用后耐火材料在铁沟中的应用技术前程似锦The application technology of recycled refractory materials in iron troughs has a promising future.

据行业内专家预测：2025年我国钢铁工业固废年产量将达5亿吨，其中铁沟系统产生的废旧耐材占比约1.5%-2%，推算出其年产量为75万-100万吨。当前其实际进入回收体系的量约30万吨（含企业自循环与社会回收），整体再生利用率约30%-35%，显著低于高炉渣（99.94%）等大宗固废的利用水平，剩余填埋处理导致资源浪费、成本增加和污染环境。铁沟系统耐材更换频繁（3个月/次，有的使用周期甚至更短），成本占炼铁工序12%，因此，铁沟系统耐材消耗成本降低仍有很大空间。

Industry experts predict that by 2025, my country's annual output of solid waste from the steel industry will reach 500 million tons, of which waste refractory materials generated from the iron trough system will account for approximately 1.5%-2%, estimating an annual output of 750,000-1,000,000 tons. Currently, only about 300,000 tons actually enter the recycling system (including enterprise self-recycling and social recycling), with an overall recycling rate of about 30%-35%, significantly lower than the utilization level of bulk solid wastes such as blast furnace slag (99.94%). The remaining waste is disposed of in landfills, leading to resource waste, increased costs, and environmental pollution. Refractory materials in the iron trough system require frequent replacement (every 3 months, some even less), accounting for 12% of the cost of the ironmaking process. Therefore, there is still significant room for reducing the cost of refractory material consumption in the iron trough system.

 用后耐材在铁沟中的关键技术具有下列应用

 一是再生骨料技术。经破碎筛分分级处理的用后耐火材料（高铝质、刚玉质、Al2O3-SiC-C质）替代15%-50%原生骨料（矾土熟料、棕刚玉等）。该技术核心优势明显：可显著降低原料成本；缓解天然不可再生矿产资源消耗；高温服役后材料晶体发育更完整，可提升再生浇注料的抗热震稳定性及高温体积稳定性。

 二是基质微粉化应用。其成分稳定的用后耐材经超微粉磨，部分替代Al2O3微粉等基质组分，优化基质显微结构并降低材料成本。

 三是功能性预制件制造。采用再生骨料为主体原料制备铁沟沟盖、挡渣堰板等预制构件，实现快速更换并提升服役一致性。

 四是非工作层高掺量利用。在永久层、保温层等非直接接触熔融铁水部位规模化使用再生料，实现资源高效循环。详情见下表：

Key technologies for the application of recycled refractory materials in iron trenches include the following:

**First, recycled aggregate technology:** Recycled refractory materials (high-alumina, corundum, Al2O3-SiC-C) that have undergone crushing, screening, and grading replace 15%-50% of virgin aggregates (bauxite clinker, brown corundum, etc.). This technology offers significant advantages: it can significantly reduce raw material costs; alleviate the depletion of natural non-renewable mineral resources; and after high-temperature service, the material's crystal development is more complete, improving the thermal shock resistance and high-temperature volume stability of recycled castables.

**Second, matrix micronization application:** Recycled refractory materials with stable composition are ultra-finely ground to partially replace matrix components such as Al2O3 powder, optimizing the matrix microstructure and reducing material costs.

**Third, functional prefabricated component manufacturing:** Prefabricated components such as trench covers and slag weirs are prepared using recycled aggregates as the main raw material, enabling rapid replacement and improving service consistency.

**Fourth, high-volume utilization of non-working layers.** The large-scale use of recycled materials in non-directly contacting molten iron areas such as permanent layers and insulation layers achieves efficient resource recycling. See the table below for details:

五 是典型Al2O3-SiC-C质用后耐材使用案例如下图

Fifth, a typical example of the application of Al2O3-SiC-C refractory materials is shown in the figure below.

用后耐火材料在高炉铁沟系统中的应用前景如何？其核心驱动力有哪些呢？

 面对这个问题，专家作了下列回答：

一是靠政策法规驱动。用国家"双碳"战略目标推动工业固废资源化；环保税与矿产资源税政策倒逼企业转型。

二是讲求全生命周期经济效益。可降低铁沟耐火材料综合成本≥30%；减少用后耐材堆存处置费用；构建"回收-处理-再生"产业链价值闭环。

 三是技术成熟度获突破。例如，光谱成分识别技术提升废料分选精度；热态/冷态处理工艺标准化；再生配方中二次莫来石化反应控制技术优化；智能分选系统采用X射线荧光（XRF）+AI图像识别技术，实现金属/非金属杂质分离精度99.2%；微粉活化技术通过机械化学法制备纳米级再生粉体（d50≤1.2μm），比表面积提升至8.5m²/g。

 四是战略资源安全有了可靠保障。即，可缓解高品位铝矾土、电熔刚玉等战略资源供给风险。

What are the prospects for the application of used refractory materials in blast furnace iron trough systems? What are the core driving forces?

Experts have provided the following answers to this question:

First, it is driven by policies and regulations. The national "dual-carbon" strategic goal promotes the resource utilization of industrial solid waste; environmental protection taxes and mineral resource taxes force enterprises to transform.

Second, it emphasizes the economic benefits throughout the entire life cycle. It can reduce the overall cost of refractory materials in iron troughs by ≥30%; reduce the cost of storing and disposing of used refractory materials; and build a closed-loop value chain of "recycling-treatment-regeneration".

Third, it represents a breakthrough in technological maturity. For example, spectral component identification technology improves the accuracy of waste sorting; hot/cold treatment processes are standardized; secondary mullitization reaction control technology in regeneration formulas is optimized; intelligent sorting systems use X-ray fluorescence (XRF) + AI image recognition technology to achieve a 99.2% accuracy in separating metallic/non-metallic impurities; micro-powder activation technology prepares nanoscale regenerated powder (d50≤1.2μm) through mechanochemical methods, increasing the specific surface area to 8.5m²/g.

Fourth, the security of strategic resources is reliably guaranteed. That is, it can alleviate the supply risks of strategic resources such as high-grade bauxite and fused alumina.

 用后耐火材料在高炉铁沟系统中的应用技术面临哪些关键挑战？应采用何种技术对策？

 面对此问题，专家作了下述回答：一是再生料品质控制难。其技术瓶颈是：ZnO、K2O等低熔点杂质相影响抗熔渣侵蚀性。

 对于这些问题可采用下列解决方案：一是建立来源追溯体系；开发杂质离子捕获技术；实施梯度掺配应用策略。

 二是面临标准化体系缺失。其行业痛点是：缺乏再生骨料相组成控制指标及服役性能评价标准。其破局路径是：制定YB/T标准规范再生料分级与应用边界。

 三是面临产业化推广阻力。首先是认知局限：部分企业担忧再生料影响铁沟通铁量寿命。

 其次是协同机制：应积极构建钢厂-耐材企业-再生平台三方数据共享体系；建立万吨级示范产线。

 总之，用后耐火材料在铁沟中的应用已形成完整技术路线。未来将向高掺量（>50%）、功能化再生预制件、全流程智能管控及标准化认证方向发展，成为绿色冶金不可或缺的环节。

What are the key challenges facing the application of recycled refractory materials in blast furnace iron trough systems? What technical countermeasures should be adopted?

Experts have provided the following answers to this question: First, quality control of recycled materials is difficult. The technical bottleneck is that low-melting-point impurities such as ZnO and K2O affect resistance to slag erosion.

Solutions to these problems include: establishing a source traceability system; developing impurity ion capture technology; and implementing a gradient blending application strategy.

Second, there is a lack of a standardized system. The industry pain point is the lack of control indicators for the phase composition of recycled aggregates and standards for evaluating service performance. The solution is to formulate YB/T standards to specify the grading and application boundaries of recycled materials.

Third, there are obstacles to industrialization and promotion. Firstly, there is a limitation of understanding: some companies worry that recycled materials will affect the iron flow and lifespan of iron troughs.

Secondly, there is a lack of collaborative mechanisms: a three-way data sharing system should be actively built among steel mills, refractory companies, and recycling platforms; a demonstration production line with a capacity of 10,000 tons should be established.

In conclusion, the application of recycled refractory materials in iron troughs has formed a complete technical route. In the future, it will develop towards high doping (>50%), functionalized recycled prefabricated components, intelligent control of the entire process, and standardized certification, becoming an indispensable part of green metallurgy.