Study On The Preparation Of High Properties Magnetic Material By Ferric Oxide Powder Of Steel Mills

The paper analyzed the different batches of pickling iron oxide powder by XRD,XRF and SEM.The paper also discussed the influence law of different magazines elements.Furthermore,the impurities were dealt with different processing method and the influence to magnetic?The experimental results show that,the steel iron oxide powder were pureα-Fe₂O₃ phase alpha and the content of Fe₂O₃ is 97.80%⁹8.77 wt%,which average particle size distribution of D50 particle size is 0.02μm⁰.35μm,and grain sizes of powder particle is about between 200 nm to 500 nm.Most of powder is spherical and scattered more uniform.The morphology of solid ferric oxide powder and shape led to certain difficulty in removing impurity and influence of steel iron oxide powder.The powder has low apparent density and the average moisture content is 0.6%.The main impurity elements were sulfate（SO₃）,silica（Si O₂）,phosphorus pentoxide（P₂O₅）and ClO₂ in Ferric oxide powder,including 0.06 wt%of sulfate（SO₃^-）,which dealt with double alkaline slag processing,after that the sulfur reduction of S content of impurities were from 0.11 wt%down to 0.03 wt%and the S content isconsistent to the national standard of ferrite with iron oxide content in first class YHT1 content requirements（not more than 0.05 wt%）;And the CaO content was from the original average 0.08%down to 0.03%.The content of CaO isconsistent to the national standard of ferrite with iron oxide content YHT4（not more than 0.04%）;The average silica（SiO₂）was 0.19%that exceed national standard content of 20 times.By the method of alkaline cleaning,Si content for desilication process of iron oxide powder optimized the nearly 24 times from 0.19%to 0.008%after purification,which meet YHT1 standard of first class of the according with the national standard requirements;Average content of phosphorus pentoxide（P₂O₅）was 0.42%which exceed national standard content of 80 times and did not meet the national standard requirements.The content of P optimized for an average of 375 times average 0.75%down to 0.75%with the roasting-acid leaching dephosphorization process which has conformed to the national standard of ferrite with iron oxide content in first class YHT1（not more than 0.005%）;Average ClO₂ content was 10 times higher than the national standard content which did not meet the national standard requirements（1.14%）.The washing method is adopted to the chloride ferric oxide powder processing.After washing the chloride process,the Cl content of impurities from the average 1.52%down to 1.52%and the average 38 times was optimized and the content of Cl and meet national standard GB/T24244-20095"ferrite with iron oxide"firsts YHT1（no more than 0.1%）;After dealt with the silicon,chloride and other impurity elements of the sample for the source of iron provided by the steel iron oxide powders and add manganese zinc group in ferrite magnetic is best without silicon chloride removal process.When add manganese zinc group and sintering temperature at 1450℃with 0.06 oxygen partial pressure to balance the sintering atmosphere,the initial permeability（μ_i）properties of soft magnetic is 3426,saturated magnetic induction intensity（Bs）is 525.8m T,coercive force（Hc）is 13.87 A/m.Compared with Japan TDK model for PC40,PC44,the ferrite magnetic can be equal,and close to the high-grade PC50 power ferrite magnetic.