转炉炼钢废钢质量控制及结构优化

Quality control and structure optimization of steel scrap in converter steelmaking process

控制废钢质量、优化废钢结构有利于降低炼钢生产成本,减少环境污染,对转炉炼钢生产具有重要意义。通过理论计算和熔化试验,研究了不同废钢与转炉物料消耗及渣量之间的关系。结果表明,废钢质量对转炉钢铁料消耗和炉渣量具有显著影响。当转炉废钢比为20%时,废钢中杂质质量分数增加6%,钢铁料消耗量增加约为23 kg/t,带入渣量增加约为71.4 kg;锰的质量分数增加1%,产生钢水量约减少12.4 kg。质量较好的废钢带入转炉杂质少,利于降低钢铁料消耗和炉渣量;转炉中大量使用溢渣粉等废钢会引起钢铁料消耗和炉渣量显著增加。在此基础上,利用某企业120 t转炉进行废钢结构优化试验,研究了采用不同废钢配比冶炼对钢铁料消耗、炉渣量、终点磷含量和终点碳含量的影响。发现在该企业实际生产条件下,最优废钢配比(质量分数)为重型废钢33.3%、钢筋头16.7%、普通生铁26.7%、硫钢块6.7%和溢渣物16.6%。当120 t转炉采用最优废钢配比冶炼时,平均钢铁料消耗为1052.9 kg/t,平均炉渣量为108.7 kg/t,冶炼铁损小;且转炉终点钢水平均w([P])、w([C])分别为0.030%、0.106%,满足冶炼钢种的要求,同时可降低转炉冶炼成本。研究结果有助于钢铁企业优化转炉炼钢炉料结构,降低生产成本。

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 1052.9 kg/t,the average slag amount is about 108.7 kg/t,and there is less iron loss.The average w([P])and w([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.