复合沉淀剂制备高质量碳酸镧及氧化镧的研究  

Preparation of High Quality Lanthanum Carbonate and Lanthanum Oxide by Composite Precipitant

作　　者：张积锴 郑诗礼[2,4] 李平[2,4] 杨幼明[1] 管新地 周洁英[1,2] 陈东英 Zhang Jikai;Zheng Shili;Li Ping;Yang Youming;Guan Xindi;Zhou Jieying;Chen Dongying(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China;Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341101,China;Ganzhou Nonferrous Metallurgy Research Institute Co.,Ltd.,Ganzhou 341000,China;Innovation Academy for Green Manufacture,Institute of Process Engi-neering,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000 [2]中国科学院赣江创新研究院,江西赣州341101 [3]赣州有色冶金研究所有限公司,江西赣州341000 [4]中国科学院绿色过程制造创新研究院,中国科学院过程工程研究所,北京100190

出　　处：《中国稀土学报》2022年第4期624-632,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金面上项目(51974285);江西省重点研发计划项目(20202BBGL73116);赣州市稀土产业基金项目(IAGM2020DB10);赣州市重点研发计划项目(赣市科发[2020]60号)资助。

摘　　要：为满足稀土工业生产对环保、经济的沉淀剂及沉淀技术的需求,以氯化镧料液为原料,碳酸氢钠和碳酸钠为复合沉淀剂制备了碳酸镧和氧化镧。研究了加料方式、复合沉淀剂配比、反应温度、料液浓度、料液及沉淀剂的流量、沉淀过程pH值范围、添加晶种等因素对碳酸镧形貌、粒度及氧化镧中Cl^(-),Na_(2)O含量和稀土总量(REO)等理化性能的影响,运用SEM、粒度分析、XRD等手段对碳酸镧或对应氧化镧形貌、粒度进行了表征。结果表明,控制复合沉淀剂中碳酸氢钠和碳酸钠摩尔比为1∶4,反应温度30℃,料液浓度为110 g·L^(-1),料液流量为6.0 mL·min^(-1),沉淀过程pH值为4.0~4.5,在添加适量碳酸镧晶种和并流加料的条件下,可获得易沉降,粒度D50为23.46μm,形貌为片状堆叠成的类球形La_(2)(CO_(3))_(3)·8H_(2)O晶体;灼烧后氧化镧产品稀土总量为99.62%,Cl^(-)和Na_(2)O含量分别为0.01%和0.001%,达到国家标准GB/T 4154-2015中La_(2)O_(3)-4N_(5)牌号要求。该复合沉淀剂成本低、无氨氮污染,避免了单一沉淀剂的缺点,通过控制沉淀剂配比和沉淀条件及过程可获得质量可控的产品,为实际生产提供了技术基础。In order to meet the demand of environmental protection and economic precipitant and precipitation technology in rare earth industry production,lanthanum chloride was precipitated with sodium bicarbonate and sodium carbonate as composite precipitant,and lanthanum carbonate was prepared by concurrent feeding.Lan⁃thanum oxide was obtained by calcining lanthanum carbonate.SEM,particle size analysis,XRD and other char⁃acterization methods were used.The effects of feeding methods,ratio of composite precipitant,reaction tempera⁃ture,concentration of lanthanum chloride,flow rate of lanthanum chloride and precipitant,pH value range in precipitation process and the addition of crystal seeds on the physical or chemical properties of lanthanum car⁃bonate and corresponding lanthanum oxide,such as morphology,particle size,total rare earth(REO),content of Cl^(-)and Na_(2)O were studied.The morphology and particle size of lanthanum carbonate or lanthanum oxide were characterized by SEM,particle size analysis and XRD.The results showed that lanthanum carbonate with easy sedimentation and excellent crystal shape can be obtained under the following conditions:the molar ratio of sodi⁃um bicarbonate to sodium carbonate in the compound precipitator is 1∶4,the reaction temperature is 30℃,the concentration of lanthanum chloride is 110 g·L^(-1)and the flow rate is 6.0 mL·min^(-1),the pH value of the precipi⁃tation process is 4.0~4.5,and a proper amount of lanthanum carbonate crystal seeds are added.The particle size D50 is 23.46μm,and the morphology of La_(2)(CO_(3))_(3)·8H_(2)O is like spherical crystal with stacked sheet shape.Af⁃ter burning lanthanum carbonate,the total amount of rare earth in lanthanum oxide products is 99.62%,and the contents of Cl^(-)and Na_(2)O are 0.01%and 0.001%,respectively.It meets the requirements of La_(2)O_(3)-4N_(5)brand in national standard GB/T 4154-2015.The composite precipitant has the advantages of low cost,no ammonia nitro⁃gen pollution and avoids the disadvantages of single

关 键 词：NaHCO_(3) 复合沉淀剂 Na_(2)CO_(3) 并流加料 碳酸镧 氧化镧 

分 类 号：TF845.6[冶金工程—有色金属冶金]