保温时间对微波场中氧化钇制备的影响  

Preparation of Yttrium Oxide in Microwave Field with Different Holding Time

作　　者：吕鹏 李鑫培 张良静 陈楷华 李世伟[1] 尹少华[1] Lv Peng;Li Xinpei;Zhang Liangjing;Chen Kaihua;Li Shiwei;Yin Shaohua(Unconventional Key Laboratory,Faculty of Metallurgy and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学冶金与能源工程学院非常规省部共建教育部重点实验室,云南昆明650093

出　　处：《稀有金属》2022年第1期46-56,共11页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51604135,51504116);云南省万人计划青年精英人才项目(YNR-QNBJ-2018-323)资助。

摘　　要：介绍了一种基于微波真空干燥与微波推板窑煅烧集成工艺制备氧化钇的新方法。利用微波真空干燥炉干燥草酸钇,并结合微波推板窑煅烧干燥过的物料草酸钇,通过控制保温时间得到了粒度分布范围较窄,颗粒均匀的氧化钇粉末。利用差热-热重(TG-DSC)分析草酸钇的分解过程,得出在179℃下可得到Y_(2)(C_(2)O_(4))_(3)·_(2)H_(2)O,比微波真空干燥炉(135℃)高44℃。X射线衍射(XRD)分析表明,微波推板窑煅烧800℃保温90 min后,草酸钇水合物已形成完整的Y_(2)O_(3)立方晶体结构。傅里叶红外光谱(FT-IR)同样得出90 min是形成完整的(Y-O)峰的一个时间节点。灼减量(L.O.I.)分析结果表明,保温100 min后可将氧化物的分解量降低至1%以下。扫描电镜(SEM)分析表明,保温120 min产物的形态仍然保留水合物的无定型特征,但颗粒尺寸明显降低,并且很少有团聚体。粒度分布(PSD)分析表明,保温120 min后,粒度分布范围明显变窄,水合物的中位粒径(D_(50))从22.3μm降低至约7.0μm。从保温180 min的SEM图片和PSD图发现,微波推板窑煅烧氧化钇不会因保温时间过长而发生团聚和颗粒生长的现象。此外,本实验还对比了常规煅烧,微波加热功率和保温功率对产品的粒度和形貌的影响。综合考虑,最佳的保温时间为120 min。With the development of emerging industries,national defense science and technology industry and high-precision products industry,rare earth has become an indispensable key element,especially micro/nano rare earth materials,which integrate rare earth characteristics and micro/nano characteristics,have comprehensive excellent properties and are widely used.Microwave radiation directly heated the material through the dielectric loss inside the material,and the microwave carries out in-situ energy conversion inside the material,which had the advantages of fast heating rate and high heating efficiency.It had the advantages of reducing reaction temperature,shortening reaction time,promoting energy saving and consumption reduction.Microwave radiation method could improve the defects caused by conventional methods,such as serious sintering,lattice damage and performance degradation,irregular heterophane growth,time-consuming and laborious post grinding,and it was difficult to meet the requirements of high-end products for purity and particle size.Therefore,in this study,the two-stage process of microwave vacuum drying oven drying and microwave pusher kiln calcination was used to carry out pilot experiments with different holding time at 800℃,and investigation was perfermed on the variation law of crystal growth characteristics of materials in microwave field with holding time,especially the special data under high temperature,so as to enrich the basic data of microwave metallurgy.The microwave pusher kiln used in the experiment was mainly composed of propulsion device,feed air tight chamber,feed plug plate,preheating section,heating section,insulation section(2∶3∶5),cooling chamber,discharge air tight chamber,smoke exhaust pipe,thermometer(connecting thermocouple),circulating cooling water pipe,discharge plug plate and transmission device.The main changes of yttrium oxide before and after microwave field were systematically analyzed by laser particle size distribution(PSD)instrument,differential thermal gravimetri

关 键 词：微波真空干燥炉 微波推板窑 氧化钇 保温时间 

分 类 号：TF845.2[冶金工程—有色金属冶金]