Synthesis of BaFe12O19 by oxi-coprecipitation from hydrochloric steel pickling liquors

The steel pickling liquour is formed by HCl washing water and a high content of Fe(II). This liquor is mixed with a Ba(II) solution in a stoichiometric rate to produce a precursor powder to obtain BaFe12O19. In all cases we obtained a mixture of BaFe12O19 and alpha-Fe2O3. The qualitative and quantitative analyses were made by XRD and the magnetic properties were measured by VSM technique. We will report the relation between the oxi-coprecipitation process conditions and the magnetic properties and the role of NaCl during the calcination step. NaCl was formed from dissolution in the oxi-coprecipitation process. NaCl originates structural defects in the powder so, the solid state reaction, during the calcination process, is improved. An excess of NaCl didn't increase the magnetic properties and promoted by-products formation, so the Fe/Ba rate is stoichometric but calcined products had low magnetic properties.