Gold extraction from ores using non-cyanide lixiviants is currently a significant topic worldwide. Herein, we report the synthesis of an eco-friendly lixiviant that not only is much less toxic than sodium cyanide (NaCN) but also shows excellent effect in the leaching of gold. The lixiviant can be synthesized from roasting of the well-mixed potassium hexacyanoferrate(II) trihydrate (K₄Fe(CN)₆·3H₂O), urea (CO(NH₂)₂) and sodium carbonate (Na₂CO₃) with a mass ratio of 1:6:2 under the conditions of heating rate 10–15 °C/min, roasting temperature 700 °C, and temperature holding time 1 h. X-ray diffraction (XRD) analysis suggested that the synthetic lixiviant contained a new phase that is efficient in leaching gold playing the role of the gold lixiviant. Gold leaching results from a gold concentrate showed that the synthetic lixiviant not only has a gold leaching efficacy comparable to NaCN but also achieves faster leaching kinetics than NaCN. Under the optimal leaching conditions of lixiviant concentration 0.3 wt%, initial pH 10–11, liquid to solid ratio 2.5:1, and agitation speed 600 rpm, the synthetic lixiviant could achieve a gold extraction of 87.0% in 8 h and 97.5% in 24 h on the gold concentrate, reducing the leaching time by 12 h compared with cyanidation (97.1% gold extraction in 36 h). In addition, the method of activated carbon adsorption was shown to efficiently adsorb almost all the gold (> 99.0%) from the leach solutions, and the barren leach solution could be reused back to the leaching stage to extract gold.

使用非氰化物浸出剂从矿石中提取金目前是世界范围内的重要课题。在此，我们报告了一种环保浸出剂的合成，该浸出剂不仅毒性比氰化钠 (NaCN) 低得多，而且在金的浸出方面表现出优异的效果。浸出剂可以通过焙烧充分混合的三水合六氰合铁(II)钾(K ₄ Fe(CN) ₆ ·3H ₂ O)、尿素(CO(NH ₂ ) ₂ )和碳酸钠(Na ₂ CO ₃) 质量比为 1:6:2，升温速率 10~15 ℃/min，焙烧温度 700 ℃，保温时间 1 h。X 射线衍射 (XRD) 分析表明，合成浸出剂含有一种新相，可有效浸出金，起到浸金剂的作用。金精矿的金浸出结果表明，合成浸出剂不仅具有与 NaCN 相当的金浸出效率，而且比 NaCN 具有更快的浸出动力学。在浸出剂浓度0.3 wt%、初始pH 10~11、液固比2.5:1、搅拌速度600 rpm的最佳浸出条件下，合成浸出剂8 h提金率87.0%，1小时提金率97.5%。金精矿上 24 h，与氰化相比，浸出时间减少了 12 h (97. 在 36 小时内提取 1% 金）。此外，活性炭吸附法可以有效地吸附浸出液中几乎所有的金（> 99.0%），贫瘠的浸出液可以再利用回浸出阶段提取金。