Poster (EARTH)

[PE1-035] Synergistic effects of aluminum and other conductive particles on the cementation of gold ions from ammonium thiosulfate solutions

○Sanghee Jeon¹, Hirotaka Takahashi¹, Rongrit Ponsumrankul¹, Shinya Tanaka¹, Carlito Baltazar Tabelin¹, Mayumi Ito¹, Naoki Hiroyoshi¹ (1. Hokkaido University)

Keywords:Gold, Cementation, Conductive particles

Cementation (reductive deposition) of gold from 10ml of ammonium thiosulfate solution (1 M Na₂S₂O₃, 0.5 M NH₃, 0.25 M (NH₄)₂SO₄, 10 mM CuSO₄, pH 9.5-10) containing 100 ppm Au⁺ was done using Al powder as a reductant for 24 h at 25℃, and the effects of the addition of other conductive particles (Cu, Fe, and activated carbon) were investigated. Gold was not deposited with solo addition of 0.15 g Al, Cu, Fe and activated carbon. When 0.15 g Cu or Fe were added together with 0.15 g of Al, 50 % of gold was deposited. When 0.15 g activated carbon was added with 0.15 g Al, gold deposition was over 99 %. These results indicate that gold cementation using Al as a reductant was promoted by the addition of Cu, Fe and activated carbon.