Influence of Froth Height on Column Flotation of Kaolin Ore

The influence of the froth height in the reverse flotation of kaolinitic ore was analyzed based on the recovery by entrainment and by true flotation of iron, titanium and manganese oxides (FeO, TiO2 and MnO). Also, the influence of the particle size in the drainage process was analyzed. The recovery by entrainment and by true flotation of the three oxides is inversely proportional to the froth height. The entrained particles are drained more easily in the froth phase than the floated particles since they are not attached to the bubbles. The recovery by entrainment and drainage of the entrained material is similar for the three oxides. However, the recovery by true flotation and drainage of the floated material is different for the three oxides. FeO has the lowest recovery, as a consequence of the minor contribution of its hydrophobic minerals, while MnO has the greatest recovery values. For the entrained material, the finest fraction is entrained more easily, but it is also drained more easily, meaning these particles have more mobility in the froth zone. For the true floated material, the finest fraction is drained more easily, indicating the greater mobility of these particles in the froth; however, the coarsest fraction is drained more easily than the two intermediate fractions, indicating the weaker attachment of the larger particles to the bubbles.