A circuit board (PCB) grinding production line improves metal and resin separation efficiency by using mechanical comminution, such as shredding and crushing, to break down the boards into smaller, more manageable particles. This particle size reduction is essential for liberating the metal from the non-metallic components, which is a necessary first step before applying subsequent physical separation techniques like electrostatic separation or density-based separation. Optimizing the grinding parameters, such as crusher type and time, can enhance the release of metals and improve the purity of the resulting metal and resin fractions.