Metals

Metals

• There are two groups of Metals

1. Ferrous – consist mainly of IRON

2. Non Ferrous – contain NO IRON

Where do metals come from?

• Metals come from rocks in the ground called ORE

• The ORE is mined from the ground

• The metal must then be taken from the Ore and a big Furnace does this.

Iron

• Iron comes from Iron Ore which is excavated from the ground.

• The furnace used to separate the Iron from the rocks is called a

BLAST FURNACE

Blast Furnace

Blast Furnace Charge

1. Iron Ore-----------------------

2. Coke------------- (fuel)

3. Limestone-------------------- (Keeps waste bits together)

Iron Ore

• Iron ore is a rock that contains iron combined with oxygen.

• Some of the world's highest quality iron ore comes from Australia.

Coke

• Coke is made from coal. Once mined, the coal is crushed and washed.

• Coal is then baked in coke ovens for about

18 hours.

• During this process, by-products are removed and coke is produced.

Flux

• Flux is a term for minerals used to collect impurities during iron and steelmaking.

• Limestone and dolomite are fluxes.

• The flux causes a chemical reaction and elements not needed for steelmaking join together to form slag.

Blast Furnace

Tuyeres

Tuyeres are the nozzles that the hot air is blown through

Blast Furnace operation

• The Charge is fed in at the top,

• Bell Doors open (One at a time)

• Coke burns & makes Carbon Monoxide,

• The Carbon Monoxide mixes with the Oxygen in the Iron Ore (leaving Iron),

Blast Furnace

• The Molten Iron falls to the bottom of the Furnace,

• The limestone joins with the impurities to make Slag and floats on top of the Molten Iron.

Blast Furnace

• The slag and the Molten Iron are tapped off regularly,

Blast Furnace Waste

• Slag, Ammonia, Light Oils and Coal Tars are waste from the Furnace,

• They make raw materials for cements, plastics and fertilisers.

Blast Furnace Iron

• Special rail cars bring the Molten Iron away,

• The liquid iron typically flows into a channel and indentations in a bed of sand.

• Once it cools, this metal is known as pig iron.

Why is Pig Iron called Pig Iron ?• PIG IRON is raw iron in an ingot form.

• It is the result of smelting Iron Ore, Coke and Limestone in a blast furnace.

• It is a hard but brittle mix of iron (90% or more) and carbon (typically 4-5%), manganese, sulfur, phosphorus, and silicon (roughly 3% in total).

• The name is derived from the time when the iron ran into moulds. A row of moulds was said to resemble a litter of suckling pigs, so the single ingots were referred to as pigs.

To create a ton of pig Iron We start with 2 tons of ore,1 ton of coke and½ ton of limestone.The fire consumes 5 tons of air.The temperature reaches almost 3000 deg F

(about 1600 degrees C) at the core of the blast furnace!

• Pig iron contains 4 percent to 5 percent carbon and is so hard and brittle that it is almost useless.

We do one of two things with pig iron:

• You melt it, mix it with slag and hammer it to eliminate most of the carbon (down to 0.3 percent) and create wrought iron.

Wrought Iron

• Wrought iron is the stuff a blacksmith works with to create tools, horseshoes and so on. When you heat wrought iron, it is malleable, bendable, weldable and very easy to work with.

• Or we can create steel.

Steel

• Steel is iron that has most of the impurities removed.

• Steel also has a consistent concentration of carbon throughout (0.5 percent to 1.5 percent).

• Impurities like silica, phosphorous and sulfur weaken steel tremendously, so they must be eliminated.

• The advantage of steel over iron is greatly improved strength.

Blast Furnace Iron

• The Iron must go into a second furnace to make it into a better quality metal (Steel)

• At the Steel making factory, it is mixed with recycled steel and other alloys to make new steel

Iron into Steel

• The Iron that comes from the Blast Furnace requires further treatment to produce Steel,

• This is done in:

1. The Bessemer Converter or 2. The Basic Oxygen furnace.

To recap