MERIM: Maximized Emission Reduction in Ironmaking

The MERIM dry blast furnace gas cleaning system, combined with a specially designed cyclone for coarse dust separation, uses a fabric filter for fine dust removal. This system offers several advantages over traditional wet systems. First, it eliminates the need for wastewater and sludge management. Additionally, the pressure drop and temperature loss are significantly lower compared to wet systems, allowing the energy output of the blast furnace Top gas Recovery Turbine (TRT) to increase significantly. The new cyclone design optimizes the separation of recyclable dust and fine dust with a high zinc fraction.

Treatment Steps

1. Corse dust removal: the cyclone efficiently removes a major fraction of the dust in the coarse dedusting stage, maximizing iron recovery. The collected dust can be easily reused in sinter plants. The cyclone features three inlets, which provide several advantages over single-inlet designs, such as central support for the downcomer, simplifying maintenance at the cyclone inlet branches.
2. Fine dust removal: the MERIM bag filter system handles fine dedusting. The blast furnace gas enters several pressure-resistant filter vessels where dust is collected on high-performance filter media, ensuring clean gas with minimal dust content. Conveying systems transport the collected dust into a storage silo.
3. Energy recovery: the cleaned blast furnace gas is directed into a central duct and can be sent to a Top gas Recovery Turbine (TRT) for the generation of electrical power. To protect the fabric filters from excessive temperatures or to prevent acid condensation from low gas temperatures, MERIM includes a temperature regulation system that ensures the dry dedusting system operates safely under all conditions.

Benefits of MERIM from Primetals Technologies

• Enhance efficiency: achieve up to 30% higher energy output compared to wet-type systems
• Reduce emissions: meet current and future emission regulations with superior dust removal
• Cut costs: eliminate the need for extensive wastewater treatment, reducing operational costs
• Improve sustainability: minimize CO₂ footprint and landfill requirements
• Increase flexibility: adaptable to extreme temperature fluctuations for reliable operation