锍镍试金-高分辨率连续光源石墨炉原子吸收光谱法测定铬铁矿中铂族元素  

Determination of platinum group elements in chromite by nickel sulfide fire assay-high resolution continuum source graphite furnace atomic absorption spectrometry

作　　者：毛香菊[1,2,3,4,5] 肖芳 刘璐[1,2,3,4,5] 张宏丽 孙启亮[1,2,3,4,5] 倪文山 MAO Xiang-ju;XIAO Fang;LIU Lu;ZHANG Hong-li;SUN Qi-liang;NI Wen-shan(Zhengzhou Institute of Multipurpose Utilization of Mineral Resources, CAGS, Zhengzhou 450006, China;China National Engineering Research Center for Utilization of Industrial Minerals, Zhengzhou 450006, China;Key Laboratory for Polymetallic Ores' Evaluation and Utilization, MNR, Zhengzhou 450006, China;KeyLaboratory of Comprehensive Utilization of Gold Resource in Henan Province, Zhengzhou 450006, China;5 .Northwest China Center for Geosience Innovation, Xi′an 710054, China)

机构地区：[1]中国地质科学院郑州矿产综合利用研究所,河南郑州450006 [2]国家非金属矿资源综合利用工程技术研究中心,河南郑州450006 [3]自然资源部多金属矿评价与综合利用重点实验室,河南郑州450006 [4]河南省黄金资源综合利用重点实验室,河南郑州450006 [5]西北地质科技创新中心,陕西西安710054

出　　处：《冶金分析》2020年第7期40-46,共7页Metallurgical Analysis

基　　金：中国地质调查局地质调查二级项目(DD20190573,DD20189263,DD20190186)。

摘　　要：针对难融铬铁矿样品中铂族元素的分析,提出了过氧化钠和氧化钙预烧结样品再进行锍镍试金富集的新方法,实验方法可完全分解铬铁矿,后续采用微波消解仪在优化的加热消解程序下以10mL王水(1+1)溶解Pt、Pd、Ru、Rh、Ir的硫化物沉淀连同滤纸,在微波消解密闭高温高压条件下,被测元素被完全溶解,然后应用高分辨率连续光源石墨炉原子吸收光谱法(HRCS-GFAAS)测定。实验优化了Pt、Pd、Ru、Rh和Ir的灰化和原子化温度、原子化读数时间和电感耦合器件(CCD)检测器有效像素点。在优化的实验条件下,Pt、Pd、Ru、Rh和Ir的吸光度与其对应的质量浓度运用二次方程最小二乘法拟合校准曲线,曲线拟合良好,校准曲线决定系数均不小于0.9994;特征浓度分别为1.56、1.98、0.45、1.27、3.06ng/mL。将实验方法应用于标准物质中5种铂族元素的测试,测定值与标准值吻合良好,5次平行分析实际铬铁矿样品中结果的相对标准偏差(RSD,n=5)介于5.0%~14%之间。所建立的方法满足铬铁矿样品中痕量、超痕量Pt、Pd、Ru、Rh和Ir的测定要求。A new nickel sulfide fire assay enrichment method followed by pre-sintering sample with sodium peroxide and calcium oxide was proposed for the analysis of platinum group elements in refractory chromite sample.The chromite sample could be completely decomposed.Then,10mL of aqua regia(1+1)was used to dissolve sulfide precipitates of Pt,Pd,Ru,Rh and Ir as well as filter paper with microwave digestion system according to the optimized heating digestion program.These five elements could be fully dissolved in solution under high-temperature and high-pressure conditions of microwave digestion system,and then determined by high resolution continuum source graphite furnace atomic absorption spectrometry(HRCS-GFAAS).The ashing and atomization temperatures,atomization reading time and effective pixels of charge-coupled detector(CCD)for the determination of Pt,Pd,Ru,Rh and Ir were optimized.Under the optimal experimental conditions,the calibration curves were fitted by least square method based on the absorbance and corresponding mass concentration of Pt,Pd,Ru,Rh and Ir.The fitting of curves was good,and the determination coefficients were all higher than 0.9994.The characteristic concentration for Pt,Pd,Ru,Rh and Ir was 1.56,1.98,0.45,1.27 and 3.06ng/mL,respectively.The proposed method was applied for the analysis of these five platinum group elements in the certified reference materials.The found results were in good agreement with the certified values.The relative standard deviations(RSD,n=5)of analysis results for Pt,Pd,Ru,Rh and Ir in actual chromite samples were between 5.0%and 14%.The proposed method could meet the analysis requirements of trace and ultra-trace Pt,Pd,Ru,Rh and Ir in chromite samples.

关 键 词：铬铁矿 锍镍试金 铂 钯 钌 铑 铱 微波消解 高分辨率连续光源石墨炉原子吸收光谱法(HRCS-GFAAS) 

分 类 号：O657.31[理学—分析化学]