Direct comparison on mechanical and digital size analyses of Kemi Chromite, Finland

In order to compare sieve size and image size analyses of chromite particles, chromite in the concentrate should appear in size similarly to that in the ore. To meet this requirement, chromite ore samples were fragmented electrodynamically with the advantage that this method liberates mineral grains along natural grain boundaries and existing deep fractures without unnecessary breakage of particles. The aim was to: (1) investigate the correlation between sieve and image size analysis of chromite and (2) examine the correlation of the image size analyses of unliberated chromite in the rock and sieve size analyses of liberated chromite in the crushed ore. Results show considerable correlation between mechanical and digital size analyses methods. Image size analyses of chromite in the ore are highly correlated with the sieve analyses of chromite concentrate. Moreover, the ferets average represented by number percent and the area diameter represented as weight percent are more closely correlated to the sieve analysis than to the ferets average given as weight percent and the area diameter given as number percent.