转炉炼钢废钢质量控制及结构优化

Controlling the quality of steel scrap and optimizing the structure of steel scrap are conducive to reducing the steelmaking production cost and reducing environmental pollution, which is significant to converter steelmaking process. Through theoretical calculation and smelting test, the effect of different steel scrap on material consumption and the amount of slag in the converter was studied. It is found that the quality of steel scrap has a significant effect on the steel material consumption and the amount of slag in converter steelmaking process. When the steel scrap accounts for 20% of the total steel materials, the impurity content in steel scrap increases by 6%, the steel material consumption increases by about 23 kg/t. Manganese content in steel scrap increases by 1%, the amount of liquid steel decreases by about 12. 4 kg. The steel scrap with better quality is added into the converter with less impurities, which is beneficial to reduce the consumption of steel material and the amount of slag. The extensive use of steel scrap such as splashing slag powder in converter will cause a significant increase in steel material consumption and slag amount. On this basis, the optimization test of steel scrap structure was completed in a 120 t converter. The effects of smelting with the different proportions of steel scrap on steel material consumption, slag amount, phosphorus content and carbon content at the end point of converter smelting process were studied. It is found that the optimal steel scrap structure are 33. 3% heavy steel scrap, 16. 7% cutting of steel bar, 26. 7% regular pig-iron, 6. 7% sulphur steel and 16. 6% splashing steel-slag under the actual production conditions. When the 120 t converter is smelted with the optimal steel scrap scheme, the average steel material consumption is about 1 052. 9 kg/t, the average slag amount is about 108. 7 kg/t, and there is less iron loss. The average to([P]) and to([C]) of molten steel at the end point of converter smelting process are 0. 030% and 0. 106% respectively, which meet the requirements of smelting steel grade. It can reduce the production cost effectively. The research is helpful to optimize the material structure and to reduce the production cost in converter steelmaking process.