ArcelorMittal Global R&D was tasked with exploring and identifying alternative ways to capture dust emissions that resulted from the transport of sinter and other materials within the blast furnace operations. This was an extremely complex issue as conventional aspiration and filtration units were not available nor applicable due to the configuration of the operations and equipment.
ArcelorMittal’s research center in Asturias, Spain took the lead in testing alternative technologies capable of reducing secondary sinter dust. The objective was three-fold: improve working conditions for fine particulate matter, decrease dust emissions that release through openings of buildings and appropriately manage humidity levels in order to protect the sinter and its performance in the blast furnace.
The initial dust suppressant alternatives were based on water injection. The use of water was poor for humidity levels and rejected by the blast furnace as solution. ArcelorMittal Global R&D proposed and optimized the application of a potato-based, biodegradable dust suppressant applied as foam to minimize the water impact.
Trials were developed and implemented at ArcelorMittal Gijon, where the foam was applied over conveyor belts to cover the raw materials and prevent the dust emissions that occurred during the transport and transfer of material to the bunkers. Adjustments were made to the quantity of the foam as well as the water needed to create the foam. Both qualitative and quantitative analysis was used to assess the impact of the dust suppressant.
Dust emissions were dramatically reduced after the foam application with no significant impact in the humidity of the sinter to the blast furnace. The results of the R&D trials showed a more than 80 percent reduction of inhalable particulate matter (PM10) and a reduction of more than 85 percent for fine inhalable particulate matter (PM2.5).
"The use of a biodegradable product allowed us to suppress the diffuse dust emissions without any negative impact on the process or the product. Additionally, the solution avoided costly investments that had no guarantee of success. And, perhaps most importantly, the solution has had a significant impact on the environment, eliminating emissions from ventilation openings of the tower and improving the ambient air quality and visibility of the area, thereby offering better working conditions,” said Beatriz Gonzalez Fernandez, R&D engineer, ArcelorMittal Global R&D.
As a result, ArcelorMittal Global R&D Asturias, where the trials were developed, industrialized the solution for all the belts in the tower of the blast furnace hoppers in Gijon. The diffuse dust emission problem at Gijon has been resolved with no impact on the blast furnace due to humidity. This new formulation is now available to other operations with similar conditions and constraints.