Efficient\nGold Recovery from Cyanide Solution Using\nMagnetic Activated Carbon

Abstract

Activated\ncarbon has been used for gold recovery in the gold mining\nindustry commercially for decades. The high specific surface area\nand porosity, good affinity to aurocyanide ions, and abundant resources\nmake activated carbon an efficient and economical material for the\nadsorption of aurocyanide. However, the separation of activated carbon\nfrom the slurry is usually a challenge, and the adsorption rate of\nactivated carbon is limited by the coarse particle size. Herein, a\nsimple and sustainable way to recover gold from cyanide solution using\nmagnetic activated carbon synthesized via a solvothermal method has\nbeen developed. The synthesized magnetic activated carbon possesses\ngood magnetism (44.57 emu/g) and specific surface area equal to 249.7\nm²/g. The magnetic activated carbon showed 99.1% recovery\nefficiency of gold from 10 mg/L solution within 5 h, which is much\nfaster compared to the commercial granular activated carbon, and the\nmagnetic activated carbon can be easily separated from the solution\nwith an external magnet. The adsorption ability of this magnetic activated\ncarbon has been tested under different conditions in the cyanide solution,\nthe adsorption isotherm and kinetics are also investigated. The magnetic\nactivated carbon was also recycled in the adsorption–desorption\ntests and showed good reusability.