高炉配煤优化实验研究

Experimental Study on Optimization of Coal Blending for Blast Furnace

以烟煤和无烟煤为原料进行配煤实验,探索烟煤含量对混煤燃烧性能的影响,分析煤粉粒度组成对其燃烧率的影响机理。结果表明:烟煤质量分数在40%~70%范围时,混煤的可磨性指数在77~89之间波动;烟煤质量分数达65%时,混煤的返回火焰长度大于150 mm,混煤呈轻微爆炸性;相同粒度范围下煤粉的燃烧率差异较大,无烟煤燃烧率受煤粉粒度的影响更明显,粒径小于74μm的混煤占比80%时,小粒径煤粉对大粒径煤粉的促燃效果最佳;烟煤质量分数超过60%,混煤燃烧率提高幅度减小,结合混煤特性及烟气中CO与CO2的相对含量变化规律,建议烟煤质量分数控制在55%左右。

Coal blending experiments were carried out with bituminous coal and anthracite as raw materials to explore the influence of content of bituminous coal on the combustion performance of blended coal,and the influence mechanism of particle size composition on the combustion rate of pulverized coal was analyzed.The results show that when the mass fraction of bituminous coal is in the range of 40%-70%,the hardgrove grindability index of blended coal fluctuates between 77 and 89.When the mass fraction of bituminous coal is up to 65%,the return flame length of blended coal is more than 150 mm,and the blended coal has a slight explosiveness.In the same particle size range,the combustion rate of pulverized coal varies greatly,and the combustion rate of anthracite is more obviously affected by the particle size of pulverized coal.When the proportion of blended coal with particle size less than 74μm is 80%,the small particle size pulverized coal has the best combustion promotion effect on the large particle size pulverized coal.When the mass fraction of bituminous coal is more than 60%,the combustion rate of blended coal decreases.Considering the characteristics of blended coal and the relative content of CO and CO2 in flue gas,it is suggested that the mass fraction of bituminous coal should be controlled at about 55%.