Ammonium sulfate residue is a particulate solid and is produced during the manufacture of ammonium sulfate fertilizer. The residue used in this study contained a large portion of calcium carbonate, from which active l...Ammonium sulfate residue is a particulate solid and is produced during the manufacture of ammonium sulfate fertilizer. The residue used in this study contained a large portion of calcium carbonate, from which active lime （CaO） was recovered via thermal decomposition. We used a purpose-built device to decom- pose the residue in a semi-suspension state. We found that CaO had the highest activity when residue was decomposed at 850-900 ~C. Our experiments indicated that ammonium sulfate residue should be decom- posed in a suspension state to produce active CaO. Based on our laboratory test findings, an industrial-scale production line with a high solid/gas ratio in a suspension state was devised. The optimal operating con- ditions for the decomposition of the ammonium sulfate residue to produce high quality CaO were also investigated.We found that the CaCO3 decomposition rate was high and the CaO product was highly active, averaging 170 s by the citric acid method. Morphology measurements showed that the CaO product had a porous structure and a large specific surface ensuring high activity.展开更多
基金Wengfu Phosphate Fertilizer Plant(WPFP),WengFu(Group) Co.,Ltd,Guizhou,China for financial supportgrants from National Science and Technology Support Program(No.2012BAA08B00)Science and Technology Integrated Innovation Project of Shaanxi Province(No.2012KTZB03-04)
文摘Ammonium sulfate residue is a particulate solid and is produced during the manufacture of ammonium sulfate fertilizer. The residue used in this study contained a large portion of calcium carbonate, from which active lime （CaO） was recovered via thermal decomposition. We used a purpose-built device to decom- pose the residue in a semi-suspension state. We found that CaO had the highest activity when residue was decomposed at 850-900 ~C. Our experiments indicated that ammonium sulfate residue should be decom- posed in a suspension state to produce active CaO. Based on our laboratory test findings, an industrial-scale production line with a high solid/gas ratio in a suspension state was devised. The optimal operating con- ditions for the decomposition of the ammonium sulfate residue to produce high quality CaO were also investigated.We found that the CaCO3 decomposition rate was high and the CaO product was highly active, averaging 170 s by the citric acid method. Morphology measurements showed that the CaO product had a porous structure and a large specific surface ensuring high activity.
