With BF lifetimes extending to 20 years and beyond, it becomes increasingly important that the correct choice is made for the lining design. Short-cuts and poor choices can lead to extremely expensive unplanned stoppages. Saint-Gobain’s rich experience over more than 50 years in total design capability (not only Ceramic Cup) and supply of all required products specifically developed for BF conditions means we are a natural choice for all your lining needs.
Our design capabilities are unsurpassed, with the knowledge gained via companies such as Savoie Refractaires and Carborundum. Coupled with strong R&D investments worldwide, products backed by Saint-Gobain offer properties specifically engineered to withstand the varying and arduous conditions that prevail inside the blast furnace.
In addition to the full package of requested refractory materials, Saint-Gobain engineers will supply a budget-feasibility study, basic and detailed design (including thermal studies) and installation supervision.
Select image at right for an enlarged view.
From a materials requirements perspective, a blast furnace refractory lining may be split into five areas from top to bottom.
Upper shaft: In this low temperature area, abrasion by the solid burden is the primary mode of wear. Our SiC 85P, a silicate bonded SiC, has proven to be a cost-effective solution.
Lower shaft and belly: Abrasion by the coke burden is still a concern but driven by an increasing temperature, in depth attack by Alkali and Zinc vapor become predominant. Our Refrax® 20SBF, a nitride bonded SiC is a worldwide recognized reference for this application.
Bosh: In addition to Alkali and Zinc attack, the occurrence of molten iron and slag calls for SiAlON bonded materials. We recommend either our silicon carbide based Sicanit Al3 or our Corundum based Coranit 3S.
Tuyere belt: The tuyere surroundings experience high heat load and thermal shock in combination with corrosion by molten iron and slag and intense Alkali and Zinc vapor attacks. Backed by a unique range of refractory materials, including silicon nitride or SiAlON bonded shapes and pre-formed no and low cement castables, our engineering department will design highly customized tuyere surroundings that will fit the best to the specific requirements of your blast furnace operation.
Hearth: Traditionally, blast furnace hearths are lined with high thermal conductive carbon-based materials.
Placed inside the carbon lining the concept of the SG Ceramic Cup, first used in 1984 is now fully established and recognized by BF operators as the best design for the hearth.
Pioneered by Saint-Gobain and Savoie Refractaires, the Ceramic Cup is an example where a specific advanced design and materials render significant benefit to blast furnace operators in terms of lifetime extension and operational efficiency. Beware of cheap copies on the Ceramic Cup design, items can easily float off if not engineered correctly and material properties need to be refined for this arduous application.