Froth imaging, air recovery and bubble loading to describe flotation bank performance

Video image analysis and direct sampling of the froth surface were combined to investigate the relationship between different imaging parameters accounting for the structural features of the froth, and the separation efficiency of a flotation bank. The bubble solids loading and the air recovery were measured to introduce a new structural parameter, the froth volumetric mineral loading, additionally a new image analysis measurement, the cross correlation peak, was investigated. Both parameters were shown to be linked to the mobility of the bubbles on the froth surface. The cross correlation peak was found to be closely related to the volumetric mineral loading measured on the froth surface. Both parameters were found to follow a drop in froth stability and mineral attachment down the bank, which resulted in a relatively wetter and less viscous froth, and therefore a higher bubble mobility on the froth surface. As a result, the cross correlation peak was shown to be related to the mineral grade in the concentrate, while further analysis highlighted the possible use of a combination of air recovery and cross correlation peak to give a closer prediction of the bank performance.

[1]  Jan J. Cilliers,et al.  A technique for measuring flotation bubble shell thickness and concentration , 2000 .

[2]  P. Gauglitz,et al.  Stability of solids-coated liquid layers between bubbles , 2000 .

[3]  Stephen J. Neethling,et al.  The entrainment of gangue into a flotation froth , 2002 .

[4]  Jan J. Cilliers,et al.  Solids loading and grade on mineral froth bubble lamellae , 2004 .

[5]  Jan J. Cilliers,et al.  A model to describe flotation performance based on physics of foams and froth image analysis , 2002 .

[6]  Dee Bradshaw,et al.  Measurement of the sub-process of bubble loading in flotation , 1996 .

[7]  Stephen Grano,et al.  Case studies on the performance and characterisation of the froth phase in industrial flotation circuits , 2006 .

[8]  Zeki Aktas,et al.  Interpretation of the effect of froth structure on the performance of froth flotation using image analysis , 1998 .

[9]  V. Ross,et al.  Particle-bubble attachment in flotation froths , 1997 .

[10]  R. Pugh,et al.  The influence of particle size and hydrophobicity on the stability of mineralized froths , 1992 .

[11]  Stephen J. Neethling,et al.  Simple relationships for predicting the recovery of liquid from flowing foams and froths , 2003 .

[12]  Long Jiang,et al.  The effect of SiO2 particles upon stabilization of foam , 1989 .

[13]  L. G. Austin,et al.  A froth based flotation kinetic model , 1994 .

[14]  S. Dukhin,et al.  The interaction between particles and bubbles , 1999 .