Determination of silver in silver separating residue by sodium chloride-automatic potentiometric titration
MA Ting1,2,YUAN Gong-qi*1, YI Hui-yang2
1. Analysis and Testing Center,Daye Nonferrous Metals Co．, Ltd., Huangshi 435005,China； 2. College of Chemical and Environmental Engineering,Hubei Normal University, Huangshi 435002,China
Abstract： Silver separating residue, flux (Na2CO3, Na2B4O7·H2O and SiO2), PbO and starch were mixed in an appropriate ratio by adopting fire assay method. Then the mixed substance was heated to dissolve and form lead button in crucible at the temperature of 900-1 100 ℃. Alloy particle was obtained by cupellation of lead button. Then testing solution was gotten by dissolving the alloy particle with nitric acid. Finally, the content of silver in testing solution was determined by potentiometric titration.After testing, it was found that 3.0 g of sample, pH 2-5, room temperature and 20 mL of ethanol were the best choice to determine silver in silver separating residue. Different samples were used for precision test, with RSD (n=6) between 0.10% and 0.56%. Recovery test result indicated that the addition recovery rate of the sample was 96%-100%. Testing was conducted on different silver separating residue sample. In addition, contrast test was conducted by using fire assay - potassium thiocyanate titration. Both test results were consistent with each other.
［2］ 郭学益,肖彩梅,钟菊芽,等．铜阳极泥处理过程中贵金属的行为［J］．中国有色金属学报(Transactions of Nonferrous Metals Society of China),2010,20（5）：990-998.
［3］ 程利振,李翔翔,张三佩,等．我国铜阳极泥分银渣综合回收利用研究进展［J］．金属材料与冶金工程(Metal Materials and Metallurgical Engineering),2011,39(4)：41-43.
［4］ 国内银的分析测定研究进展(二)——国内原子光谱法测定银的研究进展［J］．光谱实验室(Chinese Journal of Spectroscopy Laboratory),2009,26(6) ： 1685-1688.
［5］ Fathi M R,Pourreza N, Purweis S．Determination of silver by flame atomic absorption spectrometry after preconcentration on naphthalene modified with dithizone［J］．Journal of the Chinese Chemical Society,2009,56:725-728.
［6］YANG Guang-yu ,FEN Wei-bo,Lei Chun,et al．Study on solid phase extraction and graphite furnace atomic absorption spectrometry for the determination of nickel, silver, cobalt, copper, cadmium and lead with MCI GEL CHP 20Y as sorbent［J］.Journal of Hazardous Materials,2009,162(1)：44-49.
［7］国内银的分析测定研究进展(一)——国内光度法测定银的研究进展［J］．光谱实验室(Chinese Journal of Spectroscopy Laboratory),2009,26(6),1682-1684.
［8］ Pravin P. Ingole,Rajiv M. Abhyankar,B.L.V. Prasad,et al． Citrate-capped quantum dots of CdSe for the selective photometric detection of silver ions in aqueous solutions［J］.Materials Science and Engineering,2010,168(1-3):60-65.
［9］ 周文勇. 沉淀分离金-电感耦合等离子体原子发射光谱法测定镀金溶液中铁、钴、镍、铜、银、铅［J］.理化检验-化学分册(Physical Testing and Chemical Analysis：Part B Chemical Analysis),2008,44(10):954-956.
［10］ Mohammad Reza Ganjali,Azadeh Daftari,Leila Hajiagha-Babaei,et al．Pico level monitoring of silver with modified hexagonal mesoporous compound (MCM-41) and inductively coupled plasma atomic emission spectrometry ［J］．Earth and Environmental Science,2006,173 (1-4)：71-80.
