Key Technology Of Producing High Performance Strontium Ferrite By Rolling Iron Oxide

With the increase of the steel production capacity in China, the amount of solid waste produced by the steel industry is getting more and more. To improve the comprehensive utilization rate of solid waste is not only significant for economic benefits, but also important for social implication. Iron oxide is one of the major solid waste produced during the rolling process, and at the same time, it is the main raw material of hard ferrite. We focus our attention on the production of high-performance permanent magnet of strontium ferrite using the iron oxide producing during rolling process in this paper.We use the iron scale and iron oxide red as the raw material, and use SrTiO3, CaCO3, SiO2 and Al2O3 as the auxiliary materials to product the strontium ferrite with high performance. The technological process is below:raw materials, ingredients, ball milling, presintering, crushing, quadratic formula, ball milling, forming, sintering, performance test. Then we use the XRD, permanent magnet automatic measurement device to measure and analyze the physical property of the samples. We mainly investigate the effects of different formula and doping-La, Co on the magnetic performance of M-type strontium ferrite. Results are as below:(1) Without rare-earth elements, we use the iron oxide red as the raw material and synthesis the sample with good property by the effects of molar ratio and the secondary additives researches. The obtained magnetic property is as below: Br=423.5 mT, Hcb=273.0 kA/m, HcJ=286.8 kA/m, (BH)max=34.5 kJ/m3. And it commensurates with FB5B and FB5H of TDK, Japan.(2) We use the iron oxide red as the pre-sintering material, and synthesis the sample with good property by addition of Co oxide and La oxide. The coercive force of sample is further improved. The magnetic property is as below:Br=421.8 mT, Hcb=323.8 kA/m, Hcj=372.5 kA/m, (BH)max=34.9 kJ/m3. And it commensurates with FB6H and FB6B of TDK.(3) By using iron scale as the raw material, through the research of the influence of the molar ratio and the secondary additives, the magnetic properties of prepared samples are as follows:Br=396.9 mT, Hcb=285.7 kA/m, Hcj=296.1 kA/m, (BH)max=30.6 kJ/m3; by the addition of La and Co, the magnetic properties of prepared samples are as follows:Br=394.7 mT, Hcb=287.4 kA/m, Hcj=350.2 kA/m, (BH)max=29.6 kJ/m3.