Sampling from large flotation cells : An invastigation of spatial distribution

The general trend in flotation technology today is towards larger flotation cells, which enables a higher throughput. However, adverse effects such as segregation and reduced froth transport efficiency have also been observed in larger cells. To better understand these problems it is of relevance to understand how the minerals of interest are moving and distributed inside flotation cells. A sampling investigation of industrial scale tank cells has been carried out. The samples have been analyzed by their physical properties, such as grade, solid concentration, particle size distribution and mineral composition. A novel method of measuring the wettability has been validated against traditional techniques for characterizing the surface properties of mineral samples. Different techniques and devices for sampling has also been evaluated. The results showed segregation inside the cells, with the quiescent zone having lower particle size (P80) and lower weight % solid. The grade profile in the vertical direction was relatively constant even though the P80 and weight % solid decreased in the quiescent zone. The smaller particles in the quiescent zone contained higher fraction of soft clay particles, which also correlated with a higher degree of hydrophilicity