【摘要】 结合传统共沉淀法和沉淀氧化法的优缺点,在不需要惰性气体保护下,采用新型的改进型共沉淀法通过对酸洗废液的氧化,制备出性能相当的四氧化三铁磁粉。系统研究了反应温度、陈化温度、有机钠盐加入量、烘干温度对四氧化三铁磁粉制备过程的影响,并采用振动样品磁强计、X射线衍射、扫描电子显微镜、透射电子显微镜、马尔文激光粒度仪、全自动比表面积和孔隙分析仪对制备的样品进行表征。结果表明:在ORP=525 mV时,酸洗废液中Fe²⁺和Fe³⁺的摩尔比为1∶1.8,反应温度为50℃,陈化温度为90℃,有机钠盐加入量为0.2 g,可制备出具有较高结晶度的球型四氧化三铁粒子,比饱和磁强度可达85.951 emu·g^-1,比表面积可达78.116 m²·g^-1。更多还原

【Abstract】 Based on the advantages and disvantages of conventional co-precipitation method and precipitation-oxidation method,a novel modified co-precipitation method was used to prepare the Fe₃O₄ by oxidation of pickling waste liquor without gas protection.The effect of reactive temperature,aging temperature,organic sodium salt concentration,drying temperature on formation process of Fe₃O₄ were systematically studied.The Fe₃O₄ magnetic powders were characterized by vibrating sample magnetometer,X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Melvin zetasizer,automatic specific surface area and pore analyzer.The results suggest that the molar ratio of Fe²⁺ and Fe³⁺ in pickling waste liquor is 1 ∶ 1.8 under ORP of 525 m V.The optimum preparation conditions are 50 ℃ of reaction temperature,90 ℃ of the aging temperature and 0.2 g of organic sodium salt.Under these conditions,Fe₃O₄ magnetic powders with higher crystallinity and spherical type can be prepared.The saturation magnetization and specific surface area are 85.951 emu·g^-1 and 78.116 m²·g^-1,respectively.更多还原