Abstract
During the roasting of gold concentrate to improve gold recovery, arsenic is released into the air and valuable elements such as Fe, Cu, Zn, and Pb are converted into oxide minerals. In this research, we evaluated the release of As and the loss of valuable metals during the acid baking and hot water leaching processes used for gold concentrate. The acid bake tests were conducted for gold concentrate using an electric furnace by applying various concentrations of H2SO4 solution under different baking times. The water leaching process was enacted using 70 °C water for the baked samples. Chemical and mineral compositions of the raw and treated samples were analyzed using AAS and XRD, respectively. The results show that soluble metal sulfates, such as rhomboclase and mikasite, were formed in the baked samples, and that the leaching of valuable metals (Fe, Cu, Zn, and Pb) was accelerated during the hot water leaching procedure. During acid baking, arsenic was partially removed by volatilization, and the rest of the arsenic‐containing minerals were converted to soluble minerals. The soluble arsenic‐containing mineral resulted in a dissolution that was 60 times higher than in the roasted sample. The maximum gold grade of solid residues increased up to 33% through the acid baking–water leaching process. It was confirmed that acid baking with H2SO4 prevented As release into the air, as well as the recovery of valuable metals through hot water leaching, such as Fe, Cu, Zn, and Pb, which were formerly discarded in the tailings.
Original language | English |
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Article number | 1332 |
Journal | Minerals |
Volume | 11 |
Issue number | 12 |
DOIs | |
Publication status | Published - 2021 Dec |
Bibliographical note
Funding Information:Funding: This work was supported by Korea Environment Industry & Technolgy Institute (KEITI) through Subsurface Environmental Pollution Risk Management Technology Development Project, funded by Korea Ministry of Environmenta(MOE)(ARQ202101728001), and by the Institute for Ko‐ rea Spent Nuclear Fuel (iKSNF) and National Research Foundation of Korea(NRF) grant funded by the Korea government (Ministry of Science and ICT, MSIT) (2021M2E1A1085202).
Funding Information:
This work was supported by Korea Environment Industry & Technolgy Institute (KEITI) through Subsurface Environmental Pollution Risk Management Technology Development Project, funded by Korea Ministry of Environmenta(MOE)(ARQ202101728001), and by the Institute for Korea Spent Nuclear Fuel (iKSNF) and National Research Foundation of Korea(NRF) grant funded by the Korea government (Ministry of Science and ICT, MSIT) (2021M2E1A1085202).
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Keywords
- Acid baking
- Arsenic
- Gold concentrate
- Hot water leaching
- Soluble metal sulfate
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Geology