1. Cobalt enrichment in a paleo-karstic bauxite deposit at Yunfeng, Guizhou Province, SW China.
- Author
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Long, Yongzhen, Lu, Anhuai, Gu, Xiangping, Chi, Guoxiang, Ye, Lin, Jin, Zhongguo, and Zhang, Dongliang
- Subjects
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BAUXITE , *ULTRABASIC rocks , *MAFIC rocks , *SULFIDE minerals , *ANALYTICAL chemistry , *SIDERITE , *HYDROXIDES , *COBALT - Abstract
• Cobalt is enriched (up to 962 ppm) in the paleo-karstic bauxite deposit at Yunfeng. • Cobalt is positively correlated with sulfur. • Cobalt occurs mainly as Co-bearing pyrites and Co-rich sulfides/sulfoarsenides. Cobalt can be enriched in a variety of different geologic settings, while it is mainly produced as a by-product of sediment-hosted stratiform Cu deposits and magmatic Ni-Cu deposits associated with mafic and ultramafic rocks. In this study, we report elevated Co concentrations in a paleo-karstic bauxite deposit at Yunfeng, Guizhou Province. Whole-rock chemical analyses indicate that Co is concentrated in carbonaceous ferruginous clay layers (167–962 ppm, average 383 ppm, n = 5) and siderite layers (47–439 ppm, average 213 ppm, n = 7) within the bauxite deposit. The positive correlation between Co and S, together with petrographic and EPMA analyses, suggests that Co occurs primarily as Co-rich/bearing sulfides/sulfoarsenides rather than cobaltiferous oxides/hydroxides as in most lateritic Ni-Co deposits. Many of the Co concentrations measured in this study are higher than the minimum grade (300 ppm) or cut-off grade (200 ppm) for economic exploitation of Co from sulfides or arsenides. Basing on these results, we put forward the scientific significance of Co enrichment in paleo-karstic environments and the potential importance of Co resources (as by-products of aluminum production) in bauxite deposits. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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