NLMK高炉喷吹煤粉优化搭配

Optimal matching of pulverized coal injection for NLMK blast furnace

得益于丰富的天然气资源,俄罗斯众多钢铁厂使用天然气进行高炉喷吹。为实现资源的合理配置以及效益最大化,提高高炉喷煤量、减少天然气使用成了新利佩茨克钢铁公司发展新方向。对俄罗斯所提供的两种高挥发分煤(1号、2号)和2种挥发分含量较低的煤(3号、4号)以及经配煤处理后的混煤进行工业分析和着火点、爆炸性、灰熔点等喷吹特性研究。研究发现1号和2号煤具有强爆炸性和较低的着火点,而3号和4号煤着火点较高,燃烧率较低。4种煤粉均不适于高炉单独喷吹。经混煤处理后的煤粉无爆炸性,燃烧率高于贫瘦煤,着火点介于对应2种单煤之间,灰分的质量分数均低于8%,低于国内高炉喷吹用煤对灰分要求。但俄罗斯煤的可磨性普遍较差。在所设定的混煤方案中,2号烟煤与4号贫瘦煤的混煤着火点适中、燃烧率较高、可磨性较好,较适合高炉喷吹,其中2号烟煤占40%时最适合高炉喷吹。

Benefit to abundant natural gas resources,many steel plants in Russia use natural gas for blast furnace injection.In order to realize the rational allocation of resources and maximize the benefits,increasing the amount of coal injection in the blast furnace and reducing the use of natural gas has become a new development direction for Novolipetsk Steel Company.Two kinds of high-volatile coals(No.1,No.2) and two kinds of low-volatile coals(No.3,No.4) provided by Russia as well as blended coals were conducted proximate analysis and research on injection characteristics such as ignition point,explosiveness,and ash melting point.The study found that No.1 and No.2 coals have stronger explosiveness and lower ignition points,while No.3 and No.4 coals have higher ignition points and lower combustion rates.The four types of coal powder are not suitable for blast furnace injection alone.The pulverized coal obtained by the mixed coal treatment is non-explosive,the burning rate is higher than that of lean coal,the ignition point is between the corresponding two kinds of single coal,and the ash mass fraction is lower than 8%,which is lower than the ash requirement of domestic blast furnace injection coal.However,the grindability of Russian coal is generally poor.In the set coal blending plan,the blended coal with No.2 bituminous coal and No.4 lean coal has a moderate ignition point,higher combustion rate and better grindability.This kind of blended coal is more suitable for blast furnace injection,of which No.2 bituminous coal accounts for 40% is the most suitable plan.