The Controlling Factors in the Content of Cr6+ in Green Strontium Ferrite
In order to reach the standard of the RoHS that the content of Cr6+ lower than 200ppm in ferrite, this reserch focused on the factors that influence on the content of Cr6+ during the preparation of Strontium Ferrite. The results show that the content of Cr6+ in Strontium Ferrit can be controlled among 91~117 ppm, and the optimum condition is as follows: the quality ratio of raw materials/graphite=10:1.25, the rate of the N2 flow 0.1~0.15 L/min, sintered temperature 950~1020°C, residence time 25~35min at the corresponding temperature point, granularity of the mixed system lower than 0.1~0.3mm.
Zhong Wei Gu, Yafang Han, Fu Sheng Pan, Xitao Wang, Duan Weng and Shaoxiong Zhou
N. C. Chen et al., "The Controlling Factors in the Content of Cr6+ in Green Strontium Ferrite ", Materials Science Forum, Vols. 610-613, pp. 28-31, 2009