Abstract:
The effects of different phosphorus sources on the oxidation of Fe
2+ by
Acidithiobacillus ferrooxidans and the formation of secondary iron-rich minerals were studied to provide a theoretical basis for the treatment of acid mine drainage. Changes in the pH, Fe
2+ oxidation rate, total Fe precipitation rate, facies of the secondary minerals and other related indicators were analyzed in shaking flask experiments. The results show that there were differences in the utilization of different phosphorus sources by
Acidithiobacillus ferrooxidans. At the end of the experiments, the results for systems with NaH
2PO
4, Na
2HPO
3 and NaH
2PO
2 as the phosphorus source, respectively, were 2.02, 2.12 and 2.11 for pH, 1.04, 2.08 and 1.04 h
-1 for average oxidation rate of Fe
2+, 33%, 30% and 28% for total iron precipitation rate, and 1.58, 1.34, and 1.17 g for mass of the collected minerals. X-ray diffraction, Fourier infrared spectroscopy and scanning electron microscopy analyses of the collected minerals show that schwertmannite was the main mineral generated in the reaction systems with Na
2HPO
3 and NaH
2PO
2. In the reaction system with NaH
2PO
4, the main generated mineral was the mixture of jarosite and schwertmannite with jarosite accounted for a large proportion.