Effects of hematite surface characteristicson filtration process

Abstract

In iron ore pelletizing plants a range of process parameters such as particle size distribution, specific surface area, and moisture, must be controlled to achieve optimized operation conditions. Particle size distribution and specific surface area are controlled during the grinding operations. Moisture, however, is controlled during filtration of the ground products. This work investigates the relationship between particle morphology, filter cake moisture and filter capacity. The samples were taken during the filtration tests and referred to three different blends presenting distinct mineralogical features and similar chemical compositions in order to investigate the effects of only the hematite surface characteristics. Six types of morphology are distinguished: granular hematite, tabular hematite, martitic hematite, polycrystalline hematite, hematitegoethite aggregates and goethite. For each filtration test, the filter cloth product was characterised. The characterisation analysis revealed that blends containing martitic hematite concentration above 11.45 percent increased substantially the filter capacity. However, it had also caused an increasing in final moisture content that reached values around 10.0 % compared with industrial moisture specification that can vary on the range of 8.5 to 9.5 %.

Influence of Hematite Particle Morphology on Friable Itabirite Concentration in Humphreys Spiral Concentrator / Influência Da Morfologia Da Hematita Presente Em Itabirito Friável Na Concentração Por Espiral Concentradora Humphreys

“…The few data about the densities of the different hematite morphologies (tabular hematite = 5.14 g/cm 3 ; martite = 5.06 g/cm 3 (Graça et al, 2016)) point to a small variation in this parameter, thus suggesting in this specific case, that the gravity concentration is dependent more with the shape of the particles than the others parameters.…”