可溶铝合金水解过程中镓的回收与浸出行为研究

Recovery and Leaching Behavior of Gallium During Hydrolysis of Bulk Soluble Aluminum Alloys

摘要:

选用Al-Ga-Mg-Sn块体可溶铝合金，采用“一步法”湿法冶金技术，以有机酸（草酸、苹果酸、乙酸）溶液、无机酸（硝酸）溶液作为浸出剂，研究酸浸出的浸出剂种类、pH值、温度和浓度对制氢过程中Ga回收率的影响。回收结果发现：在温度为70 ℃，浸出剂浓度为0.2 mol·L^-1时，有机酸溶液均能回收Ga，且回收效果为草酸（86.88%）>苹果酸（73.40%）>乙酸（13.17 %）；而无机酸（硝酸）溶液无法回收Ga。草酸为浸出剂，初始pH值约为3.8，低温高浓度（70 ℃/0.3 mol·L^-1）下回收率为94.38 %；高温低浓度（90 ℃/0.2 mol·L^-1）下回收率为93.78%。为探究Ga的浸出行为，对Al-Ga-Mg-Sn水解过程中pH值变化、回收物 Ga的形态、生成物溶液中固体颗粒粒径与 Zeta 电位进行测试分析，结果表明：Ga回收率随着生成物粒径的减小而增大，随着Zeta电位绝对值的增大而增大。草酸浸出剂的高回收率（94.38 %）对应生成物粒径为155 nm，Zeta电位值为-31.29 mV。

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.