摘要
采用HNO3-HF-HClO4湿法消解法、HNO3-HF-HClO4微波消解法、钠系碱法消解法和偏硼酸锂融熔法分别处理粉煤灰标准品和某电厂粉煤灰样品,利用ICP-OES法测定各组样品中K、Na、Ca、Mg、Al、Fe、Si 7种元素的含量,对比4种前处理方法的优劣势,探讨简单、快捷、准确的测定粉煤灰中矿物质元素的前处理方法。研究表明,HNO3-HF-HClO4湿法消解法的回收率范围为101. 00%~118. 20%,标准偏差(RSD)<1. 49%; HNO3-HF-HClO4微波消解法的回收率范围为103. 00%~109. 80%,标准偏差(RSD)<1. 58%;钠系碱法消解法的回收率范围为102. 34%~108. 61%,标准偏差(RSD)<1. 62%;偏硼酸锂融熔法的回收率范围为103. 20%~109. 30%,标准偏差(RSD)<1. 68%。4种方法均具有较好的准确度和精密度,但HNO3-HF-HClO4湿法消解法测得的元素含量平均值普遍偏低。所以综合考虑,偏硼酸锂融熔法操作简单、耗时短,与湿法消解法相比,可以避免使用大量酸造成对设备腐蚀和环境污染;与钠系碱法消解法相比,可以避免对K、Na元素的电离效应和基体影响。因而,偏硼酸锂熔融法可作为测定粉煤灰矿物质元素含量较好的前处理方法。
The fly ash standard products and a fly ash sample of a power plant were treated with HNO3-HF-HClO4 wet digestion method,HNO3-HF-HClO4 microwave digestion method,sodium-based alkali digestion method and lithium metaborate fusion method,respectively.The contents of K,Na,Ca,Mg,Al,Fe,and Si in each group of samples were determined by ICP-OES method.The advantages and disadvantages of the four pretreatment methods were compared to the simple,and quick,accurate determination and pre-processing method of minerals in fly ash was discussed.The results showed that the recoveries of HNO3-HF-HClO4 wet digestion method ranged from 101. 00% to 118. 20% and the standard deviation( RSD) was less than 1. 49%. The recoveries of HNO3-HF-HClO4 microwave digestion method ranged from 103. 00% ~ 109. 80%. The standard deviation( RSD) was less than1. 58%.The recoveries of the sodium-based soda digestion method ranged from 102. 34% ~ 108. 61% with a standard deviation( RSD) of less than 1. 62%.The lithium metaborate melting method recovery range was 103. 20% ~ 109. 30%,standard deviation( RSD) <1. 68%.All four methods have good accuracy and precision;but the mean value of elemental content measured by HNO3-HF-HClO4 wet digestion method is generally low.Therefore,considering comprehensively,the lithium metaborate fusion method is simple to operate and takes a short time.Compared with the wet digestion method,it can avoid corrosion of equipment and environmental pollution caused acid,and can avoid ionization interference during the determination of Na element content compared with Na alkali digestion method.Therefore,lithium metaborate melting method can be used as a pretreatment method for determining the content of mineral elements in fly ash.
作者
丁海萍
侯泽建
周筱
DING Haiping;HOU Ze-jian;ZHOU Xiao(Lignite Fly Ash Institute of Engineering & Technology,Xilingol Vocational College,Xilinguole 026000,China)
出处
《化学试剂》
CAS
北大核心
2019年第1期68-71,共4页
Chemical Reagents
基金
内蒙古自治区高等学校科学研究项目(NJZY18367)
