Iron is this starting point for steelmaking which has performed as a backbone to the advancement of modern technology and is vital to the upbringing of the future. It acts as the predominant reason for the industrial revolution. The foundation that is iron, more industrially known as Cast Iron has been given the second honour as it is the one of the cheapest materials for engineering, when taken to molten temperatures it gains the ability to be cast into intricate shapes. Cast Iron has been sub-divided into 5 different classes when the composition is changed or tampered with. Each of these classes have different properties but in comparison with Steel which also has its grades ranging from low to high grade carbon steel which are just alloys of purified iron with carbon and hints of other metal elements such as Manganese and Nickel so the production of Steel products differs only slightly from the commercial production of Iron. Steel which is the easily formed, cheap and yet strong and tough allowing for it to be extremely versatile creating products ranging from paperclips to reinforcing elements in the construction of buildings and skyscrapers.
The production of iron and steel is a complex one, it has a potent effect on the environment and the ecosystem due to the sheer volume and the extensive use of starting products and raw materials and energy for its operations. The pollutants and wastes that are produced in this process can be classed into three primary categories, these are Air Pollutants, waste water contaminants and solid wastes. The diagram below indicates various channels that the raw materials have to go through in the process of steel making and the pollutants that follow with its production.
It is evident that carbon based pollutants are substantial in the process of steelmaking
The production of steel happens in four steps, they are iron making, steel making, forming and finally the finishing of the semi-good into finished product.
The iron is manufactured in two different ways, these processes are employed to utilise the various raw materials and technologies, primarily is done by the use of a blast furnace; a tall metal steel vessel lined with brick or concrete for insulation (Gallaher and Depro, 2002). The blast furnace is continuously feed with the ores of iron as well as fluxing agents such as flux stone and fuelled with coal or coke and other sources of iron oxides to generate hot metal liquid iron. A brief description of the overall reaction what goes on in a blast furnace is given below:
Firstly, the coke is ignited in a sufficient amount of oxygen to form carbon dioxide. The reaction is very exothermic and temperatures are over 1000°C to effect the iron ore reduction. This acts as a fuel.
• C(s) + O2(g) ==> CO2(g)
Coke has a second function and is used as a reducing agent, at high temperatures it combines carbon to form carbon monoxide, which is used as a reducing agent.