Gold cyanidation barren solution is rich in copper/zinc cyano-complexes and possesses high recovery value. However, existing processes typically require the conversion of copper cyano-complexes into compound precipitates prior to smelting recovery, resulting in a relatively complex flowsheet and high energy consumption. To address this issue, a coupled process integrating ferrous precipitation and zero-valent aluminum reduction is proposed to achieve barren solution purification and valuable resource recovery. In this process, zinc cyano-complexes are first selectively precipitated by ferrous ions for zinc recovery; then, copper cyano-complexes are reduced by zero-valent aluminum assisted by ferrous ions to recover elemental copper; finally, ferrocyanide is precipitated by ferrous mass ions to recover Prussian blue. The results indicate that after treatment by this method, the total zinc concentration in the solution decreases from 1.95 g/L to 0.01 g/L, total copper mass concentration from 2.25 g/L to 0.03 g/L, and total cyanide mass concentration from 10.30 g/L to 0.20 g/L. The obtained zinc sludge contains over 22% zinc, the copper powder contains over 90% elemental copper, and the iron sludge contains over 50% Prussian blue. Economic analysis shows that the comprehensive reagent cost is approximately 78.4 CNY/m3 of barren solution, while the direct revenue from the produced elemental copper sludge is about 200 CNY/m3. This method provides a technical reference for the resource recycling and utilization of cyanide gold leaching barren solution.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |