Decomposition of ammonium sulfate residue in a high solid/gas ratio suspension state with an industrial-scale reactor system (production line)--颗粒学报PARTICUOLOGY

Li, Q., Xu, D., Chen, Y., Yao, Y., Sun, Z., & Ding, S. (2015). Decomposition of ammonium sulfate residue in a high solid/gas ratio suspension state with an industrial-scale reactor system (production line). Particuology, 22, 107-113. https://doi.org/10.1016/j.partic.2014.11.005

Decomposition of ammonium sulfate residue in a high solid/gas ratio suspension state with an industrial-scale reactor system (production line)

Qi Li ^a, Delong Xu ^a, Yanxin Chen ^a, Yanfei Yao ^a, Zhi Sun ^b, Songxiong Ding ^{a c *}

a College of Materials & Mineral Resources, Xi’an University of Architecture and Technology, Xi’an 710055, China
b Beijing Triumph International Engineering Co., Ltd., Beijing 100024, China
c Department of Civil Engineering, University of Agder, Grimstad, Norway

10.1016/j.partic.2014.11.005

Volume 22, October 2015, Pages 107-113

Received 29 September 2014, Revised 15 November 2014, Accepted 24 November 2014, Available online 25 February 2015, Version of Record 4 August 2015.

E-mail: songxiong.ding@uia.no

Highlights

• Ammonium sulfate residue was decomposed in suspension state with a high solid/gas ratio.

• An industrial-scale reactor system (production line) was developed to produce active CaO via decomposition.

• Optimum operating conditions for the decomposition were determined.

• The product had a porous structure and a large specific surface ensuring high activity.

Abstract

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 decompose 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 decomposed 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 conditions 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.

Graphical abstract

Keywords

Ammonium sulfate residue; Particulate solids; Active CaO; Suspension decomposition; High solid/gas ratio

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