Life cycle costing (LCC) is an enduring pain point in construction and engineering. It represents a significant investment bottleneck in heavy-duty facilities where harsh working conditions wreak havoc on materials that aren’t primed for long lengths of service. High performance materials are routinely deployed in the most challenging workflow areas to reduce infrastructural maintenance requirements.
Refractory products are commonly used in foundries and steel works to drive profitability by increasing the working lifespan of critical components. Blast furnaces, for instance, suffer enormous ceramic hearth wear via pig iron and slag erosion. Higher rates of deterioration are often correlated to greater production rates. This poses unique profitability challenges where high throughput could translate to poor life cycle costs.
One of the most common avenues for protecting the ceramic hearth of a blast furnace from severe erosion is to protect the tap hole with a high performance material – usually in the form of a clay.
Tap hole mixtures are sophisticated solutions composed of multiple high performance ingredients. These materials work in tandem to produce a unique formulation with high corrosion- and erosion-resistant properties, excellent adhesiveness, and adequate plasticity across the entire blast furnace operating temperature range.
Typical tap hole clay products protect the ceramic hearth by forming a “mushroom” over time. The mix is pushed into the tap hole after each casting, gradually accumulating close to the inner walls and forming a stable ceramic coating. This coat protects the hearth from damage by pig iron or slag, and it is sequentially replaced by new tap hole clay in-between castings. Using poor quality clay can be detrimental as more material is needed to achieve the desired effect. Once again, this translates to higher material costs and can lead to early shutdown of the furnace for maintenance.
Any precision tap hole clay should be designed based on three key performance concepts: High resistance to corrosion and erosion to ensure long casting durations and uniform casting rates; good adhesion to the blast furnace inner wall to promote stability; and decent plasticity to facilitate efficient pushing/drilling.
At Saint-Gobain High Performance Ceramics and Refractories, we have developed a novel tap hole mix for blast furnaces that innovatively maximises the protection feature by homing in on each of these design pillars. Our high performance materials are easy to drill, inherently resistant to typical corrosion mechanics, have excellent plasticity, and are highly adhesive across broad temperature regimes.
Additionally, our tap hole clays are extremely ecological formulations. This is in response to market demands that go beyond the purely fiscal, with calls for more sustainable industry solutions. The Saint-Gobain range of tap hole clay mixtures are tar-free and are made without phenolic resins, instead leveraging a specialty carbon binder. Would you like to learn more? Read our technical article on our high performance tap hole clay materials. Or, contact a member of the Siant-Gobain team today with any questionsContact Us