Study of bacterial-chemical leaching enhanced by ultrasonic radiation on ore pulp

This study examines the bacterial-chemical leaching process for extracting nickel, copper, and cobalt from sulfide ore of the Shanuch deposit (Kamchatka), utilizing ultrasonic radiation to enhance the leaching efficiency. For the experiment, ultrasonic vibrations were applied at an intensity of 21.0 W/cm2 and a frequency of 22 kHz, with a total generator power of 400 W. The ultrasonic treatment was conducted for 30 minutes in a flow chamber setup. The results showed significant improvements in metal recovery during bacterialchemical leaching with ultrasonic treatment, achieving 79.42 % recovery for nickel and 72.55 % recovery for cobalt. In contrast, the leaching process without ultrasound resulted in much lower extraction rates — 2.65 times lower for nickel and 2.49 times lower for cobalt. However, the copper extraction remained relatively low at 24.07 %, though ultrasonic treatment enhanced copper extraction by 1.58 times compared to the non-ultrasonic process. Experiments also demonstrated that bacterial-chemical leaching, with an ore pulp solid-to-liquid ratio of 1 : 5 and a bacterial suspension solid-to-liquid ratio of 1 : 7, resulted in polymetallic solutions containing up to 3.59 g/L of nickel, 0.171 g/L of copper, and 0.0984 g/L of cobalt. To further optimize metal recovery, continued research should focus on varying ore pulp and bacterial suspension densities in bacterialchemical leaching, as well as adjusting ultrasonic exposure duration, frequency, and intensity.