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Waste printed circuit boards (WPCBs) are resource-rich but hazardous, demanding innovative strategies for post-consumer collection, recycling, and mining for economically precious constituents. A novel technology for disassembling electronic components from WPCBs is proposed, using hot air to melt solders and to separate the components and base boards. An automatic heated-air disassembling equipment was designed to operate at a heating source temperature at a maximum of 260 °C and an inlet pressure of 0.5 MPa. A total of 13 individual WPCBs were subjected to disassembling tests at different preheat temperatures in increments of 20 °C between 80 and 160 °C, heating source temperatures ranging from 220 to 300 °C in increments of 20 °C, and incubation periods of 1, 2, 4, 6, or 8 min. For each experimental treatment, the disassembly efficiency was calculated as the ratio of electronic components released from the board to the total number of its original components. The optimal preheat temperature, heating source temperature, and incubation period to disassemble intact components were 120 °C, 260 °C, and 2 min, respectively. The disassembly rate of small surface mount components (side length ≤ 3 mm) was 40−50% lower than that of other surface mount components and pin through hole components. On the basis of these results, a reproducible and sustainable industrial ecological protocol using steam produced by industrial exhaust heat coupled to electronic-waste recycling is proposed, providing an efficient, promising, and green method for both electronic component recovery and industrial exhaust heat reutilization.

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CeO 2 (ceria) particles are considered as a type of ideal polishing particle used to polish glass substrate. The friction and wear of glass substrates caused by a single CeO 2 particle is the origin of material removal in polishing, but this has not been well-understood in previous research. In this investigation, the nanoscale friction and wear behaviors of the Nd-doped phosphate laser glass and the BK7 optical glass were quantitatively studied against a single CeO 2 particle by an atomic force microscopy in humid air. The investigations on the phosphate laser glass indicate directly that this type of glass cannot resist the wear when it rubs against the single CeO 2 particle in the elastic contact in humid air. During the test, high friction coefficient and severe material removal were observed in the friction process. The chemical activity of the CeO 2 particle was proved to be a cause that induces the tribochemical wear of the phosphate laser glass since the tribochemical wear cannot occur when a chemically inert diamond tip was used. On the other hand, the BK7 glass presented a much better wear-resistance, where the friction coefficient is relatively lower and the expected tribochemical wear cannot occur in the same stress condition as compared with that for the phosphate laser glass, and the damage of the BK7 glass is more like the mechanical peeling of the asperities on the glass surface. The results provide new insights into single-asperity friction and wear of glass materials, which would be useful in understanding the mechanisms of friction and material removal in polishing glass materials with ceria slurry. J ournalemphasized. The effects of the mechanical and chemical properties of glass on friction and wear were analyzed and the corresponding friction and wear mechanisms were discussed.