Investigation of flow dynamics of porous clinkers in a ball mill using technitium-99m as a radiotracer

Jimmy Gitau; Michael J Gatari; Harish J Pant

doi:10.1016/j.apradiso.2019.108902

Investigation of flow dynamics of porous clinkers in a ball mill using technitium-99m as a radiotracer

Appl Radiat Isot. 2019 Dec:154:108902. doi: 10.1016/j.apradiso.2019.108902. Epub 2019 Sep 22.

Authors

Jimmy Gitau¹, Michael J Gatari², Harish J Pant³

Affiliations

¹ Kenya Bureau of Standards, Nairobi, Kenya.
² Institute of Nuclear Science and Technology, University of Nairobi, Nairobi, Kenya.
³ Isotope and Radiation Application Division, Bhabha Atomic Research Centre, Mumbai, 400085, India. Electronic address: hjpant@barc.gov.in.

PMID: 31581062
DOI: 10.1016/j.apradiso.2019.108902

Abstract

A radiotracer investigation was carried out in a ball mill of a cement plant in Kenya. Residence time distribution (RTD) of raw feed to the mill was measured using Technetium-99m adsorbed on the clinkers as a radiotracer. From the measured RTDs, solid holdup and mean residence times (MRTs) in the ball mill and associated separator were determined. The measured RTDs were modelled using axial dispersion model (ADM) and tank-in-series model both connected with a plug flow component in series. The results of the modelling indicated significant degree of backmixing within the ball mill and no axial mixing in the separator.

Keywords: Axial dispersion model; Ball mill; Clinker; Mean residence time; Pozzolana; Radiotracer; Residence time distribution; Separator; Tank-in-series with backmixing model; Technetium-99m.