Recovery of rhenium, a strategic metal, from copper smelting effluent

Rhenium is a key metal in high technology. It is important how to effectively and selectively recover perrhenate from copper smelting acidic effluent. A CH3COOK activated hierarchical biochar from bamboo shoot shell was prepared to efficiently and selectively adsorb perrhenate in the acidic solution. Some adsorption experiment factors such as initial pH, adsorbent dose, contact time, and temperature have been comprehensively tested. The maximum adsorption capacity of the adsorbent for perrhenate reached up to 84.63 mg/g. Spontaneous physical adsorption was possible adsorption mechanism according to thermodynamic analysis. The intensified hydrophobic surface and graphitic defect structure of the adsorbent accounted for its excellent selectivity to hydrophobic perrhenate. Regeneration experiments showed that the CH3COOK activated hierarchical biochar was reusable. The CH3COOK activated hierarchical biochar has the high potency for highly efficient and selective recovery of perrhenate from the acidic solution generated by the copper smelting process.