碱熔-铬酸钡沉淀分离-碘量法测定铜阳极泥中钡  

Determination of barium in copper anode slime by idometry combined with alkali fusion and barium chromate precipitation separation

作　　者：刘芳美 黄雅娟 LIU Fangmei;HUANG Yajuan(Zijin Copper Co.,Ltd.,FuJian Key Laboratory for Green Production of Copper and Comprehensive Utilization of Associated Resources,Shanghang 364204,China)

机构地区：[1]紫金铜业有限公司,福建省铜绿色生产及伴生资源综合利用重点实验室,福建上杭364204

出　　处：《冶金分析》2023年第12期85-91,共7页Metallurgical Analysis

摘　　要：铜阳极泥中钡含量是卡尔多炉处理铜阳极泥回收贵金属生产过程中重要技术指标之一,直接影响金、银等贵金属的回收率。实验采用氢氧化钠-碳酸钠混合熔剂于镍坩埚中熔融样品,使难熔的硫酸钡转化为易溶于盐酸的碳酸钡;用热水浸取处理,过滤,弃去滤液,除去了大部分干扰离子;沉淀用盐酸溶解,然后以EDTA-钙盐掩蔽剂(CaY2-)掩蔽铁、铝、铅、铜、镍、锌等离子,用重铬酸钾与钡离子反应生成铬酸钡沉淀,从而实现了钡与其他杂质的分离,用热盐酸(1+9)溶解铬酸钡沉淀于原烧杯中,以碘量法间接测定试样中钡含量,建立了碱熔-铬酸钡沉淀分离-碘量法测定铜阳极泥中钡含量的方法。通过实验验证,称取0.50 g试样,采用6 g无水碳酸钠-氢氧化钠(质量比为1∶2)混合熔剂在700℃下熔融30 min,可以完全分解铜阳极泥试样;比对了常温陈化过夜与95℃水浴下保温陈化2~3 h这两种方式对钡测定的影响,结果表明,两种方式测定结果基本一致。干扰试验表明,样品中共存元素对测定的干扰可忽略。按照实验方法测定铜阳极泥中钡,测定结果的相对标准偏差(RSD,n=7)为0.23%~2.0%,加标回收率为99%~101%;采用电感耦合等离子体原子发射光谱法(ICP-AES)进行方法比对,两种方法测定结果基本一致。The content of barium in copper anode slime is one of the important technical indexes in the process of recovering precious metals from copper anode slime by Kaldor furnace,which directly affect the recoveries of precious metals such as gold and silver.The sample was treated in nickel crucible by alkali fusion with the mixed flux of sodium hydroxide and sodium carbonate.The refractory barium sulfate was converted into barium carbonate which could be easily dissolved in hydrochloric acid.After treatment by hot water leaching and filtration,the filtrate was abandoned so that most of the interfering ions were removed.The precipitate was dissolved with hydrochloric acid.Then masking agent of EDTA-calcium salt(CaY2-)was added to mask these ions such as iron,aluminum,lead,copper,nickel and zinc.Potassium dichromate was added to react with barium ion to form barium chromate precipitate,realizing the separation of barium from other impurities.The barium chromate precipitate was dissolved with hot hydrochloric acid(1+9)in the original beaker.The content of barium in sample was indirectly determined by iodometry.Thus,a method for determination of barium in copper anode slime was established by iodometry with alkali fusion and barium chromate precipitation separation.The experimental results showed that 0.50 g of copper anode slime sample could be completely decomposed with 6 g of the mixed flux of anhydrous sodium carbonate and sodium hydroxide(mass ratio of 1∶2)at 700℃for 30 min.The effects of overnight aging at room temperature and aging in water bath at 95℃for 2-3 h on the determination of barium were compared.It was found that the determination results of two methods were basically the same.The interference test showed that the interference of coexisting elements in the sample could be ignored.The contents of barium in copper anode slime samples were determined according to the proposed method.The relative standard deviations(RSD,n=7)of determination results were between 0.23%and 2.0%,and the recoveries were betw

关 键 词：铜阳极泥 钡 碱熔 铬酸钡 沉淀分离 碘量法 

分 类 号：O655.2[理学—分析化学] TF811[理学—化学]