Mineral analysis by simultaneous XRF and XRD spectrometery

摘要

Wavelength dispersive X-ray fluores- pence (WD-XRF) is widely used in the iron and steel industry for its flexibility, precision, ability to analyse both conducting and non-conducting samples and for its wide- dynamic range - from ppm to 100 percent concentrations. Together with spark-excited atomic emission spectrometery (AES), it has become part of standard analytical instrumentation routinely used in the process and quality control laboratories. WDXRF instruments can be fitted with an universal goniometer for sequential scanning of a spectra or a simultaneous system. While the goniometer offers flexibility and optimisation for specific requirements, the simultaneous WDXRF enables dedicated programs and high speed production control. However both WDXRF and AES are by and large elemental analysis techniques in that no information on structural or miner-alogical nature of the samples is obtained, For example, when a sample of iron ore is analysed by XRF, the total iron concentra-tion is recorded, irrespective of the fact that Fe may be present as FeO, Fe_2O_3, Fe_3O_4 or FeS_2. Information on these specific phas-os is useful in sintering to optimise the con-trol the quality of the iron ore used. Many laboratories working in this area rely on the wet chemical methods which are not only time consuming but are often not integrated in an on-line analytical system.