Energy survey of the coal based sponge iron industry

A survey is made on a typical coal based Indian sponge iron plant of capacity 500 t/d in order to identify the largest energy losses and find ways to increase the efficiency. The required data are obtained by measurements or taken from production industries. The process efficiency is about 51.31%. The energy balances of the process show that the gap between theoretical and actual energy consumption is 45.2% and the exhausts make up the largest loss of 43.5%. A huge amount of waste gas is generated during operation and substantial part of it associated with the waste gas, remains unutilized. The energy content in the exhaust gases which is found at useful temperature can be used in three different ways: by internal use; by external energy supply; or by power generation. The four possible potential areas are identified where energy is being lost and untapped. The largest improvements would be made by design modifications adopting a novel energy conservation scenario by process integration and thereby decreasing the coal and water consumption and by decreasing the cold fresh air.