Abstract

This work studies gallium preconcentration by means of an adsorption/desorption process using two mesoporous activated carbons synthesized by the replica method as adsorbents. The adsorption results indicate that both carbons can remove 90% of gallium from aqueous solution. Increasing the adsorbent dose favors gallium adsorption and makes the adsorption process strongly pH dependent. However, the most outstanding conclusion is related to the gallium recovery: by using a HF solution as desorbing agent (the same as employed in the adsorbents’ synthesis, in line with circular economy principles), it is possible to regenerate the adsorbent as well as recover 82% of the gallium previously retained. Additionally, the desorption enables sevenfold preconcentration of gallium ions, up to 250 ppm, by reducing the volume of the acidic solution eightfold. This enables further recovery by means of refining processes such as extraction.

Graphical Abstract

中文翻译：

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通过在无序介孔碳上吸附/解吸进行预浓缩从水溶液中回收镓

摘要

这项工作研究了镓的富集，该方法通过使用两种由复制方法合成的介孔活性炭作为吸附剂，通过吸附/解吸过程进行。吸附结果表明两种碳都可以从水溶液中去除90％的镓。吸附剂剂量的增加有利于镓的吸附，并使吸附过程强烈依赖于pH。但是，最杰出的结论与镓的回收率有关：通过使用HF溶液作为解吸剂（与吸附剂合成中所用的相同，符合循环经济原理），可以再生吸附剂，以及回收先前保留的镓的82％。此外，通过将酸性溶液的体积减少八倍，解吸可以使镓离子的七倍预浓缩（最高250 ppm）。

图形概要