Metal Recovery through the Stripping Plant

13 September 2023 | Corporate

A Concrete Example of Circular Economy in Action

The stripping plant, designed for the removal of metals from the surface layer, was conceived in response to Valmet’s desire to qualitatively and quantitatively expand its metal recovery capabilities, while simultaneously embodying the circular economy paradigm. The idea is simple: economically and sustainably recover surplus inventory and production waste, using renewable energy, in a closed-loop system without consuming water and reintroducing all constituent materials back into the production chain.

Valmet Refining began developing this concept through a dynamic, versatile, and ever-evolving plant designed to improve itself year after year, both in production performance and in reducing consumption and environmental impacts.

Recovery Methods
There is widespread interest in recovering specific waste materials, such as fashion accessories coated with precious metals but composed internally of metals originally considered of lower value and later reevaluated by the same market, such as copper and its alloys (zinc and brass). For this reason, the stripping plant primarily processes materials from the electroplating sector, fashion industry, and bijou world, where surplus inventory, discarded products, test samples manipulated or damaged, and defective or imperfect items are sourced.

How It Works
Through a fully automated system, the precious external coating is separated from the substrate through chemical or electrochemical reactions and a washing phase. Afterward, the metals forming the matrix are ready to be reintroduced into the market. Thanks to the adoption of a management program with dedicated software, operators never come into direct contact with solutions and reagents during the various stages that enable metal recovery. Objects and precious surface metals exiting the process are stored in designated areas and then subjected to further refinement or direct re-entry into the market, depending on their type and composition.

Progress is being made on two fronts: the first is bureaucratic, aiming to obtain the end-of-waste (EOW) qualification for metals exiting the process. As explained earlier, these are valuable metals that do not fit the “waste” label, so legal tools are being utilized to bridge the gap between technological advancement and regulatory compliance. The other project aims to make the plant even more sustainable and self-reliant by sourcing water and energy from internal production and recovery.