| MnZn ferrite is the key materials of modem electronic industry andinformation industry. With the rapid development of telecommunication andcomputer technology, MnZn ferrite is required for mass production. It willbring out a great lot of waste MnZn ferrite in the manufacture process. Ifhigh quality soft magnetic ferrite powders can be prepared from waste ferrite,the waste ferrite recycling process, having great benefits to society and theeconomy, will be an environmentally acceptable technology. MnZn softmagnetic ferrite powders which were prepared through the process ofsimultaneous leaching, reducing, purification and co-precipitation by wasteMnZn ferrite as material, finally were made into high permeability ferriteand the power fettite. The following researches have been carried out:The influence of time, the temperature and the amount of H2SO4 inmolar excess on the leaching yields of waste MnZn ferrite were studied. Theoptimal leaching conditions were: the temperature, excess molar times ofH2SO4 and leaching time in the leaching process were 100-105℃, 1.05 timesand 2.0h, respectively. The four bench scale experimental results indicatedthat the leached yields of Fe, Mn and Zn were 98.7％,98.5％and 98.6％under the optimal leaching condition.The prescription of Fe, Mn and Zn in reducing solution could meet thedemand of theoretical prescription of MnZn ferrite by the proportionreducing technology. The experimental results indicate that the relativeerrors were under +2％to theoretical prescription. The analysis results showthat the [Fe3+]≤0.1 g/L, reducing yield≥99.8％. So the reaction could carryout completely by the proportion reduction.This paper studied the influence of pH, time and temperature ofreaction and variety of the flocculants on elimination of silicon during thepurification process. The results of experiments showed that, under theoptimal conditions- the pH, the reaction time and temperature were 5.0-5.5, 3.0h and 45-50℃respectively. The percentage of removing silicon wasabove 94% by 31-C flocculant. So the qualities of the reducing solutioncould compete with the demand for the preparation of co-precipitationpowder.The influences of two different dump processes were studied by theanalysis of the content of impurities in co-precipitation powders. Theexperimental results show that the difference of impurity content betweenthe reverse-dump and obverse-dump process were tiny. The analysis data ofMnZn ferrite which was prepared by the co-precipitation powders confirmthat the technology of recycling waste ferrite under the condition ofindustrial scale in FengHua Company was available to make the high-quality power ferrite and high permeability ferrite without dopant andproportionment.
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