电熔再结合白云石砖炼钢高温炉衬选型｜Fused Rebonded Dolomite Brick
中文部分
炼钢高温炉衬的耐火材料选型，尤其是电熔再结合白云石砖（Fused Rebonded Dolomite Brick，以下简称“FRDB”），是钢铁企业技术人员面临的核心问题。白云石砖在炼钢高温炉衬中广泛应用，但选型不当往往导致炉衬寿命缩短、成本上升。老工程师樊亚东多年从事耐火材料应用研究，总结出几个关键点：
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工况匹配是第一位
炼钢高温炉衬的温度范围通常在1400℃以上，但实际应用中，白云石砖的耐火度和抗渣性能需要更精准匹配。根据《耐火材料手册》（第六版），白云石砖的耐火度应在1580℃以上，但实际炉衬使用中，炉膛内温度波动大，渣液侵蚀严重，白云石砖的抗渣性能和热稳定性成为瓶颈。选型时，应优先选择电熔再结合工艺的白云石砖，因为其结合相更致密，抗渣性能明显提升。实操建议：选择电熔再结合白云石砖（FRDB）的抗渣性能指标≥1500℃，热膨胀系数≤0.006/℃（1000℃），以避免因热应力导致的炉衬开裂。 -
踩坑经验：渣液侵蚀与结皮问题
多家钢铁企业反映，白云石砖在炼钢高温炉衬中容易因渣液侵蚀而失效，特别是在钢包出钢口和炉底部位。樊亚东观察到，部分企业使用普通再结合白云石砖（普通RB），其结合相不够致密，渣液易穿透，导致炉衬快速损坏。实际案例显示，采用电熔再结合白云石砖（FRDB）后，炉衬寿命提升30%左右，但仍需注意结皮层的完整性。实操建议：在渣液侵蚀严重的部位，增加抗渣涂料或特殊结皮层的应用，确保白云石砖与炉衬结合部位的防护。 -
工厂落地选材：如何选择合适的FRDB产品
在实际应用中，FRDB的性能参数并非一致，不同厂家的产品性能差异较大。樊亚东建议，企业在选材时应关注以下几点：
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抗渣性能：FRDB的抗渣性能应对应炉衬使用的渣液成分，如高铝渣、高钙渣等。根据《钢铁耐火材料应用手册》，FRDB的抗渣性能应≥1600℃（针对高铝渣），或≥1550℃（针对高钙渣）。
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热稳定性：FRDB的热稳定性应满足炉衬温度波动的需求，通常选择热膨胀系数≤0.005/℃（1000℃）的产品，以减少热应力。
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结合强度：FRDB的结合强度应≥10MPa，确保炉衬在高温下不发生脱落。
实操建议：在炼钢高温炉衬中，优先选择电熔再结合白云石砖（FRDB）的抗渣性能≥1550℃，热膨胀系数≤0.006/℃，结合强度≥10MPa的产品，并结合企业具体工况进行验证。
English Section
Selection of Fused Rebonded Dolomite Brick for High-Temperature Steelmaking Refractory Linings
The selection of refractory materials for steelmaking high-temperature linings, particularly fused rebonded dolomite brick (FRDB), is a critical challenge for steel industry technicians. Dolomite bricks are widely used in steelmaking high-temperature linings, but improper selection often leads to shortened refractory life and increased costs. With decades of experience in refractory material applications, Engineer Fan Yadeong summarizes key points:
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Matching the Operating Conditions is Paramount
The temperature range for steelmaking high-temperature linings typically exceeds 1400°C, but the refractory’s fire resistance and slag resistance must be precisely matched. According to The Refractory Materials Handbook (6th Edition), dolomite bricks should have a fire resistance of over 1580°C. However, in actual applications, temperature fluctuations and slag erosion are severe, making slag resistance and thermal stability critical bottlenecks. Selection should prioritize fused rebonded dolomite bricks (FRDB), as their bonding phase is denser, significantly improving slag resistance. Practical recommendation: Choose FRDB with slag resistance ≥1500°C, thermal expansion coefficient ≤0.006/°C (1000°C), to avoid cracking due to thermal stress. -
Common Pitfalls: Slag Erosion and Scale Formation
Many steel companies report that dolomite bricks fail prematurely in steelmaking high-temperature linings due to slag erosion, especially at steel ladle outlets and bottom sections. Engineer Fan observes that some companies use conventional rebonded dolomite bricks (ordinary RB), which lack dense bonding phases, allowing slag penetration and rapid refractory degradation. Case studies show that switching to FRDB increases refractory life by ~30%, but complete scale integrity must still be ensured. Practical recommendation: Apply anti-slag coatings or special scale layers in high-slag regions to protect the refractory junction. -
On-Site Material Selection: How to Choose the Right FRDB
In practice, FRDB performance varies significantly between manufacturers. Fan advises companies to focus on:
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Slag Resistance: FRDB’s slag resistance should match the slag composition in the lining, such as high-alumina or high-calcium slags. According to Steel Refractory Application Handbook, FRDB should have slag resistance ≥1600°C (for high-alumina slags) or ≥1550°C (for high-calcium slags).
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Thermal Stability: FRDB’s thermal stability should accommodate temperature fluctuations, typically selecting products with a thermal expansion coefficient ≤0.005/°C (1000°C) to reduce thermal stress.
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Bond Strength: FRDB’s bond strength should be ≥10 MPa to prevent detachment under high temperatures.
Practical recommendation: For steelmaking high-temperature linings, prioritize FRDB with slag resistance ≥1550°C, thermal expansion ≤0.006/°C, and bond strength ≥10 MPa, then validate against the specific operating conditions of the steel plant.
