Effect of Microwave on the Dielectric Properties and Drying of Lignite
MA Hongye1,2, LIU Chenhui1,2,3, ZHANG Libo1,2, PENG Jinhui1,2, LIN Guo1,2
1 Key Laboratory of Unconventional Metallurgy of Ministry of Education,Kunming University of Science and Technology,Kunming 650093; 2 National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming 650093; 3 Key Laboratory of Comprehensive Utilization of Mineral Resources in Ethnic Regions, Yunnan Minzu University, Kunming 650500
Abstract: To study the feasibility of microwave drying of lignite, Yunnan Zhaotong lignite were selected and the microwave dielectric properties of temperature testing system was adopted to study the lignite dielectric properties and microwave penetration depth with apparent density change. The results showed that the dielectric properties of lignite were positively correlated with the apparent density, and the penetration depth was negatively correlated with the apparent density, and the relationship between the apparent density and the dielectric properties and the microwave penetration depth was obtained. The heating characteristics of lignite under different power and quality were studied by microwave drying system. The results showed that the microwave could reach 100 ℃ in 1 min, the maximum drying rate was 0.198 (g/g db)·min-1, in the process of microwave heating, the temperature change showed three stages,namely the stage of rapid warming, constant temperature stage, slow heating stage. Before the lignite was heated to 100 ℃, the quality of materials and power has little effect on the heating rate, after 100 ℃, lignite heating rate increased with the increase of power, and decreased with the increase of material quality.Comparing microwave drying and conventional drying of contrast,it was found that when lignite was completely dried, microwave drying cost 17 min, conventional drying cost 320 min, microwave drying is superior to conventional drying.
马洪业,刘晨辉,张利波,彭金辉,林国,. 微波对褐煤介电特性及干燥的影响*[J]. 材料导报编辑部, 2017, 31(22): 130-134.
MA Hongye, LIU Chenhui, ZHANG Libo, PENG Jinhui, LIN Guo,. Effect of Microwave on the Dielectric Properties and Drying of Lignite. Materials Reports, 2017, 31(22): 130-134.
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2017, Vol. 31 
