| Title |
Use of Activated Carbon as a Copper Substitute during Cobalt Cementation
for Zinc Electrolyte Purification |
| Authors |
백다경(Dakyeong Baek) ; 임유진(Yoojin Lim) ; 유경근(Kyoungkeun Yoo) ; 이상훈(Sang-Hun Lee) ; Manis Kumar Jha(Manis Kumar Jha) |
| DOI |
https://doi.org/10.3365/KJMM.2026.64.4.282 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Activated carbon; Cementation; Cobalt; Electrolyte purification; Zinc hydrometallurgy |
| Abstract |
In the zinc hydrometallurgical process, a cementation process using zinc powder, copper, and
antimony is employed to remove cobalt impurities from the electrolyte. However, the precipitate from this
process contains not only cobalt but also unreacted zinc, copper, and antimony, making it difficult to
recover cobalt, a critical mineral. This study aimed to develop a cementation process that facilitates cobalt
recovery by using activated carbon instead of copper as an activator. Experiments were conducted at
85 oC and pH 3.3-3.7 using a simulated solution containing 150 g/L zinc and 10 mg/L cobalt. Complete
cobalt removal (100%) was achieved within 30 minutes when 10 g/L activated carbon and 20 mg/L
antimony were added, which is equivalent to the performance obtained with 200 mg/L copper. The
activated carbon could be easily recovered by sieving through a 1 mm screen and was successfully reused
five times. More than 94.5% of the precipitated cobalt was found on zinc powder, while only 1.9-5.5% was
deposited on activated carbon. The addition of activated carbon increased the dissolution rate of zinc in
sulfuric acid solution, suggesting that activated carbon enhances cobalt cementation by promoting zinc
dissolution rather than serving as an electron transfer pathway. This study demonstrates the feasibility
of developing an environmentally friendly zinc hydrometallurgical process that facilitates cobalt recovery
using reusable activated carbon. |