煤田火区影响下的汞迁移机理

Mechanism of mercury migration under the influence of coal field fire

为了研究煤自燃时和煤田火区影响下汞的迁移机理和迁移过程,采用理论与实验相结合的方法进行了研究;从传热传质学角度建立了多孔介质中和半无限大介质条件下汞的迁移方程,推导出温度场条件下汞的迁移方程,对12#煤样等5个地点的样本燃烧前后重金属含量测定结果表明煤燃烧后迁移出大量汞;测定了五虎山煤矿地表原煤、燃煤、12#煤层原煤的煤样中汞含量,测定结果验证了煤在燃烧时会释放出大量汞,总结了12#煤层中的汞含量变化规律。研究结果表明:可以通过测定煤田火区地表气态汞浓度来判断火区高温异常区域。

In order to study the mechanism and process of mercury migration under the influence of coal spontaneous combustion and coal field fire area,this paper uses the method of combining theory and experiment to study the migration of mercury.In this paper,the transport equation of mercury in porous medium and semi-infinite medium is established from the viewpoint of heat and mass transfer,and the transport equation of mercury in temperature field is deduced.The results of heavy metal content determination of samples from 5 sites including No.12 coal sample before and after combustion by the project team showed that a large amount of mercury migrated from coal after combustion.The project team also measured the mercury content in the surface raw coal of Wuhushan Coal Mine,coal burning and coal from No.12 coal seam.The measurement results verified that a large amount of mercury was released when coal was burned,and summarized the change rule of mercury content in No.12 coal seam.The experimental results show that the abnormal area of high temperature in coal field fire area can be judged by measuring the concentration of gaseous mercury on the surface of coal field fire area.