After years using the ball oven, the
Catalonian forge (considered the embryo of today's blast
furnaces) was developed. It appeared in Spain, soon after
the fall of the Roman Empire, and was used throughout
the entire Middle Age.
It was a fireplace made of stone and
hand-operated bellows blowing air into the forge, increasing
the temperature and the amount of iron produced. Later,
mechanical bellows operated by servants or horses were
developed. In the 12th century, water reels started to
be used. With higher temperatures in the forges, it was
possible to obtain liquid iron, rather than pasty.
The possibility of obtaining liquid
iron brought about the technique of cast firearms, cannonballs
and church bells. The use of iron was later extended to
the nobility's homes of great gates and mantels with complex
designs.
Around 1444, iron ore started to be
melted in blast furnaces, a process still used until today.
The temperatures reached by those furnaces were even higher,
which allowed higher absorption of Carbon from vegetable
coal. This made iron and steel alloys harder and more
resistant. At that time, daily production of a furnace
was around 1,500 kg.
The Industrial Revolution started in
England, in the 1800's, would make iron production even
more important for mankind. During this time, agricultural
and rural communities started to lose importance to urban,
mechanized societies.
The grate change, however, did not occur
until 1856, when the process to produce steel was discovered.
This is because steel is more resistant than cast iron
and may be produced in large quantities, serving as raw
material for various industries.
