首钢高炉喷吹煤种的灰熔融特性

为了研究首钢高炉喷吹煤粉在风口前灰渣的熔点和高温黏度特性,采用灰熔点仪和FactSage软件对首钢几种常用喷吹煤种及混煤的灰熔融特性进行了对比分析,发现两种方法得到的结果具有相同的趋势。利用FactSage热力学计算软件,分析了1 600 ℃下京唐、迁钢两地喷吹煤灰在SiO₂-CaO-Al₂O₃-MgO(w(MgO)＝2%)四元相图中的位置,并对灰组分中SiO₂、Al₂O₃、CaO、MgO、Fe₂O₃对液相线温度和对高温下煤灰黏度的影响进行了分析。研究发现,不同灰组分改变对煤灰液相线温度和黏度的影响是不同的,灰组分对液相线温度的影响相对复杂。高温状态下,首钢高炉煤灰下灰组分中Al₂O₃、Fe₂O₃、MgO质量分数增加有降低煤灰黏度的作用,而SiO₂质量分数增加会增加煤灰黏度。混煤时应考虑不同组分对煤灰液相线温度和黏度的影响,通过合理控制灰组分达到控制风口前结渣的目的。

Ash fusion property of pulverized coal injection into blast furnace in Shougang

In order to study the melting point and high-temperature viscosity of the ash produced by the pulverized coal injection into blast furnace before the tuyere in Shougang, the ash fusion properties of several common coal types and coal blends in Shougang were compared by the ash fusion melting point meter and FactSage software. The result showed that the values obtained by the two methods had the same trend. The position of the blasting coal ash in SiO₂-CaO-Al₂O₃-MgO(w(MgO)＝2%)phase diagram at 1 600 ℃ in Jingtang and Qiangang was analyzed using FactSage thermodynamic calculation software. The influence of coal ash composition of SiO₂, Al₂O₃, CaO, MgO, Fe₂O₃ on liquidus temperature and viscosity of coal ash at high temperature were studied. It was found that the influence of different ash components on the liquidus temperature and viscosity of coal ash was different. The effect of ash composition on liquidus temperature was more complex. At high temperature, the coal ash viscosity decreased with increasing the concentration of Al₂O₃, Fe₂O₃ and MgO in the ash composition of Shougang blast furnace. While the ash viscosity increased with increasing SiO₂ concentration in the coal. Therefore, the influence of different components on the liquidus temperature and viscosity of coal ash should be considered when mixing coal. It was possible to avoid slag-bonding before tuyere by controlling of ash composition.