Chemistry Task sheet
Metal from their Ores
What is an ore?
An ore is a rock that has minerals and essential elements such as metals. It occurs naturally and is obtained through mining. Valuable elements are then extracted from it through different methods. In simpler words, it is a naturally occurring solid material from which a metal or valuable mineral can be extracted profitably.
How iron is naturally found in environment?
Iron is very reactive and is found in nature in form of its oxides, carbonates and sulphates.
Iron, by mass is the most common element on Earth, forming much and inner core. It is the fourth most common element in the Earth's crust.
How is iron formed in the earth’s crust?
Iron's very common presence in rocky planets like Earth is due to its abundant production as a result of fusion in high-mass stars.
Iron ores are rocks and minerals from which metallic iron can be extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, deep purple, to rusty red. The iron itself is usually found in the form of magnetite (Fe3O4), hematite (Fe2O3), goethite (FeO (OH)), limonite (FeO (OH).n (H2O)), siderite (FeCO3) and iron pyrites (FeS2). The main iron ore is Haematite. The iron ore contains impurities, mainly silica (silicon dioxide). Since iron is below carbon in the reactivity series, so it can push out or displace the iron from iron oxide.
Ores carrying very high quantities of hematite or magnetite (greater than ~60% iron) are known as "natural ore" or "direct shipping ore", meaning they can be fed directly into iron by putting them into blast furnaces. Most reserves of such ore have now been depleted. Iron ore is the raw material used to make pig iron, which is one of the main raw materials to make steel. 98% of the mined iron ore is used to make steel.
How is iron mined?
The iron-ore bearing rock is first blasted and dug up from open pit mines, then crushed and extracted.
How is iron extracted?(Step-wise process)
The ore is crushed in crushers and is broken to small pieces. It is concentrated with gravity separation (an industrial method of where separating two components with gravity is sufficiently practical) in which it is washed with water to remove clay, sand, etc.
The ore is then heated in absence of air (calcined). This results in decomposition of carbonates into oxides.
The concentrated ore is mixed with calculated quantity of coke, limestone and the mixture is put in the Blast Furnace from top.
It is a tall cylindrical furnace made of steel.
It is lined inside with fire bricks.
It is narrow at the top and has an arrangement for the introduction of ore and outlet for waste gases.
Heated with help of Hot Gases.
What happens in the blast furnace?
Iron is separated from oxygen in iron oxide by a reduction process. It...