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2020 Vol.57, Issue 1

Research Paper

Observability of Invisible Gold using BSE Imagery and Gold Recovery by Microwave-Nitric Acid Leaching

BSE 이미지를 이용한 비가시성 금의 관찰 가능성과마이크로웨이브-질산침출에 의한 금 회수

Jong-Ju Lee1
,
Cheon-Young Park1*
이 종주1
,
박 천영1*
1조선대학교 에너지자원공학과
* Corresponding Author
29 February 2020. pp. 1-11
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Abstract

The aims of this study were to observe invisible gold, including that present in fine minerals, using back scattered electron (BSE) imagery, and to recover gold using microwave-nitric acid leaching experiments of powdered ore samples, including of invisible gold. As it is difficult to observe gold-bearing, fine minerals using a polarized microscope due to its resolution, BSE images and energy dispersive spectrometer (EDS) analyses were used in this study to easily identify brighter, fine minerals containing gold. As a microwave-nitric acid leaching test was applied to the powdered ore samples, arsenopyrite and pyrite were completely decomposed in a very short period of time. Both the nitric-acid leaching solution and insoluble residue were easily filtrated with three filter papers. In the nitric-acid leaching solution, Au was not dissolved at all, whereas Ag, Cu, and Zn were completely leached. When analyzing the insoluble residue, the first filter paper containing fine particles, as well as the second and third filtrated samples were used in the lead-fire assay respectively. All of the gold particles were effectively recovered from the samples during this experiment.

Keywords
Backscattered electron image
invisible gold
microwave-nitric acid leaching
filter paper
lead fire assay

본 연구는 BSE 이미지를 사용하여 미세한 광물에 포함된 보이지 않는 금을 관찰하고, 보이지 않는 금을 포함한 분말 광석 시료에 대한 마이크로웨이브-질산침출 실험을 통해 금을 회수하는 것을 목표로 하였다. 편광반사현미경에서 관찰하기 어려웠던 금 함유 극미립자 광물을 BSE 영상과 EDS 분석을 활용한 결과 금을 함유한 명암이 밝은 광물을 쉽게 확인할 수 있었다. 광석분말 시료를 마이크로웨이브-질산침출실험 한 결과 매우 짧은 시간에 황비철석과 황철석이 완전분해되었다. 질산침출용액과 불용성 잔류물은 여과지로 간단하게 여과할 수 있었다. 질산침출용액에서 Au는 전혀 용해되지 않았지만 Ag, Cu, 및 Zn은 완전하게 침출되었다. 첫 번째 여과지, 두 번째 그리고 세 번째 여과지 자체를 각각 납-시금법에 적용한 결과 이들 모두에서 금이 효과적으로 회수되었다.

키워드
후방산란전자 영상
비가시성 금
마이크로웨이브-질산침출
여과지
납-시금법
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Information
  • Publisher :The Korean Society of Mineral and Energy Resources Engineers
  • Publisher(Ko) :한국자원공학회
  • Journal Title :Journal of the Korean Society of Mineral and Energy Resources Engineers
  • Journal Title(Ko) :한국자원공학회지
  • Volume : 57
  • No :1
  • Pages :1-11
  • Received Date : 2019-11-04
  • Revised Date : 2020-01-03
  • Accepted Date : 2020-02-21
  • DOI :https://doi.org/10.32390/ksmer.2020.57.1.001
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