5. Briefly describe the characteristics and mineral composition of slag in the middle of smelting?
Answer: In the middle of smelting, the reaction of carbon and oxygen in the furnace is intense, and the slag is prone to “back to dry”. Its characteristics are high alkalinity and low ferrous oxide content. When the slag has a mineral composition: the main phase is dicalcium silicate and tricalcium silicate. When the lime is added, there is more free CaO. The higher the alkalinity, the larger the amount of tricalcium silicate, and the more free CaO, which is unfavorable for the smelting effect.
6. Briefly describe the principle of selecting raw materials for steelmaking?
Answer: Mass production at home and abroad proves that implementing the fine material policy is an important way to realize the automation of the converter steelmaking process and improve various technical and economic indicators. The raw materials mainly consist of: molten iron, scrap steel, slag-forming materials, ferroalloys, and oxygen. The rational selection of raw materials is based on the principle of smelting steel grades, operating processes and equipment levels to achieve low input and high quality output.
7. The main way to reduce blow losses?
Answer: (1) Concentrate policy, reducing slag volume (2) Reasonable slagging system (3) Adopting a reasonable oxygen supply system and loading system to reduce mechanical splashing. (4) Using thermal compensation technology, eat more scrap steel and reduce chemical burning. (5) Adopt reasonable re-blowing technology.
8. What is the advantage of less slag operation and less slag operation?
Answer: When the amount of lime added per ton of metal material is less than 20kg/t, the slag formed per ton of metal is less than 30kg/t, which is less slag operation. (1) The amount of lime added is small, the slag and energy consumption are reduced, and the emission of pollutants is reduced. (2) The utilization rate of oxygen is high, the end point oxygen content is low, the residual manganese is high, and the alloy yield is high. (3) Reduce the erosion of the lining and reduce the splash.