Researcher preparing x-ray diffraction machine.

Using x-ray diffraction to solve minerals processing problems

In-situ x-ray diffraction (XRD) analysis of iron ore sinter phases

Iron ore sinter.

In-situ x-ray diffraction (XRD) was used to observe intermediate phase formation in sinters over time and temperature changes.

Sinters are being increasingly used as blast furnace feedstock as world lump iron ore stocks are being depleted.

Low-temperature sintering is a process whereby fine ore particles are heated causing phase changes and formation of larger aglomerated particles.

This produces sinters that are reasonably consistent in their mineralogy. 

These sinters are composed of:

• iron oxides
• ferrites (mainly silico-ferrites of calcium and aluminium (SFCA)) 
• glasses
• calcium silicates. 

SFCA is an important bonding phase within sinters.

It has significant effect on the sinter’s physical properties, such as strength and the rate at which it reduces to metallic iron.

Despite SFCA's importance, how it forms is not fully understood.

CSIRO scientists used in-situ XRD to study the mechanism of formation of SFCA in synthetic iron ores to observe the intermediate phases formed with respect to time and temperature.

XRD clearly showed the order of decomposition and subsequent formation of SFCA phases during the sintering process. 

Experiments are planned to continue this study on a larger scale using a neutron radiation source.