Factors influencing sintering process Jul08

Factors influencing sintering process...

Factors influencing sintering process Sintering of iron ore is a metallurgical process carried out on a sintering machine. It is basically an agglomeration process achieved through combustion. In this process air is sucked at the sinter strand through a bed of raw mixture (also called sinter mix) of iron ore fines, limestone, dolomite, sand and quartzite fines (flux), solid fuel (coke breeze or anthracite) and metallurgical wastes (collected dusts, sludge and mill scale etc). The iron ore is natural ore of size 0 mm to 10 mm. This sinter mix is added with water and the return sinter fines and then granulated or pelletized in a rotating drum before it is charged as a bed on to the moving strand of the sintering machine. As the strand moves forward, the fuel particles on the top surface layer are first ignited in a furnace and as the strand move forward, the ignited or combustion front proceeds gradually downwards through the bed until the end is reached. Strand speed and sucked air flow are controlled to ensure that ‘burn through’ (the point at which the burning fuel layer reaches the base of the strand) occurs just prior to the sinter being discharged. The temperature of the sintering process is mainly controlled by the combustion of the fuel particles. During the process of sintering, there are different zones on the sinter machine strand. These zones from the charging side are wet zone, preheating and drying zone, combustion zone and product zone. In the combustion zone liquid phase is formed between iron ore, flux and other elements and the unreacted iron ore particles are bonded together by the liquid. The final product ‘sinter’ is a porous solid material having certain strength. There are several factors which affect the...