Influences of initial Fe(Ⅱ) and monovalent cation concentrations on the formation of biogenic iron hydroxysulfate precipitates in acidic su If ate-rich environments
To study the formation conditions of schwertmannite ideal formula; Fe8 O8 ( OH) 6 SO4 and jarosite (K, Na, NH4) Fe3 (SO4) 2 ( OH) 6 in acidic, sulfate-riched environments where ferrous sulfate was oxidized at a initial pH 2. 50 by Acidithiobacillus ferrooxidans, initial concentrations of Fe , K+ , Na + , NH4 + were various in batch experiments. In the FeSO4-K2SO4-H2O system, schwertmannite was the only solid phase produced at ≤ 40 mM Fe(II) and ≤S8 mM K+. At 80 and 160 raM Fe(Ⅱ) , mixtures of schwertmannite and potassium jarosite were present at ≥2. 29 and ≥1. 60 mM K+ , respectively. Monominerallic potassium jarosites were formed at 80 mM Fe(II) and 26. 7 mM K+ as well as at 160 mM Fe(Ⅱ) and ≥16 mM K+ . The lowest concentration of K+ needed for the precipitation of potassium jarosite decreased with the reduction in Fe(II) and vice versa. Increasing the concentration of Fe2+ and K+ was propitious to the formation of potassium jarosite, whereas the molar ratio of Fe/K had no direct influence on the phases of iron minerals. Compared to potassium jarosite, more NH4 + were demanded for the formation of ammoniojarosite at 160 mM Fe ( Ⅱ) , and pure ammoniojarosite was not formed. All the precipitates formed in FeSO4-Na2 SO4-H2 0 system were entirely composed of schwertmannite, even at 160 mM Fe (Ⅱ) and 320 mM Na+. The results indicated that monovalent cation ability varied widely on the formation of biogenic secondary iron minerals facilitated by Acidithiobacillus ferrooxidans, which K+ was the strongest, the jarosite-forming relative capacity of cation about K +: NH4 +: Na+ = 600 : 8 :3. The data from the present study will contribute to the understanding and prediction in iron mineral formation facilitated by Acidithiobacillus ferrooxidans in acidic natural or artificial environments.
Acidithiobacillus ferrooxidans Fe(Ⅱ) monovalent cation schwertmannite jarosite
Shuangyou Bai Min Wang Jianru Liang Lixiang Zhou
Department of Environmental Engineering, College of Resources and Environmental Sciences.Nanjing Agricultural University, 210095, Nanjing, China
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
484-490
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）