Why Top Chinese Zinc Smelters Are Switching to Silicon Nitride-Bonded Silicon Carbide Bricks

In the demanding world of non-ferrous metallurgy—where temperatures exceed 1,600°C and chemical erosion is relentless—the choice of refractory lining can make or break production efficiency. For over a decade, leading zinc and copper smelting plants in China have turned to silicon nitride-bonded silicon carbide bricks (Si₃N₄-SiC) as their go-to solution for high-temperature furnace linings.

The Real Problem: Why Standard Refractories Fail Early

Most traditional magnesia-carbon or alumina-silica bricks show visible wear within 6–8 months under continuous operation at 1,400–1,600°C. This leads to frequent shutdowns, increased maintenance costs, and inconsistent product quality—especially in continuous casting and flash smelting processes.

Lab Test Results: Si₃N₄-SiC bricks exhibit 35% higher flexural strength at 1,400°C compared to standard MgO-C bricks (tested by SGS, 2023).

Four Key Advantages That Drive ROI

• High Strength & Thermal Conductivity: 120 W/m·K thermal conductivity allows faster heat transfer—reducing energy loss by up to 15% per year.
• Exceptional Thermal Shock Resistance: Withstands 50 rapid heating/cooling cycles without cracking—ideal for intermittent operations.
• Superior Corrosion Resistance: Resists molten metal penetration and sulfur attack, extending lining life by 30% on average.
• Long-Term Stability: No significant degradation after 12+ months of continuous use in industrial-scale furnaces.

Case Study: A Leading Zinc Smelter in Yunnan Province

Before switching to Si₃N₄-SiC bricks, this facility experienced monthly furnace downtime due to refractory failure. After installation in Q2 2022, they reported:

• 炉窑寿命延长至18个月 (from 7 months previously)
• Annual energy savings of ~$120,000 USD
• Reduction in unplanned maintenance by 60%

This success has been replicated across more than 10 major facilities nationwide—including two Tier-1 copper producers in Inner Mongolia—and now forms part of our global portfolio serving clients in Germany, UAE, and South Korea.

If you're evaluating refractory upgrades for your next furnace project—or considering performance improvements in existing installations—we invite you to: