Core Attributes and Resource Value Positioning of Ferrosilicon Slag
As an industrial by-product generated during the smelting of ferrosilicon alloy, ferrosilicon slag has good chemical stability and physical properties after pretreatment such as cooling and solidification, crushing and classification. The reasonable ratio of silicon dioxide and calcium oxide in its core components enables it to not only meet the deoxidation needs of the metallurgical industry, but also adapt to raw material substitution scenarios in fields such as building materials and ceramics. It is one of the key categories for the resource utilization of bulk solid waste.
With the full implementation of the “Evaluation Standard for the Resource Utilization of Industrial Solid Waste” in 2025, the resource utilization rate of ferrosilicon slag has been included in the green production assessment indicators of iron and steel enterprises. Compliant and efficient utilization of ferrosilicon slag has become an inevitable trend in the industry. In 2025, the comprehensive utilization rate of ferrosilicon slag in China has reached 58%, and it is expected to exceed 62% in 2026, approaching the national “14th Five-Year Plan” target.
Core Technologies and Pretreatment Standards for Ferrosilicon Slag Resource Utilization
The resource utilization of ferrosilicon slag must be based on standardized pretreatment, with core technologies including three links: crushing and classification, magnetic separation for impurity removal, and composition fine-tuning. In the crushing and classification link, ferrosilicon slag needs to be processed into customized particle sizes such as 0-50mm and 50-100mm according to downstream application scenarios to ensure that the particle size uniformity deviation does not exceed ±2%; the magnetic separation for impurity removal link can remove impurities such as iron and manganese, improve the purity of core components, and meet high-end application needs.
The latest industry technical specifications in 2026 require that ferrosilicon slag used for metallurgical deoxidation must undergo secondary composition fine-tuning to ensure that the silicon content fluctuation is controlled within ±1%; ferrosilicon slag used for building materials production must undergo activation treatment to improve its compatibility with cement and concrete, and the compressive strength compliance rate must be ≥95%.
Accurate Distinction of Application Scenarios Between Ferrosilicon Slag and Silicon Slag
Although both are smelting by-products, there are clear boundaries in their application scenarios. Silicon slag has a higher silicon content (50%-70%), which is more suitable for fields with higher silicon purity requirements such as casting and metal silicon regeneration; ferrosilicon slag, with its reasonable ratio of calcium oxide and aluminum oxide, has more cost-effective advantages in diversified scenarios such as building materials and agriculture.
From a cost perspective, the market price of silicon slag (silicon content 60%) in January 2026 is 800-1200 yuan/ton, while the price of ferrosilicon slag (silicon content 60%) in the same period is only 200-500 yuan/ton. In non-high-end metallurgical scenarios, the cost advantage of ferrosilicon slag is more significant.
Policy Adaptation and Compliance Points for Ferrosilicon Slag Resource Utilization
Enterprises using ferrosilicon slag must strictly comply with two core policies: one is YB/T 6357-2025 “Technical Specifications for the Comprehensive Utilization of Solid Waste in the Iron and Steel Industry” implemented in 2025, which requires providing compliant documents such as ferrosilicon slag composition test reports and pretreatment records; the other is the “Bulk Solid Waste Comprehensive Utilization Incentive Policy”, where eligible enterprises can apply for a resource utilization subsidy of 20-50 yuan per ton.
For compliance testing, it is necessary to entrust an institution with CMA qualification to conduct testing. The core testing indicators include silicon, iron, carbon, sulfur, phosphorus content and particle size distribution. The validity period of the test report is 6 months, which needs to be updated in a timely manner to ensure compliance.