微波消解-电感耦合等离子体原子发射光谱法测定含碳化铬锌物料中铅铜铁镉铬砷

含碳化铬锌物料中含有铬的碳化物,此类碳化物熔点高、化学稳定性好,普通的酸不能完全溶解,需要在强混合酸和高温条件下才能分解。实验选择硝酸-盐酸-氢氟酸并采用微波消解法溶解样品,既能将试样中难溶的碳化铬完全溶解,又有效避免了高温溶样对易挥发元素砷的损失,并使用电感耦合等离子体原子发射光谱法(ICP-AES)测定铅、铜、铁、镉、铬、砷等元素含量。各元素测定范围为:0.10%≤w(Pb,Cu)≤5.00%;0.10%≤w(Fe)≤10.00%;0.010%≤w(Cd,Cr) ≤3.00%;0.08%≤w(As)≤3.00%。各元素在线性范围内校准曲线的线性相关系数均大于0.999,检出限为0.001~0.018μg/mL。实验方法用于测定5个典型含碳化铬锌物料原料样品铅、铜、铁、镉、铬、砷,结果的相对标准偏差(RSD,n=11)为0.75%~2.0%;按照实验方法测定3个含碳化铬锌物料样品中铅、铜、铁、镉、铬、砷,并采用其他方法(其中铅、铜、铁、镉按照GB 6730.30—2016《铁矿石化学分析方法 二苯基碳酰二肼光度法测定铬量》方法进行碱熔后,采用火焰原子吸收光谱法进行测定;铬按照GB 6730.30—2016《铁矿石化学分析方法 二苯基碳酰二肼光度法测定铬量》测定;砷按照GB/T 8151.7—2012《锌精矿化学分析方法 第7部分:砷量的测定 氢化物发生-原子荧光光谱法》测定)进行比对,结果相吻合。

Determination of lead,copper, iron,cadmium, chromium andarsenic in zinc material containing chromium carbide bymicrowave digestion-inductively coupled plasmaatomic emission spectrometry

Zinc material containing chromium carbide contained chromium carbides. These carbides had high melting point and good chemical stability, and cannot be completely dissolved with common acids. They were only decomposed by strong acid mixture at high temperature. The sample was dissolved by microwave digestion in nitric acid-hydrochloric acid-hydrofluoric acid. This method could not only fully dissolve the insoluble chromium carbides in sample, but also effectively avoid the loss of volatile arsenic under high temperature conditions. Then the contents of lead, copper, iron, cadmium, chromium and arsenic were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The determination ranges of elements were listed as follows: 0.10%≤w (Pb,Cu)≤5.00%; 0.10%≤w(Fe)≤10.00%; 0.010%≤w(Cd,Cr)≤3.00%; 0.08%≤w(As)≤3.00%. The correlation coefficients of calibration curves of elements in linear range were all higher than 0.999. The detection limit was 0.001-0.018μg/mL. The experimental method was applied for the determination of lead, copper, iron, cadmium, chromium and arsenic in five zinc materials containing chromium carbide. The relative standard deviations (RSD, n=11) of determination results were in range of 0.75%-2.0%. The contents of lead, copper, iron, cadmium, chromium and arsenic in three zinc materials containing chromium carbide were determined according to the experimental method. The found results were consistent with those obtained by other methods (the contents of lead, copper, iron and cadmium were determined by flame atomic absorption spectrometry after alkali dissolution according to GB 6730.30-2016 Methods for chemical analysis of iron ores-The diphenyl carbazide photometric method for the determination of chromium content; the content of chromium was determined according to GB 6730.30-2016 Methods for chemical analysis of iron ores-The diphenyl carbazide photometric method for the determination of chromium content; the content of arsenic was determined according to GB/T 8151.7-2012 Methods for chemical analysis of zinc concentrate-Part 7: Determination of arsenic-Hydride generation-atomic fluorescence spectrometry).