微米级尘雾耦合作用力机理及其效能优化研究

The water spray has been widely used for dust removal in the metal mine, while it needs further research on the mechanism of dust removal to improve the ability of capturing fine dust, because of the complicated composition of mineral dust, high content of silica and micro-particle. Based on previous research achievements, the interaction force beteween the fine dust and droplet is the key factor. The type and form of the forces and dominant factors are discussed by using theoretical analysis and experimental study, the surface tension between the fine dust and droplet is the key research among the interaction forces, and the mathematical model of the coupling force between the dust and droplet is built.The relative velocity、size distribution、hydrophobic properties、airflow parameters and other factors are selected to analyse the coupling effect, and get the methods and ways to optimization of the couping effect between the dust and droplet. Based on the mechanism of chemical suppression of dust, such as wettability, hygroscopicity and consolidation, the modification of droplet is carried out to optimize the coupling efficiency, to improve the water spray dusting of micron grade mine dust removal efficiency to provide the new train of thought.

金属矿尘成分非常复杂、二氧化硅含量高、微米级颗粒物浓度大，目前广泛采用的水雾除尘技术存在捕尘效率不稳定、呼吸性粉尘除尘效率低等严重问题，前期研究成果发现，固-液颗粒之间的微观作用力是主导水雾捕尘效率的关键，课题针对微米级尘雾颗粒耦合作用力种类、存在形式及影响因素进行理论分析与实验研究，重点讨论表面张力在耦合过程中的核心作用，尝试建立尘雾耦合作用力数学模型。对比分析尘雾间相对运动速度、粒径分布、疏水性能、流场参数对尘雾耦合作用的影响规律，获得优化尘雾耦合效能的实现途径与方法；结合化学抑尘的湿润性、吸湿性与固结性作用机理，开展水雾改性对尘雾耦合作用效能的优选机制研究，为提高水雾对微米级矿尘的除尘效率提供新思路。

针对呼吸性金属矿尘难湿润、难分离等防尘技术难题，自主设计了一套尘、雾接触动态观测实验系统，从宏观、细观、微观对尘雾耦合作用过程进行了多角度分析研究。从微观作用力出发，分析了雾滴的表面张力、粘度和相对运动参数对尘雾颗粒之间的耦合作用规律。从抑尘作用原理出发，研究了金属矿尘与不同抑尘溶液表面的湿润、沉降规律。从喷雾除尘应用角度出发，开展了水雾捕尘的宏观动态过程分析，并将上述研究成果应用于露天金属矿山的粉尘防治工作。研究发现：微液滴与矿尘表面接触存在碎裂直接铺展、回缩、负弹跳、一次弹跳、多次弹跳等现象，抑尘型水雾粘度会促使弹跳行为提前发生，表面张力减弱液滴的弹跳行为。实验筛选了新型Gemini湿润型抑尘水雾配方，通过现场应用试验证明：与普通水雾相比，其对呼吸性粉尘的捕尘有效作用时间缩短20%、捕尘效率提升15%以上，这对改善矿山环境、预防粉尘职业危害具有重要理论与推广应用价值。