Abstract:Aiming at the high recovery value of silver concentrate and insufficient of existing treatment technology, applying the germanium-containing silver concentrate produced by zinc hydrometallurgy as research object, a process route of concentrated sulfuric acid curing and oxygen pressure acid leaching was put forward, focusing on the principle of the process, leaching behavior of Zn, Cu and Ge in the process of curing and oxygen pressure acid leaching of germanium containing silver concentrate and phase evolution in the leaching residue. The results indicate that low valence metal sulfide in germanium containing silver concentrate and the residual organic flotation chemicals on the concentrate surface can be oxidized and decomposed by pretreatment with concentrated sulfuric acid. Under the condition of high temperature oxidation and assisted leaching by Fe3+/Fe2+ variable ion pairs, the phase composition of the germanium-containing silver concentrate mainly evolves from dominated by iron sphalerite, sphalerite, gynopyrite and cuprous chloride to dominated by elemental sulfur, lead sulfate and ferrosite (MeFe3(SO4)2(OH)6, Me: 1/2Pb,Na,K) in leaching residue. Under the optimum oxygen pressure acid leaching conditions including reaction temperature of 150 ℃, initial acidity of 150 g/L, reaction time of 180 min, partial oxygen pressure of 0.6 MPa, and liquid-solid ratio of 7 mL/g, the leaching rate of Zn, Cu and Ge is 95.34%, 98.47% and 84.35%, respectively, and the enrichment of lead and silver reaches 3.19% and 7 074 g/t, respectively, which realizes the deep leaching of Zn, Cu, and Ge, and efficient enrichment of Pb and Ag.