What is a Blast Furnace?

About Blast Furnace:

• It is a vertical shaft furnace that produces liquid metals by the reaction of a flow of air introduced under pressure into the bottom of the furnace with a mixture of metallic ore, coke, and flux fed into the top.
• The blast furnace itself is a steel shaft lined with fire resistant, refractory materials.
  • The hottest part of furnace - where the walls reach a temperature >300°C - is water-cooled.
  • The whole structure is supported from the outside by a steel frame.
• Blast furnaces are used to produce pig iron from iron orefor subsequent processing into steel, and they are also employed in processing lead, copper, and other metals. 
• The process is continuous, with raw materials being regularly charged to the top of the furnace and molten metal and slag being tapped from the bottom of the furnace at regular intervals.
• Once a blast furnace is started, it will continuously run for four to ten years with only short stops to perform planned maintenance.
• Rapid combustion is maintained by the current of air under pressure.
• Blast furnaces are the largest consumers of materials and energy in the iron and steel-making process.

What is Pig Iron?

• Pig iron is an intermediate product and first product of Iron making reduced from Iron ore.
• Pig iron has a very high carbon content, typically 3.5–4.5%, along with silica, Manganese, Sulphur, Phosphorus, Titanium and other trace elements.
• It is obtained directly from the blast furnace and cast in molds.

Q1: What is Coke?

It is the solid residue remaining after certain types of bituminous coals are heated to a high temperature out of contact with air until substantially all of the volatile constituents have been driven off. The residue is chiefly carbon, with minor amounts of hydrogen, nitrogen, sulfur, and oxygen. Also present in coke is the mineral matter in the original coal, chemically altered and decomposed during the coking process.

Source: Tata Steel commissions ‘India’s largest blast furnace’ at Kalinganagar