The FINEX process, developed by Siemens VAI and POSCO is an innovative methodology in which molten iron is produced directly using iron ore fines and non-coking coal. The main benefits of the FINEX process include process efficiency, lower environmental impact, process simplification through removal of process steps.
There are a number of ironmaking processes. The Finex process is an innovative ironmaking process which has been developed by Siemens VAI and Posco. A schematic of the process is shown below:
Figure 1: The FINEX process
Molten Iron is produced directly using iron ore fines and non-coking coal rather than processing through a sinter plant and coke ovens as traditional blast furnace route. In the Finex process, iron ore fines are charged into a series of fluidized-bed reactors. The fines pass in a downward direction where they are heated and reduced to direct-reduced iron (DRI) by means of a reduction gas – derived from the gasification of the coal – that flows in the counter – current direction to the ore. The DRI fines are then hot-compacted to hot-compacted iron, transferred to a charging bin positioned above a melter gasifier where smelting take place. The tapped product, liquid hot metal, is equivalent in quality to the hot metal produced in a blast furnace ore Corex plant.
Because the preliminary processing of raw materials is eliminated, the construction of the Finex plant cost less to build than a blast furnace facility of the same scale. Furthermore, a 10-15% reduction in production costs is expected through cheaper raw materials, reduction of facility cost, pollutant exhaustion, maintenance staff and production time. The excess gas produced from the process can be further utilized for the generation of Electricity. In addition, it is eco-friendly in that it produces less pollutant such as Sox, NOx, and carbon dioxide than traditional methods.
As the FINEX and the COREX process principles are similar, similar advantages compared to the blast furnace route can be shown. The major differences between COREX and the FINEX process is that FINEX can directly use sinter feed iron ore (up to 12 mm). Further:
- Favorable economics in comparison to the blast furnace route
- Environmental benefits due to savings in resources and energy, as well as lower emissions
- Direct utilization of non-coking coal
- High valuable export gas for a wide range of applications in metallurgical processes and energy production
- Production of hot metal with similar quality to the blast furmnace
- Flexibility in operation
- Reduction in operation
- Reduction of process steps
Table 1: Operational performance
Figure 2: Process comparison – FINEX/BF route