Synthesis of nickel-chromium-zinc ferrite powders from stainless steel pickling liquors

A low-temperature method was used to synthesize a nickel-chromium-zinc ferr ite from stainless steel pickling liquor, a waste product of the steel indu stry, which is listed in most industrialized countries as a toxic and hazar dous waste. This article reports the recovery (as a valuable ferric product ) of the total metal content of this waste (namely, iron, chromium, nickel, and minor manganese), by coprecipitation of the multi-ionic solution and Z n2+ (provided by ZnO) with I Mn-butylamine at room temperature. The spinel- type ferrite produced was characterized by x-ray diffraction, thermogravime tric analysis and differential scanning calorimetry, and scanning electron microscopy. Its recorded magnetization of 2600 emu cm(-3) allows its use in different magnetic applications. Furthermore, the synthesis method is a lo w-cost technology that yields a more environmentally friendly final effluen t.