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Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability / I. Demers in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 506–512 Titre : Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability Type de document : texte imprimé Auteurs : I. Demers, Auteur ; J. Finch, Auteur ; E. El-Ammouri, Auteur Année de publication : 2009 Article en page(s) : pp. 506–512 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Acid  rock  drainage  Flocculation  Leaching  Environmental Résumé : The most common treatment for acidic drainage is lime neutralization. The process involves neutralization and precipitation of a metal hydroxide-gypsum sludge using a flocculant, generally Percol. In the short term, the sludge is stable, but in the long term, any tendency of pH to drop can re-dissolve metal hydroxides and contaminate the surrounding area and groundwater. The use of activated silica sol, an inorganic silicate polymer used in municipal water treatment, as a replacement to Percol is investigated to improve long term stability of sludge. Silica sol is an effective flocculant, has neutralization potential, and forms metal–silica bonds more resistant to pH variation than metal hydroxides. Various mine effluents and simulated solutions were treated with lime and silica sol or Percol to pH 9–10. Results show that settling characteristics with low dosages of silica sol and Percol are similar. Leachability tests showed that the stability of the sludge improved when silica sol was used for one cycle, and after 4 cycles results were similar to Percol. Activated silica sol, therefore, has the potential to increase sludge stability in a single stage lime treatment process. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000065 [article] Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability [texte imprimé] / I. Demers, Auteur ; J. Finch, Auteur ; E. El-Ammouri, Auteur . - 2009 . - pp. 506–512. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 506–512 Mots-clés : Acid  rock  drainage  Flocculation  Leaching  Environmental Résumé : The most common treatment for acidic drainage is lime neutralization. The process involves neutralization and precipitation of a metal hydroxide-gypsum sludge using a flocculant, generally Percol. In the short term, the sludge is stable, but in the long term, any tendency of pH to drop can re-dissolve metal hydroxides and contaminate the surrounding area and groundwater. The use of activated silica sol, an inorganic silicate polymer used in municipal water treatment, as a replacement to Percol is investigated to improve long term stability of sludge. Silica sol is an effective flocculant, has neutralization potential, and forms metal–silica bonds more resistant to pH variation than metal hydroxides. Various mine effluents and simulated solutions were treated with lime and silica sol or Percol to pH 9–10. Results show that settling characteristics with low dosages of silica sol and Percol are similar. Leachability tests showed that the stability of the sludge improved when silica sol was used for one cycle, and after 4 cycles results were similar to Percol. Activated silica sol, therefore, has the potential to increase sludge stability in a single stage lime treatment process. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000065