Extract Useful Metal Waste Alkaline Manganese Batteries Through The Process Of Hydrothermal Synthesis Of Mn-zn Ferrite Study

The manganese zinc ferrites are one kind of extremely important ferrite material which has excellent high-frequency properties, wear resistance, fine chemical stability, well workability and high anti-flaking performance. They are foundation materials of the modern electronics industry and the information industry. More and more requirements are put forward to the manganese zinc ferrites material along with the communication technology and the computer technology develop rapidly. The development of soft magnetic materials has experienced a period from crystalline state, the amorphous state to the nanomicrocrystalline state.In this work, nano crystalline Mn-Zn ferrites were synthesized from spent alkaline Zn-Mn batteries through the leaching, the co-precipitation and the hydrothermal process. Firstly, the acid leaching process was investigated and the useful metallic ion recovery with different condition was compared to obtain the optimized condition to recycle Fe, Zn and Mn metal in the spent battery. The result show that the acid concentration of 3.0 mol/L, leaching time of 2 h, leaching temperature of 80℃and liquid solid ratio of 15:1 are optimal. Each kind of influence factor was studied simultaneously. Then the multianalysis of the co-precipitation process was carried out to study the pH value scope which may make sure various metallic ions to precipitate and the complexes species which possibly exists in the system. The relationship between concentration of Fe(III), Mn(II), Zn(II) and the pH value was obtained through the thermodynamic analysis of Fe(III)-Mn(II)-Zn(II)-NaOH-H₂O system The result showed that all irons were precipitated completely at the pH value of 10～11. Finally this paper has studied the hydrothermal preparation process and the crystal structure of the product. Studies on the different hydrothermal condition and their influences on the formation of the crystal, particle size and the lattice constant were carried out. The optimum condition of the hydrothermal process and an initial discussion on the relationship between the metallic ion position in A, B site and the lattice constant ware obtained subsequently.This method to handle of spent alkaline batteries without all kinds of the metallic ion being separated may synthesize the manganese zinc ferrites directly through the adjustment proportion of the precursor. The magnetic particles with uniform grain size, less aggreg- ation and excellent crystallinity can also be prepared by hydrothermal method. This process is an effective method to recycle the spent alkaline Zn-Mn batteries harmlessly and it has provided a new raw material for the production of manganese zinc ferrites, which can be expected to be applied in the future.