CATALYSTS XXXXXX and reducing the environmental impact of sourcing the. In particular, liquid streams can be processed with a view to recovery and re-use. For palladium, for example, we have clearly demonstrated that concentrations as low as 20 ppm( and as high as 6,000 ppm) are economic to recycle.
Using this approach, industrial manufacturers have a constant and sustainable supply of precious metals, a simplified, localised supply chain and a reduced carbon footprint to contribute to their sustainability objectives. A study by Indaver and KU Leuven in Belgium in 2025 showed that Indaver’ s recycling processes for precious metals resulted in carbon savings of up to 98 %, compared with primary mining.
Recycling precious metals
Indaver’ s Inda-MP facility in Antwerp specialises in recovering precious metals directly from the liquid phases originating from processes based on homogeneous precious metal catalysts, primarily from the agrochemicals, speciality chemicals and pharmaceuticals industries. Once the precious metal has been recovered, a liquid fraction remains that also needs to be treated. This includes liquids that may be hazardous, toxic, flammable or corrosive. It is important that all installations recovering precious metals also have the ability to deal with these liquid fractions. Indaver has the facilities and relevant permits to deal with such complex streams.
The facility is focused entirely on isolating precious metals from aqueous and solvent streams and treating the remaining liquid fractions. This includes tailored processes for precious metal isolation from hazardous streams. It uses three key techniques:
• Precipitation: Metals are selectively separated from solution by converting soluble metal species into insoluble solid compounds, through the formation of a precipitate that can then be separated by filtration.
• Adsorption: Adsorbents selectively recover metals from complex liquid phases. Carbon materials, metal-organic frameworks, biopolymers and resins have all been developed for this purpose.
• Thermal methods, such as thermal reduction
Figure 1 shows how the two installations at Antwerp operate. Typically, organic and solvent streams are routed to Line 1, which uses thermal methods, while aqueous streams and streams with sediment are routed to Line 2, which performs precipitation and adsorption.
This two-line approach enables flexibility in providing the optimal process for any individual stream, while ensuring a completely pure process that is dedicated to precious metals recovery and allows tailored streams to achieve high efficiencies. Waste streams are never mixed to avoid contamination and the work is done in a batch process with full traceability.
Based on laboratory testing, the recovery method that offers the highest efficiency at the most favourable cost is selected. For example, some streams might be suited to both precipitation and adsorption, but the adsorption material might be very expensive, or it might become quickly saturated. In this case, precipitation would be chosen.
Liquid fraction treatment
Once the metal fraction has been removed, the remaining liquid fractions are dealt with appropriately. It is very important that any installations recovering precious
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