【作者】 何环宇；

【导师】 王庆祥；

【作者基本信息】 武汉科技大学 ， 钢铁冶金， 2002， 硕士

【摘要】 随着钢铁工业生产的进步，特别是洁净钢生产技术的发展，炼铁和炼钢生产均对生铁含硅量提出了越来越高的要求，而冶炼低硅生铁是降低钢铁成本，提高钢水洁净度的有效措施之一。在高炉生产中，影响生铁含硅量的因素很多，其中，提高炉渣中MgO含量是一个很有效的措施之一。本课题对高炉低硅生铁冶炼的机理，炉渣中MgO的含量与生铁含硅量的关系进行了理论探讨，并对渣中MgO含量与炉渣性能的关系进行了试验研究，最后对低硅生铁的冶炼提出了生产操作指导建议。 文中首先对硅在高炉内的行为进行了详细分析，发现影响生铁含硅量的因素很多，而提高炉渣中MgO含量对降低生铁含硅量有很大影响。 适当提高炉渣中MgO的含量可以降低生铁含硅量的原因是改善了炉渣的性能，主要表现在：①降低渣中SiO₂活度；②提高炉渣的软温度；③降低炉渣粘度；④提高炉渣的稳定性；⑤减少炉渣—焦炭间反应界面；⑥渣中MgO的还原气化促进了生铁含硅量的减少。 在理论研究的基础上，文中对渣中MgO含量与炉渣性能的关系进行了试验研究。试验研究结果表明：适当提高炉渣中MgO含量，炉渣的粘度下降，熔化性温度降低，稳定性提高。因而，炉渣的性能得到改善。 最后，根据本论文的研究结果，对生产中如何提高炉渣中MgO含量提出了操作指导建议，主要有：①采用精料入炉，以增加烧结矿和球团矿中MgO含量的方式直接提高炉渣中MgO的百分含量；②降低焦比，相对提高炉渣中MgO的含量，包括：一、采用精料、高风温、富氧鼓风、高压操作以及喷吹燃料等强化冶炼操作手段，降低焦比；二、采用上、下部调剂相结合的方式，改善煤气利用，降低焦比。更多还原

【Abstract】 With the development of the iron and steel industry, especially the development of the clean-steel production technology, the production of iron-making and steel-making increase the requirements on the silicon content in pig iron. It is one of the effective ways of smelting the low silicon pig iron to increase the cleanliness degree of steel and to decrease the cost of iron and steal. There are a lot of factors affecting the silicon content in pig iron in the blast furnace production, and increasing the MgO content in the slag is one of the effective methods. This essay has a theoretical analysis on the mechanism of smelting low silicon content pig iron in the blast furnace and the relationship between the MgO content in slag and the silicon content in pig iron, and the author has experimental research on the relationship between the MgO content in slag and the slag nature. The essay puts forward the guiding suggestions of the production operation on the smelting of low silicon content pig iron in the end.The essay first analyses in detail the performance of silicon in the blast furnace, and the author finds that there are many factors affecting the silicon content in pig iron. Increasing the MgO content in slag will have great influence on the decreasing of silicon content in pig iron.The reason that increasing appropriately the MgO content in slag can decrease the silicon content in pig iron lies in the improvement of the nature of slag, which is mainly shown as follows: 1) decrease the activityof SiO2 in slag; 2) increase the softening temperature of slag; 3) decrease the viscosity of slag; 4) increase the stability of slag; 5) decrease the reaction surface between slag and coke; 6) the reduction gasification of MgO in slag contributes to the decrease of silicon content in pig iron.Based on the theoretical research, the author has experimental analysis on the relationship between the MgO content in slag and the slag nature. The result of the experiments shows: the appropriate increase of MgO content in slag course the decrease of slag viscosity, the decrease of flowing temperature and the increase of certainty , that improve the slag nature.In the end, based on the research results of this essay, the author puts forward operation guidance suggestions on how to increase MgO content in slag. The suggestions are as follows: 1) use the beneficiated burden for blast furnace to increase MgO content in sinter and pellet, which is a direct way to increase MgO content in slag of blast furnace; 2) decrease the coke rate and then increase comparatively MgO content in slag, which includes: first, adopt the intensification of smelting process to decrease coke rate such as using beneficiated burden, high hot-blast temperature, oxygen-enriched blast, high top pressure operation and fuel injection etc; second, combine the upper and lower conditioning to improve the utility of gas to decrease the coke rate.更多还原