The increasing amount of electronic waste (e-waste) has placed significant burdens on society and the environment, particularly with regards to waste printed circuit boards (WPCBs), which are essential in electronics manufacturing. As natural resources become scarce, it is crucial to effectively recycle and reclaim WPCBs due to their high value and large output. Comminuting printed circuit boards is a crucial step in enabling the recovery of valuable materials, and this review provides an in-depth analysis of WPCB comminution. It explores the structure, types, and composition of the WPCBs, including their mechanical properties. The review thoroughly surveys conventional mechanical comminution machinery and also discusses emerging technologies such as innovative pretreatment approaches, electrodynamic disintegration, high voltage electrical pulses, and abrasive waterjet cutting. The literature has been critically examined to identify research gaps and inconsistencies, and future directions for increased efficiency and sustainability are proposed.

A study was carried out in the framework of international R&D Project to determine the effect of water quality changes due to mine backfilling on talc flotation performance. The influence of two types of cemented paste backfill (Shotcrete and backfill) on flotation process water was investigated using the indoor soaking method, and the water quality was evaluated through water chemistry analysis, in addition to measuring pH, conductivity, and zeta potential as a function of soaking time. At the same time, talc batch flotation tests were performed using a KHD Humboldt Wedag lab cell for a period of 20 minutes. Soaking water at different soaking times was used as a process water for flotation, and tap water was also used to establish a reference response. Based upon the experimental results from the talc flotation and the several water quality parameters measured in the soaking water, conclusions were drawn.