Optical sorting technology for fast selection of metals in recycling process.

An Italian research Institute with specific expertise in optical systems for scientific and industrial applications has developed an innovative technology system for metals sorting. Traditional metal sorting systems are based on the separation of metals from the mixed scrap metal stream or the mixed multi-material waste stream. In automated recycling operations, magnets and sensors are used to aid in material separation. At the entrepreneurial level, scrappers may employ a magnet, and may also observe the material color or weight to help in determining the metal type. For example, aluminum will be silver and light. Other important colors to look for are copper, yellow (for brass) and red (for red brass). However, all the methods currently used have a shortfall: they are not strictly selective and they can be more selective only by the synergistic use of multiple technologies. The technology offered uses the spectral emission from the plasma generated by the melting, vaporization and ionization processes of materials obtained by focusing powerful laser pulses on the surface of the metals. The laser system can be coupled with a very fast and highly efficient image processing system that combines hyperspectral imaging and highly selective spectroscopy with a robust algorithm for data analysis. The spectroscopic analysis of the radiation emitted by the plasma is therefore applied to identify specific spectral features characterizing different materials so as to allow their accurate identification and selection to be carried out. The system results are particularly effective if applied on a wide (1-2 m) conveyor belt running at high speed (several meters per second) on which the material is distributed as a single layer in relatively small pieces. The selection apparatus, in this case the spectroscopy equipment, observes a transverse line of the belt and correspondingly a hyperspectral image can be recorded giving for each point on the conveyor belt imaged the corresponding spectrum. The operation efficiency of the system relies on the image-processing unit and in particular on the identification procedures and data processing. International partnerships are sought for developing the technology at industrial level, and bring it to the market by companies manufacturing material sorting systems. Companies operating in fields like waste processing systems, systems for material sorting (metal, plastic, wood), optical and spectroscopic analysis and processing methods are preferential partners. The institute is looking for partners to cooperate via financial agreement and license agreement.