Recycling technology of precious metals are undergoing critical iterations focused on efficiency, selectivity, and environmental sustainability. DONGSHENG precious metal recyclers have discovered that the core of the latest recycling technologies lies in developing intelligent, precise separation methods. Metal-organic frameworks (MOFs) represent a significant advancement, enabling targeted capture of specific precious metal ions in solutions for efficient separation from complex materials like electronic waste. Another cutting-edge technique adopted by DONGSHENG integrates advanced hydrometallurgy with physicochemical methods. For instance, integrated processes combining membrane separation and selective precipitation significantly enhance the purity and yield of gold and silver recovered from low-concentration waste liquids. Photocatalytic recovery, as a low-energy-consumption novel precious metal recovery technique, is also gaining attention. It utilizes light energy to drive reactions, reducing chemical consumption. The common goal of these latest precious metal recovery technologies is to reduce the energy consumption and chemical footprint of traditional processes. For example, research has optimized ion exchange processes to treat smelting slag leachate, enabling more sustainable metal extraction. These advances mark a shift in precious metal recovery technology from extensive processing to molecular-level precision resource recycling.
Over the past fifteen years, improvements in precious metal recovery technologies by recyclers have primarily manifested in methodological diversification, greening, and adaptability to complex feedstocks. While traditional pyrometallurgical and hydrometallurgical methods remain widely used, new technologies and integrated processes have significantly expanded the boundaries. The table below outlines key evolutionary pathways.
| Period | Technical Focus | Representative Methods | Key Advancements & Characteristics |
|---|---|---|---|
| Around 2010 | Traditional methods dominant | Pyrometallurgy (high-temperature smelting), conventional hydrometallurgy (cyanidation, aqua regia dissolution) | High recovery rates (80-99%), mature processes; however, high energy consumption, significant chemical reagent usage, and notable environmental pollution risks. |
| Around 2015 | Emergence of green solvents and biotechnology | Ionic liquid extraction, bioleaching | Ionic liquids: High selectivity, recyclable, but relatively high cost. Bioleaching: Environmentally friendly, low energy consumption, but longer processing cycles. |
| Around 2020 | Selective recovery and integrated processes | Selective precipitation, solvent extraction, membrane separation | Developed high-selectivity separation technologies for complex secondary resources (e.g., spent catalysts, electronic waste), enabling stepwise recovery of multiple metals and enhancing overall resource utilization rates. |
| 2025 Frontier | Precision Separation and Intelligence | Metal-Organic Frameworks (MOFs) adsorption, photocatalysis, process integration and optimization | MOFs materials: Achieve ion-level precision adsorption through designable pore structures. Process Integration: Intelligently coupling distinct unit operations (e.g., leaching-membrane separation-electrodeposition) and optimizing via process simulation software (e.g., Aspen Plus) to achieve efficient, low-waste precious metal recovery. |
The most widely applied classical precious metal recovery technologies in industry fall into two major categories: pyrometallurgy and hydrometallurgy. Pyrometallurgy relies on high-temperature smelting, processing precious metal-bearing waste (e.g., discarded circuit boards, catalysts) at temperatures exceeding 1200°C to concentrate precious metals in metallic phases or sulfides. This process handles large volumes and is suitable for complex solid wastes, serving as the cornerstone of high-throughput precious metal recovery. Classic hydrometallurgical precious metal recovery centers on chemical dissolution, using aqua regia, cyanide solutions, or hydrochloric acid-chlorine systems to leach precious metals from materials. Metals are then recovered from the solution via displacement, chemical precipitation, or activated carbon adsorption. While hydrometallurgy generates wastewater, its selective dissolution capability makes it irreplaceable for processing specific waste streams. These two classic precious metal recovery technologies continue to play a central role in large-scale smelters and refineries due to their processing capacity, reliability, and cost-effectiveness.
The most environmentally friendly precious metal recovery technologies aim to eliminate pollution at the source and reduce energy consumption. Bioleaching utilizes microorganisms or their metabolic products to leach metals, causing minimal environmental impact and representing a quintessential green precious metal recovery method. Ionic liquid extraction, with its extremely low volatility and reusability, effectively replaces traditional volatile organic solvents, reducing atmospheric emissions during recovery. Supercritical fluid extraction, particularly using carbon dioxide, produces almost no chemical waste and recovers high-purity metals, though it involves higher equipment and energy costs. Additionally, synergistic processing of waste materials offers an innovative approach. For instance, a 2025 study co-melted lead paste with yellow potassium iron sulfate slag at 1200°C, not only recovering silver-rich alloys but also sulfur-fixing the slag to prevent sulfur dioxide generation at the source. These green precious metal recovery technologies share a common characteristic: adherence to green chemistry principles, dedicated to achieving resource regeneration within closed-loop systems. They represent the sustainable future direction for precious metal recovery technology.
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