Ultrasonic assisted solvent extraction in synthesis of ceria nanofluids from rare earth material for heat exchange application

R Giri, M Ghosh, A Tripathy and G Nath

Abstract

Power ultrasound energy has been extended to sample pretreatment and particle disruption, as a consequence of which its penetration to atomic and subatomic spacing enhances the extraction of materials from their ores. Solvent extraction technique was employed for extraction of cerium from rare earth element by use of compatible optimum blended solvent. Nanoceria was prepared using cerous nitrate (Ce(NO₃)₃  6H₂O) and ammonium acid carbonate (NH₄HCO₃) as starting materials resulted from extraction of rare earth material by ultrasonic cavitation method. Experimental techniques like x-ray diffractometer, scanning electron microscope, transmission electron microscope, infrared spectroscope, UV-Vis spectra and fluorescence spectrophotometer are employed for characterisation and analysis of other material properties of the ceria nanoparticles. Thermo physical properties like density and viscosity were measured in aqueous ceria nanofluids for different temperatures and volume fractions. Measured values of thermal conductivity and ultrasonically computed values are compared for optimum concentration of CeO₂ nanofluid and the effect of ultrasonication in enhancement of thermal conductivity is discussed.