炼钢温度下石灰石粉分解速率实验研究

Experimental study on the decomposition rate of limestone powder at steelmaking temperature

石灰石粉在炼钢温度下的分解行为直接影响后续的成渣和脱磷脱硫反应,其分解速率会对熔池冶炼效果产生较大影响。基于热重-差热分析和高温管式炉开展石灰石粉煅烧实验,研究了升温速率、粒径、气氛对石灰石粉分解速率的影响。结果表明:在炼钢温度下,较大粒径石灰石粉煅烧分解过程发生裂解,粒径为0.074 mm的石灰石粉煅烧分解过程发生粘结现象;随着升温速率的提高,石灰石粉分解时间显著缩短;随着粒径的逐渐增大,分解时间呈现先降低后增加的趋势,其中粒径为0.73 mm的石灰石粉分解时间最短;与氮气和空气气氛相比,纯CO_(2)分压下石灰石粉分解时间明显缩短约2/3;在1350℃的煅烧温度下,1.5 mm以下石灰石粉分解所需时间相差不大,均可以在3 min内完成分解。

The decomposition behavior of limestone powder at steelmaking temperature directly affects the subsequent slag formation and dephosphorization and desulfurization reactions,and its decomposition rate will have a greater impact on the effect of molten pool smelting.Based on the thermogravimetric-differential thermal analysis and high-temperature tube furnace,the calcination experiment of limestone powder was carried out,and the effects of heating rate,particle size and atmosphere on the decomposition rate of limestone powder were studied.The results show that in the steelmaking temperature,larger particle size limestone powder calcined decomposition process occurs cracking,particle size of 0.074 mm limestone powder calcined decomposition process occurs bonding phenomenon.With the increase in the heating rate,the limestone powder decomposition time is significantly shortened.With the gradual increase in the particle size,the decomposition time shows a trend of decreasing and then increasing,of which the particle size of 0.73 mm limestone powder decomposition time is the shortest.Compared with nitrogen and air atmosphere,the decomposition time of limestone powder under the partial pressure of pure CO_(2)is obviously shortened by about 2/3.Under the calcination temperature of 1350℃,the decomposition time of limestone powder below 1.5 mm does not differ much,and the decomposition can be completed within 3 min.