Scale Growth in the Dewatering of Iron Ore

The upgrading of iron ore is a high-tonnage industry where cost efficiency plays an important role. Reducing costs of the filtration section can be done by the introduction of technology which results in decreased specific energy consumption. The use of the ceramic filter medium can offer this advantage. In addition, the filter medium can withstand chemical regeneration beyond that which a conventional filter cloth could, extending the time in operation of the filter elements. To regenerate the filter medium efficiently, the particular blinding processes need to be understood. This study offers new knowledge on the growth of scales in the dewatering of magnetite and hematite slurries. Whereas the magnetite process was highly affected by scale growth, only few observations of scaling were found for the hematite process. Three distinct stages of development of the scale were identified: (1) initial nucleation, (2) overlapping growth, and finally (3) complete solidification.