不同配比对混煤可磨性指数及粒度分布的影响

为解决高炉喷吹煤可磨性的问题，研究了3种具有代表性的煤种以不同质量配比搭配后的混合样可磨性指数的变化规律，并利用卡方检测研究了不同配比的混煤可磨性指数与加权可磨性指数的关系。试验结果表明：经过卡方检测证明2种单煤混合样的可磨性指数具有线性加和性；然后在-0.074mm的粒度下，根据粒度指数的概念，混煤的粒度分布并没有加合效果，这与两种单煤的可磨性指数差异大小有关，试验证明：可磨性指数差异较大的两种煤混煤研磨，在较细的粒级范围内粉碎方式倾向于表面粉碎，难磨煤对易磨煤的粉碎起到促进作用。

Effect of different proportion on grindability index and particle size distribution of mixed coal

To solve the grindability problem of pulverized coal injection into blast furnace, the variation of the grindability index of mixed coal, which was obtained by mixing three typical coals in different proportion, was studied and the relationship between grindability index and weighted grindability index was analyzed by Chi- square test. Results showed that there was a liner additive relationship between the grindability indexes of the mixed coal and the two sample coals. But in the condition of the particle size of 0.074mm, the particle size distribution of the mixed coal was not additive according to the concept of the particle size index, which was related to the difference in the grindability indexes of the two sample coals. The experiments indicated that when the coal that was mixed by the two sample coals with significant difference of the grindability index was grinded, the pulverizing mode in a small range of particle size was surfacegrinding, which was due to the promotion effect of the low grindability coal on the high grindability coal.