Abstract:Al-Ga-Mg-Sn soluble aluminum alloy was selected for a one-step hydrometallurgical technique. Acid leaching agents, including organic acid solutions (e.g., oxalic, malic, and acetic solutions) and inorganic acid solutions (e.g., nitric acid) were used. The type of leaching agent, pH value, temperature, and solution concentration are key factors influencing the recovery of Ga during hydrogen production. Recovery results show that under the temperature of 70 ℃ and the agent concentration of 0.2 mol·L–1, the organic acid solution successfully recovers gallium, with oxalic acid exhibiting the highest recovery efficiency (86.88%), followed by malic acid (73.40%) and acetic acid (13.17%). In contrast, the inorganic acid (nitric acid) solution fails to recover gallium. Oxalic acid, with an initial pH value of approximately 3.8, achieves a recovery efficiency of 94.38% under 70 °C/0.3 mol·L–1 and 93.78% under 90 °C/0.2 mol·L–1. The leaching behavior of gallium was then tested and analyzed based on changes in pH value, shape of the recovered gallium, solid particle size and Zeta potential of the product during the hydrolysis process. The results show that the recovery of gallium from oxalic acid leachate increases with the decrease in particle size of the product and increase in absolute value of Zeta potential. The highest recovery efficiency (94.38%) is achieved with a product particle size of 155 nm and a Zeta potential value of –31.29 mV.