Documents disponibles écrits par cet auteur

a - Calcium sulfate hemihydrate preparation from FGD gypsum in recycling mixed salt solutions / Baohong Guan in Chemical engineering journal, Vol. 174 N° 1 (Octobre 2011) 

Public ISBD [article]  in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp. 296–303 Titre : a - Calcium sulfate hemihydrate preparation from FGD gypsum in recycling mixed salt solutions Type de document : texte imprimé Auteurs : Baohong Guan, Auteur ; Yang Li, Auteur ; Hailu Fu, Auteur Année de publication : 2012 Article en page(s) : pp. 296–303 Note générale : Génie chimique Langues : Anglais (eng) Mots-clés : Alpha-calcium  sulfate  hemihydrate  FGD  gypsum  Salt  solution  recycling  Pilot  test Résumé : A pilot scale preparation of α-calcium sulfate hemihydrate (α-HH) from flue gas desulfurization (FGD) gypsum was conducted for the first time in mixed salt solutions under atmospheric pressure. The effects of salt solution recycling on the transition of α-HH from FGD gypsum were investigated by a comparison with that in laboratory scale, focusing on the dehydration rate of FGD gypsum, the crystal morphology, chemical composition and mechanical strength of the products. α-HH could be transformed from FGD gypsum in 3.5–6.0 h even though the salt solution was recycled seven times in laboratory tests and eight times in pilot tests. The product obtained in pilot scale has a purity of 95% and the α-HH crystals are mostly a prismatic morphology, with volume weighted mean diameter (D[3,4]) in the range of 52.9–84.0 μm, 2 h bending strength of 5.6–6.2 MPa and 3 d compressive strength of 15.7–25.3 MPa. The salt solution recycling achieves 56% recovery of salts in pilot scale and puts almost no negative impact on the product quality, which can be one of the best strategies to reduce the production cost. It is very likely that the process of salt solution recycling can be adopted in industry. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010916 [article] a - Calcium sulfate hemihydrate preparation from FGD gypsum in recycling mixed salt solutions [texte imprimé] / Baohong Guan, Auteur ; Yang Li, Auteur ; Hailu Fu, Auteur . - 2012 . - pp. 296–303. Génie chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp. 296–303 Mots-clés : Alpha-calcium  sulfate  hemihydrate  FGD  gypsum  Salt  solution  recycling  Pilot  test Résumé : A pilot scale preparation of α-calcium sulfate hemihydrate (α-HH) from flue gas desulfurization (FGD) gypsum was conducted for the first time in mixed salt solutions under atmospheric pressure. The effects of salt solution recycling on the transition of α-HH from FGD gypsum were investigated by a comparison with that in laboratory scale, focusing on the dehydration rate of FGD gypsum, the crystal morphology, chemical composition and mechanical strength of the products. α-HH could be transformed from FGD gypsum in 3.5–6.0 h even though the salt solution was recycled seven times in laboratory tests and eight times in pilot tests. The product obtained in pilot scale has a purity of 95% and the α-HH crystals are mostly a prismatic morphology, with volume weighted mean diameter (D[3,4]) in the range of 52.9–84.0 μm, 2 h bending strength of 5.6–6.2 MPa and 3 d compressive strength of 15.7–25.3 MPa. The salt solution recycling achieves 56% recovery of salts in pilot scale and puts almost no negative impact on the product quality, which can be one of the best strategies to reduce the production cost. It is very likely that the process of salt solution recycling can be adopted in industry. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010916

Thermodynamic preparation window of alpha calcium sulfate hemihydrate from calcium sulfate dihydrate in non - electrolyte glycerol – water solution under mild conditions / Baohong Guan in Industrial & engineering chemistry research, Vol. 50 N° 23 (Décembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13561-1356 Titre : Thermodynamic preparation window of alpha calcium sulfate hemihydrate from calcium sulfate dihydrate in non - electrolyte glycerol – water solution under mild conditions Type de document : texte imprimé Auteurs : Baohong Guan, Auteur ; Guangming Jiang, Auteur ; Hailu Fu, Auteur Année de publication : 2012 Article en page(s) : pp. 13561-1356 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Electrolyte  Preparation Résumé : Through vapor pressure measurements, water activities of the glycerol-water solution were first examined under temperatures of 30―85 °C and glycerol concentrations of 0―50 mol %. The water activity is the only determinant of phase-transition point among CaSO4·2H2O (DH), α-CaSO4·0.5H2O (α-HH), and CaSO4 (AH) in glycerol-water solution. Accordingly, a phase-transition diagram was constructed as a function of temperature (0―140 °C) and glycerol concentration (0―50 mol %), which provided a thermodynamic preparation window of α-HH from DH. Controlling glycerol concentration and temperature within the window, direct transition of DH to α-HH can be regnlated. However, the window is apt to shrink as the operating time is shortened, indicating that its available profile is directed by transition kinetics ofDH to α-HH besides transition thermodynamics. Overall, the glycerol―water solution could act as a novel category of nonelectrolyte medium for α-HH preparation from DH. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25267515 [article] Thermodynamic preparation window of alpha calcium sulfate hemihydrate from calcium sulfate dihydrate in non - electrolyte glycerol – water solution under mild conditions [texte imprimé] / Baohong Guan, Auteur ; Guangming Jiang, Auteur ; Hailu Fu, Auteur . - 2012 . - pp. 13561-1356. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13561-1356 Mots-clés : Electrolyte  Preparation Résumé : Through vapor pressure measurements, water activities of the glycerol-water solution were first examined under temperatures of 30―85 °C and glycerol concentrations of 0―50 mol %. The water activity is the only determinant of phase-transition point among CaSO4·2H2O (DH), α-CaSO4·0.5H2O (α-HH), and CaSO4 (AH) in glycerol-water solution. Accordingly, a phase-transition diagram was constructed as a function of temperature (0―140 °C) and glycerol concentration (0―50 mol %), which provided a thermodynamic preparation window of α-HH from DH. Controlling glycerol concentration and temperature within the window, direct transition of DH to α-HH can be regnlated. However, the window is apt to shrink as the operating time is shortened, indicating that its available profile is directed by transition kinetics ofDH to α-HH besides transition thermodynamics. Overall, the glycerol―water solution could act as a novel category of nonelectrolyte medium for α-HH preparation from DH. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25267515