碱熔-EDTA络合滴定法测定含氟铈基稀土抛光粉中氟  

Determination of fluorine in fluorine-containing cerium-based rare earth polishing powder by alkali fusion-EDTA titration

作　　者：张红[1,2] 王素梅 王丹[1,2] ZHANG Hong;WANG Su-mei;WANG Dan(Baotou Research Institute of Rare Earths,Baotou 014030,China;State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization,Baotou 014030,China)

机构地区：[1]包头稀土研究院,内蒙古包头014030 [2]白云鄂博稀土资源研究与综合利用国家重点实验室,内蒙古包头014030

出　　处：《冶金分析》2020年第11期97-101,共5页Metallurgical Analysis

摘　　要：含氟铈基稀土抛光粉中氟含量为1%~8%(质量分数),采用水蒸气蒸馏法处理样品时操作繁琐不易掌握。实验选择氢氧化钠-过氧化钠混合熔剂高温(750℃)熔融样品10min,再用水浸取过滤,使氟全部转至滤液中并与稀土分离,调节酸度为pH 2左右以过量镧沉淀氟,煮沸1~2min,在六次甲基四胺-盐酸缓冲体系下用EDTA滴定剩余镧,间接测定样品中氟含量。实验方法用于测定含氟铈基稀土抛光粉中氟,结果的相对标准偏差(RSD,n=11)为0.88%~2.9%;方法用于标准样品抛光粉GSB04-3426-2017中氟的测定,测定值与认定值一致;分别按照实验方法和国标GB/T 20166.2—2006中的方法对标准样品GSB04-3426-2017和含氟铈基稀土抛光粉实际样品中氟进行测定,两种方法测定结果相吻合。The content of fluorine in fluorine-containing cerium-based rare earth polishing powder is 1%-8%(mass fraction).During the sample treatment by steam distillation,the operation is cumbersome and difficult to master.The sample was melted with sodium hydroxide-sodium peroxide mixed flux at high temperature(750℃)for 10 min followed by water leaching and filtration.The fluorine in sample was totally transferred to filtrate,realizing the separation with rare earths.The pH of solution was adjusted to about 2 to precipitate fluorine with excessive lanthanum.After boiling for 1-2 min,the residual lanthanum was titrated with EDTA in hexamethylenetetramine-hydrochloric acid buffer system.The content of fluorine in sample was indirectly determined.The proposed method was applied for the determination of fluorine in fluorine-containing cerium-based rare earth polishing powder.The relative standard deviations(RSD,n=11)of measurement results were between 0.88%and 2.9%.The content of fluorine in standard sample of polishing powder(GSB04-3426-2017)was determined according to the experimental method,and the found results were consistent with the certified values.The contents of fluorine in standard sample(GSB04-3426-2017)and actual sample of fluorine-containing cerium-based rare earth polishing powder were determined according to the experimental method and the method in national standard GB/T20166.2-2006.The determination results of two methods were consistent.

关 键 词：含氟铈基稀土抛光粉 氟 碱熔融 EDTA滴定 

分 类 号：O655.2[理学—分析化学] TF845[理学—化学]