Making Cast Iron in Cupola Furnace

Cupola Furnace:

Cast Iron is manufactured during a furnace referred to as cupola furnace. Cupola furnace is cylindrical in shape with an almost uniform diameter (about 1 meter) and a height of about 5 to six meters. The cylinder has an inner lining of Refractory Bricks which is given tuyers near rock bottom for injecting the availability of air blast. The outer shell is made of Steel. The top of the furnace remains open. The cupola furnace contains a charging door, a platform and tapping holes for the purpose of blasting the air.

Manufacturing of Cast Iron:

 Cupola Furnace

The mixture of Pig Iron, coke, and limestone, known as a charge, is prepared in correct proportions. Coke is used as fuel and limestone as a fluxing material. Flux is the material which easily fuses and mixes with impurities to form a slag, which can be taken through the top of the furnace. The molten metal in almost pure form is collected at the bottom of the furnace along with the floating slag. The slag is removed intermittently through the hole and molten metal taken out through its tap hole. The molten metal taken out are fed into the molds prepared to get desired shapes. The Iron obtained is understood as forged iron, and therefore the shapes obtained are called forged iron castings. The forged iron thus obtained, has 1.7 to 4% of carbon with small impurities of manganese, phosphorus, silicon, and sulfur.