SMS group has successfully executed a partial hearth repair of blast furnace BF4 at Třinecké Železárny a.s. in the Czech Republic. The furnace, which has a production volume of 3100 tons of hot metal per year, was showing a high degree of wear in the hearth area and the hearth linings in the tapping hole area were nearing their end of life. SMS group replaced the carbon blocks and reprofiled the entire hearth with heat-resistant concrete. This targeted approach prevented the need for a full rebuild and significantly reduced downtime, delivering a safe, durable hearth profile within the planned schedule. 

The Paul Wurth technology applied—sectoral carbon block replacement combined with specialized heat-resistant concrete reprofiling—offers clients the ability to restore hearth integrity and serviceability with minimal operational interruptions. By limiting the scope to the worn sector and optimizing drying and follow-on activities, the client benefited from a shortened repair window, reduced project risk, and lower overall downtime costs compared to a full hearth replacement. 

Jan Zmrzlík, project manager at SMS, comments: “We delivered a targeted, high-quality partial hearth repair that met the customer’s need for the shortest possible outage. The chosen method allowed us to confine interventions to the critical sector and complete full reprofiling efficiently, while unexpected tasks such as cutting a frozen salamander were executed rapidly without delaying the handover.”