间接还原度对交互作用和高炉冶炼的影响研究

Influence of Indirect Reduction Degree on Interaction and Blast Furnace Smelting

随着国家“双碳”政策的实施,高炉生产面临着减排压力。富氢和全氧高炉工艺减排效果明显,但这些工艺会使炉内的还原性气氛变强,从而使炉料在高炉内的物理化学反应与传统高炉不同。针对这一问题,通过使用还原度分别为60%、70%、80%和90%的预还原炉料进行熔滴实验,研究了还原度升高对交互作用和高炉冶炼的影响。研究结果表明,随着还原度升高,炉料的软化开始温度、熔化开始温度和滴落温度均呈现升高趋势,软熔滴落过程的透气性改善;随着还原度的提高,脉石相中的FeO含量降低,脉石相熔点升高,抑制了熔融还原渗碳,使金属铁的熔点升高,造成滴落物的重量逐渐降低,滴落物中金属铁的碳含量降低。基于研究结果,富氢高炉和氧气高炉需控制富氢量和富氧量,避免间接还原度过高,同时可以通过改变成渣路径,避免交互作用过渡抑制。

With the implementation of the national"dual carbon"policy,blast furnace production is under pressure to reduce emissions.The hydrogen-rich and oxygen blast furnace processes have obvious emission reduction effects,but these processes will promote the reduction atmosphere in the furnace,so that the physical and chemical reactions of the burdens in the blast furnace are different from traditional blast furnaces.In response to this problem,by using pre-reduced burdens with reduction degrees of 60%,70%,80% and 90%,the droplet experiments were carried out to systematically study the effect of increasing reduction degrees on the interaction and blast furnace smelting.The research results show that with the increase of the reduction degree,the softening start temperature,melting start temperature and dripping temperature of the burdens all show an increasing trend,and the gas permeability during the dripping process is improved.With the increase of the reduction degree,the FeO content in the gangue phase decreases,the melting point of the gangue phase increases,and at the same time,the melting reduction carburization is inhibited,so that the melting point of the metallic iron increases,resulting in a gradual decrease in the weight of the droplets and carbon content of metallic iron is reduced.Based on the research results,it is necessary to control the hydrogen-rich and oxygen-rich amounts of hydrogen-rich blast furnaces and oxygen blast furnaces to avoid excessive indirect reduction.At the same time,the transition inhibition of the interaction can be avoided by changing the slag-forming path.