몽골 광산폐기물로부터 유가자원의 품위 향상 및 회수에 관한 연구

Abstract

The purpose of this study was to investigate the possibility of eco-friendly and efficient recovery of valuable resources such as gold from Mongolian mine wastes, which are environmental pollutants in the Mongolian mine sector. For the purpose, this study selected 4 samples of mine tailings in the Mongolian mine sector and carried out a froth flotation test to concentrate the valuable resources in the tailings. A microwave nitric acid leaching test was conducted to secure higher gold content in the concentrate obtained by the froth flotation test and effective leaching of valuable resources except gold, and a chloride leaching test was conducted to recover the gold in the test residue. The content of gold in selected tailings samples was 0.56 ~ 5.13 g/ton and as a result of the froth flotation test, the recovery rate of the concentrate was 85.59 ~ 95.38 %. The enrichment ratio was 21.87 ~ 67.39 times based on the weight ratio, and the gold grade in the concentrate increased to 21.45 ~ 45.67 times. It indicates that gold in the tailings existed invisibly in sulfide minerals. The results of the TCLP test conducted to determine the harmlessness of the tailings obtained after the froth flotation test showed that there was no leaching of heavy metals such as As, Se, and Cd, Pb and but it was below the environmental standard although Pb was leached. As a result of the microwave nitric acid leaching test, it was discovered that the gold content in the leaching residue increased to 5.39 ~ 57.58 %, the leaching rate of valuable resources was 22.74 ~ 100.00 % in Ag, 51.78 ~ 94.80 % in Fe, 69.95 ~ 97.82 % in Cu, 94.44 ~ 98.04 % in Zn and 98.96 ~ 100.00 % in Pb. The microwave nitric acid leaching test through the chloride leaching test showed that the leaching rate of the gold in the residue was 76.76 ~ 100%. As a result of this study, it was confirmed that the possibility of valuable resources recovery was positive when a combined process of froth flotation, microwave nitric acid leaching and chloride leaching was applied to the mine tailings in the Mongolian mine sector.