Low Shaft Furnace Smelting ofPig Iron in India

AS IRON and steel enter in all other industries in some form or other, the industrialisation of a country depends on the production of iron and steel. Production of pig iron, which is ultimately converted into steel, depends on the availability of raw materials like iron-ore, and coking coal of suitable grades. The conventio- nal method depends on the reduction of lumpy iron-ore or sintered iron-ore with abrasion resistant coke in prese-nce of limestone in a blast furnace. The increase is the height of the furnace to increase the capacity and ther- mal efficiency necessitates the use of good strong coke which call only be obtained by carbonisation of coking coal. As the modern blast furnace consumes 1,500-2,000 lb of coke per ton. of pig iron, considerable attention is paid to minimise the coke-rate and thereby reduce the cost of iron production.For this purpose the temperature of the blast furnace gas should be as low as possible to reduce the sensible heat carried away by the gas and the, ratio of CO : CO2 in the top gas should be as near as possible to the equilibrium value. Both these factors have contributed towards the increase in the height of the furnace. Requisite raw materials for blast smelting are becoming scarce, as in some countries coking coals are not available and the ores are soft and obtained as fines.