Grinding Behaviors of Components in Heterogeneous Breakage of Coals of Different Ash Contents in a Ball-and-Race Mill
Grinding Behaviors of Components in Heterogeneous Breakage of Coals of Different Ash Contents in a Ball-and-Race Mill
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DOI：
10.3390/min10030230
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发表时间：
2020-03-01
期刊：
影响因子：
2.5
通讯作者：
Zhu, Xiangnan
中科院分区：
文献类型：
--
作者：
Duan, Jin;Lu, Qichang;Zhu, Xiangnan
用于发电厂的煤通常具有不同的灰分含量，并且通过球磨机或辊磨机破碎煤是能量密集型过程。火电厂磨矿机的磨矿现象比较复杂，与实验室理想的磨矿试验也不尽相同。与单次破碎相比，煤种间的相互作用会导致煤的磨矿特性和能耗特性发生变化。本研究选用不同灰分的无烟煤和烟煤进行非均质磨煤。利用混合物的硫含量与混合物中一种组分的质量收率之间的关系实现了产物中组分的定量。确定了组分的产品细度t（10），并在比能量平衡和能量-粒度减小模型的前提下，采用遗传算法计算了分解能。试验结果表明，随着混合料中硬质无烟煤含量的增加，混合料的破碎率和产品细度t（10）降低。无烟煤在非均质磨矿中的t（10）值与单次破碎相比有较大幅度的提高，而烟煤的t（10）值与单次破碎相比有较大幅度的提高。组分间的相互作用导致混合物的比能比单一破碎时组分的质量平均比能降低。软质烟煤的加入降低了硬质无烟煤的抗破碎性，同时也提高了无烟煤的磨矿能量利用率。
Coals used for power plants normally have different ash contents, and the breakage of coals by the ball-and-race mill or roller mill is an energy-intensive process. Grinding phenomena in mill of power plants is complex, and it is also not the same with ideal grinding tests in labs. The interaction among various coals would result in changes of grinding behaviors and energy consumption characterization if compared with those of single breakage. In this study, anthracite and bituminous coal of different ash contents were selected to be heterogeneously ground. Quantitation of components in products was realized using the relation between sulfur content of the mixture and mass yield of one component in the mixture. Product fineness t(10) of the component was determined, and split energy was calculated on the premise of specific energy balance and energy-size reduction model by a genetic algorithm. Experimental results indicate that breakage rate and product fineness t(10) of the mixture decrease with the increase of hard anthracite content in the mixture. Unlike the single breakage, t(10) of anthracite in heterogeneous grinding is improved dramatically, and bituminous coal shows the opposite trend. The interaction between components results in the decrease of the specific energy of the mixture if compared with the mass average one of components in single breakage. Breakage resistance of hard anthracite decreases due to the addition of soft bituminous coal, and grinding energy efficiency of anthracite is also improved compared with that of single grinding.