Determination of silver in silver-absorbing resin by fire assay enrichment-gravimetry
An analysis method is established for determining the silver content in silver-absorbing resin by fire assay enrichment-gravimetry.The silver-absorbing resin was mixed with assay flux,melted in a crucible,and cupelled to obtain metallic silver granules.After washing and drying the silver granules,their mass was directly measured using a balance.Parting is conducted to remove other precious metals,and the difference was taken as the mass of the silver granules.The method was optimized for factors such as sample weight,flour dosage,assay flux,correction coefficient for silver,and impurity elements.To account for silver losses during the fire assay,pure silver,with a mass close to the silver content in the sample,was added and a correction coefficient for pure silver was calculated.The final silver content in the sample was obtained by multiplying the mass of the silver granules by the correction coefficient.The relative standard deviation of the method ranged from 0.27%to 1.57%,and the recovery rate ranged from 99.57%to 100.54%.The results were consistent with those obtained by fire assay enrichment-potassium thiocyanate titration.This method is simple,provides effective silver enrichment,and is suitable for determining silver in silver-absorbing resin.