电感耦合等离子体发射光谱法测定西藏矽卡岩型铜多金属富矿石中8种成矿元素

Determination of 8 Metallogenic Elements in Tibetan Skarn-type Copper-polymetallic Rich Ore from Tibet by Inductively Coupled Plasma-Optical Emission Spectrometry

矽卡岩型铜多金属富矿石是西藏特有矿产,具有成矿元素多样且含量普遍较高的特点,矿物类型主要为硫化物型,成矿元素有Cu、Pb、Zn、Fe、Ag、Bi、Cd、Co等。采用湿法处理此类样品时常因银、铅等元素含量较高出现难溶解、易沉淀现象,导致测定结果偏低。本文采用盐酸预处理、硝酸-氢氟酸-高氯酸溶矿体系,能有效除去样品中的硫,样品分解效果好,选择稀释倍数为1000、溶液介质为10%盐酸,样品溶液不会产生沉淀,采用电感耦合等离子体发射光谱法测定各待测元素均可获得较好的准确度、精密度。方法测定范围为:Cu 0.0056%~20.0%,Pb 0.0087%~20.0%,Zn 0.0031%~20.0%,Fe 0.0090%~20.0%,Ag 5.40~3000μg/g,Bi 10.8~5000μg/g,Cd 0.69~5000μg/g,Co 2.09~5000μg/g。用国家标准物质进行验证,方法准确度小于5.40%,精密度(RSD,n=11)小于4.41%。该方法具有前处理流程简单、分析速度快、同时测定元素多、线性范围宽等优点,经实际样品测试与不同方法分析数据吻合。

Skarn-type copper-polymetallic rich ore is a unique mineral resource in Tibet and is characterized by numerous diverse elements with high content.The mineral type is mainly sulfide,while the metallogenic ore elements are typically Cu,Pb,Zn,Fe,Ag,Bi,Cd and Co.The use of wet methods to analyze the samples will result in low measurement results due to the high content of silver,lead and other elements,which are difficult to dissolve and precipitate.The analytical results of these samples tend to be on the low side,due to the insoluble and easy-to-precipitate state during the wet pre-treatment caused by the relatively high amount of certain elements.In this study,hydrochloric acid was introduced to pre-desulfurize the ore,followed by dissolution with a mixed acid of nitric,hydrofluoric,and perchloric acid.As a result,the samples can be decomposed completely with effective desulphurization.When the dilution factor was optimized to 1000 and 10%hydrochloric acid was chosen as the solution medium,the sample solution did not precipitate and the multi-element analysis by Inductively Coupled Plasma-Optical Emission Spectrometry(ICP-OES)yielded good accuracy and precision.The method measurement ranges are 0.0056%to 20.0%for Cu,0.0087%to 20.0%for Pb,0.0031%to 20.0%for Zn,0.0090%to 20.0%for Fe,5.40μg/g to 3000μg/g for Ag,10.8μg/g to 5000μg/g for Bi,0.69μg/g to 5000μg/g for Cd,2.09μg/g to 5000μg/g for Co,respectively.The method accuracy was less than 5.40%and the precision(RSD,n=11)was less than 4.41%,which was verified by the national standard reference materials.This method has distinct advantages of simple preliminary treatment,efficient analysis,simultaneous detection of multiple elements,and a wide linear range.The results are in agreement with other methods according to actual sample test analysis.