GB/T 30900-2025 in English

Standard Revision Background and Technological Evolution

GB/T 30900-2025, "LF Furnace Refining Slag Agglomerates for Steelmaking," is the first revision to the 2014 edition, reflecting the continuous improvement of refining process requirements in my country's steel industry. This revision is primarily based on the recent growth in market demand for low-silicon and low-sulfur steel grades, stricter environmental protection requirements, and advances in production processes and technologies.

LF furnace refining slag agglomerates are an important auxiliary raw material in the steelmaking process, and their quality directly affects the purity of molten steel and refining results. By adding specific technical requirements for low-silicon and low-sulfur steel grades, the new standard better meets the needs of high-end steel production. Furthermore, the strengthening of environmental protection requirements also conforms to the trend of green development in the steel industry.

In-depth Analysis of Major Technical Changes

Compared with the 2014 edition, GB/T 30900-2025 has undergone significant revisions in several areas:

Detailed Explanation of Chemical Composition Requirements

The new standard significantly optimizes the chemical composition requirements for LF furnace refined slag agglomerates, particularly with differentiated regulations for different steel grades:

Low-silicon and low-sulfur steel gradesThe SiO₂ content is required to be ≤3.0%, significantly lower than the limit for ordinary steel grades. This change stems from the strict control of silicon content in low-silicon steel to avoid abnormal increases in silicon during the refining process. At the same time, the requirements of phosphorus content ≤0.01% and sulfur content ≤0.05% ensure that the refined slag does not negatively impact the purity of the molten steel. Other steel grades: While there are no specific restrictions on SiO₂ content, strict control over phosphorus and sulfur contents remains, reflecting the universal purity requirements of modern steelmaking. The physical properties of LF furnace refined slag agglomerates directly impact their performance: Moisture content control: A requirement of ≤1.0% ensures that the agglomerates do not create a risk of splashing due to water evaporation in high-temperature environments, while also helping to maintain chemical composition stability. Particle size distribution: The 10-50mm particle size range ensures rapid melting in the LF furnace while avoiding environmental issues caused by overly fine powder. A 10% over-range ratio is permitted to ensure flexibility in actual production. Strength Requirements: Dual guarantees of drop resistance ≥ 5 times (1.2m height) and compressive strength ≥ 150N ensure the integrity of the briquettes during transportation, storage, and use. Key Points for Implementation of Inspection Rules: The new standard further improves the quality inspection system: Batching Rules: The 300t batch rule ensures both production continuity and representative inspection results. Quantities less than 300t are counted as one batch, demonstrating the standard's practicality. Factory Inspection: This covers key indicators such as chemical composition, moisture content, particle size, and strength to ensure that products meet basic requirements. Type Inspection: Newly added type inspection requirements mandate compliance in the event of changes in raw material processing, extended production stoppages, or quality issues. Regular inspections are also mandated at least once a year, establishing a comprehensive quality monitoring system.

Application Implementation Recommendations

Production Process Control

Manufacturers should focus on raw material ratios and pressing techniques: select high-quality raw materials with low silicon and low phosphorus content, strictly control moisture content below 1.0%, and optimize pressing parameters to ensure briquette strength meets standards. For briquette used for low-silicon, low-sulfur steel grades, dedicated production lines or production periods should be established to avoid cross-contamination.

Usage Process Management

Steel companies using LF furnace refining slag briquette should pay attention to the following: select the appropriate briquette type based on the steel grade requirements, strictly control the amount and timing of addition, and monitor slag system changes during the refining process. Dedicated storage and usage procedures should be established, especially for low-silicon, low-sulfur steel grades.

Quality Monitoring System

Establish full-process quality control from raw material intake to product shipment: raw material inspection, process control, finished product inspection, and type inspection are essential. Statistical Process Control (SPC) methods are recommended to monitor fluctuations in key quality characteristics in real time.

Environmental Protection and Sustainable Development

The added environmental protection requirements in the new standard reflect industry development trends: manufacturers should optimize production processes to reduce energy consumption and emissions; users should pay attention to the rational use of agglomerates to avoid waste and environmental pollution. It is recommended to conduct research on agglomerate recycling technologies to improve resource utilization.

With the advancement of ultra-low emission requirements in the steel industry, the production and use of LF furnace refined slag agglomerates face new environmental challenges. Companies need to implement environmental protection requirements in all aspects, including raw material selection, production processes, and waste disposal, to achieve green production.