Production of magnetite nanoparticles from Ethiopian iron ore using solvent extraction and studying parameters that affect crystallite size

Crystallite size is one of the fundamental factors controlling the magnetic property of magnetic nanoparticles. In this study, magnetite nanoparticles were produced from Ethiopian iron ore and the effect of solvent extraction parameters on the crystallite size were investigated by considering classical nucleation theory. First, the iron ore was crushed and unwanted gangues were discarded, then followed by further grinding to get a black powder. Finally, the magnetite nanoparticles were produced using solvent extraction and co-precipitation method. For the solvent extraction, tri-butyl phosphate (TBP) and tri-octyl phosphine oxide (TOPO) was used as an extractant, while 2-ethyl-hexanol, and heptanol were used as a modifier and diluent, respectively. The synthesized nanoparticles was characterized using XRD, SEM (EDS), TGA, and FTIR. The results show that leaching temperature and modifier concentration have a significant effect on the crystallite size of the nanoparticles. Comparison of the crystallite size using the Scherrer equation reveals the mean crystallite size of the sample extracted using TBP is smaller than the sample extracted using TOPO.