Novel Pretreatment Process of Critical Metals Bearing E-Scrap By Using Electric Pulse Disintegration
- 62 Downloads
Recovering various metals, involving minor rare metals, from electronic devices is important for conserving resources and establishing a sustainable society. This paper describes an economically feasible and radical process for such recovery, especially, for Ta concentration from printed circuit boards (PCBs) which is the two-stage electric pulse disintegration (ED) process. Ta capacitors are detached from the PCBs in the first stage, and the sintered Ta contained within the capacitors is liberated from the capacitor in the second stage. It has been indicated that as much as 100% of Ta capacitors was detached from PCBs in nondestructive form in the first stage of ED and that 95% of sintered Ta and MnO2 phases was liberated from covered plastics, which is much higher than the 46% detachment achieved when using mechanical roll crusher. The detailed detachment and liberation mechanisms of both stages were also described, and an upper limit of the solution’s conductivity in the second-stage ED was indicated.
KeywordsElectric pulse disintegration Printed circuit board Ta capacitor Detachment Liberation
This research was financially supported in part under the research project, “High Efficiency Rare Element Extraction Technology Area” organized by the Tohoku University and the Ministry of Education, Culture, Sports, Science and Technology (MEXT). The authors hereby sincerely express their deep gratitude to both the institutions.
- 1.Owada S, Kiuchi Y, Yamagata Y, Tokoro C (1998) Possibility of elemental concentrating from wasted communication PCBs by using device separation. In: Proceedings of MMIJ fall meeting, pp 85–90Google Scholar
- 2.Owada S, Koga C, Kageyama S, Tokoro C, Shiratori T, Yumoto T (2012) Concentration of minor rare metals for wasted cell phones by using novel crushing and device/powder separation. JMMIJ 128(12):626–632Google Scholar
- 3.Ono T, Komuro T, Owada S, Tokoro C (2013) Proposal of an optimum concentration flow to recover minor rare metals from wasted communication PCBs by device separation. In: Proceedings of MMIJ spring meeting, pp 320–321Google Scholar
- 4.Koga C, Goto M, Owada S, Tokoro C (2009) Concentration of minor rare metals from wasted cell phones by device separation—for establishing artificial deposit (reserve to stock) concept. In: Proceedings of MMIJ spring meeting, p PY68Google Scholar
- 7.Owada S, Ohta T, Yamashita T, Oki T (2000) Application of electrical disintegration to coal for better liberation. In: Proceedings of MMIJ spring meeting, no. 2, pp 3–4Google Scholar
- 8.Owada S, Ito M, Ota T, Nishimura T, Ando T, Ymashita T, Shinozaki S (2003) Application of electrical disintegration to coal. In: 22nd international mineral processing congress, Cape Town, South Africa, pp 623–631Google Scholar
- 9.Ito M, Owada S (2004) Novel comminution methods in mineral processing. In: Proceeding of MMIJ fall meeting, no. C/D, pp 173–176Google Scholar
- 13.Hayashi R, Urabe T, Owada S (2011) Electromagnetic field analysis on the behavior of selective breakage at phase boundary in electrical disintegration. In: EcoDesign2011, Kyoto, pp 115–119Google Scholar
- 14.Hayashi R, Owada S (2012) Clarifying liberation mechanism of electrical disintegration by electromagnetic field analysis. In: Int. Min. Proc. Congr., New Delhi, no. 522, pp 01951–01961Google Scholar
- 16.Suzuki R, Kamata Y, Owada S, Nakamura T (2014) Liberation behavior of sintered Ta from Ta capacitors by electric disintegration. In: Proceedings of MMIJ spring meeting, vol 24–26, pp 1–5Google Scholar