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Thermal treatment of dredged sediment in a rotary kiln / Jocelyn Ramaroson in Industrial & engineering chemistry research, Vol. 51 N° 21 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7146-7152 Titre : Thermal treatment of dredged sediment in a rotary kiln : Investigation of structural changes Type de document : texte imprimé Auteurs : Jocelyn Ramaroson, Auteur ; Moussa Dia, Auteur ; Jean-Louis Dirion, Auteur Année de publication : 2012 Article en page(s) : pp. 7146-7152 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Rotary  kiln  Sediments  Heat  treatment Résumé : Sediment deposits cause the silting of channels, rivers, and lakes. This completely natural phenomenon is exacerbated by the introduction of industrial and urban wastes into the erosion and sedimentation process. Other problems then appear, such as an increased risk of flooding, a reduced capacity for biological purification, and an associated loss of biodiversity. The presence of toxic compounds in the sediments (of industrial, household, or agricultural origin) worsens the situation, and measures must be taken to restore the natural environmental conditions and processes. This study assesses the technology of treating heavy metals from dredged sediments using phosphoric acid (the NOVOSOL process, which was developed by SOLVAY), which aims to convert metals, mainly Pb, Cd, Zn, and Cu, into insoluble metallic phosphates, and (by calcination) to engineer the properties of the final residues for beneficial use. The effectiveness of this treatment was evaluated by creating the chemical reaction, followed by convective drying and maturation of the treated sediment at ambient temperature, and finally by calcination (400—1000 °C). This paper focuses on the study of the decomposition of organics and structural change in the sediment during thermal treatment in a rotary kiln. The results showed that the specific surface, the particle size, and the total organic of the sediment are dependent on the calcination parameters such as the residence time, the calcination temperature, and the flow rate. The degradation of the organic compounds is effective at 600 °C. An increase in specific surface is observed until 600 °C, followed by a significant reduction accompanied by a densification and growth of particles. This increase in specific surface area observed attributed to the formation of pores due mainly to the decomposition of organics and the gas evolve (CO2, H2O, ...) from 600 °C to 900 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948454 [article] Thermal treatment of dredged sediment in a rotary kiln : Investigation of structural changes [texte imprimé] / Jocelyn Ramaroson, Auteur ; Moussa Dia, Auteur ; Jean-Louis Dirion, Auteur . - 2012 . - pp. 7146-7152. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7146-7152 Mots-clés : Rotary  kiln  Sediments  Heat  treatment Résumé : Sediment deposits cause the silting of channels, rivers, and lakes. This completely natural phenomenon is exacerbated by the introduction of industrial and urban wastes into the erosion and sedimentation process. Other problems then appear, such as an increased risk of flooding, a reduced capacity for biological purification, and an associated loss of biodiversity. The presence of toxic compounds in the sediments (of industrial, household, or agricultural origin) worsens the situation, and measures must be taken to restore the natural environmental conditions and processes. This study assesses the technology of treating heavy metals from dredged sediments using phosphoric acid (the NOVOSOL process, which was developed by SOLVAY), which aims to convert metals, mainly Pb, Cd, Zn, and Cu, into insoluble metallic phosphates, and (by calcination) to engineer the properties of the final residues for beneficial use. The effectiveness of this treatment was evaluated by creating the chemical reaction, followed by convective drying and maturation of the treated sediment at ambient temperature, and finally by calcination (400—1000 °C). This paper focuses on the study of the decomposition of organics and structural change in the sediment during thermal treatment in a rotary kiln. The results showed that the specific surface, the particle size, and the total organic of the sediment are dependent on the calcination parameters such as the residence time, the calcination temperature, and the flow rate. The degradation of the organic compounds is effective at 600 °C. An increase in specific surface is observed until 600 °C, followed by a significant reduction accompanied by a densification and growth of particles. This increase in specific surface area observed attributed to the formation of pores due mainly to the decomposition of organics and the gas evolve (CO2, H2O, ...) from 600 °C to 900 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948454