Abstract:Spent automobile catalysts are an important secondary source of platinum group metals (PGMs). The pyrometallurgical capture process has been widely studied in recent years because of its advantages such as high recovery rate and small wastewater volume. In this paper, cordierite-type spent automobile catalysts is used as raw material. The main components and phase structures of samples were characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES)and X-ray diffraction (XRD). The distribution of the elements was determined by electron probe micro analyzer (EPMA). The melting behavior of the specimens was investigated by in situ observation using high temperature confocal scanning laser microscopy (HT-CSLM). The effect of CaO as an additive on the slag characteristics of the smelting and capture of platinum group metals was studied by simulation using FactSage software and experiments. The results show that: the platinum group metals of cordierite-type spent automobile catalysts include platinum (Pt), palladium (Pd), rhodium (Rh), and relatively dispersed on the cordierite (2MgO-2Al₂O₃-5SiO₂) carrier; melting of raw material occurs at 1345℃~1548℃; The addition of CaO can reduce the melting temperature and viscosity of the slag system , and shorten the melting temperature interval; as the CaO addition increases from 5 wt.% to 25 wt.% (with a gradient of 5 wt.%), the complete melting temperature of the slag is 1500°C, 1480°C, 1460°C, 1440°C, and 1430°C in that order. The above work is a good guide for the study of Enrichment of platinum group metals (PGMs) by pyrometallurgical capture.