I. Strategic Status of Refractories
As the core lining material for high-temperature equipment in metallurgy, cement, glass and other industries, refractories serve as critical "guardians" ensuring the safe operation of industrial kilns, thanks to their high temperature resistance (generally above 1580°C), chemical corrosion resistance and excellent thermal shock stability. Particularly in the metallurgical sector, they withstand direct erosion from high-temperature molten metals and slags, acting as a core factor determining equipment service life and production efficiency.
II. Current Development Status and Challenges of the Industry
1,Structural Contradictions in Production Capacity
China accounts for 69% of the world's total refractory output (reaching 29.5 million tons in 2011), yet the industry is plagued by widespread overcapacity - surplus production capacity exists across all product grades, including high-end varieties.
2,Technical Bottlenecks
Traditional materials are prone to cracking and spalling under extreme working conditions, such as sharp temperature fluctuations and mechanical abrasion in the coke dry quenching (CDQ) process, so their thermal shock resistance and corrosion resistance need urgent improvement.
III. Core Applications and Technological Breakthroughs
1,Multiple Defensive Barriers for the Metallurgical Industry
Shaped Refractories: Magnesia-carbon bricks (relying on chromium oxide to form an anti-oxidation protective layer) are adopted for blast furnace linings and converter bottoms.
Unshaped Refractories: Castable refractories feature flexible construction and repairability, so they are widely applied to complex structures such as ladle side walls.
2,Innovation of Key Raw Materials
Chromium Oxide (Cr₂O₃): A dominant raw material with a melting point as high as 2265 °C and superior Mohs hardness. It remarkably improves the slag resistance and wear resistance of refractories by forming a passivation film, and is applied in refractory bricks, coatings and special cements.
IV. Future Development Trends: Green Development and Intelligent Manufacturing
1,R&D of High-Performance Refractory Materials
Nanocomposite Technology: Nanoparticles are used to increase material density and reduce thermal conductivity.
Self-healing Smart Materials: Equipped with sensing components to realize self-adaptive repair of damaged areas.
2,Practices of Circular Economy
The recovery rate of spent refractories has been increased, and industrial solid wastes such as blast furnace slag are used as substitutes for natural raw materials.
Low-carbon production processes (e.g., electrofusion technology) cut carbon emissions.
3,Optimization of Structural Design
For scenarios such as coke dry quenching (CDQ), the load-bearing structure of the flue ramp area is optimized to reduce the risk of thermal stress concentration.
V. Conclusion
The refractory industry is shifting from scale expansion to dual-track development featuring high performance and sustainability. Through innovations in materials science and full-life-cycle ecological design, refractories will continuously support the transformation and upgrading of high-temperature industries toward high efficiency and green development.