PROCESSING OF METALS

PROCESSING METALS

 

Iron ore

This is the first material needed in the process of making metals, but iron ore will have to go through many processes with the addition of many other elements before it becomes a metal that can

be used in engineering and construction industries.

 

Iron are is a solid mineral usually dug out from the ground.

From iron ore, valuable materials such as metals are extracted.

This is after the iron are has uil dergone some extraction processes.

 

Pig Ir­on

The first step to be carried out in the process of extracting metals

from iron are is the separation of other elements present in the

iron are. After removing these elements, which are called

impurities, the product is pig iron. The pig iron is produced in a

blast furnace after burning out those unwanted elements such as

silicon, phosphorus, manganese, etc.

 

Pig Iron to Steel

we have seen how the iron ore is processed to form pig iron. 1he

next stage is to use pig iron to produce steel or metal that can be

used in engineering industry, because pig iron is a metal that

cannot be worked upon. Steel or metal can be made from pig iron

by taking out some of the carbon. The main difference between

steel and pig iron is the amount of carbon each contains. Pig iron

contains from 3 to 5% carbon while steel contains less than 29%. In

this case, in making steel from pig iron, it is necessary to take out

some carbon.

 

How the Pig Iron is produced

The blast furnace is loaded with iron are, coke and limestone. A

blast of hot air is then forced into the furnace to heat the limestone and iron are to a molten condition. This blast of hot air enters the

furnace from stoves through four nozzles usually called tuyeres.

These tuyeres are located close to the base of the furnace.

 

The burning coke and the blast of hot air melt the iron are. Slag,

which is one of the unwanted elements from the iron are, is formed

on top of the molten iron and drops to the bottom of the furnace

leaving molten iron in the furnace.

 

The molten iron is then transferred into a ladle which will be

used to transfer the molten iron to the mould. It is here the molten

iron will cool down and form what is called pig iron.

 

How the Carbon in Pig Iron can be Reduced

The carbon content in the pig iron can be reduced to the rignt

amount to form a metal that can be used in engineering industry Dy

using that process called the Bessemer Converter. In the operation

to produce steel in the Bessemer Converter, the carbon and other

unwanted elements called ‘impurities are burnt out of melted pig

iron by allowing a current of cold air through it. When the cold air

is blown into the molten pig iron, it starts to boil. This is taking

place because the carbon in the pig iron combines with the oxygen

in the air and when this happens a forceful burning takes place. We

 

can compare this with a cold wind blowing through a burning lire,

which will make it burn more forcefully.

 

The Bessemer Converter is made like a tank with a big opening

 

at thé top.

 

 

 

Updated: January 22, 2020 — 5:40 am

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