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.

This research evaluates the modification of the lithium carbonate (Li₂CO₃) production process and particularly the boron removal step, which currently employs a recirculated stream. This recirculated stream is a liquor with low boron content but rich in lithium, currently being wasted. In this process, the recirculating stream is substituted with a freshwater stream. Boron is re-extracted from the loaded organic stream to form an input stream for a boric acid process. Under certain operational conditions, the formation of emulsions was observed; due to this, the analysis of emulsion formation involved controlling the pH of each sample, which lead to the development of a procedure to prevent such formations. From this analysis, it was determined that emulsions form in water with pH values below 1.3 and above 6.9. In addition, a speciation analysis showed that the concentrations of the H₂BO₃⁻ and H⁺ species influence the formation of emulsions. The mass balance of the process showed that by replacing the recirculated stream, boron recovery of 89% was achieved, without the need to add new stages or equipment.

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.

This study focuses on the thermodynamic modeling of the crystallization by the drowning process for two lithium salts: lithium hydroxide (LiOH) and lithium formate (CHLiO₂). The modeling involves utilizing thermodynamic properties, such as the activity, osmotic, and solubility coefficients, within the ternary systems of LiOH + cosolvent + water and CHLiO₂ + cosolvent + water, as well as their respective binary constituent systems. Ethanol is chosen as the cosolvent for both salts, facilitating a comparative analysis. Given the limited availability of thermodynamic data for lithium formate with different cosolvents, the study aims to address this gap. The modified Pitzer model was employed for the modeling process, where the parameters were successfully obtained for both systems, with a deviation of less than 1%. Additionally, the mass and energy balance for the drowning-out crystallization process of both salts was performed.

The accelerating global demand for cobalt, driven primarily by lithium-ion batteries, has intensified the search for alternative sources of supply. Mine tailings represent a promising secondary resource, particularly in regions with extensive mining histories such as Chile. This study evaluates cobalt leaching from copper tailings using a deep eutectic solvent (DES), choline chloride–citric acid (ChCl–CA), with controlled addition of hydrogen peroxide. The tailings were subjected to pretreatments (froth flotation, chlorination, and thermal roasting) and then leached with choline chloride–citric acid-based DES or H₂SO₄. Temperature, leaching time, and solid–liquid ratio were evaluated. Results show that roasting significantly enhanced cobalt recovery when followed by citric acid or DES leaching, reaching up to 100% Co recovery. Under optimized conditions, DES-based leaching was effective and selective in a polymetallic matrix and achieved recoveries comparable to or better than acid leaching without generating toxic emissions. Although flotation and chlorination had limited effects on overall recovery, the results demonstrate the viability of integrated and cleaner technologies for valorizing tailings that contain critical metals such as cobalt.