利用红土镍矿直接制备多元金属铁氧体磁性材料的研究

摘要

以褐铁矿型和腐泥土型红土镍矿为原料,分别采用酸浸-共沉淀-煅烧与碱浸脱硅-煅烧方法进行了尖晶石铁氧体材料的合成研究,重点考查了不同合成方法对于制备得到的铁氧体材料结构和性能的影响.通过 X射线衍射(XRD)、傅里叶红外分析(FT-IR)和综合物性测量系统(PPMS)对铁氧体的结构和性能进行了表征.结果表明,采用两种方法都能合成单一尖晶石铁氧体材料,当采用酸浸-共沉淀-煅烧法,以氢氧化钠溶液为沉淀剂时,合成的是 Ni-Co-Mn 共掺杂 MgFe2O4;而采用碱浸脱硅-煅烧法合成的是含有少量 SiO2的多元金属掺杂 Mg-Fe2O4.磁性能结果显示制备得到的铁氧体材料在常温下均表现出典型的亚铁磁性.多元金属的协同效应和少量SiO2(2%左右)的掺杂有利于磁性能的提高和改善.%In this paper,the preparation of spinel ferrites using limonite laterite ore and saprolite laterite ore as raw materials by acid leaching-coprecipitation-calcination and alkali leaching desilication-calcination methods was proposed.The effects of preparation methods on the structure and magnetic properties of as-prepared spinel fer-rites were focused and investigated,which were characterized by X-ray diffraction (XRD),Fourier transfer-in-frared spectrometry(FT-IR)and physical property measurement system (PPMS).The results showed that sin-gle phase of spinel ferrite could be obtained by both the two methods.Using acid leaching-coprecipitation-calci-nation method,Ni-Co-Mn co-doped magnesium ferrites were synthesized with NaOH solution as precipitant, while using alkali leaching desilication-calcination method,polymetallic ferrites with small amount of impurity SiO2were obtained.The magnetic properties showed that all the as-prepared samples exhibited typical ferro-magnetism.The synergistic effect of multiple metals and doping of a small amount of SiO2(about 2%)could be beneficial to the enhancement and improvement of the magnetic properties.