Detailed information was gathered concerning the bulk weight of inputs and the level of impurities present. In addition, the precise nature of the final-output material was decided upon in consultation with the client.
Having clarified the inputs and determined the specified outputs, TOMRA's engineers devised an optimum solution which called for the deployment of an AUTOSORT™unit working alongside a COMBISENSE™ unit. This particular sorting configuration, which could be run in either online- or batch-processing modes, employed an array of detection technologies such as color line cameras, metal sensors and visual spectrometers capable of working flexibly and interactively to recover the specified scrap components.
The role of the AUTOSORT™ unit was to sort a throughput of plastics according to polymer type. Via a one-step process, the AUTOSORT™'s specification allows for a material flow of 1-3 t/h/m, producing recovered granule sizes of 20-80mm. Location testing showed the machine output delivered ABS fractions with a purity of 95%, and PP fractions with a purity of 93%.
The task of sorting and recovery of metals was delegated to a COMBISENSE™ unit, primarily to recover high-value fractions of copper and aluminum. Likewise operating a one-step process, each COMBISENSE™ machine can deliver a throughput of 1-3 t/h/m whilst outputting fractions in the 10-60mm range. The outcome of location tests demonstrated that COMBISENSE™ sorting of e-scrap materials could recover copper fractions of 99% purity, and aluminum fractions with a purity of 98%.
Advantages and benefits of the new set-up
The TOMRA-designed application was able to deliver an increased-value final product resulting in a considerable boost to the profitability of the sorting process. MERC's new equipment consistently recovers ABS and PP polymers as plastic granules which are virtually metal-free. Consequently, these fractions now attract a price which is five times higher than the mixed plastics recovered via the previous method. In addition, the process now ensures there is only a minimal loss of valuable metals. As a direct result, the copper and aluminum products recovered via the sensor-based sorting process are significantly upgraded in quality, thus adding further to the profitability of the scheme.
Sintaek Lee, MERC’s Chief Operating Engineer, comments: “We are very pleased to work with TOMRA Sorting. With TOMRA Sorting we are able to achieve the high quality product for market demand, while also minimizing the product losses. The additional benefit is a very stable plant operating for both, sorting performance and minimizing production interruptions."
The upgraded sorting performance which the new TOMRA equipment facilitates brings the MERC plant fully in line with the Korean government's policies of 'environmental preservation' and development of a 'resources recirculation society'. MERC's advanced recycling process now makes an important contribution to Korea's Eco-Assurance targets which measure the impact of environment-friendly recycling.