The FINEX Process

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Introduction to FINEX Technology

There are numerous ironmaking processes available in the steel industry today. The FINEX process stands out as an innovative ironmaking technology developed through collaboration between Siemens VAI and POSCO. This advanced process represents a significant departure from conventional blast furnace operations.

Figure 1: A schematic diagram showing the complete FINEX process flow

In the FINEX process, molten iron is produced directly using iron ore fines and non-coking coal, eliminating the need for processing through a sinter plant and coke ovens as required in the traditional blast furnace route. Iron ore fines are charged into a series of fluidized-bed reactors where they move downward while being heated and reduced to direct-reduced iron (DRI). This reduction occurs through interaction with reduction gas flowing in the counter-current direction. The reduction gas is derived from coal gasification within the system.

The DRI fines are subsequently hot-compacted to form hot-compacted iron, which is then transferred to a charging bin positioned above a melter gasifier where smelting takes place. The final product, liquid hot metal tapped from the process, is equivalent in quality to hot metal produced in conventional blast furnaces or Corex plants.

Economic and Operational Advantages

The FINEX process delivers compelling economic benefits for steel producers. By eliminating preliminary raw material processing steps, a FINEX plant costs significantly less to build than a blast furnace facility of equivalent capacity. Furthermore, operators can expect a 10-15% reduction in production costs through several factors:

• Utilization of cheaper raw materials (iron ore fines and non-coking coal)
• Lower facility construction costs
• Reduced pollutant emissions requiring less environmental control equipment
• Decreased maintenance staff requirements
• Shorter production time

The excess gas produced during the FINEX process can be further utilized for electricity generation, creating additional value from the operation. This integration capability enhances the overall efficiency of steel production facilities.

Environmental Benefits

The FINEX process demonstrates superior environmental performance compared to traditional ironmaking methods. The technology produces significantly lower levels of pollutants such as SOx, NOx, and carbon dioxide than conventional blast furnace operations. This environmental advantage stems from both the elimination of sintering and coking processes and the inherent efficiency of the FINEX reduction approach.

Comparison with Other Ironmaking Technologies

The FINEX and COREX process principles share similarities, and both offer advantages over the blast furnace route. However, the major difference is that FINEX can directly use sinter feed iron ore (up to 12 mm in size), providing greater raw material flexibility.

Additional benefits of the FINEX process include:

• Favorable economics compared to the blast furnace route
• Environmental benefits through resource and energy savings
• Direct utilization of non-coking coal
• Production of high-value export gas suitable for various metallurgical processes and energy production
• Hot metal quality similar to blast furnace output
• Operational flexibility
• Reduction in process steps and complexity

Table 1. Operational performance - A table showing comparative performance metrics of the FINEX process

Indices			Pohang BF4	1.5MT FINEX
Production		t/y	3.2 M	1.5 M
Availability		%	97.7	96.8
Coal Rate		kg/thm	750	710
	PCR	kg/thm	166	160
Hot Metal	[S]	%	0.03	0.03
Hot Metal	[Si]	%	0.48	0.65

* PCR : Pulverized Coal Injection Rate

Figure 2: Process comparison - FINEX/BF route - A diagram comparing the process flows of FINEX and conventional blast furnace ironmaking

Conclusion

The FINEX process represents a significant advancement in ironmaking technology, offering substantial economic, operational, and environmental benefits. As steel producers face increasing pressure to reduce costs and environmental impact, technologies like FINEX provide viable alternatives to traditional blast furnace operations while maintaining product quality and operational reliability.