High-Tc superconducting high gradient magnetic separator using solid nitrogen cooling system for purification of CMP wastewater

Jung Bin Song, Kwang Lok Kim, Donggyu Yang, Young Gyun Kim, Jongseok Lee, Min Chul Ahn, Haigun Lee

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17 Citations (Scopus)


This paper presents recent progress in the fabrication and test of a 3 T/60 mm room temperature bore high-Tc superconducting high gradient magnetic separator (HGMS) using a solid nitrogen (SN2) cooling system. The aim of the study was to develop an inexpensive, compact, and stable superconducting HGMS for the purification of chemical-mechanical-planarization wastewater in the semiconductor industry. The HGMS's magnet, which was cooled by SN2, was comprised of an assembly of 18 GdBCO double pancake coils, each of which was wound without turn-to-turn insulation. Cooling test results showed that the thermal stability of the high-Tc superconducting-HGMS magnet with SN2 was enhanced due to the large heat capacity of SN2. Moreover, in the filtration tests, the suspended solids value of filtrated wastewater at 2 T in a flow rate of 400 ml/min decreased to 1.6 mg/L, resulting in a 99.6% reduction in SS value compared to raw wastewater.

Original languageEnglish
Article number6491455
JournalIEEE Transactions on Applied Superconductivity
Issue number3
Publication statusPublished - 2013 May 22



  • Chemical-mechanical-planarization
  • GdBCO
  • high gradient magnetic separator (HGMS)
  • solid nitrogen (SN2)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

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