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The Geochemical Characterization of Mine Effluents from the Phosphorite Processing Plant of Kpémé (Southern Togo)

  • K. GnandiEmail author
  • M. H. Rezaie Boroon
  • P. Edorh
Technical Article

Abstract

Sedimentary phosphorites are being exploited in southern Togo. The ore is processed to high-grade purified commercial phosphorite by wet sieving, using water pumped directly from the sea. The resultant muddy tailings are dumped directly into the sea without any pretreatment. We have separated the solid and liquid phases of the muddy tailings and characterized their metal contents. Leaching tests were conducted with weak acid and saline water to evaluate the solubility and the potential bioavailability of various metals. The results show that the purification process leads to the enrichment of certain metals (Cr, Cu, Ni, V, Zn, Ba, Sr, Fe, and Al) in the tailings due to their association with the clay minerals, whereas Cd, Th, and U are enriched in the purified apatite-rich phase. The leaching tests showed that the solubility of metals generally increases when salinity increases or when pH decreases. Thus, the processing of phosphorites with sea water and the dumping of phosphorite tailings into the sea represent a serious potential risk for the marine ecosystem and for human health through the food chain.

Keywords

Phosphorite mine tailings Trace metals Toxicity Salinity Coastal pollution Togo 

Notes

Acknowledgments

The authors would like to express sincere thanks to the Geosciences Institute (Geochemistry Laboratory) of the University of Mainz (Germany) for laboratory facilities and the German Academic Exchange Service (DAAD) for the financial support. The authors acknowledge the critical reading of the manuscript by the referees of the journal and the language improvements made by an anonymous reviewer.

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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.Department of GeologyUniversity of LomeLomeTogo
  2. 2.Department of Geological SciencesCalifornia State UniversityLos AngelesUSA
  3. 3.Department of Biochemistry and Cellular BiologyUniversity of Abomey-CalaviCotonouBenin

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