Circular Materials has developed a patented technology, based on the properties of supercritical water, designed to effectively remove and recover metals from water. This innovative process also allows the oxidation of most organic matter (COD) and cyanides (>99.5%) to return a demetallized liquid that is easy to treat and can be routed to existing physicochemical plants without sludge production or at a much lower cost than the cost of disposing of the original untreated effluent.

Circular Materials' plant is designed to facilitate the precipitation of metal ions in solution, enabling the direct recovery of metals in industrial wastewater with 99% efficiency. The liquids to be treated are mixed with supercritical water (T>374 °C and P>221 bar) in a patented mixer where an instantaneous precipitation occurs. The dissolved metals behave as they would in an apolar liquid and form nucleation sites that grow in clusters to become nano- or microparticles.

The extreme reduction in the dielectric constant of water under supercritical conditions (εRT=77 → εSC=2) drastically reduces the solubility of metal ions, causing them to precipitate into finely dispersed powders. The speciation of the product (oxide, hydroxide, metal) is determined by the redox and pH conditions, process parameters that are easily controlled through 'recipes' developed by Circular Materials engineers according to customer requirements.

The suspension is finally cooled, and the heat is recovered through exchangers while the pressure is restored to ambient pressure. The liquids then enter a separation process, where the solid is recovered for utilization. The water can then be sent to the normal chemical-physical purification process without dissolved metals or complex organic forms, drastically simplifying its treatment.