The present study explores the use of gas-filled micro- and nanobubblesNanobubbles (MBs and NBs) in the hydrometallurgical extractionExtraction via leachingLeaching of critical and strategic metalsCritical and strategic metals from a zinc-plant industrial residue. These gas-filled bubbles have sizes typically ranging from 1 to 100 μm and 1 to 1000 nm, respectively. Compared to ordinary macrobubbles, MBs and NBs are more stable with unique physicochemical properties such as low floating rate, large specific area, high charge density and surface tension, tremendous mass transfer efficiency, and self-pressurized dissolutionDissolution. These properties are dependent upon the type and nature of the gas (e.g., oxygen (O2)) filling these bubbles, which often possess the ability to produce reactive oxygen species which provide excellent oxidative capacity. In this work, O2 gas-filled MBs, and NBs were generated in 500 mL of 1 M sulfuric acidSulphuric acid (H2SO4) for the entirety of the experiment. This O2 NB charged solution was used in a leachingLeaching experiment of critical and strategic metalsCritical and strategic metals from the zinc-plant industrial residue performed at 80 °C for 1.5 h. LeachingLeaching with H2SO4 without NBs was used for comparison. The results from this work hold significant value, especially in the realm of improving the performance of hydrometallurgical processesHydrometallurgical processes in an eco-friendly and cost-effective manner.