水平式球磨机用于POPs机械化学处置的能量传递

Energy transfer in mechanochemical treatment of POPs in a horizontal ball mill

机械化学法对各种氯代、溴代和氟代POPs均具有高效的降解效率,有很好的规模化应用的潜力.然而该技术目前多处于实验室研究阶段,实验室常用设备行星式球磨机的处理量有限,不具备规模化应用的条件.因此,提出以水平式球磨机代替行星式球磨机的观点,并通过建立两种球磨形式的单个磨球宏观运动模型和磨球微观撞击能量传递模型,对二者的有效碰撞功率进行定量研究和对比.研究结果表明,行星式球磨机的能量密度高于水平式球磨机;水平式球磨机的有效碰撞功率随滚筒半径的增大而增大,且存在最佳球磨转速.水平式球磨机能量密度低这一缺点可以通过增大球料比和延长球磨时间等方式进行有效弥补,此外,由于其能量利用效率和处理量远远超过行星式球磨机,因此其作为POPs规模化处置设备具备很高的可行性.

In recent years,mechanochemical（ MC） treatment of persistent organic pollutants（ POPs） has received extensive research attention. As an easy-to-use and non-combustion treatment technology,MC is known for its high destruction rate for chlorinated, brominated, and even fluorinated pollutants. Consequently,there is great potential for large scale application of MC for POPs treatment. However,due to the limited treatment capacity,planetary ball mills are not suitable for full scale MC treatment. On the other hand,a horizontal ball mill is proposed in this study to replace the planetary ball mill in MC treatment. The kinetic model for the trajectory of a single milling ball in two types of devices and the local energy transfer model during the ball collision were established. The effective collision energy was also investigated and compared quantitatively in the two devices. The results indicated that the energy density of the planetary ball mill was higher than that of the horizontal ball mill. For the horizontal ball mill,the effective collision energy increased with the increasing roller radius,and there was an optimal revolving speed for ball milling.The low energy density of the horizontal ball mill could be compensated by high charge ratio and extended milling time. Besides,since the energy utilization efficiency and treatment capacity of the horizontal ball mill is much higher than that of the planetary ball mill,the horizontal ball mill is morefeasible for large scale MC treatment of POPs.