金属铱多孔材料过滤性能分析

金属多孔材料因其良好的过滤和理化性能，在气-固分离方面得到广泛的应用。采用氦质谱检漏仪、扫描电子显微镜及比表面积测试仪等对金属铱多孔材料的孔隙率、微观结构、孔隙特征及孔隙分布等方面进行了研究。研究表明，该金属铱多孔材料由粉体颗粒和孔隙组成，其内部孔隙相互连通构成复杂的三维结构；孔隙率约为16.93%，有98.7%的孔隙孔径为0.002~0.05 μm，1.3%的孔径为0.05~0.46 μm；根据多孔材料微过滤理论及气体中微粒捕集理论（不考虑多孔材料厚度），该金属铱多孔材料对粒径不小于0.46 μm粉体颗粒过滤效率达100%，且不受气体流速的影响；对粒径小于0.46 μm的粉体颗粒，当气体流速不大于5.28 m/s时，过滤效率同样达100%，而当气体流速大于5.28 m/s时，则会有部分粉体颗粒通过。多孔材料微过滤理论及气体中微粒捕集理论可为多孔材料过滤性能评价提供参考，该金属铱多孔材料也可用于放射性同位素材料的气-固分离。

Analysis of Filtration Properties of Iridium Metal Porous Materials

The metal porous material has been widely used in gas-solid separation, due to its excellent filtering performance and good physical and chemical properties. This research adopted the helium mass spectrometer leak detector, scanning electron microscope (SEM) and specific surface area analyzers etc. to analyze the porosity, microstructure,pore characteristic and distribution etc. of the iridium porous material. The results showed that the iridium porous material with interconnected internal pores and complex 3D structure was composed of iridium powder particles and pores. The porosity of the iridium porous material was about 16.93%. The pore diameter of 98.7% pores of the iridium porous material was between 0.002 to 0.05 μm, and the rest pore diameter was 0.05 to 0.46 μm. According to the filtering theory of porous material and particle capture theory (The thickness of the porous material is not considered), when the diameter of powder particles was not less than 0.46 μm, the filtration efficiency of iridium porous material reached to 100%. In addition, when the diameter of powder particles was less than 0.46 μm and the gas flow speed was no more than 5.28 m/s, the filtration efficiency of iridium porous material reached to 100% as well. However, when the gas flow speed was more than 5.28 m/s, part of powder particles (less than 0.46 μm) would pass though the iridium porous material. Obviously, it provides a novel approach for evaluating the filtration performance of porous materials by using filtering theory and particle capture theory. In addition, the iridium porous material can be used for the gas-solid separation in certain special fields, such as gas-solid separation of radioactive isotope materials.