胜利褐煤提质过程中水分的迁移及其干燥动力学研究

Study of Moisture Migration and Drying Kinetics of Shengli Lignite During Its Upgrading Process

利用低场核磁共振研究褐煤在不同温度下脱水的横向弛豫时间特征及赋存状态演变。结果表明:煤样中水分主要存在于微孔结构中,随着脱水温度的升高,留在样品中水的弛豫时间逐渐缩短,微孔水含量降低。此外,利用热重分析褐煤在连续升温条件下质量的变化,采用FWO法求解活化能。实验结果表明,随着温度的升高,活性能E先逐渐减小而后逐渐增大,当脱水率为60%时活化能E最小(51.79kJ/mol)。实验数据为褐煤干燥工艺和干燥转换点的确定提供了参考。

The transverse relaxation time and the moisture-preserving condition of lignite during the dehydra tion process at different temperature were studied, using low field nuclear magnetic resonance. The results showed that the moisture of lignite mainly existed in its microporous structure, and the higher the dehydration temperature, the shorter the transverse relaxation time of the moisture and the lower the moisture content in its microporous struc- ture. In addition, the change in the weight of lignite during continuous heating process was also investigated using thermogravimetric analysis, and the activation energy E was also calculated using FWO, a multiple rate iso-tempera- ture method. It showed that with the temperature rising, the activation energy E first decreased and then increased gradually. When the dehydration rate was 60 %, the activation energy value E reached its minimum, 51.79 kJ/mol. The data will provide references for the determination of the lignite drying technology and drying transition point.