Interactions among the rate parameters of feed constituents in flotation

Kinetic modelling of flotation is very important from both a designing and operation perspective. However, considering of the rate parameters of the overall recovery may not enough to determine the kinetic response of flotation of an ore. It is known that water is an important feed constituent affecting the separation selectivity. Therefore, recovery of each feed constituent, namely water and minerals, was modelled by a well known first order kinetic equation. The rate data generated from the experimental results were evaluated to obtain a better understanding of interactions among the flotation feed constituents. The rate parameters of the recovery models were determined by using non-linear regression. In the experimental programme, a three level, three factor, face centred cubic experimental design was used to determine effects of some important operating variables, i.e. airflow rate, froth depth and pulp density, on kinetic behaviour of the feed constituents. Furthermore, the modified rate parameters (i.e. selectivity index and modified rate constants) of the constituents derived from those kinetic model parameters were evaluated statistically to elucidate behaviour of these constituents. Effects of the rate of the feed constituents on the separation selectivity were determined by using selectivity indices calculated for both water and minerals. The results of additional tests were verified that effects of the operating variables on the separation selectivity and performance can be comprehensively identified considering not only the constituent recoveries and the operating variables selected but also the selectivity indices for the constituents.