Reduction-Sulfurization Smelting Process of Waste Hydrogenation Catalysts, Automotive Exhaust Purifier Waste Catalysts, and Laterite Nickel Ore

Reduction-sulfurization smelting is an effective method for treating solid hazardous waste and recovering valuable components from them. In this work, a waste hydrogenation catalyst (WHC), an automotive exhaust purifier waste catalyst (AEPWC), a vulcanizer, and laterite nickel ore were mixed, and the reduction smelting behavior of this solid waste was investigated. XRD (X-ray diffractometry), TG-DSC (thermogravimetric/differential scanning calorimetry), SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy), OM (optical microscopy), and ICP-OES (inductively coupled plasma-optical emission spectrometry) methods were used to examine the chemical composition, thermal stability, structure, and morphology, as well as the metal content of the samples. Under the Al2O3-FeO-SiO2 ternary slag system, at a smelting temperature of 1450 degrees C, smelting time of 2 h, mass ratio of coke, pyrite, and CaO to waste catalysts of 16, 25, and 0%, respectively, nickel (Ni) and molybdenum (Mo) recovery reached 91.1 and 92.9%, respectively, where average PGMs (platinum group metals, platinum (Pt), palladium (Pd), rhodium (Rh)) recovery reached 96%, although vanadium (V) recovery was only 25.1%. The characterization of the slag shows that Al, Si, and Fe are mainly bound in the form of chemical compounds, while V is intercalated with ferro- or aluminosilicate, which hinders the reduction and sulfurization of V. A series of tests using reduction smelting without sulfurization were also conducted, after which the Ni, Mo, and V recovery reached 96.8, 96.6, and 89.7%, respectively, while PGMs (Pt, Pd, Rh) recovery ranges from 90.2 to 98.0%. The collaborative disposal of primary ore and multisource solid waste has been achieved through two process paths: reducing smelting and reducing sulfurization smelting, which provide reference for the collaborative smelting of multisource secondary resources.