What is metal?
In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic
Metals are sometimes described as a lattice of positive ions surrounded by a cloud of
The metals are one of the three groups of elements as distinguished by their ionization and
bonding properties, along with the metalloids and nonmetals
Metals are generally defined as being solid elements which share certain physical, chemical
and mechanical properties that differentiate them. Apart from their
shine, malleability, ductility, hardness, resilience and elasticity, they are good conductors of
heat and electricity, and have a high light reflection capacity.
The following are ferrous metals and the kind of uses to which they are usually put:
Mild Steel – Carbon content of 0.1 to 0.3% and Iron content of 99.7 – 99.9%. Used for
engineering purposes and in general, none specialised metal products.
Carbon steel – Carbon content of 0.6 to 1.4% and Iron content of 98.6 to 99.4 %. Used to make
cutting tools such as drill bits.
Stainless Steel – Made up of Iron, nickel and chromium. Resists staining and corrosion and is
therefore used for the likes of cutlery and surgical instrumentation. See our infographic
celebrating 100 years of stainless steel usage in buildings or the different types of stainless steel.
Cast Iron – carbon 2 – 6% and Iron at 94 to 98%. Very strong but brittle. Used to manufacture
items such as engine blocks and manhole covers.
Wrought Iron – Composed of almost 100% iron. Used to make items such as ornamental gates
and fencing. Has fallen out of use somewhat
Non Ferrous Metals
These are the non ferrous metals and their uses:
Aluminium – An alloy of aluminium, copper and manganese. Very lightweight
and easily worked. Used in aircraft manufacture, window frames and some
Copper – Copper is a natural occurring substance. The fact that it conducts
heat and electricity means that it is used for wiring, tubing and pipe work.
Brass – A combination of copper and zinc, usually in the proportions of 65% to
35% respectively. Is used for ornamental purposes and within electrical fittings.
Silver – Mainly a natural substance, but mixing with copper creates sterling
silver. Used for decorative impact in jewellery and ornaments, and also to solder
different metals together.
What is iron?
Iron is a chemical element with the symbol (Fe) and atomic number 26. It is a metal in the first
transition series. It by mass is the most common element on Earth, forming much of Earth's outer
and inner core.
Iron, one of the most abundant metals on Earth, is essential to most life forms and to normal
human physiology. Iron is an integral part of many proteins and enzymes that maintain good
health. In humans, iron is an essential component of proteins involved in oxygen transport. It is
also essential for the regulation of cell growth and differentiation
What is steel?
Steel is an alloy of iron, with carbon being the primary alloying element. The carbon
content of steel is between 0.002% and 2.1% by weight. Too little carbon content leaves
(pure) iron quite soft, ductile, and weak. Carbon contents higher than those of steel make
an alloy commonly called pig iron that is brittle and not malleable.
Additional elements may be present in steel:
manganese, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen
Alloy steel is steel to which additional alloying elements have been
intentionally added to modify the characteristics of steel. Common
alloying elements include:
manganese, nickel, chromium, molybdenum, boron, titanium, vanadium
IRON & STEEL
Iron making in the Blast Furnace Plant
Top Gas Mains
Above Burden Probe
Sub Burden Probe
1: Iron ore + Calcareous sinter
3: conveyor belt
4: feeding opening, with a valve that prevents direct
contact with the internal parts of the furnace
5: Layer of coke
6: Layers of sinter, iron oxide
7: Hot air (around 1200°C)
9: Liquid pig iron
11: Tap for pig iron
12: Dust cyclon for removing dust from
exhaust gasses before burning them in
13: air heater
14: Smoke outlet (can be redirected to
carbon capture & storage (CCS) tank)
15: feed air for Cowper air heaters
16: Powdered coal
17: cokes oven
18: cokes bin
19: pipes for blast furnace gas
Iron-carbon Phase Diagram
Iron-carbon phase diagram describes the
iron-carbon system of alloys containing up
to 6.67% of carbon, discloses the phases
compositions and their transformations
occurring with the alloys during their
cooling or heating.
Carbon content 6.67% corresponds to the
fixed composition of the iron carbide