| Autor: |
Maree, J. P., Hlabela, P., Nengovhela, R., Geldenhuys, A. J., Mbhele, N., Nevhulaudzi, T., Waanders, F. B. |
| Zdroj: |
Mine Water and the Environment; December 2004, Vol. 23 Issue: 4 p195-203, 9p |
| Abstrakt: |
The integrated barium sulphide process consists of: preliminary treatment with lime, sulphate precipitation as barium sulphate, H 2S-stripping, crystallization of CaCO 3, and recovery of barium sulphide. Our tests showed that during lime pre-treatment, sulphate was lowered from 2 800 mg/L to 1 250 mg/L by gypsum crystallization; metals were precipitated as hydroxides. The BaS treatment then lowered sulphate to less than 200 mg/L. Sulphide was lowered from 333 to less than 10 mg/L (as S) in the stripping stage, using CO 2 gas for stripping. The stripped H 2S-gas was contacted with Fe (III)-solution and converted quantitatively to elemental sulphur. The alkalinity of the calcium bicarbonate-rich water was reduced from 1 000 to 110 mg/L (as CaCO 3) after CO 2-stripping with air due to CaCO 3 precipitation. Fe (II), after sulphur production, was re-oxidized to Fe (III) using an electrolytic step. The running cost of the BaS process is R2.12/m 3 (US$1 = SAR6.5) for the removal of 2 g/L of sulphate. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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