鉱物処理

[2201-09-05] ロイヤング褐炭の物理化学的性質に及ぼす真空凍結乾燥の影響

^○Liu Xiangchun¹、平島 剛¹、野中　 壮泰¹、笹木　 圭子¹ (1. 九州大学大学院工学研究院　地球資源システム工学部門)

司会: 綱澤有輝（産業技術総合研究所）

キーワード：凍結乾燥、残存水分、水分再吸着、ケロシン

Loy Yang lignite was dewatered using freeze drying (FD). Residual water content, sorption behavior, and pore size distributions were studied. Moreover, coating different amounts of kerosene using adsorption or direct mixing methods to reduce water re-adsorption was also investigated. The results showed that FD dewatering can be divided into three steps, i.e., a fast dewatering step (∼2 h), a reduced drying rate step (2∼3 h), and an apparently falling rate step (> 3 h). Moisture holding capacity (MHC) of the FD treated samples was lower than that of raw lignite. This is because of effects of water–lignite bond strength and diffusion adsorption or desorption force. Moreover, adding kerosene using adsorption or direct mixing methods can both decrease MHC since kerosene is coated on the surface and in the pores of the lignite, which forbid water re-adsorption. Adsorption method consumed less kerosene than direct mixing method.