Use of Nut Coke in a blast furnace Apr27

Use of Nut Coke in a blast furnace...

Use of Nut Coke in a blast furnace Metallurgical coke is produced during the carbonization of coking coal blend in a coke oven battery. This coke is produced normally in three size fractions namely coke breeze (size – 10 mm), nut coke (size +10 mm to – 25 mm) and blast furnace (BF) coke (+ 25 mm to – 80 mm).  BF coke is one of the most important factors which affect the economic efficiency of a blast furnace. It also constitutes a great portion of the production costs of the hot metal. The use of nut coke in blast furnace is the essential factor to reduce the costs of iron making. The consumption of the BF coke is strongly related to the CO2 emissions. History Earlier there was no use of nut coke in an integrated steel plant and it was sold to other users. Prof. V. I. Loginov suggested in 1960s to charge nut coke into the blast furnace in mixture with sinter.  Though this idea was successfully tested, yet there was initial resistance to use nut coke in blast furnace. In mid 90s Visakhapatnam Steel Plant started using nut coke in their blast furnaces and soon achieved a monthly specific consumption level of over 50 Kg/tHM. The blast furnace of Neelachal Ispat Nigam Limited which was commissioned in February 2002 achieved by 2004-05 a monthly average specific consumption level of over 100 Kg/tHM. Presently the use of nut coke in blast furnace as a substitute of a part of BF coke is considered as a proven technology and nut coke is being used extensively in blast furnaces all over the world. Modern blast furnaces use nut coke in different amount (10-140 Kg/tHM) and in different size of nut coke (10-40 mm)....