燃烧炉-离子色谱联用法测定铁矿石中氯  

Determination of chlorine in iron ore by combustion furnace-ion chromatography

作　　者：李婷 任丽萍[2] 闵红[2] 刘曙[2] 张琳琳[2] 林苗[1] LI Ting;REN Li-ping;MIN Hong;LIU Shu;ZHANG Lin-lin;LIN Miao(College of Chemistry,Chemical Engineering and Biotechnology,Donghua University,Shanghai 201620,China;Shanghai Entry-Exit Inspection and Quarantine Bureau,Shanghai 200135,China)

机构地区：[1]东华大学化学化工与生物工程学院,上海201620 [2]上海出入境检验检疫局工业品与原材料检测技术中心,上海200135

出　　处：《冶金分析》2018年第7期51-56,共6页Metallurgical Analysis

基　　金：上海检验检疫项目(HK012-2017)

摘　　要：铁矿石中的氯对钢铁冶炼设备及大气环境都存在危害,是铁矿石质量评价的重要指标。针对目前铁矿石中氯的检测存在样品前处理过程复杂、前处理与检测分开进行等问题,实验采用燃烧炉-离子色谱联用技术,即样品在燃烧炉内分解、燃烧,生成的各类气体被吸收液吸收后进入离子色谱仪进行分析,实现固体进样、燃烧、吸收、检测的自动化分析。为提高铁矿样品的燃烧效率,对称样量、燃烧温度、燃烧保持时间和助熔剂进行了条件优化。结果表明,在50mg称样量、1 050℃燃烧、燃烧保持500s条件下,无须使用助熔剂即可实现样品的充分燃烧。在氯的质量浓度在0~25μg/mL范围内线性关系良好,校准曲线线性相关系数R=0.999 3。方法的检出限为0.000 7%。对5个铁矿石标准样品进行测定,结果的相对标准偏差(RSD,n=6)为2.4%~5.0%。与现有水蒸气蒸馏-离子色谱法测定铁矿石中氯的国家标准检测方法(GB/T 6730.69—2010)进行比对,采用F检验、t检验进行验证,两种方法间不存在显著性差异,但燃烧炉-离子色谱联用法自动化程度高,可在20min内完成铁矿石样品中氯的检测。The chlorine in iron ore is harmful to the steal smelting equipment and atmospheric environment,and it is an important index to evaluate the quality of iron ore.At present,the determination methods of chlorine in iron ore usually have some disadvantages.For example,the sample treatment process is complicated;the pretreatment and determination are not simultaneous.Aiming at these problems,the combined combustion furnace-ion chromatography method was adopted.In other words,the samples were decomposed and combusted in combustion furnace and the generated gases were absorbed followed by analysis by ion chromatography.This process realized the automation analysis of solid injection,combustion,absorption and determination.In order to improve the combustion efficiency of iron ore sample,the conditional experiments of sampling amount,combustion temperature,combustion time and flux were conducted.The results showed that the sample could be fully combusted without use of flux under the following conditions：the sampling amount was 50 mg,the combustion temperature was 1 050℃,and the combustion time was 500 s.The linearity of calibration curve was good when the mass concentration of chlorine was in range of 0-25μg/mL.The linear correlation coefficient was R=0.999 3,and the detection limit of method was 0.000 7%.Five standard samples of iron ore were determined,and the relative standard deviations（RSD,n=6）were between 2.4% and 5.0%.The determination results were compared with those obtained by the current national standard method（GB/T 6730.69-2010 Determination of chlorine in iron ore by steam distillation-ion chromatography）.Ftest and t test were conducted for verification.It was found that there was no significant difference between two methods.However,the degree of automation was higher for combustion furnace-ion chromatography.The determination of chlorine in iron ore could be finished within 20 min.

关 键 词：燃烧炉 离子色谱 铁矿石 氯含量 

分 类 号：O657.7[理学—分析化学] P575[理学—化学]