A New Process Study Of Producing Manganese Zinc Soft Magnet Ferrite Powder Directly By Mineral

Tradition method of preparation of soft magnet ferrite and directly co-precipitation process has following disadvantages:high production costs, complex purification process and so on. This paper proposed a new purification process of preparation manganese zine soft magnet ferrite (type of lack ferrite manganese zine powder). Some conditions of this new process were studied under the theoretical analysis, such as leaching, purification, co-precipitation. Depth removal of silicon, calcium and magnesium in purification process was particularly study. Finally, those two difficult problems were solved. We also achieved the purpose of reducing cost and simplifying process. Co-precipitation powder of experimental output reached the preparation of midrange soft magnetic ferrite requirements. The main research contents in thos papers are described below:1. The basic principle of the new process in leaching, purification, co-precipitation were analyzed. This study laid a theoretical foundation for process study.2. The influence of temperature, mineral acid ratio, liquid-solid ratio, time etc. factors in leaching rhodochrosite, zinc ash alone and comprehensive leaching were studied in this process. Experimental results show that under such best conditions:leaching temperature 80℃, mineral acid 0.64, liquid-solid ratio 4:1, leaching time 2h, the manganese zinc leaching rate in manganese zinc comprehensive leaching process were 98.9%,91.1% respectively.3. The influence of dosage of flocculant, molecular weight, pH value, Fe3+, types of neutralizer, Aging time, filtering form, washing etc. factors were studied in silicon removal process. Experimental results show that under such best conditions:flocculent addition amount 2(v/v)%, flocculant molecular 8 million, total concentration of Fe3+ about 22g/L reaction time 1h, temperature 60℃, ending pH 4.8, ammonia as neutralizer, immediately filtering after reaction completed and washing slag by hot water, washing water about 15(v/v)%, the recovery rate of manganese and zinc were about 91.4%,82.3% respectively, and silicon content in solution were about 10mg/L.Also the method of using sulfide precipitation to remove Cu, Pb, Cd and such heavy metal ions in solution were studied, and the experimental results show that under such best conditions:pH 3, sulfide ammonia 1.4 times of theoretical addition, reaction time 40min, the removal rate of Cu, Cd, Pb achieved 96.38%,91.92%,82.68% respectively.4. As raw material with high magnesium, the method of using fluoride precipitation to removal calcium magnesium is difficult, and the cost is high, so the calcium magnesium impurities distribution rule in solution by using ammonium bicarbonate as precipitation agent were studied. Experimental results show that ammonium bicarbonate addition amount and precipitation pH value had very big effect on calcium magnesium precipitation rate, when ammonium bicarbonate addition amount 90% times of theoretical addition, ending pH 7, the average recovery of manganese zinc were about 90.2%,97.77%. Removal rate of calcium magnesium achieved 90% and 99%, the content in powder of Ca, Mg, silicon were 0.08wt%,0.05wt%,0.01wt% after calcining, it reached the preparation of midrange soft magnetic ferrite requirements.