Optimag

On-line monitoring of particle size distribution, morphology and mineralogy

Scenery

Responsible person : Ir S Leroy

Supervisors : Pr E Pirard, Ir D Bastin

Academic partner : University of Cape Town

Sponsor : Magotteaux, Walloon Region

Budget :  300 k€

Context

Mill performances are traditionally measured at the mill discharge, on the basis of a mass percentage passing a certain sieve. This approach does not reflect at all what happen to the fines through milling. Furthermore, grinding efficiency measurement should take into account the particle size distribution at the mill feed, since this can be more or less unstable.

Fig 1 : In pulp particle imaging

Objectives

The aims of the particle characterization Work Package was to fully measure the particle size distribution as well as other parameter such as particle shape. The final result would propose a new milling efficiency index based on those measurement. This index will integrate both information from the feed and from the mill discharge.

Equipment

The specificity of the project is to developed image-based techniques that allow a single particle analysis of particle in slurry. Particle represent the real state of material in mineral processing so it should be the scale the material is studied and investigated.Moreover, Mica Lab has developed an unique expertise on optical measurement techniques and it benefit from the technical support of it’s spin-off Occhio.

Results

First the the measurement methods was validate by other methods such as x-ray tomography, polished section and chemical assays. During the project it was found to be possible to get relevant information on particle nature. The possibility of getting separate particle size distribution curves was demonstrate (see figure).