TABLE 1.
Formation of sulfur compounds by chemical metal sulfide oxidation with 10 mM Fe(III) chloride (3) at pH 1.9 and 28°C
| Metal sulfide | Formula | Structure (28) | Purity (%)a | S8 (%)b | SO42− (%)b | S4O62− (%)b | S5O62− (%)b |
|---|---|---|---|---|---|---|---|
| Pyrite | FeS2 | Disulfide | >99 | 16.1 | 81.7 | 1.3 | 0.9 |
| Molybdenite | MoS2 | Layer | 93 | 8.4 | 90.4 | 0.6 | 0.6 |
| Hauerite | MnS2 | Disulfide | >99 | 93.6 | 3.7 | 1.2 | 1.5 |
| Sphalerite | ZnS | Sphalerite | 95 | 94.9 | 4.8 | 0.1 | 0.2 |
| Chalcopyrite | CuFeS2 | Sphalerite | >99 | 92.2 | 7.3 | 0.3 | 0.2 |
| Galena | PbS | Halite | >99 | 99.9 | 0.1 | 0.0 | 0.0 |
| Orpiment | As2S3 | Layer | >99 | 94.8 | 5.2 | 0.0 | 0.0 |
| Realgar | As4S4 | Ring | >99 | 92.5 | 7.5 | 0.0 | 0.0 |
a
Purity calculations are based on ICP measurements of the elemental composition. No impurities were detected by X-ray diffraction except for some geerite (Cu8S5) in the case of chalcopyrite.
b
Percentages were calculated after 24 h of incubation except for galena (1 h), hauerite (5 h), and realgar (168 h), due to the different reaction rates. In the case of hauerite, traces of hexathionate were formed. The data are means of three parallel experiments. Standard deviations were less than 15%.