采用过氧化钠和氢氧化钠高温熔融铬矿石样品,以盐酸溶解熔块,合并溶液后用电感耦合等离子体原子发射光谱法测定样品中硅、铝、镁和铁的含量。选择212.412,308.215,285.213,238.204 nm分别作为硅、铝、镁、铁的分析谱线。用铬矿石标准样品配制标准溶液,对标准溶液的贮存方法进行了研究,对影响标准曲线稳定性的因素进行了讨论。SiO2、Fe2O3、Al2O3和MgO的线性范围依次为0.61%~14.64%,13.62%~27.74%,9.29%~15.17%和9.87%~21.49%。采用该法对铬矿石样品进行30d的连续测定,SiO2、Fe2O3、Al2O3和MgO测定值的相对标准偏差分别在0.51%~1.3%,0.45%~2.0%,0.50%~2.5%和1.4%~2.3%之间。

Sample of chromium ore was fused with Na2O2 and NaOH at high temperature and the melt block obtained was dissolved with HCl. The contents of Si, Al, Mg and Fe in sample solution were determined by ICP-AES. Wavelengths of 212.412, 308.215, 285.213 and 238.204 nm were selected as analytical lines for the determination of Si, Mg, Al and Fe, respectively. The storage method of standard solution of chromium ore was studied, and influential factors of stability of standard curve were discussed. Linearity ranges of SiO2, Fe2O3, Al2O3 and MgO were obtained in the ranges of 0.61%-14.64%, 13.62%-27.74%, 9.29%-15.17% and 9.87%-21.49% respectively. The proposed method was applied to the analysis of sample of chromium ore within 30 d, giving values of RSD′s in the ranges of 0.51%-1.3% for SiO2, 0.45%-2.0% for Fe2O3, 0.50%-2.5% for Al2O3 and 1.4%-2.3% for MgO.