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| Titel |
The effect of portland cement for solidification of soils contaminated by mine tailings containing heavy metals |
| VerfasserIn |
Jian-jun Chen, Zheng-miao Xie |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250037091
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| Zusammenfassung |
| Portland cement(PC) was used to solidify the lead-zinc mine tailings contaminated soils(CS)
in this work. The soils were heavily polluted by heavy metals with lead(up to 19592
mg/kg), zinc(up to 647mg/kg), Cd(up to 14.65mg.kg) and Cu(up to 287mg/kg).
Solidified/stabilized(s/s)forms with a range of cement contents, 40–90 wt%, were evaluated
to determine the optimal binder content. Unconfined compression strength test(UCS),
Chinese solid waste-extraction procedure for leaching toxicity - Horizontal vibration method,
toxicity characteristic leaching procedures(TCLP) were used for physical and chemical
characterization of the s/s forms. The procedure of Tessier et al.(1979) was used to separate
S/S forms Pb, Zn, Cd, Cu into different fractions. The results show that addition of 50%
cement was enough for the s/s forms to satisfy the MU10 requirements (0.10 MPa). Under the
50% addition, the content of the water-exchangeable fraction of Pb reduced from 2.25% to
0.2%, the carbonate-bound fraction and organic-bound fraction reduced by about half, while
the Fe-Mn oxide-bound fraction was more than doubled. The residual fraction decreased 8%
on the contrary. For Zn, except for the carbonate-bound fraction increased slightly, the
features of other items were same as that of Pb. For Cd, the water-exchangeable
fraction was reduced largely, the residual fraction and Fe-Mn oxide-bound fraction
increased 2-3%. For Cu, A distinct feature is the organic-bound fraction reduced with
the reduction in consumption of cement, at the same time, the residual fraction
increased corresponding. Leaching test results indicate that the leaching contents of
Pb2+ of the six specimens are quite different at low pH value( |
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