Relationship between coal size reduction and energy input in Hardgrove mill

• Published in: International journal of mining science and technology 2012, Vol.22 (1), p.121-124
• Main Authors: Zuo, Weiran, Zhao, Yuemin, He, Yaqun, Shi, Fengnian, Duan, Chenlong
• Format: Article
• Language: English
• Subjects: Bed breakage; Coal; ECS; Grindability index; Hardgrove mill; Shi–Kojovic model; vic模型; 可磨性指数; 扭矩传感器; 物理参数; 磨煤机; 能量输入; 非线性关系
• ISSN: 2095-2686
• DOI: 10.1016/j.ijmst.2011.07.011

Hardgrove grindability index （HGI） is an important indicator of coal grindability, and is one of the most important parameters to determine the capacity of coal pulverizer in power station. However, HGI is an empirical grindability index without linkages to any known physical parameters. To investigate the effect of energy input on the grinding in Hardgrove mill. a T20WN torque meter was installed on the shaft of a modified Hardgrove mill to record the torque driving the mill. Samples from four kinds of coals with HGI ranging from 36 to 72 were prepared according to the procedure of standard HGI test and ground in a modified Hardgrove mill at different revolutions. The relation of sample size reduction degree to specific comminution energy （Ecs） was studied with Shi-Kojovic model, The results show that Shi-Kojovic model predicted well the coal size reduction degree with Ecs in Hardgrove mill. The griadability index given by Shi-Kojovic model has a similar trend with HGI. The relation of sample size reduction degree to Ecs reveals that HGI has a non-linear relationship with effective specific energy in Hardgrove mill, which explains the non-linear relation of HG1 to industrial pulverizer capacity.