Prakt. Met. Sonderband 46 (2014) 217 
;arriers their 
rogramming 
| processing 
of an edge 
er produces 
urs between 
ry image is 
>ssion of the 
xd. With this 
(e.g. out of 
bright areas 
routine like 
hresholding. 
3, saturation 
r reflections 
vde/dilate or 
Fig. 2: Danielsson distance map from a binary image. 
Depending on the reducibility of each phase an assured number of shells is excluded from 
one calculation step to the next, starting at the border of the phases. The remaining area is 
measured. This simulates the progress of the reduction front in a certain period of time 
For pellets which is distinctive for every mineral phase [2]. For each of these calculation steps the 
i pores are removed area is displayed as diagram (amount of steps/ cum. removed area). The results 
> by image. correlate with the reduction progress (time/ reduction grade) as measured with standard 
of Cavalieri reduction tests for the same samples performed at the Department of Metallurgy. 
The pellet evaluation is based on a pore size distribution model. The pore area is 
measured and the diameter of a coextensive circle is calculated. The result is displayed as 
a cumulative distribution diagram (equivalent diameter/ relative frequency). Compared to 
the reduction curves from standard reduction tests the performance of pellet samples is 
assumed to be positively influenced by a high amount of large pores. 
5. SUMMARY 
Semi-automated image processing is a tool for the evaluation of lump iron ore and pellets 
in terms of their reduction performance. With defined algorithms it is possible to get 
information about mineralogy and quality parameters. After identification of the mineral 
phases a concentric phase front movement simulates the progress of the reduction front 
for lump ore. A statistical analysis of the equivalent pore diameter of pellets shows 
correlation with results from the standard reduction tests. 
- glass) of a 
ACKNOWLEDGMENTS 
rocess by a This is a contribution to the K1-MET project (Competence Center for Excellent 
el value of a Technologies in Advanced Metallurgical and Environmental Process Development) of the 
he border of Austrian Research Promotion Agency (FFG). Support by Siemens VAI Metals 
m border to Technologies Linz, voestalpine Stahl Linz and voestalpine Stahl Donawitz is gratefully 
“ig. 2). acknowledged.