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Incorporation of arsenic during the formation of Mg-bearing minerals at alkaline condition / E.M. Opiso in Minerals engineering, Vol. 23 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 3 (Fevrier 2010) . - pp. 230–237 Titre : Incorporation of arsenic during the formation of Mg-bearing minerals at alkaline condition Type de document : texte imprimé Auteurs : E.M. Opiso, Auteur ; T. Sato, Auteur ; K. Morimoto, Auteur Année de publication : 2011 Article en page(s) : pp. 230–237 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Arsenic  Incorporation  Alkaline  wastes  Mg-bearing  minerals Résumé : The release of toxic anions during the chemical weathering of alkaline wastes such as blast furnace slag and coal fly ash presents a serious problem to public health and the environment. This study investigated arsenate sorption behavior onto Mg-bearing minerals formed in the Mg–Si–Al system at alkaline pH conditions in order to understand the safe removal and encapsulation of arsenate by Mg-bearing minerals under such conditions. Sorption experiments were performed during and after mineral formation and leaching tests using phosphate bearing solution were conducted to understand arsenic association with the minerals. The results revealed that brucite (Mg(OH)2), hydrotalcite (Mg6Al2(CO3)(OH)16·4(H2O)) and serpentine (MgSi2O5(OH)4) have high uptake capacity for arsenate. However, arsenic incorporation was only observed during the formation of high Al content hydrotalcite and serpentine minerals and was greatly enhanced at higher temperature. This implies that by controlling pore water chemistry of alkaline wastes with high reactivity, the irreversible fixation of arsenic by Mg-bearing minerals in alkaline conditions can be expected. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001939 [article] Incorporation of arsenic during the formation of Mg-bearing minerals at alkaline condition [texte imprimé] / E.M. Opiso, Auteur ; T. Sato, Auteur ; K. Morimoto, Auteur . - 2011 . - pp. 230–237. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 3 (Fevrier 2010) . - pp. 230–237 Mots-clés : Arsenic  Incorporation  Alkaline  wastes  Mg-bearing  minerals Résumé : The release of toxic anions during the chemical weathering of alkaline wastes such as blast furnace slag and coal fly ash presents a serious problem to public health and the environment. This study investigated arsenate sorption behavior onto Mg-bearing minerals formed in the Mg–Si–Al system at alkaline pH conditions in order to understand the safe removal and encapsulation of arsenate by Mg-bearing minerals under such conditions. Sorption experiments were performed during and after mineral formation and leaching tests using phosphate bearing solution were conducted to understand arsenic association with the minerals. The results revealed that brucite (Mg(OH)2), hydrotalcite (Mg6Al2(CO3)(OH)16·4(H2O)) and serpentine (MgSi2O5(OH)4) have high uptake capacity for arsenate. However, arsenic incorporation was only observed during the formation of high Al content hydrotalcite and serpentine minerals and was greatly enhanced at higher temperature. This implies that by controlling pore water chemistry of alkaline wastes with high reactivity, the irreversible fixation of arsenic by Mg-bearing minerals in alkaline conditions can be expected. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001939