ISSN:
0006-3592
Keywords:
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Pyrite single-crystal cubes were cut, polished. and x-rayed to produce orientations of (100), (110), (111), and (112). These crystallographically developed surfaces then were prepared to expose an area of 1 cm2, and the remainder of the crystal was coated with an acid-resistant silicone cement. Crystals with representative orientations then were leached in ferric sulfate solutions adjusted to a pH of 2.3 with H2SO4 containing up to 6 × 103 ppm of Fe3+ at 30 and 55°C. Leaching was also conducted in acid-bacterial lixiviants containing Thiobacillus ferrooxidans at 30°C and a thermophilic microorganism at 55°C. Surface corrosion and pitting associated with pyrite leaching were examined by scanning electron microscopy. Pyrite leaching in ferric sulfate solutions was observed to be different when compared to acid-bacterial leaching. Ferric sulfate leaching required nearly 2 × 103 ppm of Fe3+ at 30°C while acid-bacterial leaching at 30°C occurred without additions of Fe3+, and values of Fe3+ never exceeded 102 ppm. Because of precipitate formation, an accurate assessment of the role of crystallographic orientation on the leaching of pyrite is difficult.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260240108
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