自动电位滴定法间接测定除氯铜渣中氯  

Indirect determination of chlorine in chlorine-removing copper slag by automatic potentiometric titration

作　　者：张积锴 张旭[1] 沈庆峰[1] 胡安生[1] 孙敬会[1] 张云彭 

机构地区：[1]昆明理工大学冶金与能源工程学院,云南昆明650093

出　　处：《冶金分析》2014年第12期78-82,共5页Metallurgical Analysis

摘　　要：除氯铜渣是生产硫酸铜或再生后用于除氯的一种重要原料,为确保其使用质量,需要对其中氯含量进行测定.该渣中氯主要以难溶CuCl形态存在,为了将该渣中的Cl-全部溶出且在溶样过程中确保Cl不挥发,提出了银量法处理待测试样、自动电位滴定法间接测定除氯铜渣中氯的方法.测定时先将定量过量的AgNO3标准溶液加入到样品中,然后加入硝酸（1＋3）溶解,溶液中的Cl及时与Ag＋形成AgCl胶体,加热煮沸使AgCl胶体迅速凝聚并沉淀完全,冷却定容,干过滤.取定量滤液,加入定量过量Cl标准溶液,煮沸使之沉淀完全,采用自动电位滴定法测定滤液中剩余的Cl量,通过计算间接得到除氯铜渣中的氯含量.试液中F-、SO42-、Na＋、Cu2＋、Zn2＋、Cd2-、Mg2＋、Fe3＋、As（Ⅴ）等杂质离子对测定没有影响.采用实验方法测定4种除氯铜渣样品中氯的含量,测定结果与火焰原子吸收光谱间接测定法一致,相对标准偏差（RSD,n=5）在0.75％～2.6％之间,回收率在99％～101％范围内.The chlorine-removing copper slag was an important material to produce copper sulfate or remove chlorine after regeneration.The content of chlorine in chlorine-removing copper slag must be determined to guarantee its quality.The chlorine in this slag mainly existed in the form of indissolvable CuCl.The sample was treated by argentometry in this study to guarantee the complete dissolution and non-volatilization of Cl-in sample preparation process.Then,the content of chlorine in chlorine-removing copper slag was indirectly determined by automatic potentiometric titration.In this method,the quantitative excessive AgNOa standard solution was firstly added into sample.When nitric acid （1＋3） was added,Cl-in solution would immediately react with Ag＋ to form AgCl colloid.The solution was heated and boiled for rapid agglomeration and complete precipitation of AgCl colloid.After cooling and dilution to constant volume,the solution went through dry filtration.The filtrate was sampled quantitatively.Then,the quantitative excessive Cl-standard solution was added.The solution was boiled for complete precipitation of AgCl.The residual Cl-content in filtrate was determined by automatic potentiometric titration.Therefore,the content of chlorine in chlorine-removing copper slag could be indirectly calculated.The impurities in sample solution including F-,SO42-,Na＋,Cu2＋,Zn2＋,Cd2＋,Mg2＋,Fe3＋ and As（Ⅴ） had no interference with the determination.The proposed method was applied to the determination of chlorine content in four chlorine-removing copper slag samples.The results were consistent with those obtained by indirect flame atomic absorption spectrometry.The relative standard deviation （RSD,n=5） was 0.75%-2.6%,and the recoveries were between 99% and 101%.

关 键 词：自动电位滴定法 除氯铜渣 间接测定 氯 

分 类 号：O657.1[理学—分析化学]