New sieving tech for solar cell silver recovery

<p class="p1"><span class="s1">Researchers at University of New South Wales have reported details about a novel sieving-aids technology that improves the separation of metal fragments from other components when recycling end-of-life PV panels. The patented process reportedly enhances the recovery of silver.</span></p><p>Researchers at the <a href="https://www.pv-magazine.com/2024/04/29/unsw-researchers-warn-of-surprising-topcon-solar-module-vulnerabilities/" rel="noopener" target="_blank">University of New South Wales</a> (UNSW) in Australia reported research details of their improved sieving separation method to enhance the recovery of silver and other metals from end-of-life solar panels. The technology <a href="https://www.pv-magazine-australia.com/2023/07/20/unsw-team-scores-99-result-with-solar-panel-recycling-process/" rel="noopener" target="_blank">has been patented. </a></p>
<p>“The method relies on a simple mechanical sieving process and is enhanced with sieving aids (stainless steel balls), which are low-cost, durable, and widely available,” corresponding author, Yansong Shen, told <strong>pv magazine</strong>, adding that the efficient separation of PV cells from other components facilitates high-value recovery of silicon and other valuable metals, making it “economically attractive.”</p>
<p>The sieving process comes in after the pyrolysis delamination upstream step and before the chemical leaching downstream step for silver recovery.</p>
<p>In the experimental work, the team used monocrystalline silicon PV panels, standard ethylene vinyl acetate (EVA) encapsulants, protective cover glass and a foil back sheet in an anodized aluminum alloy frame.</p>
<p>These were processed via thermal delamination for polymer removal, mechanical separation, and chemical leaching. Then samples were extracted. Measurements of the samples included particle weight and size, as well as scanning electron microscopy (SEM).</p>
<p>“The results indicate that over 96.3 wt.% of the chip-like PV cell particles can be separated from the debris mixture under the optimized sieving conditions using the new sieving aids technology, compared to the separation rate of 31.7% in the conventional sieving methods,” according to the research.</p>
<p>“The leaching result shows that over 98.9% of the silver contained in the PV modules can be recovered by this integrated method,” reported the team.</p>
<p>The research appears in “<a href="https://doi.org/10.1016/j.resconrec.2025.108594">Improving particle separation and recovery of valuable materials from end-of-life solar panels</a>,” published by <em>Resources, Conservation and Recycling.</em></p>
<p>Regarding commercialization potential, Shen said that although the current results were obtained at the lab scale, the method could be developed into a practical product and integrated into industrial PV recycling lines through further optimization and scale-up.</p>
<p>The researchers plan to continue to develop and improve the proposed separation method, with a focus on industrialization, and to investigate the thermal delamination process to develop a more “sustainable and effective approach for polymer removal.”</p>
<p>There is ongoing activity at the national <a href="https://www.pv-magazine-australia.com/2024/07/09/unsw-researchers-eye-redesigned-panel-as-part-of-recycling-plans">Research Hub for Solar Panel Recycling and Sustainability</a> where the researchers work with industry partners to commercialize recycling technology and invent new PV recycling technologies.</p>