As demand for resource recycling becomes increasingly urgent, the metal recycling industry remains constrained by the limitations of traditional sorting. Manual sorting relies on operators' experience and judgment. It is not only inefficient—a single production line often processes less than 1 ton per hour—but also prone to serious errors: stainless steel is sometimes confused with galvanized steel, and brass with pure copper, directly reducing the purity of recycled materials.
Simple physical detection methods such as magnetic separation and eddy current separation can only distinguish ferromagnetic metals from nonferrous metals; they cannot identify metals with different grades or compositions within the same category. As a result, large quantities of high-value rare metals are misclassified and wasted, and operating costs remain high across the industry. These challenges call for more precise and efficient technical solutions. The emergence of hyperspectral imaging has opened new space for development in the metal recycling industry.
Hyperspectral metal sorting
Understand metals at their core and identify their composition
Technical principles: deep fusion of spectra and images
Hyperspectral imaging moves beyond the single dimension of conventional detection by closely combining spectral analysis with image acquisition. Because different metals have distinct atomic structures, their absorption and reflection characteristics vary across wavelengths. By comparing the “spectral information” of each pixel in the data cube with a standard spectral library of known metals, the metal composition and purity of the target object can be accurately identified.
Core advantages: redefining metal sorting standards
Compared with conventional detection, hyperspectral technology offers four core advantages in metal recycling.
1. High detection accuracy: it can identify and distinguish different materials of the same color, such as iron, stainless steel, and aluminum alloy, solving the “fine-grained identification” challenge that conventional methods cannot overcome;
2. Fast detection: a single detection can take as little as milliseconds; paired with an automated conveyor belt, a single hyperspectral sorting line is more than 3 times as efficient as manual sorting;
3. Non-destructive testing: the process requires no contact with the metal surface and no material pretreatment, avoiding scratches and deformation during inspection and preserving the original value of the recycled materials;
4. Adapts to complex surfaces: Even when metal surfaces have rust, oil contamination, coatings, or slight deformation, hyperspectral technology can still penetrate surface interference and capture the spectral signature of the metal itself, solving sorting challenges under harsh conditions such as moisture and contamination.
Hyperspectral technology
Real-world applications in metal recycling
Scrap metal recycling yard: improve sorting purity and value
At small and medium-sized scrap metal recycling facilities, mixed scrap metal often includes steel, aluminum, copper, zinc, and other categories, and traditional manual sorting is prone to misclassification. With a hyperspectral sorting system, material passes along a conveyor into the inspection area. The system can complete spectral acquisition and analysis of each piece of metal within 1 second, mark in real time the positions of different metal categories such as copper, aluminum, and stainless steel, and separate them precisely using a pneumatic sorting device. With the hyperspectral sorting system, the sorting purity of copper materials improves while labor costs fall, and the equipment investment is expected to be recovered within six months.
End-of-life vehicle dismantling: uncovering the "hidden value" in components
During the dismantling of end-of-life vehicles, body frames, engine components, wires, and cables contain various metals. These include aluminum alloys in engine cylinder blocks, copper-nickel alloys in air-conditioning lines, and silver-plated copper wire in wiring harnesses, which traditional methods struggle to identify quickly.
Hyperspectral technology can directly scan dismantled components, quickly distinguish the metal composition of different parts, and enable targeted disassembly and sorted recycling. With a hyperspectral solution, the recovery rate of rare metals such as nickel and silver can increase by more than 15%, and disassembly efficiency improves significantly.
E-waste processing: precise extraction of precious metal resources
E-waste (such as discarded mobile phones and computer motherboards) contains gold, silver, palladium, and other precious metals, but its composition is complex and the concentrations are low. Conventional pyrometallurgical and hydrometallurgical refining is prone to pollution and yields low recovery rates. Hyperspectral technology can scan particles from shredded e-waste one by one, using spectral information to precisely locate metal particles, which are then extracted through downstream processes.
After adopting hyperspectral detection equipment, gold and silver recovery rates increased by more than 40%, while chemical reagent use was reduced and environmental pollution risks were lowered.
Supporting downstream integrators
SPECU provides core equipment and solutions.
To advance the large-scale adoption of hyperspectral technology in metal recycling, SPECU offers downstream integrators full-chain support, from core equipment to complete solutions.
Core equipment: SPECU provides hyperspectral cameras covering different wavelength bands, supporting optical modules, and data acquisition. The devices offer a resolution of 2048 pixels to meet the inspection needs of different metal recycling scenarios;
For solution design, the SPECU team works with integrators' production line layouts to provide customized sorting system solutions. These include equipment installation and commissioning, spectral library development, and software algorithm optimization (such as real-time sorting decision algorithms and false detection correction algorithms). The solutions are designed to be compatible with mainstream industrial control systems and to integrate seamlessly with existing production lines, helping integrators shorten equipment time to market and reduce R&D costs.