Bulk flow properties of fly ashes at ambient and high temperature--颗粒学报PARTICUOLOGY

Liu, Y., Lu, H., Barletta, D., Poletto, M., Guo, X., Gong, X., & Jin, Y. (2018). Bulk flow properties of fly ashes at ambient and high temperature. Particuology, 38, 113-125. https://doi.org/10.1016/j.partic.2017.04.013

Bulk flow properties of fly ashes at ambient and high temperature

Yi Liu a, Haifeng Lu ^a, Diego Barletta ^b, Massimo Poletto ^b *, Xiaolei Guo ^a, Xin Gong ^a ^*, Yong Jin ^a

a Key Laboratory of Coal Gasification and Energy Chemical Engineering of the Ministry of Education, Shanghai Engineering Research Center of Coal Gasification, Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai 200237, China
b Dipartimento di Ingegneria Industriale, Università degli Studi di Salerno, Via Giovanni Paolo II, 132, I-84084 Fisciano, SA, Italy

10.1016/j.partic.2017.04.013

Volume 38, June 2018, Pages 113-125

Received 8 September 2016, Revised 10 April 2017, Accepted 24 April 2017, Available online 14 October 2017, Version of Record 2 April 2018.

E-mail: mpoletto@unisa.it; gongxin@ecust.edu.cn

Highlights

• Shear testing of fly ashes were conducted at ambient temperature and 500 °C with the HT-ASC.

• A model was provided to predict isostatic tensile strength of fly ashes at elevated temperatures.

• Effect of temperature on bulk flow properties were investigated with a microscale approach.

Abstract

The bulk flow properties of four different fly ashes were assessed at ambient temperature and at 500 °C, using a high temperature annular shear cell. These powders all resulted from industrial processes and had similar chemical compositions but different particle size distributions. Applying a high temperature was found to increase the powder cohesion, with this effect being more significant in the case of the sample with the highest proportion of fines. To better understand the effect of temperature on the bulk flow properties of these materials, a model previously proposed by some of the authors was used to correlate the powder isostatic tensile strength with the interparticle forces and microscale particle contact structure. This model combines the continuum approach with description of particle-to-particle interactions. A comparison with experimental data indicated that the effects of consolidation and temperature on the tensile strength of the fly ashes were correctly described by the model. This theoretical approach also elucidates the mechanism by which the temperature affects the bulk flow properties of fly ashes through modifications of the microscale interparticle contacts.

Graphical abstract

Keywords

Fly ash; High temperature annular-shear cell; Flow modelIsostatic tensile strength; Interparticle force

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