粉煤低温等离子体氧化过程效率及模型构建研究

Research on the process efficiency and model building of low temperature plasma oxidation of pulverized coal

低温等离子体氧化是研究煤中矿物赋存的重要前处理技术,其存在着灰化反应速度慢、过程效率低等问题,需针对设备运行的操作参数进行优化研究,尤其应侧重等离子体与粉煤的反应过程模式及反应速度控制因素以提高粉煤的氧化过程效率。采用等离子体设备灰化典型气肥煤,以单次灰化时间、设备电参数为操作变量,考察反应速度与灰化时间、有机质含量的关系,分析等离子体等效反应深度、速度控制方程及氧化过程效率优化,并建立粉煤等离子体氧化过程模型。在等效反应深度内,有机质含量小于0.3 g/g后进入降速灰化阶段,需优化操作过程以确保灰化整体速度维持匀速,从而提高氧化过程效率。制定典型气肥煤的综合灰化速度控制方案,即有机质含量在>0.69、0.69~>0.57、0.57~0.46、<0.46 g/g时设置单次灰化时间分别为8、4、2、1 h。

Low temperature oxygen plasma oxidation is an important pretreatment technology for studying the occurrence of coal minerals.However,it has problems such as slow ashing reaction rate and low process efficiency.Optimization research is needed for the operating parameters of the equipment,especially focusing on the reaction process mode and reaction rate control factors between plasma and coal powder to improve ashing efficiency.Using plasma equipment to ashing typical gas-fat coal,with single ashing time and equipment electrical parameters as operating variables,the relationship between reaction rate,ashing time,and organic matter content was investigated.The plasma equivalent reaction depth,velocity control equation,and oxidation process efficiency optimization were analyzed,and a coal powder plasma oxidation process model was established.Within the equivalent reaction depth,when the organic matter content is less than 0.3 g/g,it enters the reduced rate ashing stage.Therefore,it is necessary to optimize the operation process to ensure that the overall ashing speed remains constant,thereby improving the ashing efficiency.A comprehensive ashing rate control plan for gas fertilizer coal was developed,single ashing times would be set at 8、4、2 and 1 hour when organic matter content is>0.69、0.69~>0.57、0.57~0.46 and<0.46 respectively.