Abstract: Abstract:The Hunan Huadian Changsha Power Generation Company Limited had a try to use the double ended ball mill to mill the blended coal, in which the Indonesia lignite with low calorific value and high volatiles was mixed by certain ratio. A process of “to mill different coal by different mill separately and to mix and burn the different pulverized coals in furnace” was adopted. The system application features, which include how to control the explosion of the coal pulverizing system, how to ensure safety of the persons and equipments and how to prevent cooking in the boiler, were investigated. In order to improve the economic efficiency of the blended lignite combustion and to standardize the operation mode, according to actual conditions, the separately mill process, the blended mill process and the blended ratio were tested and compared with each other. The test results show that to adopt the process of “to mill different coal by different mill separately and to mix and burn the different pulverized coals in the furnace” to burn the lignite is feasible.

Key words: Keywords:double ended pressure direct fired ball mill, firing lignite, coking in boiler, optimized reformation, test, economic analysis