Application Of Inductively Coupled Plasma Atomic Emission Spectrometry In The Determination Of Silver And Copper In Geological Samples

The quantitative analysis of metallic samples in ores is particularly important in the evaluation of ore reserves.Among many metals,the exploitation and quantitative analysis of silver and copper have been attracted by many researchers.At present,there are many methods for the quantitative determination of silver and copper,such as precipitation titration,high performance liquid chromatography,electrochemical analysis,spectrophotometry,fluorescence spectrometry,atomic absorption spectrometry and atomic emission spectrometry.In this thesis,in order to improve efficiency,reduce costs and better meet the needs of analysis and testing,the author employed ICP-OES method to determine the contents of silver and copper in the ore samples for establishing a feasible analysis method.On the basis of previous study,the effects of acid type,dissolving temperature and dissolving time on the determination of silver and copper content were investigated through comparative experiments.The optimal pretreatment for the ore samples was adopted as follows.The hydrochloric acid-nitric acid is selected to dissolve ore samples;the dissolving temperature is 200 C and the dissolving time is controlled for 30 minutes.According to the standard value of reference material,the working parameters of ICP-OES instrument are optimized.Through single factor experiments on the adjustment of carrier gas,auxiliary gas,cooling gas and carrier gas pressure,the load is obtained under the analysis environment conditions of 25 C and humidity 40% as follows.The air flow rate is 25L/h,the auxiliary air flow rate is 8L/h,the cooling air flow rate is 770 L/h,the carrier pressure is 0.2MPa.The experiments optimization also simplifies the overall analysis process and reduces the analysis cost.Through the determination of the first-class national standard material,the precision RSD of ICP-OES method is between 0.76% and 2.13%;the accuracy RE is between-1.30% and 2.13%;the recovery of standard addition is between 99.4% and 101.3%;RSD is less than 1.54%.The comparison experiment on ICP-OES with atomic absorption spectrometry method shows that ICP-OES method is suitable for the determination of standard ore samples.The results show that the ICP-OES method developed in the present study has better accuracy,higher repeatability and better analysis stability for multi-elements.