Abstract The effect of ultrasound on gold leaching rate and kinetics was investigated in the Co-NH3-S2O32− system. First, the effects of ultrasound power, temperature, the concentration of thiosulfate, cobalt and ammonia on gold leaching rate were studied under ultrasound. The optimized leaching parameters are 0.03 M Co2+, 0.2 M S2O32−, 1 M NH3, 323 K, and 750 W ultrasonic power. Moreover, the leaching rate of gold is 8 times faster, and the extraction percentage is approximately 25% higher, under ultrasound than under conventional conditions. The experimental results show that ultrasound can effectively enhance the leaching rate and the extraction percentage. The kinetic analysis indicates that the internal diffusion step controlled the ultrasound leaching process. The increase in the leaching rate under ultrasound is due to the decrease of activation energy from 22.65 kJ/mol to 13.86 kJ/mol. Therefore, ultrasound efficiently improved the leaching rate of gold in the Co-NH3-S2O32− leaching system.

中文翻译：

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钴氨催化硫代硫酸盐浸出过程中金的超声浸出动力学

摘要 在 Co-NH3-S2O32− 体系中研究了超声波对金浸出速率和动力学的影响。首先，研究了超声功率、温度、硫代硫酸盐、钴和氨的浓度对金浸出率的影响。优化的浸出参数为 0.03 M Co2+、0.2 M S2O32-、1 M NH3、323 K 和 750 W 超声波功率。此外，在超声波下，金的浸出速度比常规条件下快 8 倍，提取率提高约 25%。实验结果表明，超声能有效提高浸出率和提取率。动力学分析表明内部扩散步骤控制了超声浸出过程。超声浸出率的增加是由于活化能从 22.65 kJ/mol 降低到 13.86 kJ/mol。因此，超声波有效地提高了 Co-NH3-S2O32− 浸出系统中金的浸出率。