Rheological properties and small-angle X-ray scattering studies of phosphate dust obtained from baghouse collectors

Abstract Baghouse dust collectors are using in the drying unit of Beni Idir situated in Beni-Idir Khouribga city, Morocco, to retrieve phosphates particles from dust air-drying before its expulsion through the smokestacks. The phosphate dust samples used in this study were taken from the filtration chamber of the baghouse dust collectors. The first sample (S1) is untreated calcium phosphate dust, the second (S2) is the calcium phosphate dust from the outside of filter media while the third one (S3) is the calcium phosphate dust from the inside of filter media which causes clogging depth. In this paper, the rheology and the small-angle X-ray scattering (SAXS) of the three samples were investigated to elucidate the changes in terms of local structure, the viscosity, and the shear stress parameters. The rheological behavior of the dust samples was investigated for a solid mass concentration ranging from 50 to 60%, the three samples (S1) (S2) and (S3) had a solid mass concentration of C1=60%, C2=55% and C3=50% and a shear rate in the range from 1 to 1000 s−1. The results indicated that during the filtration process, the pseudo-plastic behavior of the dust phosphate changed to that of Bingham. Comparing the results of the sample’s viscosity, we found that the viscosity decreased during the process filtration. The SAXS results suggested that the dust phosphate samples possess a fractal surface structure of enormous dust particles with a rough surface interface. This new study highlights the rheological behavior of grain phosphates that could be extrapolated to other mining powder as grains material or in solution. It is important to understand the rheological characteristics of materials, their flow, and the subsequent deformation of matter as a result of the flow.