans and cooking foil.
What is titanium used for?
Fighter aircraft, artificial hip joints, and pipes in nuclear power stations.
Why were existing methods of extracting aluminium and titanium expensive?
The processes had many stages
Large amounts of energy were needed
