High-quality zirconia powder resulting from the attempted separation of acetic acid from acrylic acid with zirconium oxychloride

Both acetic and acrylic acids are low molecular weight carboxylic acids with very similar physical and chemical properties. As a result it is difficult to separate these two acids by the now commercially significant separation techniques such as distillation, solvent extraction, adsorption, ion exchange, calcium salt precipitation, and membrane processes. We propose a metal–organic precipitation process using zirconium oxychloride to separate acetic acid from acrylic acid in the effluent of an acrylic acid plant. The process developed is based on the selective precipitation of acrylic acid, at suitable pH values, by the addition of zirconium oxychloride to the effluent. The resulting precipitate is a precursor that can yield a pure, ultrafine, and partially-stabilized zirconia powder which has been characterised using thermal analysis, infrared spectroscopy, and X-ray diffraction. Environmental, technological and cost advantages will make the present process feasible for the manufacture of advanced zirconia-based ceramics.