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Controlled supersaturation precipitation of hydromagnesite for the MgCl2−Na2CO3 system at elevated temperatures / Cheng, Wenting in Industrial & engineering chemistry research, Vol. 49 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1964–1974 Titre : Controlled supersaturation precipitation of hydromagnesite for the MgCl2−Na2CO3 system at elevated temperatures : chemical modeling and experiment Type de document : texte imprimé Auteurs : Cheng, Wenting, Auteur ; Zhibao Li, Auteur Année de publication : 2010 Article en page(s) : pp 1964–1974 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydromagnesite  MgCl2−Na2CO3  System  Chemical  Modeling. Résumé : A new chemical model of supersaturation (S) was developed and applied to test for the precipitation of hydromagnesite [Mg5(CO3)4(OH)2·4H2O] in the MgCl2−Na2CO3 system in supersaturated solutions over the temperature range of 50−90 °C. Based on the new model with the help of the OLI platform, the contour supersaturation of Mg5(CO3)4(OH)2·4H2O has been exactly constructed by calculating the activity coefficients of species in unstable solutions. Mg5(CO3)4(OH)2·4H2O crystals were identified using X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) images. It was found that the crystal properties, such as morphology, particle size distribution, filtration, and sedimentation characteristics, can be optimized by controlling the supersaturation during precipitation. With the control of supersaturation, well-developed spherical-like Mg5(CO3)4(OH)2·4H2O crystals can grow to an average size of 30−40 μm, indicating a narrow particle size distribution, good filtration characteristics, and a high sedimentation rate. In addition, the Mg5(CO3)4(OH)2·4H2O obtained was calcined to produce high-purity MgO at 800 °C. The size and morphology of MgO were similar to the same characteristics of the corresponding precursors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015073 [article] Controlled supersaturation precipitation of hydromagnesite for the MgCl2−Na2CO3 system at elevated temperatures : chemical modeling and experiment [texte imprimé] / Cheng, Wenting, Auteur ; Zhibao Li, Auteur . - 2010 . - pp 1964–1974. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1964–1974 Mots-clés : Hydromagnesite  MgCl2−Na2CO3  System  Chemical  Modeling. Résumé : A new chemical model of supersaturation (S) was developed and applied to test for the precipitation of hydromagnesite [Mg5(CO3)4(OH)2·4H2O] in the MgCl2−Na2CO3 system in supersaturated solutions over the temperature range of 50−90 °C. Based on the new model with the help of the OLI platform, the contour supersaturation of Mg5(CO3)4(OH)2·4H2O has been exactly constructed by calculating the activity coefficients of species in unstable solutions. Mg5(CO3)4(OH)2·4H2O crystals were identified using X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) images. It was found that the crystal properties, such as morphology, particle size distribution, filtration, and sedimentation characteristics, can be optimized by controlling the supersaturation during precipitation. With the control of supersaturation, well-developed spherical-like Mg5(CO3)4(OH)2·4H2O crystals can grow to an average size of 30−40 μm, indicating a narrow particle size distribution, good filtration characteristics, and a high sedimentation rate. In addition, the Mg5(CO3)4(OH)2·4H2O obtained was calcined to produce high-purity MgO at 800 °C. The size and morphology of MgO were similar to the same characteristics of the corresponding precursors. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015073