DOI QR코드

DOI QR Code

순도가 향상된 금속급 실리콘 제조를 위한 산침출 연구

A Study of Acid Leaching for Metallurgical Grade Silicon Manufacturing Improved Purity

  • 엄명헌 (국립공주대학교 화학공학부) ;
  • 하범용 (영진전문대학 신재생에너지전기계열)
  • Um, Myeong-Heon (Division of Chemical Engineering, Kongju National University) ;
  • Ha, Beom-Yong (Department of Renewable & Electrical Engineering, Yeungjin College)
  • 투고 : 2017.09.21
  • 심사 : 2017.11.03
  • 발행 : 2017.11.30

초록

다양한 산업에 사용되고 있는 금속급 실리콘(MG-Si, Metallurgical grade silicon)을 제조하기 위해 실리콘 원료 내 가장 많이 함유하고 있는 불순물인 알루미늄(Al) 및 철(Fe)을 제거하고자 산(Acid) 침출 실험을 수행하였다. 5가지 종류의 산(HCl, HF, H2SO4, HNO3, H3PO4)을 1, 2, 4, 6M로 조제하여 실리콘 원료에 반응시킨 결과, 1M 농도의 HF가 가장 우수한 Al 및 Fe 제거율을 나타내었으며 각각 97.9%와 95.2로 나타났다. 그러나 HF는 실리콘 부식 특성으로 인해 18% 가량의 수율 감소가 발생하였으며 이러한 수율감소를 최소화하기 위해 두 번째로 제거율이 우수하게 나타난 2M HCl과 혼합하여 실리콘 원료에 적용하였다. 혼합용액의 최적조건을 선정하기 위해 실험을 수행하여 $80^{\circ}C$, 2시간의 침출 최적조건으로 결정되었으며 이 혼합용액의 적용 결과 Al 및 Fe 잔류농도가 각각 141 ppmw 및 93ppmw로 나타나 3N급의 순도를 갖는 금속급 실리콘을 제조하기에 매우 용이한 것으로 확인되었다.

To manufacture MG-Si (Metallurgical grade silicon) for use in various industries, Acid leaching experiments were performed to remove aluminum (Al) and iron (Fe), which are the most common impurities found in the silicon raw material. The silicon raw material was reacted with five types of acids (HCl, HF, H2SO4, HNO3, H3PO4) at 1, 2, 4, and 6M; 1M HF showed the highest Al and Fe removal rates, 97.9% and 95.2%, respectively. HF, however, resulted in an 18% reduced yield due to the silicon corrosion properties. To minimize the yield reduction, 2M HCl, which has a second removal ratio result, was mixed with 1M HF and applied to the silicon raw material. The experiment was conducted to select the optimal conditions for the mixed solution, which were $80^{\circ}C$ and 2hr. Under the optimal conditions, the residual Al and Fe concentrations were 141 ppmw and 93 ppmw, respectively, and it very easy to produce MG-Si with 3N grade purity.

키워드

참고문헌

  1. M. S. Lee and D. H. Kim, "Removal of Impurities from Metallurgical Grade Silicon by Acid Washing", J. of Korean Inst. of Resources Recycling, vol. 20, no. 1, 61-68, 2011. DOI: https://doi.org/10.7844/kirr.2011.20.1.061
  2. B. R. Bathey and M. C. Cretella, "Review, Solar-grade silicon", J. of Materials Science, vol. 17, no. 11, 3077-3096, 1982. DOI: https://doi.org/10.1007/BF01203469
  3. Y. C. Yang, S. B. Jeong, Y. B. Chae and S. Kim, "Preparation of High-grade Silica Sand for Metallurgical-grade Si Using a Physical Beneficiation", J. Miner. Soc. Korea, vol. 22, no. 3, 191-197, 2009.
  4. J. H. Eum, H. S. Chang, H. T. Kim and K. Choi, "Silicon Purification through Acid Leaching and Unidirectional Solidification", J. of the Korean Crystal Growth and Crystal Technology, vol. 18, no. 6, 232-236, 2008.
  5. J. M. Junegia and T. K. Mukherjee, "A Study of the Purification of Metallurgical Grade Silicon", Hydrometallugy, vol. 16, no. 1, 69-75, 1986. DOI: https://doi.org/10.1016/0304-386X(86)90052-6
  6. C. E. Norman, R. E. Thomas, and E. M. Absi, "Solar-grade Silicon Substrates by a Powder-to-ribbon Process", Can. J. Phys., vol. 63, no. 6, 859-862, 1985. DOI: https://doi.org/10.1139/p85-139
  7. T. L. Chu and S. Chu, "Partial Purification of Metallurgical Silicon by Acid Extraction", J. Electrochem. Soc., vol. 130, no. 2, 455-457, 1983. DOI: https://doi.org/10.1149/1.2119730
  8. I. C. Santos, A. P. Gongalves, V. C. Silva Santos, M. Almeida, M. H. Afonso and M. J. Cruz, "Purification of metallurgical grade silicon by acid leaching", Hydrometallurgy, vol. 23, no. 2/3, 237-246, 1990. DOI: https://doi.org/10.1016/0304-386X(90)90007-O