LAUSR

Abstract Bubble-particle attachment has been studied in the most fundamental way from as early as 1934 by bringing a bubble into contact with a flat mineral surface and since then, techniques measuring this interaction have advanced. Water quality within flotation will impact the bubble particle attachment and as more operations recycle their water on site, an understanding of this process becomes vital. This study uses an Automated Contact Time Apparatus (ACTA) to assess the effect of water quality on bubble-particle attachment of selected sulfide minerals; galena and chalcopyrite, from a fundamental perspective. Classical microflotation tests are complemented with collector adsorption and mineral potential under degrading water quality to validate the ACTA and gain an understanding of the effect of water quality on bubble-particle attachment as well as subsequent flotation. This investigation showed that the results from the ACTA qualitatively showed similar trends as that of the classical microflotation technique for measuring floatability, however the quantitively these methods showed very different results. Due to the dynamic nature of the microflotation technique it may be assumed that plant recovery will resemble the results from this technique closer than that of the ACTA. Furthermore, this investigation showed an increase in zeta potential of both minerals as the concentration of inorganic electrolytes in the water increased. It can thus be speculated that the increase in bubble-particle attachment with increasing ionic strength of synthetic plant water may be attributed to electrical double layer compression and particle agglomeration.