钙盐脱铝-树脂吸附法从镓电积贫液中选择性分离镓铝

Selective separation of gallium-aluminum from gallium depleted electrolyte by calcium salt de-alumination and resin adsorption

  • 摘要: 镓为一种战略稀散金属,通常与锌、铝等元素伴生。氧压湿法炼锌中,一般采用浸出-富集-萃取-电积工艺回收镓,电积后的贫液中镓浓度一般为5~10 g/L,铝浓度最高可达25 g/L,循环回用时铝不断累积,会增加镓电积负担、降低镓品质。为此,本研究设计了氧化钙脱铝-树脂(ZGD887)吸附镓的脱铝/富镓双效工艺,以企业提供的镓电积贫液为原料,探究了氧化钙脱铝的较优条件,考察了吸附条件对树脂吸附脱铝后液中镓性能的影响。结果表明:氧化钙可诱导镓电积贫液中的铝转化为六水合铝酸钙,实现铝的脱除。在温度为90 ℃、反应时间为120 min、2.00倍理论值氧化钙质量的条件下,铝的沉淀率为92.44%,镓的损失率仅为12.60%。在吸附温度为30 ℃、树脂用量为0.1 g/mL、振荡速率为250 r/min的条件下,进行4次吸附后,镓的总回收率为83.05%。采用钙盐脱铝-树脂吸附法,铝的脱除率为92.44%,镓的综合回收率为72.59%,可实现镓电积贫液中铝的开路和低浓度镓的高效富集。

     

    Abstract: Gallium, as a strategic rare metal, is often associated with elements such as zinc and aluminum. In the oxygen-pressure zinc hydrometallurgical system, gallium is typically recovered through a leaching-enrichment-extraction-electrowinning process. The gallium concentration of the depleted solution after electrowinning is generally 5~10 g/L. The aluminum concentration can reach as high as 25 g/L, and the accumulation of recycled aluminum increases the burden of gallium electrowinning and reduces gallium quality. For this reason, this study designed a calcium oxide de-alumina-resin (ZGD887) adsorption of gallium de-alumina / gallium-rich double-effect process, with the gallium electrowinning depleted solution provided by an enterprise as the raw material, to explore the optimal conditions of calcium oxide de-alumina, and examined the effect of adsorption conditions on the gallium performance of the resin adsorption of de-alumina solution after the performance of gallium. The results showed that calcium oxide could induce the conversion of aluminum to calcium aluminate hexahydrate in the electro-gallium depleted solution, thereby achieving aluminum removal. Under conditions of a temperature of 90 ℃, a reaction time of 120 min, and twice the theoretical mass of calcium oxide, the precipitation efficiency of aluminum reached 92.44% and the loss efficiency of gallium was only 12.60%. Then, under adsorption conditions of 30 ℃, resin dosage of 0.1 g/mL, and oscillation rate of 250 r/min, the total recovery efficiency of gallium reached 83.05% after four adsorption cycles. By applying the calcium salt de-aluminized resin adsorption method, the aluminum removal rate was 92.44% and the comprehensive gallium recovery rate was 72.59%, achieving open-circuit of aluminum in the electro-gallium lean solution and efficient enrichment of low-concentration gallium.

     

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