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Effect of moisture on energy-size reduction of lignite coal in Hardgrove mill

Yang, Y ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1016/j.fuel.2020.117477
  3. Publisher: Elsevier Ltd , 2020
  4. Abstract:
  5. The effect of moisture on Shengli lignite breakage behavior and energy efficiency was studied experimentally using a standard Hardgrove mill fitted with a wattmeter. The grinding process concerned both the inputs, namely the occurrence and content of water and instantaneous energy consumption and the outputs, size-reduction and product fineness. Results show that the energy-size reduction process for grinding lignite is markedly influenced by moisture occurrence and content. Removing surface moisture from 37.90% to 16.61% (the air-dried condition) resulted in a slight increase of input energy by 0.04 kWh.t−1 per 10 s. However, with further drying inherent moisture to 0%, the consumed energy significantly increased by 0.16 kWh.t−1 per 10 s. Meanwhile, the mass fraction remained on top size decreased from 42.29% to 24.73% and then to 13.00%, while the pulverized coal production increased sharply from 6.28% to 10.68% and to 23.64%, both at a grinding time of 6 min. The energy efficiency was also significantly improved as the moisture content of lignite was reduced to below the air-dried level. The air-dried moisture content was the inflecting point for lignite grinding in the Hardgrove mill. A two-stage pre-drying system was proposed accordingly. © 2020 Elsevier Ltd
  6. Keywords:
  7. Breakage behavior ; Energy-size reduction ; Hardgrove mill ; Lignite ; Moisture content ; Drying ; Energy efficiency ; Energy utilization ; Grinding (machining) ; Lignite ; Moisture ; Moisture determination ; Pulverized fuel ; Size determination ; Consumed energy ; Grinding process ; Pulverized coals ; Size reduction process ; Size reductions ; Surface moistures ; Coal industry
  8. Source: Fuel ; Volume 270 , 2020
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0016236120304725