疏基棉分离富集-滴定法测定高含量银

Separation and enrichment of mercapto cotton-titration analysis of high quantitative silver

讨论了一种化学滴定测定高含量银的方法.在2.23mol/L硝酸介质中,巯基棉对Ag+有较强的吸附作用,其饱和吸附量可达53mg/g.用10mol/L硝酸解脱,以铁铵矾作指示剂,硫氰酸铵滴定银.对原矿样经过王水溶解,在碱性条件下以过量氨水分离杂质,以本法测定,其误差较允许误差还低.该法操作手续简便、快速,适用于高含量银的测定.

The method to determine high quantitative silver in ore samples by chemical titration is studied. The results show that mercapto cotton has high selection ability of absorption and absorbs silver well in 2.23 mol/L HNO3 solution. The saturate value is 53 mg/g.To extricate silver with 10mol/L HNO3solution, sulfate dodecagydrate is taken as indication reagent and ammonium thipcyanate as titration reagent. After disposing with HNO3-HCl(1∶3),silver is seperated with NH3·H2O in an alkaline solction. The test error is 5% lower than permitted. The operation procedure is convenient. This method can be used in analysis of high quantitative silver.