Study on the preparation of spinel ferrites with enhanced magnetic properties using limonite laterite ore as raw materials

Preparation of spinel ferrites using limonite laterite ore as raw materials was proposed. The effect of Zn substitution on the structure, magnetic properties of as-prepared spinel ferrites were systematically characterized and discussed. The results show that single-phase spinel ferrite was directly synthesized from the precursor solution with the leaching temperature and leaching acid concentration of 200 °C and 2.25 mol·L−1, respectively, and after calcination at 1000 °C for 2 h. Moreover, single-phase of spinel ferrites with different Zn substitution contents (x = 0.00, 0.05, 0.23, 0.35, 0.47, 0.58) could be also obtained. All the lattice constant (a), average grain sizes (d) and X-ray density (Dx) increase with increasing Zn substitution content. With Zn substitution content increasing from 0.00 to 0.58, the saturation magnetization (Ms) value increased from 34.0 to 65.9 emu·g−1 for x = 0.35, and then decreased to 50.7 emu·g−1 while the coercivity (Hc) value decreased from 50 Oe to 14 Oe. This paper provides a pathway for comprehensive utilization of limonite laterite ore and synthesis of spinel ferrites with excellent magnetic performance.