This review examines the technological surveillance of photovoltaic panel recycling through a bibliometric study of articles and patents. The analysis considered the number of articles and patents published per year, per country, and, in the case of patents, per applicant. This analysis revealed that panel recycling is an increasingly prominent research area. However, the number of patents filed annually has varied in recent years, averaging fewer than 200 per year. The state-of-the-art review identified three main types of treatment for photovoltaic panel recycling: mechanical, chemical, and thermal. Among these, mechanical treatment serves as a preliminary stage before the recovery of valuable elements, which is achieved through chemical or thermal processes. The articles reviewed cover a range of processes, including hydrometallurgical and pyrometallurgical methods, and explore various classification processes, solvents, and oxidizing agents. In contrast, patents predominantly focus on pyrometallurgical processes. This analysis is supplemented by a survey of market-ready technologies, many of which include stages such as size reduction or delamination followed by pyrometallurgical processes. Additionally, the review highlights the collection processes implemented by some companies, noting that the volume of panels considered waste is currently insufficient to maintain a continuous and year-round operational process. This study identifies key challenges such as (i) reducing solar panel size due to the EVA polymer complicating conventional machinery use, (ii) high process costs from the need for high temperatures and costly additives, (iii) the environmental impact of thermal treatments with high energy consumption and air pollution, and (iv) the necessity for environmentally friendly solvents in hydrometallurgical treatments to reduce contamination during recycling. Future directions include developing specific machinery for panel size reduction, either creating or modifying a polymer to replace EVA for easier treatment, adopting hydrometallurgical treatments with green solvents proven effective in recycling minerals and electronic waste, and addressing the lack of detailed information on industrial processes to make more precise recommendations.

A less harmful approach for the environment regarding chalcopyrite concentrate leaching, using seawater/brine and caliche’s salts as a source of chloride and nitrate ions, was investigated. Different variables were evaluated: sulfuric acid concentration, sodium nitrate concentration, chloride concentration, source of water (distilled water, seawater, and brine), temperature, concentrate sample type, nitrate source (analytical grade and industrial salt), and pre-treatment methods in order to obtain maximum copper extraction. All tests were performed at moderate temperatures (≤45 °C) and atmospheric pressure. The leaching system using distilled water, seawater, and brine base media resulted in copper extraction of 70.9%, 90.6%, and 86.6% respectively. The leaching media, with a concentration of 20 g/L Cl⁻, obtained a maximum Cu extraction of 93.5%. An increase in the concentration of H₂SO₄ and NaNO₃ from 0.5 to 0.7 M, led to an increase in the copper extraction. The use of an industrial salt compared to the analytical salt did not show great variations in the percentage of extraction achieved, which would be a good and cost effective alternative. The increase in temperature from 25 to 45 °C showed a great effect on the copper leaching (of 60% until 90.6%, respectively). The pre-treatment is suggested to increase copper extraction from 60.0% to 71.4%.

The adoption of photovoltaic solar technology for renewable energy generation has been growing rapidly worldwide. In decarbonization processes, the use of photovoltaic panels has been preferred due to their reliability, safety, and efficiency. Specifically, the use of photovoltaic panels has increased significantly in Chile, as the climatic conditions are ideal for photovoltaic solar technology. The expected lifespan of a photovoltaic panel is approximately 25 years, so the amount of photovoltaic waste is projected to rise significantly in the coming decades. Consequently, interest has emerged in establishing policies and processes for recycling and recovering value from photovoltaic waste. The objective of this study is to develop a life cycle assessment (LCA) of the leaching process of photovoltaic modules using nitric acid as a leaching agent and to employ the results to analyze the projected scenario for the Antofagasta region in 2040. Through statistical analysis of currently approved photovoltaic installations, projections were made to estimate the amount of photovoltaic waste and the total value of recyclable material expected to be available in 2040, resulting in an approximate figure of 30,676,367 discarded modules. Simultaneously, a life cycle assessment of the leaching process for photovoltaic waste using nitric acid was conducted using the OpenLCA software. The analysis showed that the proposed process has a high impact on global warming potential (GWP), generating 7.07 kg of CO₂ equivalent per kilogram of photovoltaic cell waste. Finally, an environmental and economic comparative analysis was performed, comparing nitric acid with ionic liquids previously studied by the research group. Preliminary results concluded that nitric acid has a significantly lower environmental impact and production cost.