A study was carried out to compare the environmental impacts of the two major iron ore agglomeration processes, sintering and pelletising, using life cycle assessment (LCA) methodology._x000D_
The following agglomeration processing routes, with the fuel options shown, were investigated: sintering with combined natural gas/coke breeze or charcoal as fuel, grate-kiln pelletising with combined natural gas/coke breeze as fuel, and straight-grate pelletising with combined natural gas/coke breeze as fuel._x000D_
Inventory data for each process derived from the literature, and in some instances supplemented by additional simulations and calculations, were used in the study and the environmental impact categories considered were gross energy requirement (GER), global warming potential (GWP) and acidification potential (AP)._x000D_
The results of the study showed that the GER, GWP and AP for a sinter plant are higher than those for a pellet plant for the same amount of metallic iron in the agglomerated products. These results are partly due to higher consumption of solid fuel and flux in the sintering process. However, it should be pointed out that the study only compared substantially fluxed sinters with acid pellets that may require additional flux (and hence potentially more greenhouse gases emissions) to be a balanced blast furnace feedstock. Extending the LCA to the blast furnace process stage was beyond the scope of the current study. Within the sinter plant, the sintering stage itself is the largest contributor to the GER, GWP and AP. In the case of pellet plant, the pellet induration stage is the largest contributor to the various environmental impacts._x000D_
The GER and GWP of a straight-grate pellet plant are marginally higher than those of a grate-kiln pellet plant due to the higher electrical power required by the straight grate system._x000D_
The substitution of coke breeze with charcoal in the sintering process results in an increase in GER but a decrease in GWP. However, a substantial proportion of the GER is derived from renewable sources (wood), resulting in a decrease in the non-renewable components of this environmental impact._x000D_
Given the source of the inventory data and the assumptions and approximations made in carrying out the LCAs, it is emphasised that the results presented in this paper should be considered as indicative rather than as definitive results for the two iron ore agglomeration processing routes considered._x000D_
FORMAL CITATION:Trang, S C T, Norgate, T E and Vining, K R, 2006. Environmental assessment of iron ore agglomeration processes, in Proceedings Green Processing 2006, pp 155-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).