Comparative study of dewatering characteristics of metal precipitates generated during treatment of monometallic solutions.

Djedidi, Zied; Khaled, Jihen Ben; Cheikh, Ridha Ben; Blais, Jean-François ORCID: https://orcid.org/0000-0003-3087-4318; Mercier, Guy et Tyagi, Rajeshwar Dayal (2009). Comparative study of dewatering characteristics of metal precipitates generated during treatment of monometallic solutions. Hydrometallurgy , vol. 95 , nº 1-2. pp. 61-69. DOI: 10.1016/j.hydromet.2008.04.014.

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Résumé

The sludge dewatering properties (settling, filtration and centrifugation) of metal precipitates generated during treatment of monometallic solutions (0.020 mol/L) have been evaluated in this research. The precipitation tests carried out on 15 different metals gave metal removal yields generally similar to those predicted by MINEQL+ software, with the exception that kinetic aspects should be considered during precipitation of metal sulphides and phosphates. Hydroxides precipitation at pH 10.0 was the most efficient technique for the removal of eight metallic ions (Al^-1, Cd^-1, Co^-1, Fe^-1, Fe^-1, Mg^-1, Mn^-1, Ni^-1), whereas phosphates precipitation (at pH 6.0 with an addition of 0.0133 mol PO4^-1/L) gave highest removal yields for Ba^-1, Ca^-1, Cr^-1. Sulphides precipitation (at pH 7.0 and using, 0.020 mol S^-1/L) has been found the most efficient technique only for Cu^-1 and Sn^-1 precipitation, whereas carbonates precipitation (at pH 8.0 and using 0.020 mol CO3^-1/L) gave better removal yield only for Pb^-1. Results have also shown that metal phosphates have generally better dewatering characteristics (SVI, filtration capacity, SRF, sludge solids content) than metal carbonates, sulphides and hydroxides. In fact, considering only the sludge dewatering characteristics, phosphates precipitation appears the most appropriate technique for the precipitation of many metals (Al^-1, Ba^-1, Cd^-1, Co^-1, Cr^-1, Fe^-1, Fe^-1, Ni^-1 and Zn^-1). Metal hydroxides formation constitutes the best option for Ca^-1, Cu^-1, Mg^-1 and Sn^-1 removal, whereas precipitation of metal carbonates is particularly interesting for treatment of Mn^-1 and Pb^-1 containing solutions.

Type de document:	Article
Mots-clés libres:	metal; precipitation; sludge; dewatering; hydroxide; sulphide; phosphate; carbonate
Centre:	Centre Eau Terre Environnement
Date de dépôt:	11 janv. 2021 15:47
Dernière modification:	18 févr. 2022 20:02
URI:	https://espace.inrs.ca/id/eprint/10800

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