Acid/Alkali Recovery & Metals

The chemical stability of Aemion™ across the full pH scale (0-14) helps to unlock the recovery and reuse of various strong chemicals, previously constrained by the chemical stability of common AEMs.

Recovery of spent acids from various industrial applications, such as the pickling process in steel production and leaching solutions in mining and recycling, can reduce overall operating costs by decreasing raw material and disposal costs. It will also lead to increased productivity by reducing the downtime associated with dumping and recharging of acid baths. There is a large, pent-up demand for acid recycling with only a fraction of the spent acids today being recycled, and global environmental regulations are becoming ever more stringent.

In diffusion and electro dialysis of spent acids, waste acid and clean water streams are separated by an anion exchange membrane, where anions (SO₃^2–, Cl^–, etc.) are transported through the AEM leaving behind the unwanted metal salts. The driving force for diffusion dialysis is the concentration gradient between the two liquid streams, while in electrodialysis, an electric potential is imposed across the streams to further promote separation.

Traditionally, caustic recovery or generation has been more difficult due to insufficient membrane stability limiting the alkalinity of feeds and products. Aemion™ is stable in strong alkaline and enables direct treatment of alkaline waste streams without neutralization to recover valuable products. This increases resource efficiency for industries such as pulp & paper, electronics manufacturing, textiles and carbon-capture.