Extracting Ores Flashcards
What are ores
minerals with enough metal so that it can be economically extracted
Give an example of an ore
Haemaetite-iron ore Bauxite-Aluminium ore
What is meant by an uncombined element?
A pure element found in native ground
Give an example of an uncombined element
Gold or silver
Which metals are extracted using carbon extraction
The metals which are less reactive than carbon, specifically zinc iron and lead
Where are these metals in the reactivity series relative to carbon
All below carbon
Which metals are extracted using electrolysis
Those above carbon, specifically potassium, sodium, lithium, magnesium, calcium, aluminium
where are these metals relative to hydrogen in the reactivity series
all above hydrogen
What are the three raw materials that go into the blast furnace
Iron ore, coke and limestone
What are the three reactions that make iron
Carbon + oxygen –> carbon dioxide
C + O2 –> CO2
Carbon + carbon dioxide –> carbon monoxide
C + CO2 –> 2CO
Iron oxide + carbon monoxide –> iron + carbon dioxide
Fe2O3 +3CO –> 2Fe + 3CO2
What are the two reactions that make slag
Calcium carbonate –> calcium oxide + carbon dioxide
CaCO3 + CaO + CO2
Calcium oxide + silicone dioxide –> calcium silicate
CaO + SiO2 –> CaSiO3
Why is the pig iron from the blast furnace useless
Since it has so much carbon in it (4%) it is brittle
What is done to make it useful
It is turned into steel using the Basic Oxygen Steel making process - this removes most of the carbon
what is the ore of aluminium
Bauxite
what is Bauxite mixed with before electrolysis
Cryolite
Why do we mix bauxite and cryolite
To lower the melting point OF THE MIXTURE to a practical level (900 degrees rather than over 2000 degrees - costs less)
Which electrode does the aluminium form on
Cathode (negative end)
During electrolysis, what forms on the anode (positive) side
Oxygen
What does oxygen do to the electrode
It burns away as it reacts with carbon
Write an equation to show the overall reaction of aluminium’s formation in electrolysis
Aluminium oxide –> aluminium + oxygen
What is an alloy
An alloy is a mixture of a metal and one or more elements
Give an example of some alloys and their composition of elements
Brass - Copper (67%) & Zinc (33%)
Solder - Tin (80%-31%) & Lead (20%-69%)
Steel- Iron (99%) & Carbon (1%)
Explain using diagrams why alloys are harder than pure metals
- Pure metal has regular layers
- These layers can slide over each other when a force is applied
- In an alloy the layers are distributed by the addition of other elements atoms consequently stopping the layers from sliding
