Abstract：The copper smelting dust contains high content of lead, copper, arsenic, aluminum, iron, antimony, bismuth, and other elements, which will interfere with the determination of cadmium by titration. The sample was decomposed using ammonium fluoride-hydrochloric acid-nitric acid-perchloric acid. The interference elements such as arsenic, antimony and tin were removed with hydrobromic acid. Lead was separated by lead sulfate precipitation. The coexisting elements including iron, bismuth and partial aluminum were separated by ammonia precipitation. Sodium thiosulfate was added into dilute sulfuric acid medium to separate copper ions from the solution in the form of cuprous sulfide. Excessive Na2EDTA standard titration solution was added to the filtrate, and potassium fluoride was added to mask the residual aluminum. In hydrochloric acid-hexamethylenetetramine buffer solution at pH 5.5-5.6, the zinc standard titration solution was used for back titration using xylenol orange as the indicator. The measured result was the total amount of zinc and cadmium. After deducting the amount of zinc, the amount of cadmium could be obtained. The amount of ammonia and potassium fluoride were optimized. The method for the determination of cadmium content in copper smelting dust by Na2EDTA back titration was established. The experimental method was applied to the determination of cadmium in copper smelting dust, and the found results were consistent with those obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES). The relative standard deviations (RSD, n=11) were between 0.56% and 0.92%. The standard addition recovery tests for the copper smelting dust sample were conducted according to the experimental method. The recoveries were between 99.6% and 100.2%.
[1] 狄聚才,李卫锋.铅、铜冶炼烟尘中有价金属的综合回收[J]. 中国有色冶金,2015(3):50-53. DI Jucai,LI Weifeng.Comprehensive recovery of valuable metals in lead and copper smelting flue dust[J].China Nonferrous Metallurgy,2015(3):50-53. [2] 曲俊月.浅析冶炼烟灰的综合回收利用[J].有色矿冶,2019,35(3):47-50. QU Junyue.Brief analysis on comprehensive recovery and utilization of smelting soot[J].Non-ferrous Mining and Metallurgy,2019,35(3):47-50. [3] LIU Jianning,ZHANG Bing,WU Bowan,et al.Spectrofluorimetric determination of trace amounts of cadmium with 2,4-dihydroxyacetophenone benzoylhydrazone[J].Rare Metals,2006,25(2):184-189. [4] Li Yang,Han Guiqin,He Nan,et al.Determination of cadmium content in CHUANXIONG RHIZOMA by microwave digestion-graphite furnace atomic absorption method[J]. Medicinal Plant, 2016,7(7-8):28-30,32. [5] 任悦,刘楠,王笑娟,等.火焰原子吸收光谱法和电感耦合等离子体原子发射光谱法测定仿真饰品中铅、镉的对比探讨[J].冶金分析,2017,37(8):69-72. REN Yue,LIU Nan,WANG Xiaojuan,et al.Comparison of flame atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry for the determination of lead and cadmium in imitation jewelry[J].Metallurgical Analysis,2017,37 (8):69-72. [6] 邓楠鑫,李中宝,李升锦,等.分光光度法测定污水中的镉离子含量[J].广州化工,2018,46(4):96-98. DENG Nanxin,LI Zhongbao,LI Shengjin,et al.Determination of cadmium in wastewater by spectrophotometry[J].Guangzhou Chemical Industry,2018,46(4):96-98. [7] 甘婷婷,赵南京,殷高方,等.水体中铬、镉和铅的X射线荧光光谱同时快速分析方法研究[J].光谱学与光谱分析,2017,37(6):1912-1918. GAN Tingting,ZHAO Nanjing,YIN Gaofang,et al.Study on simultaneous and rapid analysis method of X-ray fluorescence spectrum for determination of chromium,cadmium and lead in water[J].Spectroscopy and Spectral Analysis,2017,37(6):1912-1918. [8] 石如祥,张丽,陈树莲,等. EDTA滴定法测定锡铅焊料中高含量镉[J].冶金分析,2017,37(10):79-83. SHI Ruxiang,ZHANG Li,CHEN Shulian,et al.Determination of high content cadmium in tin-lead solder by EDTA titration[J].Metallurgical Analysis,2017,37(10):79-83. [9] 李蓉,杨谅孚.容量法测定粗镉中镉含量[J].云南冶金,2012,41(1):53-55. LI Rong,YANG Liangfu.Determination of cadmium content in crude cadmium by volumetric method[J].Yunnan Metallurgy,2012,41(1):53-55. [10] 王小琴,郭崇武.返滴定法测定氯化钾无氰镀镉溶液中氯化镉[J].电镀与精饰,2018,40(2):44-46. WANG Xiaoqin,GUO Chongwu. Back titration method for measuring cadmium chloride in a cyanide-free potassium chloride cadmium plating bath[J]. Plating and Finishing,2018,40(2):44-46.
