The paper presents an assessment of flotation efficiency in the separation of plastics from metals derived from printed circuit boards (PCBs). The PCBs were ground in a knife mill prior to flotation. The contact angles of various materials corresponding to the grains from ground PCBs were measured, and a series of flotation tests was carried out to obtain the best product. The impact of the following parameters were investigated: the reagent and its dose, the airflow rate through the flotation tank and the feed concentration. The highest efficiency of metal recovery from PCBs was achieved for Dimethoxy dipropyleneglycol at a concentration of 157 mg/dm3 and with an airflow of 200 dm3/h and a feed concentration of <50 g/dm3. In the hydrophilic product (concentrate), it was mainly Cu (40%) and Sn (7.8%) that were identified by means of XRF, but there were also trace amounts of precious metals such as Au (0.024%), Ag (0.5797%) and Pd (149 ppm). Impurities in the form of Si (5%), Ca (3.2) and Br (2.1) were also identified in this product. Small amounts of metals in their metallic form were identified in the hydrophobic product (waste), mainly Cu (2.3), Al (1.7) and Sn (1.1). As a result of the research, high recovery ratios were obtained for Cu (93%), Sn (84), Ag (83) and Au (69). The purity of obtained metal concentrate with this method was lower in comparison with the other methods of the recovery of metals from ground PCBs for the same feed, i.e. electrostatic or gravity separation. Also considering other factors such as the environmental impact of the flotation process, the number of facilities and their energy consumption, this process should not be used in the developed metal recovery technology. Using electrostatic separation for the same feed obtained much better results.

The paper presents the financial potential of recycling waste electronic equipment (WEE) in the form of printed circuit boards, hard drives, and lithium-ion batteries. Metal contents in selected types of WEE were presented, as well as their price and importance from an environmental, economic, and geopolitical perspective using indicators of relative supply risk and abiotic depletion potential (ADP). The potential benefits that recycling can bring to the company and the environment were presented. Furthermore, the mass balance and value of recovered metals were estimated for southern Poland, and potential possibilities for the management of the remaining separation products were presented. Finally, verified physical recycling methods for the presented WEE were described.

This article presents a technology for the physical recycling of printed circuit boards (PCBs) that is consistent with the principles of circular economy and sustainable production. A life cycle assessment (LCA) was performed for PCB recycling using shredding, grinding, and physical and physicochemical processes such as electrostatic separation, gravity separation, and flotation for the separation of metals and plastics. Based on this assessment and the selectivity criterion, electrostatic separation was found to be the best separation method, followed by shredding and cryogenic grinding. For this option, the yield of metals and plastics was 25.1% and 72.5% of feed, respectively, while the yield of the middling’s product (mixture of metals and plastics) was only 2.4%. Furthermore, the financial benefits of recycling, including economics of the business case and the environmental benefits are presented. The possibility of using non-metallic fraction (plastic) generated during recycling as an additive in the production of composite materials was also assessed. The results suggest that low filler contents (2.5–5%) provide a compromise between maintaining mechanical performance and improving hardness and tribological properties. Physical recycling technology is a pretreatment method for WPCB, complementing conventional chemical recycling methods. The global warming potential for the entire physical and chemical process is then lowered by about 70%, due to the smaller mass of input material going to the downstream metallurgical processes.

The article presents a technology for the physical recycling of printed circuit boards (PCBs) that is consistent with the principles of circular economy and sustainable production. A Life Cycle Assessment (LCA) was performed for PCB recycling using shredding, grinding and physical and physicochemical processes such as electrostatic separation, gravity separation and flotation for the separation of metals and plastics. On the basis of this assessment and the selectivity criterion, electrostatic separation was found to be the best separation method used after shredding and cryogenic grinding. Furthermore, the financial potential of recycling and other benefits that recycling can bring to the economics of the business and to the protection of the environment were presented. The possibility of using non-metallic fraction (plastic) generated during the recycling as an additive in the production of composite materials was assessed. The functional properties of the composite were assessed (static tensile, hardness, pin-on-disc, and Schopper-Schlobach abrasion tests), as well as the ecotoxicity of the powder added to polymeric materials such as polyester and epoxy resins, and silicone, used in the production of consumer goods.

The paper presents the financial potential of recycling waste electronic equipment (WEE) in the form of printed circuit boards, hard drives, and Lithium-ion batteries. The metal contents in selected types of WEE were presented, as well as their price and importance from an environmental, economic, and political perspective using the indicators of relative supply risk and abiotic depletion potential (ADP). The potential benefits that recycling can bring to the company and the environment were presented. Furthermore, the mass balance and value of recovered metals were estimated for southern Poland and potential possibilities for the management of the remaining separation products were presented. Finally, verified methods for physical recycling of the presented WEE were described.