The Behavior of Thallium(III) During Jarosite Precipitation
The behavior of thallium(III) under the general conditions employed for jarosite precipitation in the zinc industry was investigated in a series of laboratory experiments. Thallium(III) does not appear to form end-member jarosite-type compounds, MTl{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}, where M is Na, K, NH{sub 4}, etc. In acid solutions at pH > 0.7, the thallium(III) hydrolyzes to Tl{sub 2}O{sub 3}; in more strongly acid media, two K-Tl(III) sulphate phases crystallize at temperatures < 90 C. The K-Tl(III) sulphate phases were investigated by chemical and X-ray diffraction analyses and by thermogravimetry. Although end-member Tl(III) analogues of jarosite-type compounds could not be synthesized, it is possible to incorporate significant amounts of Tl(III) in potassium jarosite (KFe3(SO4)2(OH)6), and over 20 at.% substitution of Tl(III) for Fe(III) was achieved. The presence of Tl(III) in the potassium jarosite structure was confirmed by microscopic methods, electron microprobe analyses and X-ray absorption near-edge structure (XANES) spectroscopy. The Tl(III)-bearing species forms rapidly, and excess Fe(III) precipitates as nearly Tl-free potassium jarosite which envelops the initially formed Tl(III)-bearing potassium jarosite phase.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 913808
- Report Number(s):
- BNL-78376-2007-JA; HYDRDA; TRN: US200804%%79
- Journal Information:
- Hydrometallurgy, Vol. 79; ISSN 0304-386X
- Country of Publication:
- United States
- Language:
- English
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