ICP-AES Determination of Silicon, Aluminum, Magnesium and Iron in Chromium Ore

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.