Economic and Environmental Geology (자원환경지질)

The Korean Society of Economic and Environmental Geology (대한자원환경지질학회)
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Improvement of Au Leaching from Gold Concentrates Using a Microwave and Thiourea-mixed Solvent

마이크로웨이브를 이용한 금정광 내 금 용출 효율 증가 기작

  • 김봉주 (한국원자력연구원 방사성폐기물처분연구부) ;
  • 권장순 (한국원자력연구원 방사성폐기물처분연구부) ;
  • 고용권 (한국원자력연구원 방사성폐기물처분연구부) ;
  • 박천영 (조선대학교 에너지.자원공학과)
  • Received : 2020.03.15
  • Accepted : 2020.04.13
  • Published : 2020.04.28
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Abstract

In this research, we investigate the effect of microwave pretreatment on the recovery of gold from the gold concentrates by thiourea leaching. The changes in mineral phases by decomposition of pyrites in the gold concentrates using microwave were observed, and the result of microwave irradiation showed that the temperature of the irradiated sample increases with increasing irradiation time. With the reaction of temperature increases, Sulfur (S) in pyrites was converted to sulfur dioxide (SO2), and then the content of S in the sample was reduced. The analytical results of XRD and SEM-EDS showed that pyrites are converted to magnetite and hematite, and its surfaces are changed to a porous shape where micro-cracks are developed. The Au leaching efficiency from the irradiated gold concentrates using thiourea-mixed solvent increased with the increases of irradiation time and solvent concentration. The experimental results considering leaching parameters indicate that the mechanism of microwave irradiation increases the maximum leaching efficiency and leaching rate of the gold concentrates, and the solvent does a role for the increasing of leaching rate constant.

본 연구에서는 금정광내 금회수율을 증진하고자 마이크로웨이브 전처리방법을 이용하여 티오요소용출 실험을 수행하였다. 이에 본 연구에서는 먼저 마이크로웨이브를 이용하여 금정광 시료 내 황철석의 분해에 따른 광물상 변화를 관찰하였다. 마이크로웨이브의 조사시간이 증가함에 따라 시료의 온도는 증가하였고, 황철석 내 S가 SO2로 변환되어 시료 내 S의 함량이 감소되었다. X-선 회절분석 및 주사전자현미경 에너지 분산 분광분석을 통해 황철석은 자류철석과 적철석으로 변환되었으며, 미세균열이 발달된 다공질의 형태로 변질되었음을 확인할 수 있었다. 다양한 조건의 티오요소 혼합 용매를 이용하여 시료의 광물상변화에 따른 금 용출효율을 측정한 결과, 마이크로웨이브 조사시간 증가 및 용출실험 조건 내 용매의 농도 증가에 따라 용출효율이 증가하였다. 결론적으로, 마이크로웨이브를 활용한 금정광 조사는 시료 내 금의 최대용출효율과 용출속도를 증가시켰으며, 티오요소 용매제는 용출속도상수를 증가시켜주는 역할을 하였다.

Keywords

References

  1. Allan, G.C. and Woodcock, J.T. (2001) A review of the flotation of native gold and electrum, Minerals Engineering, v.14, p.931-962. https://doi.org/10.1016/S0892-6875(01)00103-0
  2. Almeida, M.F. and Amarante, M.A. (1995) Leaching of a silver bearing sulphide by-product with cyanide, thiourea and chloride solutions. Minerals Engineering, v.8, p.257-271. https://doi.org/10.1016/0892-6875(94)00124-U
  3. Amankwah, R.K. and Pickles, C.A. (2009) Microwave roasting of a carbonaceous sulphidic gold concentrate, Minerals Engineering, v.22, p.1095-1101. https://doi.org/10.1016/j.mineng.2009.02.012
  4. Amankwah, R.K., Khan, A.U., Pickles, C.A. and Yen, W.T. (2005) Improved grindability and gold liberation by microwave pretreatment of a free-milling gold ore, Mineral Processing and Extractive Metallurgy(Trans. Inst. Min. Metall. C), v.114, p.C30-C36.
  5. Aylmore, M.G. (2001) Treatment of a refractory goldcopper sulfide concentrate by copper ammoniacal thiosulfate leaching Minerals Engineering, v.14, p.615-637. https://doi.org/10.1016/S0892-6875(01)00057-7
  6. Coetzee, L.L., Theron, S.J., Martin, G.J., Juan-David van der Merwe and Stanek, T.A. (2011) Morden gold deportments and its application to industry, Minerals Engineering, v.24, p.565-575. https://doi.org/10.1016/j.mineng.2010.09.001
  7. Deng, T.L., Liao, M.X., Wang, M.H., Chen, Y.W. and Belzile, N. (2001) Enhancement of gold extraction from biooxidation redidues using an acidic sodium sulphite-thiourea system, Minerals Engineering, v.14, p.263-268. https://doi.org/10.1016/S0892-6875(00)00181-3
  8. Filmer, A.O. (1982) The dissolution of gold from roasted pyrite concentrate, Journal of the South African Institute of Mining and metallurgy, March, p.90-94.
  9. Haque, K.E. (1999) Microwave energy for mineral treatment processes-a brief review, International Journal of Mineral Processing, v.57, p.1-24. https://doi.org/10.1016/S0301-7516(99)00009-5
  10. Huang, J.H. and Rowson, N.A. (2001) Heating characteristics and decomposition of pyrite and marcasite in a microwave field, Minerals Engineering, v.14, p.1113-1117. https://doi.org/10.1016/S0892-6875(01)00117-0
  11. Kim, E.J. and Batchelor, B. (2009) Macroscopic and X-ray Photoelectron Spectroscopic Investigation of Interactions of Arsenic with Synthesized Pyrite, Environmental Science & Thchnology, v.43, p.2899-2904. https://doi.org/10.1021/es803114g
  12. Kingman, S.W., Jackson, K., Bradshaw, S.M., Rowson, N.A. and Greenwood, R. (2004) An investigation into the influence of microwave treatment on mineral ore comminution, Powder Technology, v.146, p.176-184. https://doi.org/10.1016/j.powtec.2004.08.006
  13. Kingman, S.W., Vorster, W. and Rowson, N.A. (2000) The influence of mineralogy on microwave assisted grinding, Minerals Engineering, v.13, p.313-327. https://doi.org/10.1016/S0892-6875(00)00010-8
  14. Li, J. and Miller, J.D. (2006) A review of gold leaching in acid thiourea solutions. Mineral processing & Extractive Meatall. Rev., v.27, p.177-214. https://doi.org/10.1080/08827500500339315
  15. Ma, S.J., Luo, W.J., Mo, W., Su, X.J., Liu, P. and Yang, J.L. (2010) Removal of arsenic and sulfur from a refractory gold concentrate by microwave heating, Minerals Engineering, v.23, p.61-63. https://doi.org/10.1016/j.mineng.2009.09.018
  16. McGill, S.L., Walkiewicz, J.W. and Clark, A.E. (1995) Microwave heating of chemicals and minerals, United States Department of the Interior, Bureau of Mines, RI 9518, Report of Investigations/ 28p.
  17. Mclaughlin, J. and Agar G. E. (1991) Development and application of a first order rate equation for modeling the dissolution of gold in cyanide solution, Minerals Engineering, v.4, p.1305-1314. https://doi.org/10.1016/0892-6875(91)90174-T
  18. Olubambi, P.A., Potgieter, J.H., Hwang, J.Y. and Ndlovu, S. (2007) Influence of microwave heating on the processing and dissolution behaviour of low-grade complex sulphide ores, Hydrometallurgy, v.89, p.127-135. https://doi.org/10.1016/j.hydromet.2007.07.010
  19. Pickles, C.A. (2009) Microwave in extractive metallurgy: part2-a review of applications, Minerals Engineering, v.22, p.1112-1118. https://doi.org/10.1016/j.mineng.2009.02.014
  20. Robinson, J.J. (1988) The extraction of gold from sulhidic concentrates by roasting and cyanidation, J. S. Atr. Inst. Metall., v.88, p.117-130.
  21. Swash, P.M. (1988) A mineralogical investigation of refractory gold ores and their beneficiation, with special reference to arsenical ores, J. S. Afr. Min. Metall., v.88, p.173-180.
  22. Uslu, T. and Atalay, U. (2003) Microwave heating of coal for enhanced magnetic removal of pyrite, Fuel Processing Technology, v.85, p.21-29. https://doi.org/10.1016/S0378-3820(03)00094-8
  23. Uslu, T., Atalay, U. and Atol, A.I. (2003) Effect of microwave heating on magnetic separation of pyrite, Colloids and Surface, v.225, p.161-167. https://doi.org/10.1016/S0927-7757(03)00362-5
  24. Vorster, W., Rowson, N.A. and Kingman (2001) The effect of microwave radiation upon the processing of Neves Corvo copper ore, International Journal of Mineral Processing, v.63, p.29-44. https://doi.org/10.1016/S0301-7516(00)00069-7