电感耦合等离子体发射光谱法测定黑钨矿精矿和中矿中的锰

摘要

A simple, rapid and interference-free method of NaO2 ore fusion and complexometric extraction with tartaric acid is proposed for the determination of manganese (Mn) in black tungsten concentration and middling by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The precipitation of tungstic acid was successfully avoided by this preparation method, which resolved problems such as incomplete ore digestion and encapsulation/adsorption of the target elements. Under the optimized conditions, the detection limit ( LOD) for this method was 0. 019 g/mL with relative standard deviations (RSD, n = 11 ) in the range of 0. 92% - 1. 50%. Moreover, good recoveries were obtained (97.5% -104.0% ). The deviation between a single determination result and a certification result was much lower than the allowable deviation of national standards with ferrous ammonium sulfate (GB/T 6150. 14-2008) between laboratories. This method met the requirements of national standards for the accurate determination of Mn in black tungsten concentration and middling.%样品采用过氧化钠熔融,酒石酸络合提取,电感耦合等离子体发射光谱法测定黑钨精矿和中矿中的锰含量,碱熔络合体系避免了酸处理样品时大量钨酸沉淀的生成,解决了钨酸沉淀导致的溶矿不完全和夹杂、吸附待测元素的问题.在优化的工作条件下,方法检出限为0.019μg/mL,精密度(RSD,n=11)为0.92％～1.50％,并且具有较高的回收率(97.5％～104.0％),单次测定结果与协同定值结果的偏差小于国家标准GB/T6150.14-2008硫酸亚铁铵法实验室间允许差.方法简便快速,无明显基体干扰,满足了国家标准黑钨精矿中锰的检测要求,可用于高、中品位钨矿石样品中低含量锰的准确测定.