硫磷混酸蒸馏-离子选择性电极法测定钨矿及其浸出渣中氟  

Determination of fluorine in tungsten ore and its leaching residue by ion selective electrode method with distillation of sulfuric-phosphoric mixed acid

作　　者：侯贵琼 肖刘萍 张元霞 李飞 HOU Guiqiong;XIAO Liuping;ZHANG Yuanxia;LI Fei(Chenzhou Tungsten Products Branch,Hunan Shizhuyuan Nonferrous Metals Co.,Ltd.,Chenzhou 423037,China)

机构地区：[1]湖南柿竹园有色金属有限责任公司郴州钨制品分公司,湖南郴州423037

出　　处：《冶金分析》2024年第9期77-82,共6页Metallurgical Analysis

摘　　要：钨矿及其浸出渣中氟含量的准确测定对优化工艺、降低成本具有重要意义。利用硫磷混酸强酸性、高沸点的特性,采用硫磷混酸溶解样品并加热蒸馏,将氟化物转化为氟化氢,利用酸碱中和的原理以氢氧化钠溶液吸收使之反应生成氟化钠,实现了氟与铝、钙等金属离子的分离;以溴甲酚绿作指示剂,用盐酸和乙酸钠溶液调pH值为5~6,再加入总离子强度缓冲液,用离子选择性电极法对吸收液进行测定,实现了对钨矿及其浸出渣中氟的测定。以氟质量浓度为横坐标,其对应的电位值为纵坐标绘制校准曲线,校准曲线的线性相关系数为0.9996,线性范围为0.025%~12.50%。按照实验方法对钨矿及其浸出渣样品中氟进行11次平行测定,结果的相对标准偏差(RSD)为3.0%~5.9%;在样品中加入氟离子标准溶液进行加标回收试验,回收率在97%~105%之间。用实验方法、YS/T 1115.13—2016中的氢氧化钠熔融-离子选择性电极法和GB/T 18114.11—2010中的高氯酸蒸馏-EDTA滴定法同时测定钨矿及其浸出渣中氟的含量,结果表明,实验方法与这两个标准方法测定值的差值在相应标准方法规定的允许差范围内。The accurate determination of fluorine in tungsten ore and its leaching residue is of great significance for process optimization and cost reduction.Taking advantage of strong acidity and high boiling point of sulfuric-phosphoric mixed acid,the sample was dissolved by sulfuric-phosphoric mixed acid and heated for distillation.The fluorides were converted to hydrogen fluoride.Then hydrogen fluoride was absorbed with sodium hydroxide solution and converted to sodium fluoride based on the principle of acid-base neutralization.Therefore,the separation of fluorine from metal ions such as aluminum and calcium were realized.The bromocresol green was selected as the indictor.After adjusting the pH of solution to 5-6 using hydrochloric acid and sodium acetate solution,the total ion strength buffer solution was added.The absorption solution was determined by ion selective electrode method,realizing the determination of fluorine in tungsten ore and its leaching residue.The calibration curve was drawn with the mass concentration of fluorine as abscissa and its corresponding potential as ordinate.The linear correlation coefficient of calibration curve was 0.9996.The linear range was 0.025%-12.50%.The contents of fluorine in samples of tungsten ore and its leaching residue were determined for 11 times according to the proposed method,and the relative standard deviations(RSD,n=11)of determination results were between 3.0%and 5.9%.The standard solution of fluorine ion was added into samples for standard addition recovery test,and the recoveries were between 97%and 105%.The contents of fluorine in samples of tungsten ore and its leaching residue were simultaneously determined by the proposed method,sodium hydroxide fusion-ion selective electrode method in YS/T 1115.13-2016,and perchloric acid distillation-EDTA titration in GB/T 18114.11-2010.The results showed that the differences of determination values between the proposed method and two standard methods were within the allowable ranges specified in the corresponding standard m

关 键 词：钨矿 浸出渣 蒸馏分离 氟 离子选择性电极 硫磷混酸 

分 类 号：O657.1[理学—分析化学] TF031[理学—化学]