Abstract—

With an approach to improve the strength performance and rate of blast-furnace smelting, especially when pulverized coal fuel is involved, the improvement of the hot coke strength has been considered. A crude oil additive is introduced into the coal charge in PJSC Novolipetsk steel mill (NLMK) to improve the quality of coke. This brings about an increase in coke sulfur resulting in the sulfur content growth in pig iron. Therefore, the task of finding ways to improve pig iron desulfurization in the blast furnace becomes important. The following are key factors that affect the pig iron desulfurization rate: slag basicity, the content of MgO oxide in the slag, the temperature of smelting products, and the slag viscosity. The purpose of this work deals with comparing the desulfurization efficiency through the improvement of the slag basicity and increasing the MgO content. An algorithm is developed based on known equations in order to achieve this goal. The increase of MgO content in the slag provides better input into pig iron desulfurization than the increase in slag basicity. In addition, an increase in MgO content by 1% results in growing slag to pig iron ratio amounting to 3.0 to 3.5 kg/MT. At the same time, an increase in basicity by 0.01 leads to an increase in the slag to pig iron ratio 4 to 5 kg/MT. Consequently, reducing the sulfur content in pig iron by controlling the slag basicity is less heat intensive. Recalculating to the reduced coke consumption rate, the difference in heat demand amounts to 0.4 to 0.5 kg/MT of pig iron. It is shown that the slag viscosity increases to a lesser extent than when caused by a basicity increase when MgO content grows in slag at a temperature of 1450°С.

中文翻译：

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降低生铁中硫含量的可能方法分析

摘要—

通过改善高炉熔炼的强度性能和速度的方法，特别是当涉及煤粉燃料时，已经考虑了热焦炭强度的提高。在PJSC新利佩茨克钢厂（NLMK）的煤料中引入了原油添加剂，以提高焦炭的质量。这导致焦炭硫的增加，导致生铁中硫含量的增加。因此，寻找改善高炉中生铁脱硫的方法的任务变得重要。以下是影响生铁脱硫率的关键因素：炉渣碱度，炉渣中MgO氧化物的含量，冶炼产品的温度和炉渣粘度。这项工作的目的是通过提高矿渣碱度和增加MgO含量来比较脱硫效率。为了实现该目标，基于已知方程式开发了一种算法。炉渣中MgO含量的增加比炉渣碱度的增加为生铁脱硫提供了更好的投入。此外，MgO含量增加1％会导致炉渣与生铁的比例增加，达到3.0至3.5 kg / MT。同时，碱度增加0.01会导致炉渣与生铁的比例增加4至5 kg / MT。因此，通过控制炉渣的碱度来降低生铁中的硫含量是不那么耗费热量的。重新计算以降低焦炭消耗率，热需求的差异为生铁的0.4至0.5 kg / MT。