Background

Iron ore is the most abundant mineral resource and is also one of the most important materials in modern industries. Since the amount of seaborne trade and price is increasing in recent years, analytical requirements become more stringent. Total iron concentration in iron ore is focal point for trading. Therefore analysis for determination of total iron requires high accuracy. In the mining site, laboratory analysis covers quality check for Run-of-Mine and products, grade check for beneficiation and blending and also research for area exploration. Similarly, iron ore analysis is required in pelletizing plants near mining site and also sintering plants and stockyards in steel manufacturing sites. Wet chemical analysis is the traditional analytical technique for total iron determination but it needs analytical skill and is time-consuming. The requirement for analysis is strongly focused on cost-efficient parameters such as speed of analysis, simplicity and accuracy. For powder samples in X-ray fluorescent spectrometry, pressed powder method is the best solution in terms of quickness and simplicity. Since iron ore has complex matrix owing to its varied mineral composition, appropriate corrections for these matrix effects are required in XRF analysis. Conventional correction technique for total iron is a method using Compton scattering as internal standard (Compton scattering ratio method) but it has not been rigorous enough to meet the requirement of the iron ore industry. RIGAKU developed an improved Compton scattering method by integration of theoretical alpha corrections so that analytical result is significantly improved. This note demonstrates improved method to determine total iron in natural and processed iron ores by pressed powder method.