硫酸-硫酸钾-高氯酸-硝酸体系分解-硫酸铈滴定法测定浸锑石墨中锑  

Determination of antimony in antimony impregnated graphite by ceric sulfate titration after decomposition of sulfuric acid-potassium sulfate-perchloric acid-nitric acid system

作　　者：肖刘萍 田宁郴 刘伟 XIAO Liuping;TIAN Ningchen;LIU Wei(Chenzhou Product and Commodity Quality Supervision and Inspection Institute,Chenzhou 423000,China)

机构地区：[1]郴州市产商品质量监督检验所,湖南郴州423000

出　　处：《冶金分析》2025年第3期84-89,共6页Metallurgical Analysis

摘　　要：准确测定浸锑石墨中锑的含量,对优化其生产工艺、提升材料性能具有重要意义。浸锑石墨含有结构稳定的石墨,存在较难分解完全的难题,实验提出用20 mL硫酸-1.0 g硫酸钾-1.5 mL高氯酸-1.5 mL硝酸分解样品,若样品的石墨化度高,一次难以分解完全,可分数次补加1.5 mL高氯酸、1.5 mL硝酸继续分解,实现了对样品的完全分解,由此建立了硫酸铈滴定法测定浸锑石墨中锑含量的分析方法。以2#浸锑石墨样品(石墨化度为98%)为考察对象,采用拉曼光谱对样品分解前、第1次分解后残渣、4次补加高氯酸和硝酸后溶液分别进行表征。结果表明,经第1次分解后,残渣中代表碳原子晶格缺陷的D峰消失,而分别代表sp2杂化的面内伸缩振动、层间堆垛方式的G峰、2D峰仍然存在但强度变弱,说明加入分解体系后,有缺陷的石墨先被分解,残留的为结构完善的无缺陷石墨;4次补加高氯酸、硝酸后溶液的G峰、2D峰均消失,说明多次补加高氯酸、硝酸后,无缺陷石墨得以完全分解。将实验方法应用于浸锑石墨样品中锑的测定,测定结果的相对标准偏差(RSD,n=7)为0.32%和0.78%,加标回收率为99.5%~103%。参照浸锑石墨样品组成,称取一定量的高纯石墨和锑粉配制成锑质量分数在10%~30%范围内的3个浸锑石墨模拟样品,按照实验方法测定,结果表明测定值和理论值基本一致。The accurate determination of antimony content in antimony impregnated graphite is of great significance for optimizing production process and improving material performance.The antimony impregnated graphite contains graphite with stable structure,which is difficult to be decomposed completely.In experiments,the sample was decomposed with 20 mL of sulfuric acid-1.0 g of potassium sulfate-1.5 mL of perchloric acid-1.5 mL of nitric acid.If the graphitization degree of sample was too high which could not be decomposed completely at one time,the sample could be fully decomposed by adding 1.5 mL of perchloric acid,1.5 mL of nitric acid for several times.The method for the analysis of antimony in antimony impregnated graphite by ceric sulfate titration was established.2#antimony impregnated graphite sample(the graphitization degree was 98%)was selected as the object of investigation.The sample before decomposition,the residue after the first decomposition,and the solution after adding perchloric acid and nitric acid for four times were characterized by Raman spectroscopy.The results showed that the D peak which represented the lattice defect of carbon atom in residue disappeared after the first decomposition,while the G peak and 2D peak(which represented in-plane telescopic vibration of sp2 hybrid and interlayer stacking,respectively)still existed but the strength was weakened.It indicated that the defective graphite was decomposed firstly,and the residue was non-defective graphite with perfect structure.After adding perchloric acid and nitric acid for four times,the G peak and 2D peak of solution disappeared,indicating that the non-defective graphite could be decomposed completely after adding perchloric acid and nitric acid for several times.The experimental method was applied to the determination of antimony in antimony impregnated graphite samples.The relative standard deviations(RSD,n=7)of determination results were 0.32%and 0.78%,and the recoveries were between 99.5%and 103%.According to the composition of antimo

关 键 词：浸锑石墨 锑 硫酸铈滴定法 拉曼光谱 硫酸 硫酸钾 高氯酸 硝酸 

分 类 号：O655.2[理学—分析化学] O652.4[理学—化学]