| Part of the precious metal in the form of particles can be captured and recovered by filter in the nitric acid production process. The particle size, morphology, composition and surface valence of the particles were analyzed by laser particle size analyzer, scanning electron microscope (SEM), inductively coupled plasma optical emission spectrometer (ICP-AES), and X-ray photoelectron spectroscopy (XPS). The results show that the size of captured precious metal-containing particles is mainly concentrated in 10 μm, and some of them have a metal hollow structure. The elemental composition of the particles is relatively complex. The valence analysis of the captured precious metals, platinum and palladium by XPS reveals that they mainly exist in the form of compound state. |
