Laboratory Evaluation of Physical and High Temperature Properties of Commercial Pellets
1979 Volume 65 Issue 3 Pages 349-357
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1979 Volume 65 Issue 3 Pages 349-357
Sampled commercial pellets are classified into 6 types according to the chemical composition of gangue in pellets, that is SiO2-type, (SiO2+Al2O3) -type, high total Fe-type, CaO-type, (CaO+MgO) -type, and the rest.
This paper mainly evaluated high temperature-reducing properties of 44 kinds of commercial pellets in the world, which were measured with one-ball softening test under load.
As to beginning temperatures of softening of acid pellets, those of high total Fe-type pellets are higher, those of SiO2-type pellets with large amounts of gangue minerals are lower, those of (SiO2+Al2O3) -tyep pellets vary widely depending on indurating conditions and SiO2/Al2O3ratio in them. Beginning temperatures of softening of self-fluxed pellets are in the highest level.
Melting down temperatures of pellets are linearly increased with the increase of total Fe-contents in acid pellets and that of melting points of gangue minerals in self-fluxed pellets.
Therefore, in pelletizing of low grade ores, addition of MgO-contained minerals is contributed to improvement of high temperature properties. In acid pellets, the range of SiO2/ (SiO2+Al2O3) ratio =0.75-0.85 in raw ores should avoid in order to attain better high temperature properties of pellets.
