Speciality Chemicals Magazine MAY / JUN 2026 | Page 66

CATALYSTS

metals also have the ability to deal with these liquid fractions, which may make up 95 % or more of the liquid stream by volume( see case studies).

In the case of solvent streams, developments in available technologies enable the efficient and sustainable of solvent recycling processes. 3 Valuable solvents can also be further purified and reused, while hazardous components are safely destroyed. Companies can typically expect to recover up to 95 % of used solvents, even from more complex mixtures. In terms of quality and purity, recovered solvents are equal to virgin material.

Conclusion

The recovery and recycling of precious metals and solvents improves process efficiency, saves costs and simplifies the supply chain by eliminating the need to constantly purchase new materials. It also brings considerable environmental benefits as it reduces the need for polluting mining activities and demonstrates up to 98 % reduction in carbon footprint.

By developing and applying tailored processes for precious metal isolation from hazardous solvent-or aqueousbased streams, techniques like precipitation, adsorption and thermal methods enable the efficient recovery of precious metals, even at very low ppm concentrations. This is helping to drive advances in recycling technology and increase demand for recycled materials, thus closing the loop on precious metals and clearing the path towards a circular economy. ●

In one example, a customer needed to extract palladium from organic waste that included 600 ppm of palladium. Thermal reduction on Line 1 resulted in a ~ 5 % metal fraction, which manifested as semisolid with high precious metal concentration. The metal fraction was thermally treated and resulted in 0.1-0.3 % volume of platinum group metal-rich ashes with ~ 30 % palladium.

Meanwhile, the remaining liquid fraction, which comprised 94- 96 % of the mixture, comprised solvent with minor impurities, so it was possible to also recycle the solvents from the mixture, providing a full circular process for the entire waste stream.

Another customer needed to extract palladium from an organic aqueous mixture that included 30 ppm of palladium. Treatment on Line 2 resulted in a 2 – 5 % metal fraction in the form of a dry powder with high precious metal concentration. The metal fraction was thermally treated and resulted in 1 – 3 % palladium-rich ashes.

Meanwhile, the remaining liquid fraction, an aqueous solvent mixture that comprised 95 – 98 % of the original volume, was treated on the on-site waste to energy installation, maximising energy recovery and safe destruction of hazardous components.

66 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981