高炉热风炉喷涂料莫来石刚玉的应用与优势分析Analysis of the application and advantages of mullite-corundum Gunnning Mass for blast furnace and hot blast stove

引言：高炉热风炉内衬材料的技术挑战与革新

Introduction: Technological Challenges and Innovations in Blast Furnace  and Hot Blast Stove Lining Materials

高炉热风炉作为钢铁冶炼关键设备，长期承受 1200 - 1400℃ 高温烟气冲刷与 0 - 150℃/min 热震循环的极端工况，内衬材料性能直接决定炉体寿命与能源效率。传统耐火砖砌筑体系存在三大核心问题：顶部拱脚因热应力集中导致 3 - 5 年开裂率超 60%，环形砌砖的 1.5 - 2 mm 砖缝成为热量流失薄弱环节，且单座炉子施工周期长达 45 - 60 天，严重制约钢厂连续生产。

As a key piece of equipment in steelmaking, the blast furnace hot blast stove endures extreme conditions for extended periods, including high-temperature flue gas scouring at 1200-1400℃ and thermal shock cycles at 0-150℃/min. The performance of the lining material directly determines the furnace's lifespan and energy efficiency. Traditional refractory brick masonry systems suffer from three major problems: the top arch foot experiences cracking rates exceeding 60% within 3-5 years due to concentrated thermal stress; the 1.5-2 mm brick joints in the ring-shaped masonry become weak points for heat loss; and the construction cycle for a single furnace is as long as 45-60 days, severely restricting continuous production in steel plants.

技术革新方向：莫来石刚玉喷涂料通过 无接缝整体喷涂工艺 实现内衬结构变革，其 Al₂O₃ - SiO₂ 复合相体系 可同步提升高温强度与热震稳定性，为解决传统砌筑缺陷提供全新技术路径。

Technological innovation direction: Mullite corundum spray coating achieves structural transformation of lining through seamless integral spraying process. Its Al₂O₃-SiO₂ composite phase system can simultaneously improve high temperature strength and thermal shock stability, providing a new technical path to solve the defects of traditional masonry.

本文将系统分析高炉热风炉喷涂料莫来石刚玉的材料组成优化、施工工艺创新及服役性能优势，揭示其在延长炉体寿命、降低能耗方面的技术价值。

This article will systematically analyze the material composition optimization, construction process innovation, and service performance advantages of mullite-corundum coating for blast furnace hot blast stoves, revealing its technical value in extending furnace life and reducing energy consumption.

莫来石刚玉喷涂料的材料组成与技术特性

Material composition and technical properties of mullite corundum spray coating

莫来石刚玉喷涂料的核心性能源于其独特的 "Al₂O₃-莫来石相"协同体系。材料体系中Al₂O₃含量≥60%，通过与莫来石相（3Al₂O₃·2SiO₂）形成致密网络结构，实现高耐火度与低蠕变率的平衡。其中，Al₂O₃作为刚性骨架相确保高温结构稳定性，莫来石基质则通过微裂纹增韧机制缓解热应力，而SiC（≥5%）的引入进一步提升抗热震性能。

The core performance of mullite-corundum spray coatings stems from their unique "Al₂O₃-mullite phase" synergistic system. The material system contains ≥60% Al₂O₃, which forms a dense network structure with the mullite phase (3Al₂O₃·2SiO₂), achieving a balance between high refractoriness and low creep rate. Al₂O₃ acts as a rigid framework phase to ensure high-temperature structural stability, while the mullite matrix alleviates thermal stress through a microcrack toughening mechanism. The introduction of SiC (≥5%) further enhances thermal shock resistance.

关键技术参数（符合YB/T 4194-2018标准）：

Al₂O₃ ≥ 60%，SiC ≥ 5%

1450 ℃ 高温耐压强度 ≥ 65 MPa

常温施工性与高温体积稳定性双重达标

Key technical parameters (compliant with YB/T 4194-2018 standard):

Al₂O₃ ≥ 60%, SiC ≥ 5%

High-temperature compressive strength at 1450℃ ≥ 65 MPa

Dual compliance with standards for room-temperature workability and high-temperature volume stability

与传统高铝喷涂料相比，该材料在1450 ℃ 工况下表现出更优异的力学性能保持率，其耐压强度较普通高铝材料提升40%以上，且线变化率控制在±1.5%以内，有效降低热风炉内衬的剥落风险。这种性能优势源于刚玉颗粒与莫来石基质的界面烧结强化效应，通过液相烧结形成的低黏度玻璃相填充孔隙，使材料致密度提升至92%以上。

Compared to traditional high-alumina spray coatings, this material exhibits superior mechanical property retention at 1450 ℃, with its compressive strength increased by more than 40% compared to ordinary high-alumina materials, and its linear shrinkage rate controlled within ±1.5%, effectively reducing the risk of spalling of the hot blast furnace lining. This performance advantage stems from the interfacial sintering strengthening effect between corundum particles and the mullite matrix. The low-viscosity glass phase formed by liquid-phase sintering fills the pores, increasing the material density to over 92%.

材料设计严格遵循"成分-结构-性能"的递进逻辑，通过控制Al₂O₃/SiO₂比值在3.5~4.0区间，确保莫来石相（3Al₂O₃·2SiO₂）的充分生成。工业应用数据显示，当Al₂O₃含量稳定在62%~65%范围时，材料的抗蠕变性能最优，1500 ℃ 下蠕变率可控制在0.8%/h以下，完全满足高炉热风炉长期高温运行要求。

The material design strictly follows the progressive logic of "composition-structure-performance," ensuring the full formation of the mullite phase (3Al₂O₃·2SiO₂) by controlling the Al₂O₃/SiO₂ ratio within the range of 3.5 to 4.0. Industrial application data shows that when the Al₂O₃ content is stable within the range of 62% to 65%, the material exhibits optimal creep resistance, with the creep rate controlled below 0.8%/h at 1500 ℃, fully meeting the requirements for long-term high-temperature operation of blast furnace hot blast stoves.

高炉热风炉中的应用场景与部位适配性

高炉热风炉作为高炉炼铁系统的关键热能设备，其不同结构部位因工况条件差异对耐火材料提出差异化需求。莫来石刚玉喷涂料凭借其抗热震性、耐磨性与高温稳定性的综合优势，在热风炉各关键区域展现出良好的适配性，以下从结构 - 工况 - 材料匹配视角展开分析。

Application Scenarios and Component Adaptability in Blast Furnace Hot Blast Stove

As a key thermal energy device in the blast furnace ironmaking system, the hot blast stove exhibits differentiated requirements for refractory materials in different structural parts due to varying operating conditions. Mullite-corundum spray coatings, with their comprehensive advantages in thermal shock resistance, wear resistance, and high-temperature stability, demonstrate excellent adaptability in various key areas of the hot blast stove. The following analysis examines this from the perspective of structure-operating condition-material matching.

炉身上部：温度波动下的抗热震解决方案

炉身上部作为热风炉热交换的核心区域，实际运行中承受800 - 1000℃的周期性温度波动，热应力交替作用易导致内衬剥落。莫来石刚玉喷涂料通过莫来石相（3Al₂O₃·2SiO₂）与刚玉相（α - Al₂O₃）的微结构协同，形成低膨胀系数（≤ 6.5×10⁻⁶ / ℃）与高断裂韧性（≥ 3.2 MPa·m¹/²）的复合体系，能够有效缓解温度骤变产生的热冲击。某工业应用数据显示，该材料在炉身上部的热震循环寿命（1100℃水冷）可达50次以上，较传统高铝质喷涂料提升40%以上。

Upper Furnace Body: Thermal Shock Resistance Solution Under Temperature Fluctuations

As the core area for heat exchange in a hot blast stove, the upper furnace body is subjected to periodic temperature fluctuations of 800-1000℃ during actual operation. Alternating thermal stress can easily lead to lining spalling. Mullite-corundum spray coating, through the synergistic microstructure of mullite phase (3Al₂O₃·2SiO₂) and corundum phase (α-Al₂O₃), forms a composite system with a low coefficient of thermal expansion (≤ 6.5×10⁻⁶ / ℃) and high fracture toughness (≥ 3.2 MPa·m¹/²), effectively mitigating thermal shock caused by sudden temperature changes. Data from an industrial application shows that the thermal shock cycle life (1100℃ water cooling) of this material on the upper furnace body can reach over 50 cycles, an improvement of more than 40% compared to traditional high-alumina spray coatings.

燃烧室：高温氧化环境下的抗侵蚀保障

燃烧室是热风炉燃料燃烧的核心区域，长期暴露于1200 - 1400℃的高温火焰环境中，并受到燃烧产物（如SO₂、CO₂）的化学侵蚀。莫来石刚玉喷涂料通过引入Cr₂O₃微粉（3% - 5%） 形成表面釉质保护层，同时利用刚玉相的高化学惰性（耐酸性指数≥ 98%），有效抵抗高温氧化与腐蚀性气体侵蚀。工业检测数据显示，该材料在1300℃静态空气中氧化增重率≤ 0.3%/h，在含硫气氛下的腐蚀速率较黏土砖降低70%。

Combustion Chamber: Corrosion Resistance in High-Temperature Oxidation Environments

The combustion chamber is the core area of ​​fuel combustion in a hot blast stove, constantly exposed to a high-temperature flame environment of 1200-1400℃ and subjected to chemical corrosion from combustion products (such as SO₂ and CO₂). Mullite-corundum spray coatings introduce Cr₂O₃ micropowder (3%-5%) to form a protective glaze layer on the surface, while utilizing the high chemical inertness of the corundum phase (acid resistance index ≥ 98%) to effectively resist high-temperature oxidation and corrosive gas corrosion. Industrial testing data shows that this material has an oxidation weight gain rate ≤ 0.3%/h in static air at 1300℃, and its corrosion rate in a sulfur-containing atmosphere is 70% lower than that of clay bricks.

上图为高炉出铁沟部分展示

The image above shows a portion of the blast furnace tapping trough.

工程验证：宁钢案例的寿命提升效果

宁波钢铁股份有限公司（以下简称“宁钢”）在3200 m³高炉热风炉修复工程中，采用莫来石刚玉喷涂料对炉身上部、炉喉及燃烧室进行整体喷涂施工。监测数据显示，修复后内衬平均使用寿命延长至18个月，较传统铝硅质喷涂料（12个月）提升50%，同时热风温度稳定性提高（波动幅度从±15℃降至±8℃），年减少热风炉检修停机时间约36小时，直接创造经济效益约280万元/座。该案例充分验证了莫来石刚玉喷涂料与热风炉关键部位工况的适配性，为行业推广提供了重要工程依据。

Engineering Verification: Lifespan Improvement Effect of the Ningbo Iron & Steel Case

In the repair project of the 3200 m³ blast furnace hot blast stove, Ningbo Iron & Steel Co., Ltd. (hereinafter referred to as "Ninggang") used mullite-corundum spray coating to comprehensively spray the upper part of the furnace body, the furnace throat, and the combustion chamber. Monitoring data shows that the average service life of the lining was extended to 18 months after repair, a 50% increase compared to the traditional aluminosilicate spray coating (12 months). At the same time, the stability of the hot blast temperature was improved (fluctuation range reduced from ±15℃ to ±8℃), reducing the annual downtime for hot blast stove maintenance by approximately 36 hours, directly generating economic benefits of approximately RMB 2.8 million per stove. This case fully verifies the adaptability of mullite-corundum spray coating to the operating conditions of key parts of the hot blast stove, providing important engineering basis for industry promotion.

关键适配特性总结

炉身上部：低膨胀系数（≤ 6.5×10⁻⁶ / ℃）适配温度波动

炉喉区域：高硬度（≥ 85 HRA）抵抗物料冲刷

燃烧室：Cr₂O₃改性增强高温抗侵蚀能力

工程验证：宁钢案例寿命提升50%（18个月 vs 12个月）

Key Adaptability Characteristics Summary

Upper Furnace Body: Low coefficient of expansion (≤ 6.5×10⁻⁶ / ℃) adapts to temperature fluctuations

Thorough Area: High hardness (≥ 85 HRA) resists material erosion

Combustion Chamber: Cr₂O₃ modification enhances high-temperature corrosion resistance

Engineering Verification: Ninggang case shows a 50% increase in service life (18 months vs 12 months)