What is the role of blast furnace serpentine
As an important metallurgical raw material, blast furnace serpentine plays a key role in blast furnace iron smelting. This article will combine popular topics and hot topics across the network for the past 10 days to structure the role of blast furnace serpentine, and attach relevant data comparison.
1. Chemical composition and characteristics of blast furnace serpentine
Blast furnace serpentine is a magnesium-containing silicate mineral with its main component as Mg₃Si₂O₅(OH)₄, and its chemical properties determine its important role in blast furnaces. Here are its typical chemical composition analysis:
| Element | content(%) |
|---|---|
| MgO | 35-40 |
| SiO₂ | 40-45 |
| H₂O | 12-15 |
| Other impurities | ≤3 |
2. The main functions of blast furnace serpentine
1.Adjust the alkalinity of the slag: MgO and SiO₂ in serpentine can effectively neutralize the acidic components in the slag, optimize the slag flowability and improve the desulfurization efficiency. Recent metallurgical industry reports show that the alkalinity of slag (CaO/SiO₂) of added serpentine can be stable between 1.0-1.2.
2.Protective furnace lining: MgO can react with Al₂O₃ in the furnace lining to form high melting point magnesium aluminum spinel, extending the blast furnace life. Data from a steel company shows that the average life of furnace lining after using serpentine is increased by 15%.
| parameter | Serpentine not used | After using serpentine |
|---|---|---|
| Slag melting point (℃) | 1350 | 1450 |
| Desulfurization rate (%) | 75 | 88 |
| Liquid life (years) | 8 | 9.2 |
3.Energy saving and consumption reduction: The decomposition and endothermic reaction of serpentine can balance the heat distribution of the blast furnace and reduce the coke ratio. Industry experimental data in 2023 show that each ton of molten iron can reduce the amount of coke consumption by 5-8kg.
3. Recent hot application cases
1.Low-carbon smelting technology: A large steel company disclosed in its annual report released in the past 10 days that it has achieved CO emission reduction of 32,000 tons per year by replacing some limestone by serpentine.
2.Rare Earth Element Recycling: Latest research has found that trace rare earth elements (such as La, Ce) contained in certain serpentines can be enriched in slag, providing a new way to recover rare earths.
| Rare Earth Elements | Original content (ppm) | After slag enrichment (ppm) |
|---|---|---|
| La | 15 | 120 |
| Ce | 18 | 150 |
4. Precautions for use
1.Granularity control: The particle size of serpentine into the furnace should be controlled at 5-30mm. If it is too fine, it is easily taken away by the airflow, and if it is too rough, it will affect the reaction speed.
2.Match ratio: It is recommended to use it in a 1:2 ratio with dolomite, which can not only ensure the supply of MgO, but also avoid the increase in the viscosity of the slag due to excessive SiO₂.
3.Moisture control: The water content of serpentine must be less than 15%, otherwise it is easy to cause firefighting accidents.
5. Future development trends
In light of recent industry trends, the application of blast furnace serpentine will show the following trends:
1.Functional complexity: Develop multifunctional composite serpentine additives such as dephosphorization and sulfur solidification.
2.Intelligent mineral distribution: Establish a serpentine composition-slag performance prediction model based on big data.
3.Resource recycling: Recycling the active serpentine from the discarded slag to achieve closed-loop utilization.
To sum up, blast furnace serpentine plays an irreplaceable role in the iron smelting process through its unique physical and chemical properties. With the development of green smelting technology, its application value will continue to expand and innovate.
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