摘要
为评定铁矿石中酸溶亚铁含量重铬酸钾氧化还原滴定测量的不确定度,对样品前处理及重铬酸钾与酸溶亚铁的化学反应过程、滴定等步骤建立数学评定模型。通过科克伦检验,得出日常的酸溶亚铁检测精度没有显著性差异,回归分析表明,标准偏差和酸溶亚铁含量之间没有显著性的相关关系,以合并样本标准偏差作为A类不确定度。B类不确定度的来源主要涉及天平、滴定管、容量瓶等误差,对其逐一量化并通过数学模型进行合成,从而计算合成不确定度和扩展不确定度。最终得到氧化亚铁测量值在0.2%~20%,单次检测的A类不确定度为0.06%。在评定过程发现,滴定体积是不确定度的最大来源,实验改进措施是适当扩大滴定体积和使用更高精度的滴定管。
In order to evaluate the uncertainty of measurement of acid soluble ferrous content in iron ores by potassium dichromate redox titration,a mathematical evaluation model was established through sample pretreatment,chemical reaction process and titration of potassium dichromate and acid soluble ferrous.Through Cochrane test,it was concluded that there was no significant difference in the daily detection accuracy of acid-soluble ferrous iron,and regression analysis showed that there was no significant correlation between the standard deviation and acid-soluble ferrous iron content.The combined sample standard deviation was taken as the Type A uncertainty.The source of Type B uncertainty mainly involves the errors of balance,burette and volumetric bottle,etc.They are quantified one by one and synthesized by mathematical model,so as to calculate the synthetic uncertainty and extended uncertainty.Finally,the measured value of ferrous oxide is between 0.2%and 20%,and the Type A uncertainty of a single test is 0.06%.During the evaluation process,it was found that the titration volume was the largest source of uncertainty.The experimental improvement measures were to appropriately expand the titration volume and use a buret with higher accuracy.
作者
宋飞
马李
陈哲
丁仕兵
管嵩
SONG Fei;MA Li;CHEN Zhe;DING Shibing;GUAN Song(Technology Center of Qingdao Customs;Huangdao Customs)
出处
《现代矿业》
CAS
2023年第1期187-190,194,共5页
Modern Mining
基金
海关总署科研计划项目(编号:2020HK250)。
关键词
铁矿石
酸溶亚铁
不确定度
包含概率
iron ore
acid soluble ferrous
uncertainty
inclusion probability
