Improving the recovery of precious metals from spent catalysts is a significant challenge, especially considering the challenges posed by incineration and potential metal loss. Here are some strategies and alternative methods:
- Supercritical Water Oxidation (SCWO):
- SCWO is an innovative method that operates at high temperatures (above 500°C) and high pressures using supercritical water.
- During SCWO, all metals present in the spent catalyst form metal oxides. The resulting stream is cooled to ambient temperature, causing all condensable material to partition into the liquid phase.
- Excellent recovery of rhenium has been demonstrated using SCWO, resulting in the formation of perrhenic acid.
- Advantages of SCWO:
- Efficient: SCWO efficiently breaks down organic components and converts metals to oxides.
- Environmental Friendliness: Unlike incineration, SCWO does not produce ash or incomplete combustion products.
- Precise Metal Recovery: By analysing the liquid phase, we can accurately determine the precious metal content without relying solely on ash measurements.
- Rhenium Volatilisation: Rhenium, especially in the form of rhenium oxide, tends to volatilise at 350°C, making incineration particularly challenging for rhenium-based catalysts.
In summary, exploring alternatives like SCWO can significantly enhance precious metal recovery while minimising environmental impact and potential losses. Please see our technologies and case studies below for more information, and don’t hesitate to contact us.
Technologies
Case Studies
