2004 Volume 44 Issue 1 Pages 59-68
The use of cement-bonded agglomerates of iron-rich by-products generated in iron and steel plants as burden material for blast furnaces is becoming quite common. It has been observed that under certain conditions the briquettes containing pellet-fines show a tendency to swell catastrophically when reduced at 900-1000°C using carbon monoxide as a reducing agent. This swelling is dependent upon a number of processing parameters, such as: composition of briquettes, particle size of raw material, amount of cement, composition of cement, and coke content. It is not dependent upon the size of agglomerate or hydration period. From the optical micrographs, it is apparent that the swelling may be attributed to the formation of small spheroidal iron particles that move apart, thereby causing swelling. This paper describes the effect of various processing parameters that cause the abnormal swelling in cement-bonded briquettes made of pellet-fines.
