Review on the role of density-based separation in PCBs recycling

With increasing global demand for metals and escalating concerns about the environmental impact of traditional mining practices, the recycling of electronic waste, particularly waste printed circuit boards (WPCBs), has become a topic of significant interest. Extensive research has explored various methodologies for treating WPCBs. However, a persistent challenge remains in establishing processing conditions that are both economically viable and efficient. The efficiency of metal recovery from WPCBs using pyrometallurgy, hydrometallurgy, and biometallurgy depends on how effectively non-metallic elements are removed during the pretreatment stage. Removing non-metallic elements reduces energy, chemical, and biochemical requirements, and decreases the need for additional purification steps. Improving these pretreatment techniques could result in more costeffective and environmentally sustainable solutions for printed circuit boards (PCBs) recycling, enhancing the efficiency and sustainability of metal recovery processes. This review explores the effectiveness of wet and dry density-based separation techniques for increasing metal content in crushed PCBs particles. It highlights the role of these methods in optimizing metal recovery, reducing waste, and their potential for environmental and economic benefits in PCBs recycling. Advancements in technology and process optimization continue to improve their efficiency and significance in the e-waste recycling industry.