2. Steelmaking is the process for producing steel from
iron ore and scrap.
What it is the Steel making process?
3. First stage
Preparing the mineral of iron
It starts in the mine or quarry, where it´s obtained. In nature is
a rock whith iron, oxide, dirt and other impurities.
4. The first process:
The impurities are removed in the first part of the process, when
de gangue is separated from the ore.
5. The second process of preparing the mineral of iron is:
• The mineral is washed to remove dirt.
• It´s crushed into sand.
•The sand is sieved, and then, again separated from the ore.
7. • Coke: is a fuel whith few impurities and high carbon
content, usually made from coal.
• Limestone: a sedimentary rock consting predominatly
of calcium carbonate.
• Ore: the usable part of the rock of iron.
8. The hot is injected from nozzles at the bottom of the furnace,
this way, the reaction is acelerated and the temperature rises
higher.
The temperature is very high, over 1500ºC
9. The lower part of the blast furnace is called crucible.
Melted minerals precipitate on it.
Pig iron acomulates at the botton and the slag stays above
it. They are separated, the pig iron is the usable part.
The pig iron usually cool in molds, after, they are transported to
steel companies.
10. PROBLEM:
The pig iron contents too much carbon and impurities in the
composition. Needs to reduce it before becoming steel.
12. Scrap is added to the pig iron, so the scrap is
recicled.
Oxygen is injected in order to burn the carbón
and eliminate the impurities.
After, slag is remove. And the liquid Steel is
ready to get the final shape.