Precipitation of monodispersed basic iron(III) sulfate (sodium jarosite) particles

Abstract

Uniform sodium jarosite particles were obtained by forced hydrolysis of ferric salt solutions to which copper sulfate, sodium sulfate, and sodium nitrate were added. It was found that at the same concentrations of ferric and sulfate ions the particle size and yield decreased with the lowering of the concentration of sodium ions, but the morphology remained the same. At a sufficiently small content of sodium in the reacting solution, no precipitation of sodium jarosite particles was observed. Finally, chemical and XRD analyses showed that small amounts of copper ions are incorporated in the crystal lattice which, with the change in the Na⁺/H₃O⁺ ratio, slightly affected the structure of this mineral, but not its other properties.