过氧化钠碱熔-电感耦合等离子体发射光谱法测定多金属矿中的锡钨钛等主次量成分

摘要

准确、快速测定多金属矿中的主次量成分,对矿产资源的综合利用具有十分重要的意义,但针对锡、钨、钛三种元素等难以被酸溶解的元素,选择适宜的样品前处理方法和电感耦合等离子体发射光谱(ICP-OES)技术结合起来,有利于提高准确度和测试效率.本文以过氧化钠为熔剂,样品经高温熔融,盐酸+酒石酸+过氧化氢混合酸提取,结合内标法建立了测定多金属矿中铜铅锌以及锡钨钛等15个主次量成分的分析方法.实验优化了各元素的分析谱线和背景校正模式,系统研究了坩埚、熔剂的选择、铝元素和内标元素的影响,获得方法检出限为7~995 μg/g,加标回收率为90.3%~105.0%,精密度(RSD,n=12)为0.8%~6.6%.本方法针对5种不同类型的典型多金属矿,具有不分矿种、前处理步骤相同、多成分同时测定和测试范围宽(40 μg/g~25%)的技术特点,尤其对于矿种类型不确定、测定范围在百分含量以上的多金属矿具有优势.%For tin, tungsten, titanium and other elements not easily digested by acid, a suitable sample preparation method combined with Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) can help to improve the accuracy and efficiency.Polymetallic ore samples were melted with Na2O2 and then extracted by mixed leaching solution (hydrochloric acid-tartaric acid-hydrogen peroxide).15 major and minor elements including Cu, Pb, Zn, Sn, W and Ti were determined by ICP-OES using an internal standard method.The analytical lines of analyzed elements and the correction mode of the background were optimized.The effect of crucible contamination, solvent, Al and internal standard element on the results were systematically studied.The method has detection limits of 7-995 μg/g, recoveries of 90.3%-105.0% (in Table 4), and relative standard deviations (RSD, n=12) of 0.8%-6.6% (in Table 3) by the standard addition method.For five different types of polymetallic ores, the method has a wide test range (40 μg/g to 25%).